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ISSN (Print) 0895-3996 - ISSN (Online) 1095-9114
Published by IOS Press
[92 journals]
Follow Subscription journalISSN (Print) 0895-3996 - ISSN (Online) 1095-9114
Published by IOS Press
[92 journals]- Adenosine stress thallium-201 myocardial perfusion imaging for detecting coronary artery disease at an early stage
- Abstract: The aims of this study were to evaluate the diagnostic value of adenosine thallium-201 myocardial perfusion imaging and to compare it with exercise stress thallium-201 myocardial perfusion imaging for detecting coronary artery disease (CAD) at an early stage. Forty-one patients suspected with CAD were randomly divided into two groups. In Group 1 (n=21) adenosine stress was undertaken; the exercise stress myocardial perfusion imaging was performed in Group 2 (n=20). Coronary angiography (CAG) was performed in each patient within 2 weeks before or after single photon emission computed tomography (SPECT). Adenosine stress group vs. exercise stress group, the sensitivity was 92.86% vs. 100.0%, specificity 57.14% vs. 60.0%, positive predictive value 81.25% vs. 71.43%, negative predictive value 80.0% vs. 100.0%, accuracy 80.95% vs. 80.0% respectively. Detection rates of vessels of coronary artery lesions were 66.67% in Group 1 and 72.22% in Group 2 (P> 0.05). The side effects were mild and transient. Our results demonstrated that adenosine stress myocardial perfusion imaging is a safe and reliable diagnostic method for an early stage of CAD. As a comparative sensitivity and accuracy with exercise stress thallium-201 myocardial perfusion imaging, adenosine stress testing may provide a feasible alternative pharmacological stress method in myocardial SPECT for detection of CAD.
Content Type Journal Article
Pages 317-322
DOI 10.3233/XST-130380
Authors
Gui-Bing Chen, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Hua Wu, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Xiao-Jiang He, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Jin-Xiong Huang, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Dan Yu, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Wei-Yi Xu, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Hao Yu, Department of Nuclear Medicine, The First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:43:30 GMT
- Abstract: The aims of this study were to evaluate the diagnostic value of adenosine thallium-201 myocardial perfusion imaging and to compare it with exercise stress thallium-201 myocardial perfusion imaging for detecting coronary artery disease (CAD) at an early stage. Forty-one patients suspected with CAD were randomly divided into two groups. In Group 1 (n=21) adenosine stress was undertaken; the exercise stress myocardial perfusion imaging was performed in Group 2 (n=20). Coronary angiography (CAG) was performed in each patient within 2 weeks before or after single photon emission computed tomography (SPECT). Adenosine stress group vs. exercise stress group, the sensitivity was 92.86% vs. 100.0%, specificity 57.14% vs. 60.0%, positive predictive value 81.25% vs. 71.43%, negative predictive value 80.0% vs. 100.0%, accuracy 80.95% vs. 80.0% respectively. Detection rates of vessels of coronary artery lesions were 66.67% in Group 1 and 72.22% in Group 2 (P> 0.05). The side effects were mild and transient. Our results demonstrated that adenosine stress myocardial perfusion imaging is a safe and reliable diagnostic method for an early stage of CAD. As a comparative sensitivity and accuracy with exercise stress thallium-201 myocardial perfusion imaging, adenosine stress testing may provide a feasible alternative pharmacological stress method in myocardial SPECT for detection of CAD.
- X-ray computed tomography and sonography features of continuous splenogonadal fusion
- Abstract: Splenogonadal fusion is a rare congenital anomaly where the spleen is attached to either testicular or ovarian tissues. In present case, splenogonadal fusion presents as a large mass consciously connected to atrophic testis in left scrotum. The diagnosis of splenic gonadal fusion relies on radiologic and pathologic findings. Uniform density and vessels connection originating from splenic hilum between principle spleen and let testicle were observed with ultrasound and X-ray computed tomography (CT). Surgical exploration ruled out malignancy, extratesticular scrotal mass with affected testicle was removed. Pathologic examination demonstrated that ectopic spleen tissue and ipsilateral atrophic testis. Our data suggested that orchiectomy should be performed when contralateral testicle is normal and the affected testicular appeared significantly atrophy.
Content Type Journal Article
Pages 303-308
DOI 10.3233/XST-130378
Authors
Yong Zhang, Department of Urology, The Military General Hospital of Beijing, Beijing, China
Zang Tong, Department of Urology, The Military General Hospital of Beijing, Beijing, China
Yuanyuan Zhang, Instutitue for Regnerative Medicine, Wake Forest Univeristy, Winston-Salem, NC, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:43:16 GMT
- Abstract: Splenogonadal fusion is a rare congenital anomaly where the spleen is attached to either testicular or ovarian tissues. In present case, splenogonadal fusion presents as a large mass consciously connected to atrophic testis in left scrotum. The diagnosis of splenic gonadal fusion relies on radiologic and pathologic findings. Uniform density and vessels connection originating from splenic hilum between principle spleen and let testicle were observed with ultrasound and X-ray computed tomography (CT). Surgical exploration ruled out malignancy, extratesticular scrotal mass with affected testicle was removed. Pathologic examination demonstrated that ectopic spleen tissue and ipsilateral atrophic testis. Our data suggested that orchiectomy should be performed when contralateral testicle is normal and the affected testicular appeared significantly atrophy.
- Safety and efficacy of 120w high performance system greenlight laser vaporization for non-muscle-invasive bladder cancer
- Abstract: OBJECTIVE: We evaluated the safety and efficacy of 120W potassium-titanyl-phosphate (KTP) laser vaporization on patients with non-muscle invasive bladder cancer compared with standard transurethral resection of bladder tumor (TUR-BT).MATERIALS AND METHODS: One hundred and fifty-eight patients of non-muscle invasive bladder cancer who underwent either 120W potassium-titanyl-phosphate (KTP) laser vaporization (HPS group, n=74) or transurethral resection of the bladder tumor (TUR-BT group, n=84) were analyzed respectively. The preoperative, intraoperative and postoperative clinical data were recorded and compared in two groups.RESULTS: All patients were successfully treated with 120W-KTP laser vaporization or TUR-BT. No significant differences were observed in operative time, perioperative and postoperative serum sodium and hemoglobin levels between two groups. Importantly, HPS had less specific side effects of TURBT, such as obturator nerve reflex, postoperative bladder irrigation and catheterization time, which shows statistic difference significantly (p< 0.05). Recurrence rate was lower in HPS group than those in TUR-BT group.CONCLUSION: The 120W-HPS KTP laser as a safe and feasible procedure provids an alternative for the patients with non-muscle invasive bladder cancer, especially for those on anticoagulation therapy.
Content Type Journal Article
Pages 309-316
DOI 10.3233/XST-130379
Authors
Wei Tao, Department of Urology, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Dongrong Yang, Department of Urology, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Yuxi Shan, Department of Urology, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Boxin Xue, Department of Urology, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Chuanyang Sun, Department of Urology, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Yangchen Zang, Department of Urology, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
Yuanyuan Zhang, Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine, Winston-Salem, NC, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:43:16 GMT
- Abstract: OBJECTIVE: We evaluated the safety and efficacy of 120W potassium-titanyl-phosphate (KTP) laser vaporization on patients with non-muscle invasive bladder cancer compared with standard transurethral resection of bladder tumor (TUR-BT).MATERIALS AND METHODS: One hundred and fifty-eight patients of non-muscle invasive bladder cancer who underwent either 120W potassium-titanyl-phosphate (KTP) laser vaporization (HPS group, n=74) or transurethral resection of the bladder tumor (TUR-BT group, n=84) were analyzed respectively. The preoperative, intraoperative and postoperative clinical data were recorded and compared in two groups.RESULTS: All patients were successfully treated with 120W-KTP laser vaporization or TUR-BT. No significant differences were observed in operative time, perioperative and postoperative serum sodium and hemoglobin levels between two groups. Importantly, HPS had less specific side effects of TURBT, such as obturator nerve reflex, postoperative bladder irrigation and catheterization time, which shows statistic difference significantly (p< 0.05). Recurrence rate was lower in HPS group than those in TUR-BT group.CONCLUSION: The 120W-HPS KTP laser as a safe and feasible procedure provids an alternative for the patients with non-muscle invasive bladder cancer, especially for those on anticoagulation therapy.
- Transurethral bipolar plasma kinetic resection of ejaculatory duct for treatment of ejaculatory duct obstruction
- Abstract: To evaluate the efficacy of transurethral bipolar plasma kinetic resection of ejaculatory duct for ejaculatory duct obstruction. The clinical information of 42 cases of ejaculatory duct obstruction was analyzed between July 2008 and June 2012. The diagnostic criteria included semen analysis, fructose and neutral α-glucosidase measurement in seminal plasma, transrectal ultrasonography, magnetic resonance imaging and vasography necessarily. Endoscopic procedure with bipolar plasma kinetic resection of ejaculatory duct was performed in all patients. Among these cases followed up 6∼24 months after operation, 38 patients (90.5%) had improved semen parameters, 23 azoospermic patients (60.5%) had sperm in the semen and 13 patients' wife (31%) achieved pregnancies in 42 cases of bipolar plasma kinetic resection of ejaculatory duct. Postoperative complications ensued as epididymitis in 1 case, watery ejaculate in 1, but no serious complication was observed. Bipolar plasma kinetic resection of ejaculatory duct appears to represent a promising endoscopic treatment alternative for ejaculatory duct obstruction patients, with high efficacy, less complications, quicker recovery and satisfactory follow-up parameters.
Content Type Journal Article
Pages 293-302
DOI 10.3233/XST-130377
Authors
Xiang-An Tu, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Jin-Tao Zhuang, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Liang Zhao, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Liang-Yun Zhao, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Ji-Quan Zhao, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Kun-Long Lü, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Xiang-Zhou Sun, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Shao-Peng Qiu, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Yuanyuan Zhang, Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, USA
Chun-Hua Deng, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:42:59 GMT
- Abstract: To evaluate the efficacy of transurethral bipolar plasma kinetic resection of ejaculatory duct for ejaculatory duct obstruction. The clinical information of 42 cases of ejaculatory duct obstruction was analyzed between July 2008 and June 2012. The diagnostic criteria included semen analysis, fructose and neutral α-glucosidase measurement in seminal plasma, transrectal ultrasonography, magnetic resonance imaging and vasography necessarily. Endoscopic procedure with bipolar plasma kinetic resection of ejaculatory duct was performed in all patients. Among these cases followed up 6∼24 months after operation, 38 patients (90.5%) had improved semen parameters, 23 azoospermic patients (60.5%) had sperm in the semen and 13 patients' wife (31%) achieved pregnancies in 42 cases of bipolar plasma kinetic resection of ejaculatory duct. Postoperative complications ensued as epididymitis in 1 case, watery ejaculate in 1, but no serious complication was observed. Bipolar plasma kinetic resection of ejaculatory duct appears to represent a promising endoscopic treatment alternative for ejaculatory duct obstruction patients, with high efficacy, less complications, quicker recovery and satisfactory follow-up parameters.
- Comparison of the diagnostic efficiency for breast cancer in Chinese women using mammography, ultrasound, MRI, and different combinations of these imaging modalities
- Abstract: To compare the respective diagnostic efficiency for breast cancer in Chinese women with x-ray mammography (XRM), ultrasound (US), magnetic resonance imaging (MRI; standard dynamic contrasted-enhanced MRI with diffusion-weighted imaging), and different combinations of these imaging modalities, ninety Chinese women patients with clinically suspected breast cancer underwent prospective breast XRM, US, and MRI. The diagnostic performance of each imaging method and different combinations of methods was compared, with the pathological report serving as the gold standard. In this cohort study 54.4% cases with age of 53.2 ± 7.6 years old were categorized as ACR 3 or 4 tissue density. In the diagnosis of breast cancer, sensitivity and diagnostic accuracy [area under the Receiver Operating Characteristic curve (AUC)] were significantly higher for MRI alone than for either XRM alone or US alone (P< 0.05). Of the misdiagnosed cases on XRM, up to 86.7% cancers were located in dense breasts. US and MRI can play important role in screening young Chinese women. The diagnostic sensitivity was significantly higher for combined MRI+US+XRM (98.2%, χ^2=25.9, P< 0.001), MRI+US (94.5%, χ^ 2 53.3, P=0.002) and MRI+XRM (92.9% combination of two or three methods significantly improved the diagnostic sensitivity for breast cancer in Chinese women. When the results based on different imaging modalities or their combinations are inconsistent, further pathological diagnosis is very important for arriving at a correct diagnosis.
Content Type Journal Article
Pages 283-292
DOI 10.3233/XST-130376
Authors
Hongda Shao, Department of Radiology, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China
Baoping Li, Department of Radiology, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China
Xiao Zhang, Department of Radiology, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China
Zhaoming Xiong, Department of Radiology, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China
Yong Liu, Department of Radiology, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China
Guangyu Tang, Department of Radiology, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:42:38 GMT
- Abstract: To compare the respective diagnostic efficiency for breast cancer in Chinese women with x-ray mammography (XRM), ultrasound (US), magnetic resonance imaging (MRI; standard dynamic contrasted-enhanced MRI with diffusion-weighted imaging), and different combinations of these imaging modalities, ninety Chinese women patients with clinically suspected breast cancer underwent prospective breast XRM, US, and MRI. The diagnostic performance of each imaging method and different combinations of methods was compared, with the pathological report serving as the gold standard. In this cohort study 54.4% cases with age of 53.2 ± 7.6 years old were categorized as ACR 3 or 4 tissue density. In the diagnosis of breast cancer, sensitivity and diagnostic accuracy [area under the Receiver Operating Characteristic curve (AUC)] were significantly higher for MRI alone than for either XRM alone or US alone (P< 0.05). Of the misdiagnosed cases on XRM, up to 86.7% cancers were located in dense breasts. US and MRI can play important role in screening young Chinese women. The diagnostic sensitivity was significantly higher for combined MRI+US+XRM (98.2%, χ^2=25.9, P< 0.001), MRI+US (94.5%, χ^ 2 53.3, P=0.002) and MRI+XRM (92.9% combination of two or three methods significantly improved the diagnostic sensitivity for breast cancer in Chinese women. When the results based on different imaging modalities or their combinations are inconsistent, further pathological diagnosis is very important for arriving at a correct diagnosis.
- Influence of permittivity and electrical conductivity on image pattern of MRI
- Abstract: In proton density-weighted (PDW) MR imaging, the patterns of signal intensity vary depending on the imaged material, and change with the flip angle (FA) applied to the imaged material. The correlation between the pre-determined FA and the actual FA applied to imaged objects was investigated using 4 types of phantoms having different dielectric properties. PDW images were acquired using the spin-echo (SE) method and different pre-determined FA. Dependency of the signal intensity distribution in the phantom on the pre-determined FA differed among phantoms: patterns for water and 0.402 w/w% saline solution phantoms changed with the pre-determined FA, whereas those for olive oil and 4.02 w/w% saline solution phantoms were barely affected by the pre-determined FA. Causes of these phenomena were considered to be the differences between the pre-determined FA and the actual FA among the phantoms; differences were also influenced by the positioning of the phantom. Our study showed that the actual FA in the phantom is greater than the pre-determined FA in high permittivity media, whereas it is reduced by an increased conductivity of the media.
Content Type Journal Article
Pages 147-159
DOI 10.3233/XST-130375
Authors
Takashi Harimoto, Graduate School of Health Sciences, Okayama University, Shikata-cho, Okayama, Japan
Seiichiro Ohno, Central Division of Radiology, Okayama University Hospital, Shikata-cho, Okayama, Japan
Kengo Hattori, Graduate School of Health Sciences, Okayama University, Shikata-cho, Okayama, Japan
Miyuki Hirosue, Murakami Neurosurgery Internal Medicine, Oiminami, Kasaoka, Japan
Masahiro Miyai, Department of Radiology, Shimane University Hospital, Enya-cho, Izumo, Japan
Koichi Shibuya, Graduate School of Health Sciences, Okayama University, Shikata-cho, Okayama, Japan
Masahiro Kuroda, Graduate School of Health Sciences, Okayama University, Shikata-cho, Okayama, Japan
Susumu Kanazawa, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikata-cho, Okayama, Japan
Hirokazu Kato, Graduate School of Health Sciences, Okayama University, Shikata-cho, Okayama, Japan
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:42:27 GMT
- Abstract: In proton density-weighted (PDW) MR imaging, the patterns of signal intensity vary depending on the imaged material, and change with the flip angle (FA) applied to the imaged material. The correlation between the pre-determined FA and the actual FA applied to imaged objects was investigated using 4 types of phantoms having different dielectric properties. PDW images were acquired using the spin-echo (SE) method and different pre-determined FA. Dependency of the signal intensity distribution in the phantom on the pre-determined FA differed among phantoms: patterns for water and 0.402 w/w% saline solution phantoms changed with the pre-determined FA, whereas those for olive oil and 4.02 w/w% saline solution phantoms were barely affected by the pre-determined FA. Causes of these phenomena were considered to be the differences between the pre-determined FA and the actual FA among the phantoms; differences were also influenced by the positioning of the phantom. Our study showed that the actual FA in the phantom is greater than the pre-determined FA in high permittivity media, whereas it is reduced by an increased conductivity of the media.
- Monte Carlo study of the dose enhancement effect of gold nanoparticles during X-ray therapies and evaluation of the anti-angiogenic effect on tumour capillary vessels
- Abstract: Gold nanoparticles (GNPs) are a promising radiosensitizer agent in radiotherapy. Through a simulation performed with the Geant4 Monte Carlo code, we evaluated the dose enhancement effect of GNPs during therapies with an x-ray tube operating at 150 kV (E=55 keV and E_{max}= 150 keV) and we studied the impact of GNP diffusion out of the tumour vessels, in terms of antiangiogenic and cytotoxic effects.Firstly, a single x-ray beam was assumed to irradiate a parallelepiped volume of soft tissue, in which a GNP-doped "target" volume was placed at different depths. Average dose enhancement factors (DEF) in presence of GNPs were obtained as a function of the target depth and GNP concentration, uniformly distributed; values ranging between 1.6 for 10 mg Au/g at 0 cm and 7.2 for 200 mg Au/g at 5 cm were determined. Furtherly, a second geometry was adopted, in which a blood capillary vessel (10 μm thick and 10 μm of inner radius) was placed at the centre of a cubic volume of soft tissue; doses and DEFs to the capillary endothelium as well as to the surrounding viable tumour were evaluated, for different models of GNP diffusion. Our results indicate that the radial DEF profiles around the vessel are in close relationship with the radial profiles of GNP concentration assumed, except for at sharp gradients of concentration. DEFs at the endothelium ranged from 1.6 to 6.5, for GNP concentrations in the blood of 10 and 200 mg/ml, respectively. These data can be helpful for the development of new and more specific GNP-based radiosensitizers of potential interest in radiotherapy, exploiting the combined benefit of anti-angiogenic and cytotoxic dose enhancement effects.
Content Type Journal Article
Pages 237-247
DOI 10.3233/XST-130374
Authors
Ernesto Amato, Section of Radiological Sciences, Department of Biomedical Sciences and of Morphologic and Functional Imaging, University of Messina, Messina, Italy
Antonio Italiano, INFN, Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Messina, Messina, Italy
Salvatore Leotta, Department of Physics and Earth Sciences, University of Messina, Messina, Italy
Stefano Pergolizzi, Section of Radiological Sciences, Department of Biomedical Sciences and of Morphologic and Functional Imaging, University of Messina, Messina, Italy
Lorenzo Torrisi, Department of Physics and Earth Sciences, University of Messina, Messina, Italy
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:42:17 GMT
- Abstract: Gold nanoparticles (GNPs) are a promising radiosensitizer agent in radiotherapy. Through a simulation performed with the Geant4 Monte Carlo code, we evaluated the dose enhancement effect of GNPs during therapies with an x-ray tube operating at 150 kV (E=55 keV and E_{max}= 150 keV) and we studied the impact of GNP diffusion out of the tumour vessels, in terms of antiangiogenic and cytotoxic effects.Firstly, a single x-ray beam was assumed to irradiate a parallelepiped volume of soft tissue, in which a GNP-doped "target" volume was placed at different depths. Average dose enhancement factors (DEF) in presence of GNPs were obtained as a function of the target depth and GNP concentration, uniformly distributed; values ranging between 1.6 for 10 mg Au/g at 0 cm and 7.2 for 200 mg Au/g at 5 cm were determined. Furtherly, a second geometry was adopted, in which a blood capillary vessel (10 μm thick and 10 μm of inner radius) was placed at the centre of a cubic volume of soft tissue; doses and DEFs to the capillary endothelium as well as to the surrounding viable tumour were evaluated, for different models of GNP diffusion. Our results indicate that the radial DEF profiles around the vessel are in close relationship with the radial profiles of GNP concentration assumed, except for at sharp gradients of concentration. DEFs at the endothelium ranged from 1.6 to 6.5, for GNP concentrations in the blood of 10 and 200 mg/ml, respectively. These data can be helpful for the development of new and more specific GNP-based radiosensitizers of potential interest in radiotherapy, exploiting the combined benefit of anti-angiogenic and cytotoxic dose enhancement effects.
- Quantitative flow measurement by digital subtraction angiography in cerebral carotid stenosis using optical flow method
- Abstract: OBJECTIVE: We analyzed intracranial regional blood flows using an optical flow method (OFM) and digital subtraction angiography in patients with internal carotid artery (ICA) stenosis. We also retrospectively explored the correlation between the patients' diagnoses and the severity of the ICA stenoses. MATERIALS AND METHODS: OFM, an image-processing algorithm to estimate motion, was applied to determine the mean velocity V_{mean} in the vessels. A group of 40 patients without vascular anomalies acted as the control group. The patients were classified as having either moderate stenosis (< 80%, n=14) or severe stenosis (> 80%, n=23). RESULTS: The V_{mean} of the ICAs was significantly lower in the stenotic group compared with the control group (p< 0.01). The V_{mean} of the ICAs was inversely correlated with the severity of the stenosis (p< 0.05). The receiver operating characteristic curve of the V_{mean} in an AP view showed substantial discriminatory power, with an optimal cutoff value of 3.48 pixels/frame for the detection of patients with carotid stenosis. The sensitivity and specificity were 84% and 50%, respectively. On a lateral view, the best cutoff for the V_{mean} was 4.01 pixels/frame, and the sensitivity and specificity were 92% and 43%, respectively. CONCLUSIONS: Digital subtraction angiography combined with the OFM is a feasible parametric method for intracranial blood flow measurements in patients with moderate to severe carotid stenosis.
Content Type Journal Article
Pages 227-235
DOI 10.3233/XST-130373
Authors
Tzung-Chi Huang, Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan
Tung-Hsin Wu, Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
Yang-Hsien Lin, Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan
Wan-Yuo Guo, Radiology Department, Taipei Veterans General Hospital, Taipei, Taiwan
Wei-Chien Huang, Graduate Institute of Cancer Biology, China Medical University, Taichung City, Taiwan
Chung-Jung Lin, Radiology Department, Taipei Veterans General Hospital, Taipei, Taiwan
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:41:56 GMT
- Abstract: OBJECTIVE: We analyzed intracranial regional blood flows using an optical flow method (OFM) and digital subtraction angiography in patients with internal carotid artery (ICA) stenosis. We also retrospectively explored the correlation between the patients' diagnoses and the severity of the ICA stenoses. MATERIALS AND METHODS: OFM, an image-processing algorithm to estimate motion, was applied to determine the mean velocity V_{mean} in the vessels. A group of 40 patients without vascular anomalies acted as the control group. The patients were classified as having either moderate stenosis (< 80%, n=14) or severe stenosis (> 80%, n=23). RESULTS: The V_{mean} of the ICAs was significantly lower in the stenotic group compared with the control group (p< 0.01). The V_{mean} of the ICAs was inversely correlated with the severity of the stenosis (p< 0.05). The receiver operating characteristic curve of the V_{mean} in an AP view showed substantial discriminatory power, with an optimal cutoff value of 3.48 pixels/frame for the detection of patients with carotid stenosis. The sensitivity and specificity were 84% and 50%, respectively. On a lateral view, the best cutoff for the V_{mean} was 4.01 pixels/frame, and the sensitivity and specificity were 92% and 43%, respectively. CONCLUSIONS: Digital subtraction angiography combined with the OFM is a feasible parametric method for intracranial blood flow measurements in patients with moderate to severe carotid stenosis.
- Enhancement of four-dimensional cone-beam computed tomography by compressed sensing with Bregman iteration
- Abstract: In four-dimensional (4D) cone-beam computed tomography (CBCT), there is a spatio-temporal tradeoff that currently limits the accuracy. The aim of this study is to develop a Bregman iteration based formalism for high quality 4D CBCT image reconstruction from a limited number of low-dose projections. The 4D CBCT problem is first divided into multiple 3D CBCT subproblems by grouping the projection images corresponding to the phases. To maximally utilize the information from the under-sampled projection data, a compressed sensing (CS) method with Bregman iterations is employed for solving each subproblem. We formulate an unconstrained optimization problem based on least-square criterion regularized by total-variation. The least-square criterion reflects the inconsistency between the measured and the estimated line integrals. Furthermore, the unconstrained problem is updated and solved repeatedly by Bregman iterations. The performance of the proposed algorithm is demonstrated through a series of simulation studies and phantom experiments, and the results are compared to those of previously implemented compressed sensing technique using other gradient-based methods as well as conventional filtered back-projection (FBP) results. The simulation and experimental studies have shown that artifact suppressed images can be obtained with as small as 41 projections per phase, which is adequate for clinical 4D CBCT reconstruction. With such small number of projections, the conventional FDK failed to yield meaningful 4D CBCT images, and CS technique using conjugate gradient was not able to recover sharp edges. The proposed method significantly reduces the radiation dose and scanning time to achieve the high quality images compared to the 4D CBCT imaging based on the conventional FDK technique and the existing CS techniques.
Content Type Journal Article
Pages 177-192
DOI 10.3233/XST-130371
Authors
Kihwan Choi, Department of Radiation Oncology, Stanford University, Stanford, CA, USA
Benjamin P. Fahimian, Department of Radiation Oncology, Stanford University, Stanford, CA, USA
Tianfang Li, Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
Tae-Suk Suh, Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea
Xing Lei, Department of Radiation Oncology, Stanford University, Stanford, CA, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:41:37 GMT
- Abstract: In four-dimensional (4D) cone-beam computed tomography (CBCT), there is a spatio-temporal tradeoff that currently limits the accuracy. The aim of this study is to develop a Bregman iteration based formalism for high quality 4D CBCT image reconstruction from a limited number of low-dose projections. The 4D CBCT problem is first divided into multiple 3D CBCT subproblems by grouping the projection images corresponding to the phases. To maximally utilize the information from the under-sampled projection data, a compressed sensing (CS) method with Bregman iterations is employed for solving each subproblem. We formulate an unconstrained optimization problem based on least-square criterion regularized by total-variation. The least-square criterion reflects the inconsistency between the measured and the estimated line integrals. Furthermore, the unconstrained problem is updated and solved repeatedly by Bregman iterations. The performance of the proposed algorithm is demonstrated through a series of simulation studies and phantom experiments, and the results are compared to those of previously implemented compressed sensing technique using other gradient-based methods as well as conventional filtered back-projection (FBP) results. The simulation and experimental studies have shown that artifact suppressed images can be obtained with as small as 41 projections per phase, which is adequate for clinical 4D CBCT reconstruction. With such small number of projections, the conventional FDK failed to yield meaningful 4D CBCT images, and CS technique using conjugate gradient was not able to recover sharp edges. The proposed method significantly reduces the radiation dose and scanning time to achieve the high quality images compared to the 4D CBCT imaging based on the conventional FDK technique and the existing CS techniques.
- An experimental survey of metal artefact reduction in computed tomography
- Abstract: We present a survey of techniques for the reduction of streaking artefacts caused by metallic objects in X-ray Computed Tomography (CT) images. A comprehensive review of the existing state-of-the-art Metal Artefact Reduction (MAR) techniques, drawn predominantly from the medical CT literature, is supported by an experimental comparison of twelve MAR techniques. The experimentation is grounded in an evaluation based on a standard scientific comparison protocol for MAR methods, using a software generated medical phantom image as well as a clinical CT scan. The experimentation is extended by considering novel applications of CT imagery consisting of metal objects in non-tissue surroundings acquired from the aviation security screening domain. We address the shortage of thorough performance analyses in the existing MAR literature by conducting a qualitative as well as quantitative comparative evaluation of the selected techniques. We find that the difficulty in generating accurate priors to be the predominant factor limiting the effectiveness of the state-of-the-art medical MAR techniques when applied to non-medical CT imagery. This study thus extends previous works by: comparing several state-of-the-art MAR techniques; considering both medical and non-medical applications and performing a thorough performance analysis, considering both image quality as well as computational demands.
Content Type Journal Article
Pages 193-226
DOI 10.3233/XST-130372
Authors
Andre Mouton, School of Engineering, Cranfield University, Bedfordshire, UK
Najla Megherbi, School of Engineering, Cranfield University, Bedfordshire, UK
Katrien Van Slambrouck, Department of Nuclear Medicine, KU Leuven, Leuven, Belgium
Johan Nuyts, Department of Nuclear Medicine, KU Leuven, Leuven, Belgium
Toby P. Breckon, School of Engineering, Cranfield University, Bedfordshire, UK
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:41:37 GMT
- Abstract: We present a survey of techniques for the reduction of streaking artefacts caused by metallic objects in X-ray Computed Tomography (CT) images. A comprehensive review of the existing state-of-the-art Metal Artefact Reduction (MAR) techniques, drawn predominantly from the medical CT literature, is supported by an experimental comparison of twelve MAR techniques. The experimentation is grounded in an evaluation based on a standard scientific comparison protocol for MAR methods, using a software generated medical phantom image as well as a clinical CT scan. The experimentation is extended by considering novel applications of CT imagery consisting of metal objects in non-tissue surroundings acquired from the aviation security screening domain. We address the shortage of thorough performance analyses in the existing MAR literature by conducting a qualitative as well as quantitative comparative evaluation of the selected techniques. We find that the difficulty in generating accurate priors to be the predominant factor limiting the effectiveness of the state-of-the-art medical MAR techniques when applied to non-medical CT imagery. This study thus extends previous works by: comparing several state-of-the-art MAR techniques; considering both medical and non-medical applications and performing a thorough performance analysis, considering both image quality as well as computational demands.
- A few-view reweighted sparsity hunting (FRESH) method for CT image reconstruction
- Abstract: In recent years, the total variation (TV) minimization method has been widely used for compressed sensing (CS) based CT image reconstruction. In this paper, we propose a few-view reweighted sparsity hunting (FRESH) method for CT image reconstruction, and demonstrate the superior performance of this method. Specifically, the key of the purposed method is that a reweighted total variation (RwTV) measure is used to characterize image sparsity in the cost function, outperforming the conventional TV counterpart. To solve the RwTV minimization problem efficiently, the Split-Bregman method and other state-of-the-art L1 optimization methods are compared. Inspired by the fast iterative shrinkage/thresholding algorithm (FISTA), a predication step is incorporated for fast computation in the Split-Bregman framework. Extensive numerical experiments have shown that our FRESH approach performs significantly better than competing algorithms in terms of image quality and convergence speed for few-view CT. High-quality images were reconstructed by our FRESH method after 250 iterations using only 15 few-view projections of the Forbild head phantom while other competitors needed more than 800 iterations. Remarkable improvements in details in the experimental evaluation using actual sheep thorax data further indicate the potential real-world application of the FRESH method.
Content Type Journal Article
Pages 161-176
DOI 10.3233/XST-130370
Authors
Ming Chang, Department of Engineering Physics, Tsinghua University, Beijing, China
Liang Li, Department of Engineering Physics, Tsinghua University, Beijing, China
Zhiqiang Chen, Department of Engineering Physics, Tsinghua University, Beijing, China
Yongshun Xiao, Department of Engineering Physics, Tsinghua University, Beijing, China
Li Zhang, Department of Engineering Physics, Tsinghua University, Beijing, China
Ge Wang, VT-WFU School of Biomedical Engineering and Sciences, Virginia Tech, VA, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:41:37 GMT
- Abstract: In recent years, the total variation (TV) minimization method has been widely used for compressed sensing (CS) based CT image reconstruction. In this paper, we propose a few-view reweighted sparsity hunting (FRESH) method for CT image reconstruction, and demonstrate the superior performance of this method. Specifically, the key of the purposed method is that a reweighted total variation (RwTV) measure is used to characterize image sparsity in the cost function, outperforming the conventional TV counterpart. To solve the RwTV minimization problem efficiently, the Split-Bregman method and other state-of-the-art L1 optimization methods are compared. Inspired by the fast iterative shrinkage/thresholding algorithm (FISTA), a predication step is incorporated for fast computation in the Split-Bregman framework. Extensive numerical experiments have shown that our FRESH approach performs significantly better than competing algorithms in terms of image quality and convergence speed for few-view CT. High-quality images were reconstructed by our FRESH method after 250 iterations using only 15 few-view projections of the Forbild head phantom while other competitors needed more than 800 iterations. Remarkable improvements in details in the experimental evaluation using actual sheep thorax data further indicate the potential real-world application of the FRESH method.
- 3D segmentation of maxilla in cone-beam computed tomography imaging using base invariant wavelet active shape model on customized two-manifold topology
- Abstract: Recent advances in cone-beam computed tomography (CBCT) have rapidly enabled widepsread applications of dentomaxillofacial imaging and orthodontic practices in the past decades due to its low radiation dose, high spatial resolution, and accessibility. However, low contrast resolution in CBCT image has become its major limitation in building skull models. Intensive hand-segmentation is usually required to reconstruct the skull models. One of the regions affected by this limitation the most is the thin bone images. This paper presents a novel segmentation approach based on wavelet density model (WDM) for a particular interest in the outer surface of anterior wall of maxilla. Nineteen CBCT datasets are used to conduct two experiments. This mode-based segmentation approach is validated and compared with three different segmentation approaches. The results show that the performance of this model-based segmentation approach is better than those of the other approaches. It can achieve 0.25 ± 0.2 mm of surface error from ground truth of bone surface.
Content Type Journal Article
Pages 251-282
DOI 10.3233/XST-130369
Authors
Yu-Bing Chang, Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
James J. Xia, Department of Oral and Maxillofacial Surgery, The Methodist Hospital Research Institute, Houston, TX, USA
Peng Yuan, Department of Oral and Maxillofacial Surgery, The Methodist Hospital Research Institute, Houston, TX, USA
Tai-Hong Kuo, Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan
Zixiang Xiong, Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
Jaime Gateno, Department of Oral and Maxillofacial Surgery, The Methodist Hospital Research Institute, Houston, TX, USA
Xiaobo Zhou, Center for Biotechnology and Informatics, The Methodist Hospital Research Institute, Houston, TX, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 2 / 2013
PubDate: Tue, 21 May 2013 14:41:22 GMT
- Abstract: Recent advances in cone-beam computed tomography (CBCT) have rapidly enabled widepsread applications of dentomaxillofacial imaging and orthodontic practices in the past decades due to its low radiation dose, high spatial resolution, and accessibility. However, low contrast resolution in CBCT image has become its major limitation in building skull models. Intensive hand-segmentation is usually required to reconstruct the skull models. One of the regions affected by this limitation the most is the thin bone images. This paper presents a novel segmentation approach based on wavelet density model (WDM) for a particular interest in the outer surface of anterior wall of maxilla. Nineteen CBCT datasets are used to conduct two experiments. This mode-based segmentation approach is validated and compared with three different segmentation approaches. The results show that the performance of this model-based segmentation approach is better than those of the other approaches. It can achieve 0.25 ± 0.2 mm of surface error from ground truth of bone surface.
- DOT corrected fluorescence molecular tomography using targeted contrast agents for small animal tumor imaging
- Abstract: PURPOSE: To demonstrate diffuse optical tomography (DOT) corrected fluorescence molecular tomography (FMT) for quantitatively imaging tumor-targeted contrast agents in a 4T1 mouse mammary tumor model. PROCEDURES: In the first set of experiments, we validated our DOT corrected FMT method using subcutaneously injected 4T1 cells pre-labeled with a near-infrared (NIR) Cy 5.5 dye labeled recombinant amino-terminal fragment (ATF) of the receptor binding domain of urokinase plasminogen activator (uPA), which binds to uPA receptor (uPAR) that is highly expressed in breast cancer tissues. Next, we apply the DOT corrected FMT method to quantitatively evaluate the ability of sensitive tumor imaging after systemic delivery of new uPAR-targeted optical imaging probes in the mice bearing 4T1 mammary tumors. These uPAR-targeted optical imaging probes are ATF peptides labeled with a newly developed NIR-830 dye being conjugated to magnetic iron oxide nanoparticles (IONPs). RESULTS: Our results have shown that DOT corrected FMT can accurately quantify and localize the injected imaging probe labeled 4T1 cells. Following systemic delivery of the targeted imaging nanoprobes into the mice bearing orthotopic mammary tumors, specific accumulation of the imaging probes in the orthotopic mammary tumors was detected in the mice that received uPAR targeted NIR-830-ATF-IONP probes but not in the mice injected with non-targeted NIR-830-mouse serum albumin (MSA)-IONPs. Additionally, DOT corrected FMT also enables the detection of both locally recurrent tumor and lung metastasis in the mammary tumor model 72 hrs after systemic administration of the uPAR-targeted NIR-830-labeled ATF peptide imaging probes. CONCLUSIONS: DOT corrected FMT and uPAR-targeted optical imaging probes have great potential for detection of breast cancer, recurrent tumor and metastasis in small animals.
Content Type Journal Article
Pages 43-52
DOI 10.3233/XST-130365
Authors
Yiyong Tan, J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
Zehong Cao, Departments of Surgery, Emory University, Atlanta, GA, USA
Hari Krishna Sajja, Departments of Surgery, Emory University, Atlanta, GA, USA
Malgorzata Lipowska, Departments of Radiology, Emory University, Atlanta, GA, USA
Y. Andrew Wang, Oceannanotech LLC, Springdale, AR, USA
Lily Yang, Departments of Surgery, Emory University, Atlanta, GA, USA
Huabei Jiang, J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: PURPOSE: To demonstrate diffuse optical tomography (DOT) corrected fluorescence molecular tomography (FMT) for quantitatively imaging tumor-targeted contrast agents in a 4T1 mouse mammary tumor model. PROCEDURES: In the first set of experiments, we validated our DOT corrected FMT method using subcutaneously injected 4T1 cells pre-labeled with a near-infrared (NIR) Cy 5.5 dye labeled recombinant amino-terminal fragment (ATF) of the receptor binding domain of urokinase plasminogen activator (uPA), which binds to uPA receptor (uPAR) that is highly expressed in breast cancer tissues. Next, we apply the DOT corrected FMT method to quantitatively evaluate the ability of sensitive tumor imaging after systemic delivery of new uPAR-targeted optical imaging probes in the mice bearing 4T1 mammary tumors. These uPAR-targeted optical imaging probes are ATF peptides labeled with a newly developed NIR-830 dye being conjugated to magnetic iron oxide nanoparticles (IONPs). RESULTS: Our results have shown that DOT corrected FMT can accurately quantify and localize the injected imaging probe labeled 4T1 cells. Following systemic delivery of the targeted imaging nanoprobes into the mice bearing orthotopic mammary tumors, specific accumulation of the imaging probes in the orthotopic mammary tumors was detected in the mice that received uPAR targeted NIR-830-ATF-IONP probes but not in the mice injected with non-targeted NIR-830-mouse serum albumin (MSA)-IONPs. Additionally, DOT corrected FMT also enables the detection of both locally recurrent tumor and lung metastasis in the mammary tumor model 72 hrs after systemic administration of the uPAR-targeted NIR-830-labeled ATF peptide imaging probes. CONCLUSIONS: DOT corrected FMT and uPAR-targeted optical imaging probes have great potential for detection of breast cancer, recurrent tumor and metastasis in small animals.
- Successive binary algebraic reconstruction technique: An algorithm for reconstruction from limited angle and limited number of projections decomposed into individual components
- Abstract: Relatively high radiation CT techniques are being widely used in diagnostic imaging raising the concerns about cancer risk especially for routine screening of asymptomatic populations. An important strategy for dose reduction is to reduce the number of projections, although doing so with high image quality is technically difficult. We developed an algorithm to reconstruct discrete (limited gray scale) images decomposed into individual tissue types from a small number of projections acquired over a limited view angle. The algorithm was tested using projection simulations from segmented CT scans of different cross sections including mid femur, distal femur and lower leg. It can provide high quality images from as low as 5–7 projections if the skin boundary of the cross section is used as prior information in the reconstruction process, and from 11–13 projections if the skin boundary is unknown.
Content Type Journal Article
Pages 9-24
DOI 10.3233/XST-130363
Authors
Alia S. Khaled, Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
Thomas J. Beck, Division of Medical Imaging Physics, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: Relatively high radiation CT techniques are being widely used in diagnostic imaging raising the concerns about cancer risk especially for routine screening of asymptomatic populations. An important strategy for dose reduction is to reduce the number of projections, although doing so with high image quality is technically difficult. We developed an algorithm to reconstruct discrete (limited gray scale) images decomposed into individual tissue types from a small number of projections acquired over a limited view angle. The algorithm was tested using projection simulations from segmented CT scans of different cross sections including mid femur, distal femur and lower leg. It can provide high quality images from as low as 5–7 projections if the skin boundary of the cross section is used as prior information in the reconstruction process, and from 11–13 projections if the skin boundary is unknown.
- Super-sparsely view-sampled cone-beam CT by incorporating prior data
- Abstract: Computed tomography (CT) is widely used in medicine for diagnostics or for image-guided therapies, and is also popular in industrial applications for nondestructive testing. CT conventionally requires a large number of projections to produce volumetric images of a scanned object, because the conventional image reconstruction algorithm is based on filtered-backprojection. This requirement may result in relatively high radiation dose to the patients in medical CT unless the radiation dose at each view angle is reduced, and can cause expensive scanning time and efforts in industrial CT applications. Sparse- view CT may provide a viable option to address both issues including high radiation dose and expensive scanning efforts. However, image reconstruction from sparsely sampled data in CT is in general very challenging, and much efforts have been made to develop algorithms for such an image reconstruction problem. Image total-variation minimization algorithm inspired by compressive sensing theory has recently been developed, which exploits the sparseness of the image derivative magnitude and can reconstruct images from sparse-view data to a similar quality of the images conventionally reconstructed from many views. In successive CT scans, prior CT image of an object and its projection data may be readily available, and the current CT image may have not much difference from the prior image. Considering the sparseness of such a difference image between the successive scans, image reconstruction of the difference image may be achieved from very sparsely sampled data. In this work, we showed that one can further reduce the number of projections, resulting in a super-sparse scan, for a good quality image reconstruction with the aid of a prior data. Both numerical and experimental results are provided.
Content Type Journal Article
Pages 71-83
DOI 10.3233/XST-130367
Authors
Sajid Abbas, Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
Jonghwan Min, Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
Seungryong Cho, Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: Computed tomography (CT) is widely used in medicine for diagnostics or for image-guided therapies, and is also popular in industrial applications for nondestructive testing. CT conventionally requires a large number of projections to produce volumetric images of a scanned object, because the conventional image reconstruction algorithm is based on filtered-backprojection. This requirement may result in relatively high radiation dose to the patients in medical CT unless the radiation dose at each view angle is reduced, and can cause expensive scanning time and efforts in industrial CT applications. Sparse- view CT may provide a viable option to address both issues including high radiation dose and expensive scanning efforts. However, image reconstruction from sparsely sampled data in CT is in general very challenging, and much efforts have been made to develop algorithms for such an image reconstruction problem. Image total-variation minimization algorithm inspired by compressive sensing theory has recently been developed, which exploits the sparseness of the image derivative magnitude and can reconstruct images from sparse-view data to a similar quality of the images conventionally reconstructed from many views. In successive CT scans, prior CT image of an object and its projection data may be readily available, and the current CT image may have not much difference from the prior image. Considering the sparseness of such a difference image between the successive scans, image reconstruction of the difference image may be achieved from very sparsely sampled data. In this work, we showed that one can further reduce the number of projections, resulting in a super-sparse scan, for a good quality image reconstruction with the aid of a prior data. Both numerical and experimental results are provided.
- In vivo mouse ^99mTc SPECT scans with bioluminescence imaging validation
- Abstract: The aim of this in vivo study was to evaluate the feasibility of ^{99m}Tc-labeled cartilage link protein (CLP) probe for the single-photon emission computed tomography (SPECT) of lung cancer. Xenograft mouse model were established from a luciferase expressing cell line derived from a human lung cancer. Bioluminescence imaging (BLI) was carried out prior to ^{99m}Tc-CLP and ^{99m}Tc-methoxyisobutyl isonitrile (MIBI) SPECT scans. The image quality of ^{99m}Tc-CLP scan was validated with BLI and compared with well established ^{99m}Tc-MIBI scan. Results of multimodal imaging analyses suggested that ^{99m}Tc-CLP was a sensitive and reliable SPECT agent for lung cancer imaging.
Content Type Journal Article
Pages 85-91
DOI 10.3233/XST-130368
Authors
Zhi-Xin Liang, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
Yong-Gang Qiang, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
Yong-Hua Liao, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
Xu-Sheng Zhu, Department of Nuclear Medicine, Guangzhou First Municipal People's Hospital, Guangzhou, Guangdong, China
Zheng Huang, Department of Radiation Oncology and Electronic Engineering, University of Colorado Denver, Denver, CO, USA
Xiu-Ping Zhang, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
Luping Wang, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: The aim of this in vivo study was to evaluate the feasibility of ^{99m}Tc-labeled cartilage link protein (CLP) probe for the single-photon emission computed tomography (SPECT) of lung cancer. Xenograft mouse model were established from a luciferase expressing cell line derived from a human lung cancer. Bioluminescence imaging (BLI) was carried out prior to ^{99m}Tc-CLP and ^{99m}Tc-methoxyisobutyl isonitrile (MIBI) SPECT scans. The image quality of ^{99m}Tc-CLP scan was validated with BLI and compared with well established ^{99m}Tc-MIBI scan. Results of multimodal imaging analyses suggested that ^{99m}Tc-CLP was a sensitive and reliable SPECT agent for lung cancer imaging.
- GPU based iterative cone-beam CT reconstruction using empty space skipping technique
- Abstract: Iterative reconstruction of high-resolution cone-beam CT data is still a difficult task due to the demand for vast amounts of computer cycles and associated memory. In order to improve the performance of iterative algorithms for cone-beam CT reconstruction, an acceleration approach integrating GPU acceleration, empty space skipping and multi-resolution technique is proposed. The approach divides the reconstructed volume into equally sized blocks, and empty blocks are identified by reconstructing an initial low-resolution volume and segmenting it with threshold method. Then all non-empty blocks are packed into a new volume, which is initialized by interpolating the low resolution volume and reconstructed at full resolution using iterative algorithms. Finally these non-empty blocks are rearranged to get the reconstructed high-resolution volume. The whole process is implemented in parallel based on GPU. Since only the voxels in non-empty blocks are calculated, the number of considered voxels is greatly reduced, which translates directly into substantial computation, memory requirements and data transfer savings. The method is evaluated by reconstructing images from simulated projection data of phantom and CT datasets. The results indicate that our approach significantly improves the performance of iterative reconstruction while maintaining a high image quality, compared to conventional GPU-based approaches.
Content Type Journal Article
Pages 53-69
DOI 10.3233/XST-130366
Authors
Xing Zhao, The CT laboratory, School of Mathematical Sciences, Capital Normal University, Beijing, China
Jing-Jing Hu, School of Software, Beijing Institute of Technology, Beijing, China
Tao Yang, The CT laboratory, School of Mathematical Sciences, Capital Normal University, Beijing, China
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: Iterative reconstruction of high-resolution cone-beam CT data is still a difficult task due to the demand for vast amounts of computer cycles and associated memory. In order to improve the performance of iterative algorithms for cone-beam CT reconstruction, an acceleration approach integrating GPU acceleration, empty space skipping and multi-resolution technique is proposed. The approach divides the reconstructed volume into equally sized blocks, and empty blocks are identified by reconstructing an initial low-resolution volume and segmenting it with threshold method. Then all non-empty blocks are packed into a new volume, which is initialized by interpolating the low resolution volume and reconstructed at full resolution using iterative algorithms. Finally these non-empty blocks are rearranged to get the reconstructed high-resolution volume. The whole process is implemented in parallel based on GPU. Since only the voxels in non-empty blocks are calculated, the number of considered voxels is greatly reduced, which translates directly into substantial computation, memory requirements and data transfer savings. The method is evaluated by reconstructing images from simulated projection data of phantom and CT datasets. The results indicate that our approach significantly improves the performance of iterative reconstruction while maintaining a high image quality, compared to conventional GPU-based approaches.
- Experimental studies on few-view reconstruction for high-resolution micro-CT
- Abstract: High-resolution micro-CT offers 3D non-destructive imaging but scan times are prohibitively large in many cases. Advancements in image reconstruction offer great reduction in number of views while maintaining reconstruction accuracy; yet filtered back projection remains the de facto standard. An extensive study of few-view reconstruction using compressed-sensing based iterative techniques is carried out. Also, a novel 3D micro-CT phantom is proposed, and used for analyzing reconstruction accuracy. Numerical tests, and studies on real micro-CT data show that if measurement noise in projections is not extremely high, the number of views may be reduced to 1/8^{th} of the typically acquired view numbers. The study motivates the adoption of advanced reconstruction techniques to allow faster scanning, lower dosage, and reduced data size in high-resolution micro-CT.
Content Type Journal Article
Pages 25-42
DOI 10.3233/XST-130364
Authors
Kriti Sen Sharma, Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, USA
Xin Jin, Department of Engineering Physics, Tsinghua University, Beijing, China
Christian Holzner, Xradia Inc., Pleasanton, CA, USA
Shree Narayanan, Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, USA
Baodong Liu, Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University Health Sciences, Winston-Salem, NC, USA
Dong Wang, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
Masoud Agah, Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, USA
Linbing Wang, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
Hengyong Yu, Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University Health Sciences, Winston-Salem, NC, USA
Ge Wang, Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, NY, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: High-resolution micro-CT offers 3D non-destructive imaging but scan times are prohibitively large in many cases. Advancements in image reconstruction offer great reduction in number of views while maintaining reconstruction accuracy; yet filtered back projection remains the de facto standard. An extensive study of few-view reconstruction using compressed-sensing based iterative techniques is carried out. Also, a novel 3D micro-CT phantom is proposed, and used for analyzing reconstruction accuracy. Numerical tests, and studies on real micro-CT data show that if measurement noise in projections is not extremely high, the number of views may be reduced to 1/8^{th} of the typically acquired view numbers. The study motivates the adoption of advanced reconstruction techniques to allow faster scanning, lower dosage, and reduced data size in high-resolution micro-CT.
- Role of MRI in assessment of ejaculatory duct obstruction
- Abstract: This study aims to analyze magnetic resonance imaging (MRI) features of ejaculatory duct obstruction, and to provide an accurate diagnostic imaging approach for surgical planning of minimally invasive procedures treating ejaculatory duct obstruction. A total of 18 men with ejaculatory duct obstruction were enrolled in the study. The patients were admitted to our hospital and had undergone MRI examination and surgical treatment from January 2003 to February 2011. The data was collected by searching keywords ('ejaculatory duct obstruction') from our PACS. Patients suspected having ejaculatory duct obstruction according to the manifestations through MRI examinations and further being confirmed by surgery were included. The MRI features of ejaculatory duct obstruction in these patients were summarized. Five cases with ejaculatory duct cysts were detected by MRI, ranging in size from 4 mm × 4 mm × 7 mm to 4 mm × 4 mm × 9 mm and located in the paramedian line; ejaculatory duct dilation near the median line, with the internal diameter ranging from 5 mm to 30 mm was detected in nine cases; and among thirteen cases who underwent both non-contrast enhanced and contrast enhanced MRI scanning, significant enhancement of the wall of the ejaculatory duct on enhanced scanning was observed in three cases. Mullerian duct cysts complicated with dilation of the ejaculatory duct and seminal vesicles were detected in four cases; in these cases, the cysts were located in the median line, ranging in size from 4 mm × 5 mm × 6 mm to 34 mm × 35 mm × 44 mm, tear-drop appearance, with the tip pointing toward the area of the seminal colliculus. Findings of MRI were confirmed by the observations during the surgery. MRI is more accurate at displaying the ejaculatory duct. We recommend that ejaculatory duct diameter of > 2 mm can be used as a diagnostic criterion with MRI image analyses for ejaculatory duct dilation.
Content Type Journal Article
Pages 141-146
DOI 10.3233/XST-130361
Authors
Yan Guo, Department of Radiology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Guihua Liu, Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
Dong Yang, Department of Radiology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Xiangzhou Sun, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Huanjun Wang, Department of Radiology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Chunhua Deng, Department of Urology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Yuanyuan Zhang, Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
Shi-Ting Feng, Department of Radiology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: This study aims to analyze magnetic resonance imaging (MRI) features of ejaculatory duct obstruction, and to provide an accurate diagnostic imaging approach for surgical planning of minimally invasive procedures treating ejaculatory duct obstruction. A total of 18 men with ejaculatory duct obstruction were enrolled in the study. The patients were admitted to our hospital and had undergone MRI examination and surgical treatment from January 2003 to February 2011. The data was collected by searching keywords ('ejaculatory duct obstruction') from our PACS. Patients suspected having ejaculatory duct obstruction according to the manifestations through MRI examinations and further being confirmed by surgery were included. The MRI features of ejaculatory duct obstruction in these patients were summarized. Five cases with ejaculatory duct cysts were detected by MRI, ranging in size from 4 mm × 4 mm × 7 mm to 4 mm × 4 mm × 9 mm and located in the paramedian line; ejaculatory duct dilation near the median line, with the internal diameter ranging from 5 mm to 30 mm was detected in nine cases; and among thirteen cases who underwent both non-contrast enhanced and contrast enhanced MRI scanning, significant enhancement of the wall of the ejaculatory duct on enhanced scanning was observed in three cases. Mullerian duct cysts complicated with dilation of the ejaculatory duct and seminal vesicles were detected in four cases; in these cases, the cysts were located in the median line, ranging in size from 4 mm × 5 mm × 6 mm to 34 mm × 35 mm × 44 mm, tear-drop appearance, with the tip pointing toward the area of the seminal colliculus. Findings of MRI were confirmed by the observations during the surgery. MRI is more accurate at displaying the ejaculatory duct. We recommend that ejaculatory duct diameter of > 2 mm can be used as a diagnostic criterion with MRI image analyses for ejaculatory duct dilation.
- X-ray fluorescence tomographic system design and image reconstruction
- Abstract: In this paper, we presented a new design of x-ray fluorescence CT imaging system. For detecting fuorescence signals of gold nanoparticles in-vivo, multiple spectroscopic detectors are arranged and rotated orthogonal to an excited region of interest so that a localized scan can be acquired with a maximized efficiency. Excitation filtration was employed to minimize the effects of low-energy x-rays and background scattering for lowering radiation dose to the object. Numerical simulations showed that the radiation dose is less than 300 mGy/second for a complete 30 views tomographic scan; and the sensitivity of 3D fluorescence signal detection is up to 0.2% contrast concentrations of nanoparticles. The x-ray fluorescence computed tomography is an important molecular imaging tool. It can be used directly in samall animal research. It has great translational potential for future clinical applications.
Content Type Journal Article
Pages 1-8
DOI 10.3233/XST-130362
Authors
Wenxiang Cong, School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA
Haiou Shen, School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA
Guohua Cao, School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA
Hong Liu, School of Electrical and Computer Engineering, University of Oklahoma, Norman, OK, USA
Ge Wang, School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA
Journal Journal of X-Ray Science and Technology
Online ISSN 0895-3996
Journal Volume Volume 21
Journal Issue Volume 21, Number 1 / 2013
PubDate: Mon, 18 Mar 2013 15:50:57 GMT
- Abstract: In this paper, we presented a new design of x-ray fluorescence CT imaging system. For detecting fuorescence signals of gold nanoparticles in-vivo, multiple spectroscopic detectors are arranged and rotated orthogonal to an excited region of interest so that a localized scan can be acquired with a maximized efficiency. Excitation filtration was employed to minimize the effects of low-energy x-rays and background scattering for lowering radiation dose to the object. Numerical simulations showed that the radiation dose is less than 300 mGy/second for a complete 30 views tomographic scan; and the sensitivity of 3D fluorescence signal detection is up to 0.2% contrast concentrations of nanoparticles. The x-ray fluorescence computed tomography is an important molecular imaging tool. It can be used directly in samall animal research. It has great translational potential for future clinical applications.
