Safety and Risk of Superselective Transcatheter Arterial Embolization for Acute Lower Gastrointestinal Hemorrhage with N-Butyl Cyanoacrylate: Angiographic and Colonoscopic Evaluation.

PURPOSE: To retrospectively evaluate the safety and risk of transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for urgent acute arterial bleeding control in the lower gastrointestinal tract by angiography and colonoscopy. MATERIALS AND METHODS: NBCA TAE was performed in 16 patients (mean age, 63.7 y) with lower gastrointestinal bleeding (diverticular hemorrhage, tumor bleeding, and intestinal tuberculosis). Angiographic evaluation was performed by counting the vasa recta filled with casts of NBCA and ethiodized oil (Lipiodol) after TAE. Patients were classified as follows: group Ia, with a single vas rectum with embolization of 1 branch (n = 6); group Ib, with a single vas rectum with embolization of ≥ 2 branches (n = 8); group II, with embolization of multiple vasa recta (n = 2). All patients underwent colonoscopy within 1 month, and ischemic complications (ulcer, scar, mucosal swelling, fibrinopurulent debris, and necrosis) were evaluated. RESULTS: The procedure was successful in all patients. No ischemic change was observed in any patients in group Ia and in two patients in group Ib. Ischemic changes were observed in six group Ib patients and both group II patients. Group Ib patients experienced ischemic complications that improved without treatment. One patient in group II underwent resection for intestinal perforation after embolization of three vasa recta. One patient in group II with sigmoid stricture with embolization of six vasa recta required prolonged hospitalization. CONCLUSIONS: NBCA embolization of ≥ 3 vasa recta can induce ischemic bowel damage requiring treatment. NBCA TAE of one vas rectum with ≥ 2 branches could also induce ischemic complications. However, these were silent and self-limited.

The evaluation of cardiac tamponade risk in patients with pericardial effusion detected by non-gated chest CT.

BACKGROUND: Although pericardial effusion is often identified using non-gated chest computed tomography (CT), findings predictive of cardiac tamponade have not been adequately established. PURPOSE: To determine the findings predictive of clinical cardiac tamponade in patients with moderate to large pericardial effusion using non-gated chest CT. MATERIAL AND METHODS: We performed a retrospective analysis of 134 patients with moderate to large pericardial effusion who were identified from among 4581 patients who underwent non-gated chest CT. Cardiac structural changes, including right ventricular outflow tract (RVOT), were qualitatively evaluated. The inferior vena cava ratio with hepatic (IVCupp) and renal portions (IVClow) and effusion size were measured. The diagnostic performance of each structural change was calculated, and multivariate analysis was used to determine the predictors of cardiac tamponade. RESULTS: Of the 134 patients (mean age, 70.3 years; 64 men), 37 (28%) had cardiac tamponade. The sensitivity and specificity were 76% and 74% for RVOT compression; 87% and 84% for an IVClow ratio ≥0.77; and 60% and 77% for an effusion size ≥25.5 mm, respectively. Multivariate logistic regression analysis demonstrated that RVOT compression, an IVClow ratio ≥0.77, and an effusion size ≥25.5 mm were independent predictors of cardiac tamponade. The combination of these three CT findings had a sensitivity, specificity, and accuracy of 81%, 95%, and 91%, respectively. CONCLUSION: In patients with moderate to large pericardial effusion, non-gated chest CT provides additional information for predicting cardiac tamponade.

Significance of combined use of MRI and perfusion SPECT for evaluation of multiple system atrophy, cerebellar type.

BACKGROUND: Multiple system atrophy, cerebellar type (MSA-C) sometimes shows asymmetrical findings on magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). PURPOSE: To assess the frequency and clinical significance of asymmetrical MRI and (99m)Tc-ethyl cysteinate dimer perfusion (ECD) SPECT findings of the cerebellum, middle cerebellar peduncle (MCP), and pons in MSA-C patients. MATERIAL AND METHODS: We retrospectively reviewed 28 patients with MSA-C who underwent MRI and (99m)Tc-ECD SPECT and evaluated laterality of atrophy and signal changes on MRI, and laterality of perfusion on (99m)Tc-ECD SPECT transversely and longitudinally. RESULTS: Laterality was identified for 64%, 61%, and 21% of atrophy in the cerebellum, MCP, and pons, respectively, on MRI and for 71% of atrophy in the cerebellum on perfusion SPECT. Concerning comparisons between the latest MRI and SPECT findings, laterality of cerebellar/MCP atrophy on MRI and decreased cerebellar perfusion on SPECT was matched in 57%, mismatched in 11%, and absent in 25% of patients. On past images, MRI and SPECT showed matched laterality in 33%, mismatched laterality in 27%, no laterality in 13%, and SPECT precedent laterality in 27% of patients. Including the latest and past images, asymmetrical changes were observed in 75% of patients. We could not identify any correlation between laterality of image findings and cerebellar symptoms in most patients. CONCLUSION: Asymmetrical changes on MRI and perfusion SPECT are common in MSA-C patients. Perfusion SPECT is useful for diagnosing MSA-C in the early stages from a functional perspective.

Accuracy of semiquantitative dynamic contrast-enhanced MRI for differentiating type II from type I endometrial carcinoma.

PURPOSE: To investigate type II endometrial carcinoma characterization using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and evaluate the diagnostic accuracy of semiquantitative DCE-MRI in differentiating type II from type I tumors. MATERIALS AND METHODS: Seventy-seven patients with endometrial carcinoma were retrospectively evaluated using 3T DCE-MRI. The maximum absolute enhancement of signal intensity (SImax), maximum relative enhancement (SIrel), wash-in rate (WIR), and the SImax/SI (piriformis) ratio were analyzed. To differentiate type I from type II tumors, optimal threshold criteria were established. The Mann-Whitney U-test was used for statistical comparison and receiver operating characteristic curve analysis was used to determine optimal cutoff values. RESULTS: The SIrel (P < 0.001), WIR (P < 0.0001), and SImax/SI (piriformis) ratio (P < 0.0001), but not SImax, differed significantly between type I and type II carcinomas. Cutoff values of SIrel ≥58.8, WIR ≥37.0, and SImax/SI (piriformis) ratio ≥1.55 had sensitivities of 93%, 93%, and 67%, specificities of 60%, 60%, and 79%, accuracies of 66%, 66%, and 67%, respectively, for predicting type II endometrial carcinoma. CONCLUSION: Endometrial carcinoma with strong (high level) enhancement on DCE-MRI is suggestive of type II endometrial carcinoma. Semiquantitative evaluation of DCE-MRI may be useful for differentiating type II from type I tumors.

Correlation of apparent diffusion coefficient value with prognostic parameters of endometrioid carcinoma.

PURPOSE: To correlate the apparent diffusion coefficient (ADC) of endometrioid carcinoma with histological tumor grade and degree of myometrial invasion. MATERIALS AND METHODS: 3T diffusion-weighted (DW) magnetic resonance (MR) images of 63 patients were retrospectively reviewed. Two readers measured tumor ADC according to a freehand region of interest (ROI) and a round ROI. Mean and minimum ADCs were correlated with prognostic parameters. RESULTS: The minimum ADC was 0.64 × 10(-3) mm(2)/s for grade 1 (G1, n = 42), 0.62 for grade 2 (G2, n = 14), 0.46 for grade 3 (G3, n = 7) on freehand ROI. There were significant differences between G1 and G3 (P = 0.007), and G2 and G3 (P = 0.038). No significant correlation was found between tumor grade and mean ADC (0.85 for G1, 0.82 for G2, and 0.72 for G3, P = 0.166). The minimum ADC was significantly lower for patients with deep (n = 21, 0.54) than for those with superficial (n = 39, 0.65) myometrial invasion. Conversely, mean ADC did not differ significantly (0.84 for superficial and 0.78 for deep myometrial invasion, P = 0.081). The same tendency was shown on round ROI. CONCLUSION: The minimum ADC correlates with prognostic parameters of endometrial carcinoma more strongly than mean ADC. Lower minimum ADC is associated with higher histological tumor grade and higher degree of myometrial invasion.

High incidence of asymptomatic cerebral microbleeds in patients with hemorrhagic onset-type moyamoya disease: a phase-sensitive MRI study and meta-analysis.

BACKGROUND: Moyamoya disease is a relatively rare cerebrovascular occlusive disorder. Several studies have reported cerebral microbleeds (CMBs) in moyamoya disease patients using T2*-weighted imaging (T2*WI) and/or susceptibility-weighted imaging (SWI). PURPOSE: To investigate the incidence, distribution patterns, and influencing factors of asymptomatic CMBs in patients with moyamoya disease. MATERIAL AND METHODS: Phase-sensitive imaging (PSI) was used to investigate 27 consecutive moyamoya disease patients with a 3-T magnetic resonance imaging system, then a meta-analysis of 245 patients (asymptomatic moyamoya disease, n = 23; ischemic moyamoya disease, n = 161; hemorrhagic moyamoya disease, n = 61) from four previous individual studies and our PSI study was performed. The meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Based on the clinical and radiological data, we divided the studies into different model groups to calculate the incidence of CMBs and discuss the distribution patterns of CMBs. RESULTS: Thirty-five asymptomatic CMBs were demonstrated in 14 moyamoya disease patients (51.9%) in our PSI study. Of these, 45.7% were located in the periventricular white matter. In the meta-analysis, the pooled incidence of asymptomatic CMBs in moyamoya disease was 46% (95% confidence interval [CI], 28.2-63.8%) on SWI or PSI and 29.6% (95% CI, 17.4-41.7%) on T2*WI. Statistical analysis showed that PSI or SWI offered better detection of CMBs in moyamoya disease than T2*WI, and 3-T T2*WI offered better detection than 1.5-T T2*WI. Furthermore, hemorrhagic onset-type moyamoya disease correlated with a high incidence of asymptomatic CMBs. CONCLUSION: PSI or SWI can detect CMBs better than T2*WI, and 3-T T2*WI. Hemorrhagic onset-type moyamoya disease seems to correlate with a high incidence of asymptomatic CMBs. The meta-analysis indicates that asymptomatic CMBs may be an important factor for hemorrhagic stroke risk. Long-term evaluation of CMBs using PSI or SWI may contribute to the management of moyamoya disease.

Apparent diffusion coefficient (ADC) measurement in endometrial carcinoma: effect of region of interest methods on ADC values.

PURPOSE: To investigate the influence of different-shaped regions of interest (ROIs) on tumor apparent diffusion coefficient (ADC) measurements and interobserver variability in endometrial carcinoma. MATERIALS AND METHODS: Sixty-nine patients (age range, 32-92 years; mean, 61 years) were evaluated in this retrospective study. Patients had undergone magnetic resonance (MR) examinations including diffusion-weighted imaging (DWI) using a 3.0-T MR system. Two readers measured tumor ADCs using four ROI methods: freehand ROI; square ROI; round ROI; and five small, round ROIs. Minimum and mean ADCs were obtained. The interclass correlation coefficient (ICC) was statistically analyzed to assess measurement reliability. Repeated-measures analysis of variance was used for comparisons of ADCs measured with each ROI method. RESULTS: ICCs were 0.93 (minimum ADC) / 0.93 (mean ADC) for freehand ROIs, 0.94/0.95 for square ROIs, 0.94/0.95 for round ROIs, and 0.95/0.96 for five small, round ROIs. All ROI methods indicated excellent correlations. Each minimum ADC was significantly different except between square ROI and round ROI (P < 0.001). Mean ADCs showed significant differences only between freehand ROI and the other ROI methods (P < 0.001). CONCLUSION: ROI shape has no marked influence on ICC in endometrial carcinoma. Compared with minimum ADCs, mean ADCs are suggested to provide more stable results regardless of the ROI method.

Coil embolization with side-holed catheter to preserve peripheral flow for visceral artery pseudoaneurysm: an experimental study in Swine.

PURPOSE: To evaluate the safety and efficacy of coil embolization with an indwelling catheter with side holes to control visceral artery bleeding while simultaneously preserving peripheral artery flow. MATERIALS AND METHODS: A 6-F anticoagulant-coated catheter with two symmetrically arranged side holes was used with coil embolization to induce hemostasis in the superior mesenteric artery (SMA) of 13 pigs. The SMA was punctured with a metal needle to induce bleeding. The catheter was advanced into the SMA immediately after the puncture, and the midpoint between its tip and side holes was adjusted to conform to the puncture site. The SMA was embolized by using microcoils placed around the catheter to achieve hemostasis. Hemostasis and gross ischemic changes of the intestine were visually observed during the abdominal surgery. Peripheral blood flow was assessed by using abdominal aortography for as long as 2 hours in 13 pigs and was assessed again at 7 days in three pigs. RESULTS: Antegrade peripheral artery flow through the indwelling catheter was preserved without stagnation for as long as 2 hours in all 13 pigs and at 7 days in two of three pigs. One catheter occlusion was seen at the 7-day time point. There were no observable instances of recurrent bleeding, ischemic changes in the intestine, or vascular adverse events during or after the procedure. CONCLUSIONS: The hemostatic method described here is a technically feasible method of controlling acute visceral artery bleeding while preserving peripheral artery flow and may be particularly useful in cases of absence of collateral circulation. Further experiments are warranted for clinical application.

CT angiography after carotid artery stenting: assessment of the utility of adaptive statistical iterative reconstruction and model-based iterative reconstruction.

INTRODUCTION: Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP. METHODS: In a phantom study, we evaluated the differences among the three reconstruction techniques with regard to the relationship between the stent luminal diameter and the degree of underestimation of stent luminal diameter. In a clinical study, 34 patients who underwent follow-up CTA after CAS were included. We compared the stent luminal diameters among FBP, ASIR, and MBIR, and performed visual assessment of low attenuation area (LAA) in the stent lumen using a three-point scale. RESULTS: In the phantom study, stent luminal diameter was increasingly underestimated as luminal diameter became smaller in all CTA images. Stent luminal diameter was larger with MBIR than with the other reconstruction techniques. Similarly, in the clinical study, stent luminal diameter was larger with MBIR than with the other reconstruction techniques. LAA detectability scores of MBIR were greater than or equal to those of FBP and ASIR in all cases. CONCLUSION: MBIR improved the accuracy of assessment of stent luminal diameter and LAA detectability in the stent lumen when compared with FBP and ASIR. We conclude that MBIR is a useful reconstruction technique for CTA after CAS.