OBJECTIVE. The purpose of this study was to clarify the natural history of unruptured visceral artery aneurysms due to segmental arterial mediolysis and the efficacy of transcatheter arterial embolization. MATERIALS AND METHODS. Patients with a pathologic or clinical diagnosis of visceral artery aneurysms due to segmental arterial mediolysis between 2005 and 2015 were enrolled. For patients with clinical diagnoses, images were collected and assessed by central radiologic review. To clarify the natural history of unruptured aneurysms, the morphologic changes were assessed. The efficacy and safety of transcatheter arterial embolization for aneurysms due to segmental arterial mediolysis were evaluated. RESULTS. Forty-five patients with 123 aneurysms due to segmental arterial mediolysis were enrolled. Among the 123 aneurysms, 70 unruptured aneurysms were evaluated for natural history. Forty-five of the 70 (64%) aneurysms had no change in morphology. Among the other 25 aneurysms, nine (13% of the 70) were reduced in size, 13 (19%) disappeared, and three (4%) were newly found at follow-up. Aneurysms of the middle colic artery were ruptured in 10 of 11 (91%) cases. Transcatheter arterial embolization was performed on 45 aneurysms and was successful in all cases but caused slight arterial injury in three cases (6.7%). CONCLUSION. At initial diagnosis, unruptured aneurysms due to segmental arterial mediolysis are likely to be stable or to resolve, but the risk of rupture of aneurysms of the middle colic artery appears high. Transcatheter arterial embolization is a useful treatment, but careful manipulation is necessary.

Inferior vena cava filter fracture (FF) may cause life-threatening complications, including cardiac tamponade, although the actual prevalence remains unclear. Therefore, we investigated the incidence of FF.

Vena caval filters are well used to prevent fatal pulmonary thromboembolism. However, the mid to long-term efficacy is not yet established because filters increase the risk of recurrent deep vein thrombosis. Moreover, filter fractures may cause severe complications leading to death including cardiac tamponade although the actual prevalence is not reported enough. Thus, we investigated the filter fractures retrospectively in several hospitals. Based on the database in 8 hospitals, filter fractures were investigated using plain X-ray or CT. The fracture prevalence of each filter brand, the position of filters (suprarenal; SR vs. infrarenal; IR), and the follow up durations were documented. 294 (SR46, IR 248) Gunther Tulip (GT), 138 (SR39, IR99) Trap/OptEase (TOE), 38ALN (SR0, IR38) and 2 (SR0, IR2) VenaTech (VT) were implanted in 472 consecutive patients (62.5 ± 15.4, 20-94y/o、M200, F272). 3 (1.02%) GT (SR0, IR3), 18 (13.04%) TOE (SR7, IR11) revealed filter fractures, while the others did not. TOE showed significantly higher rates of fractures than GT (p＜0.01). The periods until the discovery of TOE fractures (1340.2 ± 1008.9, 69-3775) were shorter than the ones of GT (2,365.0 ± 1929.6, 895-4,550 days) without significant difference. Any significant difference was identified depending on the filter positions (SR8.2% vs. IR4.0%). TOF is not suitable for permanent implantation due to relatively early and high fracture rates.

当院で使用した2 種類の回収型フィルター, Günther Tulip（GT），OptEase（OE）につき，長期合併症（穿通，破損）についてretrospective に検討した．【対象と方法】永久留置例の方針となった症例のうちCT が撮影された75 症例（GT 21，OE 54）．撮影データより3D 画像を作成，脚の穿通，破損の有無を視覚的に評価した．【結果】脚の穿通はGT 15 例（71.4％），穿通部位は大動脈3，右総腸骨動脈2，十二指腸3，大腰筋1，椎間板1，脂肪織5 例であった．破損はOE 8 例（14.8％）に，縦骨格1 カ所の離断が認められた．留置からの時間経過とともに破損率が上昇する傾向が認められた．OE の穿通例，GT の破損例は認められず，また全例で有害事象は認められなかった．【結論】これらの回収型フィルターの合併症頻度は高率であり，永久留置としての使用は合併症の発生を念頭に，慎重に決定する必要がある．

PURPOSE:The purpose of this retrospective study was to investigate the incidence of contrast-induced nephropathy (CIN) caused by transarterial chemoembolisation (TACE) in patients with hepatocellular carcinoma (HCC).MATERIALS AND METHODS:One hundred forty-one patients treated between 2005 and 2008 undergoing 305 consecutive sessions of TACE were enrolled. CIN was defined as an increase in the serum creatinine level of more than 0.5 mg/dl or more than 25 % from baseline within 3 days after TACE without any other identifiable cause of acute kidney injury.RESULTS:CIN by the present definition was observed after 2.6 % of the TACE sessions. No patient showed clinical signs or symptoms of acute renal failure, or required haemodialysis. None of the patients with an estimated glomerular filtration rate of <60 ml/min/1.73 m(2) developed CIN.CONCLUSION:The present study suggests that TACE is a relatively safe procedure in terms of the risk of CIN under vigorous periprocedural hydration and that the incidence of CIN is comparable to that of AKI associated with intravenous CM administration.KEY POINTS:• CIN would be lower for non-coronary arterial intervention than for coronary intervention. • The present study suggests that the CIN rates following TACE are low. • The incidence of CIN is comparable to that after intravenous CM administration.

Large-bowel obstruction (LBO) is a relatively common abdominal emergency. Computed tomography (CT) diagnosis of LBO is often easy, but it is essential to clarify LBO etiology and to decide how to treat it. Therefore, it is important for the radiologist to become familiar with the imaging findings of LBO, including plain radiography and CT, to determine its various causes, as well as the many diseases mimicking LBO. In this article, we show the characteristics of radiological findings of plain radiograph, barium study, and CT and their correlations with pathologic findings. LBO etiology comprises two main categories: neoplastic and nonneoplastic disease. However, the primary causes of LBO are neoplastic etiologies, and nonneoplastic causes are relatively uncommon and unfamiliar to many radiologists in clinical practice. Therefore, in this review, we present nonneoplastic etiology of LBO and diseases simulating LBO and provide critical information concerning the causes of LBO and viability of the involved bowel loops.

The purpose of this study is to illustrate computed tomography (CT) findings suggestive of small bowel strangulation. We have performed the precontrast and postcontrast CT with single and multidetector CT scanners and evaluated the bowel wall changes and mesentery changes and correlated them with the operative findings. The direct CT findings suggestive of small bowel strangulation included high-density bowel wall on precontrast scans; lack of, or diminished contrast enhancement of the involved bowel wall; localized mesenteric fluid accumulation (mesenteric congestion); and localized pneumatosis. The indirect CT signs included C- or U-shaped loops with mesenteric vessels converging toward the obstruction site, ascites, target sign, two adjacent collapsed round loops, and whirl sign. We particularly emphasize the importance of contrast enhancement of bowel mucosa for early diagnosis to differentiate strangulation from a mechanical obstruction without bowel ischemia, and also the importance to differentiate proximal secondary gas-filled dilated small bowel loops from distal primary involved fluid-filled small bowel loops because these two types of small bowel loops are present in the single peritoneal cavity. As early recognition of small bowel strangulation may help improve the patient outcome because the involved bowel loops can be preserved without resection, it is essential to become familiar with the CT signs suggested small bowel obstruction strangulation.

Poster: ECR 2011 / C-1306 / Non-traumatic acute abdomen of the elderly people; Imaging with MDCT by: K. Hayakawa1, M. Tanikake2, S. Yoshida2, Y. Urata2, E. Yamamoto, E2, T. Morimoto2; 1Kyoto, Ky/JP, 2Kyoto/JP

Neurogenic appendicopathy is a condition in which abnormalities within the appendix produce symptoms that mimic acute appendicitis. It is usually difficult to differentiate between neurogenic appendicopathy and acute appendicitis from their clinical history, symptoms, laboratory findings and physical examination. We experienced two cases of neurogenic appendicopathy diagnosed from histopathologic findings, in which patients had presented with right lower abdominal pain. On Multidetector Computed Tomography, dilated appendix was depicted with uniform enhancement, associated with calcifications (or appendicolith). Inflammatory change was not so remarkable in both cases. We suspected appendiceal tumor from imaging findings in both cases and elective surgeries were performed. Pathologically, neuroma-like proliferation of nerve fibers was found, which were stained with S-100 protein in submucosal layer. The imaging features of neurogenic appendicopathy, including Computed Tomography, have not been reported in English literatures. In this article, we reported the imaging characteristics on Multidetector Computed Tomography in these two cases of neurogenic appendicopathy, correlated them with pathologic features. It is supposed to reflect its pathological change including edematous change, proliferation of collagen and nerve fibers. There has been no definitive criterion for imaging diagnosis of neurogenic appendicopathy, and further investigation is needed to evaluate for the imaging characteristics and its significance in clinical situation.

Objective: In this study, the authors discussed the feasibility and value of diffusion-weighted (DW) MR imaging in the detection of uterine endometrial cancer in addition to conventional nonenhanced MR images.Methods and materials: DW images of endometrial cancer in 23 patients were examined by using a 1.5-T MR scanner. This study investigated whether or not DW images offer additional incremental value to conventional nonenhanced MR imaging in comparison with histopathological results. Moreover, the apparent diffusion coefficient (ADC) values were measured in the regions of interest within the endometrial cancer and compared with those of normal endometrium and myometrium in 31 volunteers, leiomyoma in 14 patients and adenomyosis in 10 patients. The Wilcoxon rank sum test was used, with a p < 0.05 considered statistically significant.Results: In 19 of 23 patients, endometrial cancers were detected only on T2-weighted images. In the remaining 4 patients, of whom two had coexisting leiomyoma, no cancer was detected on T2-weighted images. This corresponds to an 83% detection sensitivity for the carcinomas. When DW images and fused DW images/T2-weighted images were used in addition to the T2-weighted images, cancers were identified in 3 of the remaining 4 patients in addition to the 19 patients (overall detection sensitivity of 96%). The mean ADC value of endometrial cancer (n = 22) was (0.97 +/- 0.19) x 10(-3) mm(2)/s, which was significantly lower than those of the normal endometrium, myometrium, leiomyoma and adenomyosis (p < 0.05).Conclusion: DW imaging can be helpful in the detection of uterine endometrial cancer in nonenhanced MR imaging. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

BACKGROUND:In this study, the potential in detecting and evaluating pelvic lymph node metastases on body diffusion-weighted (DW) images was evaluated in patients with gynecologic malignancies.METHODS:This study included 18 patients with gynecologic malignancy who underwent magnetic resonance imaging in the pelvis using a 1.5-T superconductive magnet. The identification of pelvic nodes on only T2-weighted (T2W) axial images and on DW axial images in addition to T2W axial images was examined and compared. Moreover, we measured and calculated a short-axis diameter, a long-axis diameter, and a ratio of short- and long-axis diameter of nodes on the T2W images and the apparent diffusion coefficient (ADC) values of the nodes on the DW images. These results were compared with histopathologic results.RESULTS:First, 136 (40%) of 340 dissected nodes were identified on T2W images, and 249 (73%) of 340 dissected nodes were identified on DW images in addition to T2W images. Second, the differences in the short-axis diameter, the long-axis diameter, and the ratio of short- and long-axis diameter on T2W images between metastatic and nonmetastatic nodes were not significant. The differences in the ADC values between metastatic and nonmetastatic nodes were not significant.CONCLUSIONS:Body DW images are useful in detection of pelvic lymph nodes in patients with gynecologic malignancy. However, the measurement of ADC values does not contribute to a diagnosis of metastatic nodes.