METHODS: A systematic search was performed in PubMed, the Cochrane library, CINAHL, Web of Science, ScienceDirect and Scopus, where 20 studies were selected for analysis of scanning parameters and CM reduction methods.
RESULTS: The mean effective dose (HE) ranged from 0.31 to 2.75 mSv at 80 kVp, 0.69 to 6.29 mSv at 100 kVp and 1.53 to 10.7 mSv at 120 kVp. Radiation dose reductions of 38 to 83% at 80 kVp and 3 to 80% at 100 kVp could be achieved with preserved image quality. Similar vessel contrast enhancement to 120 kVp could be obtained by applying iodine delivery rate (IDR) of 1.35 to 1.45 g s-1 with total iodine dose (TID) of between 10.9 and 16.2 g at 80 kVp and IDR of 1.08 to 1.70 g s-1 with TID of between 18.9 and 20.9 g at 100 kVp.
CONCLUSION: This systematic review found that radiation doses could be reduced to a rate of 38 to 83% at 80 kVp, and 3 to 80% at 100 kVp without compromising the image quality. Advances in knowledge: The suggested appropriate scanning parameters and CM reduction methods can be used to help users in achieving diagnostic image quality with reduced radiation dose.
METHODS: From August 2020 to December 2021, 4 rete MCA anomalies were identified at Shuang Ho hospital. Clinical information, perfusion magnetic resonance (MR) imaging, and angiographic images were collected. Detailed angioarchitecture, including types of arterial feeders and extent of rete involvement, were analyzed based on three-dimensional volume-rendering reconstruction images obtained from the catheter-based angiographies.
RESULTS: Despite their variable clinical presentations (two hemorrhage, one ischemia, and one asymptomatic), all cases shared common angiographic findings as follows: (1) the internal carotid artery did not connect directly to the rete, (2) the anterior choroidal artery (AChA) was the artery constantly supplying the rete and (3) there was a watershed zone shift toward MCA territory. The perfusion MR cerebral blood flow map was symmetric in all studied cases.
CONCLUSION: The AChA is an artery constantly supplying the rete, which suggests that the angioarchitectural features associated with this anomaly may be the result of both congenital and acquired compensatory processes. Cerebral perfusion remains preserved at the lesion side, despite angiographic evidence of watershed zone shift. These findings will be important for making better clinical judgments about this condition.
MATERIALS AND METHODS: Nine phantoms were fabricated with different bifurcation angles ranging from 55.3° to 134.5°. General X-ray and CCTA were employed to acquire 2D and 3D images of the bifurcation phantoms, respectively. Multiplanar reformation (MPR) and volume rendering technique (VRT) were used to measure the bifurcation angle between the left anterior descending (LAD) and left circumflex arteries (LCx). The measured angles were compared with the true values to determine the accuracy of each measurement technique. Inter-observer variability was evaluated. The two techniques were further applied on 50 clinical CCTA cases to verify its clinical value.
RESULTS: In the phantom setting, the mean absolute differences calculated between the true and measured angles by MPR and VRT were 2.4°±2.2° and 3.8°±2.9°, respectively. Strong correlation was found between the true and measured bifurcation angles. Furthermore, no significant differences were found between the bifurcation angles measured using either technique. In clinical settings, large difference of 12.0°±10.6° was found between the two techniques.
CONCLUSION: In the phantom setting, both techniques demonstrated a significant correlation to the true bifurcation angle. Despite the lack of agreement of the two techniques in the clinical context, our findings in phantoms suggest that MPR should be preferred to VRT for the measurement of coronary bifurcation angle by CCTA.
Method: Computed tomography angiography was performed on 13 type B aortic dissection patients before and after procedure, and at 6 and 12 months follow-up. The lumens were divided into three regions: the stented area (Region 1), distal to the stent graft to the celiac artery (Region 2), and between the celiac artery and the iliac bifurcation (Region 3). Changes in aortic morphology were quantified by the increase or decrease of diametric and volumetric percentages from baseline measurements.
Results: At Region 1, the TL diameter and volume increased (pre-treatment: volume =51.4±41.9 mL, maximal axial diameter =22.4±6.8 mm, maximal orthogonal diameter =21.6±7.2 mm; follow-up: volume =130.7±69.2 mL, maximal axial diameter =40.1±8.1 mm, maximal orthogonal diameter =31.9+2.6 mm, P<0.05 for all comparisons), while FL decreased (pre-treatment: volume =129.6±150.5 mL; maximal axial diameter =43.0±15.8 mm; maximal orthogonal diameter =28.3±12.6 mm; follow-up: volume =66.6±95.0 mL, maximal axial diameter =24.5±19.9 mm, maximal orthogonal diameter =16.9±13.7, P<0.05 for all comparisons). Due to the uniformity in size throughout the vessel, high concordance was observed between diametric and volumetric measurements in the stented region with 93% and 92% between maximal axial diameter and volume for the true/false lumens, and 90% and 92% between maximal orthogonal diameter and volume for the true/false lumens. Large discrepancies were observed between the different measurement methods at regions distal to the stent graft, with up to 46% differences between maximal orthogonal diameter and volume.
Conclusions: Volume measurement was shown to be a much more sensitive indicator in identifying lumen expansion/shrinkage at the distal stented region.
METHODS: A cross-sectional observational study was performed on healthy and glaucoma subjects, on whom two sets of OCTA images of optic disc and macula were acquired using both AngioVue (Optovue, USA) and Swept Source (Topcon, Japan) OCTA devices during one visit. A novel in-house software was used to calculate the vessel densities. Diagnostic accuracy of the machines in differentiating healthy versus glaucomatous eyes was determined using area under the receiver operating characteristic curve (AUROC) and test-retest repeatability of the machines was also evaluated.
RESULTS: A total of 80 healthy and 38 glaucomatous eyes were evaluated. Glaucomatous eyes had reduced mean vessel density compared to healthy controls in all segmented layers of the optic disc and macula using AngioVue (p ≤ 0.001). However, glaucomatous eyes had higher mean vessel density on optic disc scans using Swept Source, with lack of statistically significant difference between healthy and glaucomatous eyes. The AUROC showed better diagnostic accuracy of AngioVue (0.761-1.000) compared to Swept Source (0.113-0.644). The test-retest reliability indices were generally better using AngioVue than Swept Source.
CONCLUSIONS: AngioVue showed better diagnostic capability and test-retest reliability compared to Swept Source. Further studies need to be undertaken to evaluate if there is any significant difference between the various machines in diagnosing and monitoring glaucoma.
Methods: An analytical cross-sectional study was performed, including 223 patients treated by the Cardiology Department, the Emergency Interventional Cardiology Departments, and the Internal Cardiology Clinic of Thong Nhat Hospital.
Results: In our cohort of 223 patients, the NAFLD was detected in 66% of the population, the mean coronary artery stenosis (CAS) was 44.54% ± 20.23%, and the mean coronary artery calcium score (CACS) was 3569.05 ± 425.99, as assessed using the Agatston method. The proportion of patients with significant atherosclerotic plaque (CAS 50%) >was 32%, whereas the remaining 68% had insignificant stenosis. Among our study population, 16% had no coronary artery calcification, 38% had mild calcification, and 46% had moderate to severe calcification. In the group of NAFLD patients, 33.3% had significant atherosclerotic plaque, which was not significantly different from the rate in individuals without NAFLD (p = 0.51). Mild coronary artery calcification was detected in 37.4% of NAFLD patients, and moderate to severe calcification was detected in 48.3% (p = 0.45).
Conclusions: NAFLD was not found to be strongly associated with coronary atherosclerosis in this study. More studies with larger sample sizes remain necessary to verify whether any correlation exists.
Methodology: A total of 123 patients were recruited into this study, comprising 82 patients who underwent a pterional approach and 41 patients who underwent a supraorbital approach. Computed tomography angiograms, the modified Rankin Scale, and the visual analogue scale were administered at 6 months to look for residual aneurysm, functional outcomes, scar tenderness, and cosmetic satisfaction. Complication data were collected from patients' case notes.
Results: The mean operating time for the pterional group was 226 min, compared to supraorbital group, which was 192 min (P = 0.07). Cosmetic satisfaction was significantly higher (P = 0.001) in the supraorbital group. There was no significant difference between the supraorbital and pterional groups' scar tenderness (P = 0.719), residual aneurysm (P = 0.719), or functional outcomes (P = 0.137), and there was no significant difference between the groups in terms of intra-operative and post-operative complications.
Conclusions: The supraorbital group had better cosmetic outcomes and shorter operating times compared to the pterional group.