Purpose: To present an application of the anisotropic diffusion (AD) method to improve the accuracy of the functional images of perfusion parameters such as cerebral blood flow (CBF), cerebral blood volume (CBV) and m...Purpose: To present an application of the anisotropic diffusion (AD) method to improve the accuracy of the functional images of perfusion parameters such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) generated from cerebral CT perfusion studies using multi-detector row CT (MDCT). Materials and Methods: Continuous scans (1 sec/rotation ×60 sec) consisting of four 5-mm-thick contiguous slices were acquired after an intravenous injection of iodinated contrast material in 6 patients with cerebrovascular disease using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. New image data were generated by thinning out the above original images at an interval of 2 sec or 3 sec. The thinned-out images were then interpolated by linear interpolation to generate the same number of images as originally acquired. The CBF, CBV and MTT images were generated using deconvolution analysis based on singular value decomposition. Results: When using the AD method, the correlation coefficient between the MTT values obtained from the original and thinned-out images was significantly improved. Furthermore, the coefficients of variation of the CBF, CBV and MTT values in the white matter significantly decreased as compared to not using the AD method. Conclusion: Our results suggest that the AD method is useful for improving the accuracy of the functional images of perfusion parameters and for reducing radiation exposure in cerebral CT perfusion studies using MDCT.展开更多
AIM： To determine the distance between the branching point of the left colic artery （LCA） and the inferior mesenteric artery （IMA） by computed tomography （CT） scanning, for preoperative evaluation before laparo...AIM： To determine the distance between the branching point of the left colic artery （LCA） and the inferior mesenteric artery （IMA） by computed tomography （CT） scanning, for preoperative evaluation before laparoscopic colorectal operation. METHODS： From February 2004 to May 2005, 100 patients （63 men, 37 women） underwent angiography performed with a 16-scanner multi-detector row CT unit （Toshiba, Aquilion 16）. All images were analyzed on a workstation （AZE Ltd, Virtual Place Advance 300）. The distance from the root of the IMA to the bifurcation of the LCA was measured by curved multi-planar reconstruction on a workstation. RESULTS： The IMA could be visualized in all the cases, but the LCA was missing in two patients. The mean distance from the root of the IMA to the root of the LCA was 42.0 mm （range, 23.2-75.0 mm）. There were no differences in gender, arterial branching types, body weight, height, and body mass index. CONCLUSION： Volume-rendered 3D-CT is helpful to assess the vascular branching anatomy for laparoscopic surgery.展开更多
Background Coronary computed tomography angiography(CCTA)is often avoided in elderly patients due to a presumption that a high proportion of patients will have heavily calcified plaque limiting an accurate assessment....Background Coronary computed tomography angiography(CCTA)is often avoided in elderly patients due to a presumption that a high proportion of patients will have heavily calcified plaque limiting an accurate assessment.We sought to assess the image quality,luminal stenosis and utility of CCTA in elderly patients with suspected coronary artery disease(CAD)and stable chest pain.Methods Retrospective analysis of elderly patients(>75 years)who underwent 320-detector row CCTA between 2012–2017 at MonashHeart.The CCTA was analysed for degree maximal coronary stenosis by CAD-RADS classification,image quality by a 5-point Likert score(1-poor,2-adequate,3-good,4-very good,5-excellent)and presence of artefact limiting interpretability.Results 1011 elderly patients(62%females,78.8±3.3 years)were studied.Cardiovascular risk factor prevalence included:hypertension(65%),hyperlipidaemia(48%),diabetes(19%)and smoking(21%).The CCTA was evaluable in 68%of patients which included 52%with non-obstructive CAD(<50%stenosis),48%with obstructive CAD(>50%)stenosis.Mean Likert score was 3.1±0.6 corresponding to good image quality.Of the 323(32%)of patients with a non-interpretable CCTA,80%were due to calcified plaque and 20%due to motion artefact.Male gender(P=0.009),age(P=0.02),excess motion(P<0.01)and diabetes mellitus(P=0.03)were associated with non-interpretable CCTA.Conclusion Although CCTA is a feasible non-invasive tool for assessment of elderly patients with stable chest pain,clinicians should still be cautious about referring elderly patients for CCTA.Patients who are male,diabetic and>78 years of age are significantly less likely to have interpretable scans.展开更多
文摘Purpose: To present an application of the anisotropic diffusion (AD) method to improve the accuracy of the functional images of perfusion parameters such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) generated from cerebral CT perfusion studies using multi-detector row CT (MDCT). Materials and Methods: Continuous scans (1 sec/rotation ×60 sec) consisting of four 5-mm-thick contiguous slices were acquired after an intravenous injection of iodinated contrast material in 6 patients with cerebrovascular disease using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. New image data were generated by thinning out the above original images at an interval of 2 sec or 3 sec. The thinned-out images were then interpolated by linear interpolation to generate the same number of images as originally acquired. The CBF, CBV and MTT images were generated using deconvolution analysis based on singular value decomposition. Results: When using the AD method, the correlation coefficient between the MTT values obtained from the original and thinned-out images was significantly improved. Furthermore, the coefficients of variation of the CBF, CBV and MTT values in the white matter significantly decreased as compared to not using the AD method. Conclusion: Our results suggest that the AD method is useful for improving the accuracy of the functional images of perfusion parameters and for reducing radiation exposure in cerebral CT perfusion studies using MDCT.
基金Supported by Kobayashi Magobe Memorial Medical Foundation
文摘AIM： To determine the distance between the branching point of the left colic artery （LCA） and the inferior mesenteric artery （IMA） by computed tomography （CT） scanning, for preoperative evaluation before laparoscopic colorectal operation. METHODS： From February 2004 to May 2005, 100 patients （63 men, 37 women） underwent angiography performed with a 16-scanner multi-detector row CT unit （Toshiba, Aquilion 16）. All images were analyzed on a workstation （AZE Ltd, Virtual Place Advance 300）. The distance from the root of the IMA to the bifurcation of the LCA was measured by curved multi-planar reconstruction on a workstation. RESULTS： The IMA could be visualized in all the cases, but the LCA was missing in two patients. The mean distance from the root of the IMA to the root of the LCA was 42.0 mm （range, 23.2-75.0 mm）. There were no differences in gender, arterial branching types, body weight, height, and body mass index. CONCLUSION： Volume-rendered 3D-CT is helpful to assess the vascular branching anatomy for laparoscopic surgery.
文摘Background Coronary computed tomography angiography(CCTA)is often avoided in elderly patients due to a presumption that a high proportion of patients will have heavily calcified plaque limiting an accurate assessment.We sought to assess the image quality,luminal stenosis and utility of CCTA in elderly patients with suspected coronary artery disease(CAD)and stable chest pain.Methods Retrospective analysis of elderly patients(>75 years)who underwent 320-detector row CCTA between 2012–2017 at MonashHeart.The CCTA was analysed for degree maximal coronary stenosis by CAD-RADS classification,image quality by a 5-point Likert score(1-poor,2-adequate,3-good,4-very good,5-excellent)and presence of artefact limiting interpretability.Results 1011 elderly patients(62%females,78.8±3.3 years)were studied.Cardiovascular risk factor prevalence included:hypertension(65%),hyperlipidaemia(48%),diabetes(19%)and smoking(21%).The CCTA was evaluable in 68%of patients which included 52%with non-obstructive CAD(<50%stenosis),48%with obstructive CAD(>50%)stenosis.Mean Likert score was 3.1±0.6 corresponding to good image quality.Of the 323(32%)of patients with a non-interpretable CCTA,80%were due to calcified plaque and 20%due to motion artefact.Male gender(P=0.009),age(P=0.02),excess motion(P<0.01)and diabetes mellitus(P=0.03)were associated with non-interpretable CCTA.Conclusion Although CCTA is a feasible non-invasive tool for assessment of elderly patients with stable chest pain,clinicians should still be cautious about referring elderly patients for CCTA.Patients who are male,diabetic and>78 years of age are significantly less likely to have interpretable scans.
