Bile duct penetrating duodenal wall sign: a novel computed tomography finding of common bile duct stone impaction into duodenal major papilla.

PURPOSE: Impacted common bile duct stones cause severe acute cholangitis. However, the early and accurate diagnosis, especially iso-attenuating stone impaction, is still challenging. Therefore, we proposed and validated the bile duct penetrating duodenal wall sign (BPDS), which shows the common bile duct penetrating the duodenal wall on coronal reformatted computed tomography (CT), as a novel sign of stone impaction. METHODS: Patients who underwent urgent endoscopic retrograde cholangiopancreatography (ERCP) for acute cholangitis due to common bile duct stones were retrospectively enrolled. Stone impaction was defined by endoscopic findings as a reference standard. Two abdominal radiologists blinded to clinical information interpreted CT images to record the presence of the BPDS. The diagnostic accuracy of the BPDS to diagnose stone impaction was analyzed. Clinical data related to the severity of acute cholangitis were compared between patients with and without the BPDS. RESULTS: A total of 40 patients (mean age 70.6 years; 18 female) were enrolled. The BPDS was observed in 15 patients. Stone impaction occurred in 13/40 (32.5%) cases. Overall accuracy, sensitivity, and specificity were 34/40 (85.0%), 11/13 (84.6%), and 23/27 (85.2%), respectively; 14/16 (87.5%), 5/6 (83.3%), and 9/10 (90.0%) for iso-attenuating stones; and 20/24 (83.3%), 6/7 (85.7%), and 14/17 (82.4%) for high-attenuating stones. Interobserver agreement of the BPDS was substantial (κ = 0.68). In addition, the BPDS was significantly correlated with the number of factors in the systemic inflammatory response syndrome (P = 0.03) and total bilirubin (P = 0.04). CONCLUSION: The BPDS was a unique CT imaging finding to identify common bile duct stone impaction regardless of stone attenuation with high accuracy.

Clinical impact of low tube voltage computed tomography during hepatic arteriography with low iodine to detect hepatocellular carcinoma before transarterial chemoembolization.

PURPOSE: This study aimed to evaluate the clinical impact of low tube voltage computed tomography (CT) during hepatic arteriography (CTHA) using low iodine contrast to detect hepatocellular carcinoma (HCC). MATERIALS AND METHODS: CTHA images were obtained using a dual-spin technique (80 kVp and 135 kVp) with 30 ml of low-dose iodine contrast (75 mgI/ml). Three radiologists reviewed 135 kVp and 80 kVp CTHA images to diagnose HCC, recording their confidence scores and evaluations of sharpness, noise, artifact, and overall image quality. Lesion-to-liver contrast ratios and objective noise were measured by a non-reader radiologist. RESULTS: We included 23 patients (body mass index, 23.6 ± 2.6 kg/m2) with 89 HCCs. The mean radiation dose index volume was 21.3 mGy at 135 kVp and 9.4 mGy at 80 kVp (P < 0.001). The overall sensitivity and positive predictive value for diagnosing HCCs at 80 kVp vs. 135 kVp were 0.787 vs. 0.730 and 0.712 vs. 0.756, respectively. The lesion-to-liver contrast ratio at 80 kVp was significantly higher than at 135 kVp in the first (3.1 vs. 2.0; P = 0.008) and second phase (3.1 vs. 2.3; P = 0.016). Objective noise was significantly higher at 80 kVp than at 135 kVp in the first (15. 6 ± 4.9 vs. 11.0 ± 3.1; P < 0.001) and second (16.9 ± 5.2 vs. 15.0 ± 7.3; P = 0.046) phases. CONCLUSION: An 80 kVp CTHA, with lower-dose iodine, improved the sensitivity and reduced the radiation dose, despite a decreased positive predictive value in comparison with a 135-kVp CTHA with the same iodine dose.

Gastrointestinal stromal tumors: a comprehensive radiological review.

Gastrointestinal stromal tumors (GISTs) originating from the interstitial cells of Cajal in the muscularis propria are the most common mesenchymal tumor of the gastrointestinal tract. Multiple modalities, including computed tomography (CT), magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography, ultrasonography, digital subtraction angiography, and endoscopy, have been performed to evaluate GISTs. CT is most frequently used for diagnosis, staging, surveillance, and response monitoring during molecularly targeted therapy in clinical practice. The diagnosis of GISTs is sometimes challenging because of the diverse imaging findings, such as anatomical location (esophagus, stomach, duodenum, small bowel, colorectum, appendix, and peritoneum), growth pattern, and enhancement pattern as well as the presence of necrosis, calcification, ulceration, early venous return, and metastasis. Imaging findings of GISTs treated with antineoplastic agents are quite different from those of other neoplasms (e.g. adenocarcinomas) because only subtle changes in size are seen even in responsive lesions. Furthermore, the recurrence pattern of GISTs is different from that of other neoplasms. This review discusses the advantages and disadvantages of each imaging modality, describes imaging findings obtained before and after treatment, presents a few cases of complicated GISTs, and discusses recent investigations performed using CT and MRI to predict histological risk grade, gene mutations, and patient outcomes.

Larger Volume and Higher Fat Content of the Pancreatic Head Are Predictive Factors for Postendoscopic Retrograde Cholangiopancreatography Pancreatitis.

OBJECTIVES: Acute pancreatitis is the most critical complication of endoscopic retrograde cholangiopancreatography (ERCP). In this study, we investigated the association between the volume/fat content of the pancreatic head and the incidence of post-ERCP pancreatitis (PEP). METHODS: We retrospectively enrolled 157 patients who underwent ERCP. The volume and fat content of the pancreas were calculated by multislice computed tomographic imaging by using a volume analyzer. Multivariate analysis was performed to identify risk factors for PEP. RESULTS: The mean volumes of the whole pancreas and pancreatic head were significantly larger, and the fat content of the pancreatic head was significantly higher in the PEP group (P < 0.01). There were no significant differences in the mean volume and fat content of the pancreatic body and tail in the PEP group. Multivariate analysis revealed that the pancreatic guidewire placement (odds ratio [OR], 12.4; P < 0.01), pancreatic head volume (OR, 5.3; P < 0.01), and the pancreatic head fat content (OR, 4.8; P < 0.01) were independent risk factors for PEP. CONCLUSIONS: The pancreatic head volume and fat content were independent predicting factors of PEP. Quantitative assessment of the pancreas may contribute to the prediction of PEP onset.

A preliminary animal study of thermal rheology fluid as a new temperature-dependent liquid intravascular embolic material.

PURPOSE: Thermal rheology (TR) fluid, which comprises polyethylene (PE) particles, their dispersant, and solvent, is a material that increases in viscosity to various degrees depending on the type and ratio of these constituents when its temperature rises. The viscosity of type 1 (TRF-1) increases more than that of type 2 (TRF-2) near rabbit body temperature. This preliminary animal study aimed to determine the basic characteristics and embolic effect of TR fluid by comparing TRF-1 and TRF-2. MATERIALS AND METHODS: Twenty-four Japanese white rabbits underwent unilateral renal artery embolization using TRF-1 or TRF-2 and follow-up angiography at 7 or 28 days (4 subgroups, n = 6 each). Subsequently, the rabbits were euthanized, and the embolized kidneys were removed for pathological examination. The primary and final embolization rates were defined as the ratio of renal artery area not visible immediately after embolization and follow-up angiography, respectively, to visualized renal artery area before embolization. The final embolization rate and maximum vessel diameter filled with PE particles were compared between materials. Moreover, the embolic effect was determined to be persistent when a two-sided 95% confidence interval (CI) for the difference in means between the embolization rates was < 5%. RESULTS: The final embolization rate was significantly higher for the TRF-1 than for the TRF-2 at both 7 (mean 80.7% [SD 18.7] vs. 28.4% [19.9], p = 0.001) and 28 days (94.0% [3.5] vs. 37.8% [15.5], p < 0.001). The maximum occluded vessel diameter was significantly larger for TRF-1 than for TRF-2 (870 µm [417] vs. 270 µm [163], p < 0.001). The embolic effect of TRF-1 was persistent until 28 days (difference between rates - 3.3 [95% CI - 10.0-3.4]). CONCLUSION: The embolic effect of TRF-1 was more persistent than that of TRF-2, and the persistency depended on the type and ratio of TR fluid constituents.

Effect of Portal Vein and Hepatic Artery Occlusion on Radiofrequency Ablation: Animal Experiment Comparing MR and Histology Measurements of the Ablation Zones.

PURPOSE: This animal experimental study evaluated how hepatic artery and portal vein transient occlusion affects the ablation zone of hepatic radiofrequency ablation (RFA). MATERIAL AND METHODS: Twenty-one rabbits were divided into three groups of seven each: (1) control, (2) hepatic artery occlusion, and (3) portal vein occlusion by a balloon catheter. For each rabbit, two or three RFA sessions were performed using an electrode needle. Ablation time, temperature around the tip of RFA needle at the end of RFA, ablation volume on fat-suppressed T1-weighted image in the hepatobiliary phase, and coagulative necrosis area on histopathology were measured and compared between the three groups using the Kruskal-Wallis paired Mann-Whitney U tests. RESULTS: In 43 RFA sessions (group 1, 15; group 2, 14; group 3, 14), mean tissue temperature in group 3 (77.0 °C ± 7.7 °C) was significantly higher compared to groups 1 (59.2 °C ± 18.8 °C; P = 0.010) and 2 (67.5 °C ± 9.9 °C; P = 0.010). In addition, mean ablation volume and coagulative necrosis in group 3 (2.10 ± 1.37 mm3 and 0.86 ± 0.28 mm2, respectively) were larger compared to groups 1 (0.84 ± 0.30 mm3; P < 0.001 and 0.55 ± 0.26 mm2; P = 0.020, respectively) and 2 (0.89 ± 0.59 mm3; P = 0.002 and 0.60 ± 0.22 mm2; P = 0.024, respectively). CONCLUSION: Portal vein occlusion potentially boosts tissue temperature, ablation volume, and area of histopathologically proven coagulative necrosis during hepatic RFA in the non-cirrhotic liver.

Vessel Occlusion using Hydrogel-Coated versus Nonhydrogel Embolization Coils in Peripheral Arterial Applications: A Prospective, Multicenter, Randomized Trial.

PURPOSE: To evaluate the safety and effectiveness of hydrogel-coated coils for vessel occlusion in the body trunk. MATERIALS AND METHODS: A total of 77 patients with various peripheral vascular lesions, treatable by embolization with coils, were randomized (hydrogel group, n = 38; nonhydrogel group, n = 39). In the hydrogel group, embolization of the target vessel was conducted using 0.018-inch hydrogel-coated coils (AZUR 18; Terumo Medical Corporation, Tokyo, Japan) with or without bare platinum coils. The nonhydrogel group received both bare platinum coils and fibered coils without the use of hydrogel-coated coils. RESULTS: Complete target vessel occlusion was accomplished in 36 patients in the hydrogel group and 37 patients in the nonhydrogel group. No major adverse events were observed in either group. The median number of coils/vessel diameter and the median total coil length/vessel diameter were significantly larger in the nonhydrogel group than in the hydrogel group (P = .005 and P = .004, respectively). The median embolization length was significantly longer in the nonhydrogel group (31.95 mm) than in the hydrogel group (23.43 mm) (P = .002). If no expansion was assumed, the median packing density in the hydrogel group was 44.9%, which was similar to that in the nonhydrogel group (46.5%) (P = .79). With full expansion assumed, the median packing density in the hydrogel group was 125.7%. CONCLUSIONS: Hydrogel-coated coils can be safely used for peripheral vascular coil embolization, and hydrogel-coated and conventional coils in combination allow for a shorter embolization segment and shorter coil length.

Fat tissue as an embolic material changes the embolization time in a size-dependent manner: a basic investigation using rabbits.

PURPOSE: To evaluate the usefulness of fat tissue as an embolic material and determine whether the embolization time depends on the size of the fat tissue. MATERIALS AND METHODS: Inguinal fat tissues from 16 rabbits were processed as follows: (1) fat tissues were cut into 2-mm squares, and (2) fat tissue squares were dissociated 20 × through a syringe without a needle (1-139 µm in diameter). The distal main trunk of the right or left renal artery was completely embolized using one of the two types of fat tissue. After 1 or 7 days, renal angiography was performed. RESULTS: On day 1 after embolization of the renal artery with 2-mm fat tissue squares (Group 1-1) and on day 7 (Group 1-2), the reperfusion rates were 4.0 ± 5.5% and 29.9 ± 6.9%, respectively. On day 1 after embolization of the renal artery with fat tissues dissociated using a 20 × pumping cycle (Group 2-1) and on day 7 (Group 2-2), the reperfusion rates were 59.9 ± 9.9% and 74.3 ± 26.0%, respectively. The reperfusion rates were significantly different between the two types of fat tissue. CONCLUSIONS: Fat tissue serves as an embolic material that changes the embolization time in a size-dependent manner.

Noncontrast MRI of acute abdominal pain caused by gastrointestinal lesions: indications, protocol, and image interpretation.

Gastrointestinal tract lesions are major causes of acute abdominal pain. A rapid, accurate, and reliable diagnosis is required to manage patients. Magnetic resonance imaging (MRI) is a nonionizing modality that is beneficial for pregnant women, children, and young adults who are sensitive to ionizing radiation. For patients with renal impairment who are not accurately diagnosed with noncontrast computed tomography, noncontrast MRI can serve as an alternative diagnostic modality. MRI protocols used for acute abdominal pain are supposed to be optimized and prioritized to shorten scanning times. Single-shot T2-weighted and fat-suppressed T2-weighted imaging are important pulse sequences that are used to reveal pathology and inflammation in the gastrointestinal tract. Diffusion-weighted imaging clearly depicts inflammation and abscesses as hyperintense lesions. Most acute gastrointestinal tract lesions, including inflammation, ischemia, obstruction, and perforation, demonstrate bowel wall thickening. Bowel obstruction and adynamic ileus present bowel dilatation, and perforation and penetration show bowel wall defects. MRI can be used to reveal these pathological findings with some characteristics depending on their underlying pathophysiology. This review article discusses imaging modalities for acute abdominal pain, describes a noncontrast MRI protocol for acute abdominal pain caused by gastrointestinal tract lesions, and reviews MRI findings of acute gastrointestinal tract lesions.

Foreign-body granulomas and abscesses caused by dropped gallstones after cholecystectomy: Four cases diagnosed with multimodality imaging.

Four cases (age range, 60-78 years, male:female = 1:3) who had undergone cholecystectomy presented with fever (n = 1), right abdominal pain with fever (n = 1), appetite loss with fever (n = 1), and absence of symptoms (n = 1). Computed tomography (CT) showed an irregular-shaped invasive mass or fluid collection in the right Morrison's pouch, right paracolic gutter, gallbladder fossa, subphrenic space, or abdominal wall. CT and ultrasound revealed gallstones in the granuloma in 3 cases and an abscess in one case. The inflammatory process induced by dropped gallstones may mimic peritoneal malignancies. Awareness of cholecystectomy and the detection of gallstones in the lesion are essential for the diagnosis of dropped gallstones.

Diagnostic Value of Serum Amylase Levels Indicating Computed Tomography-Defined Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis: A Prospective Multicenter Observational Study.

OBJECTIVE: Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis involves persistent serum amylase levels of 3 times or more the standard upper limit. However, these criteria were mostly based on retrospective studies and not necessarily supported by diagnostic imaging. Our prospective study aimed to investigate cutoff serum amylase levels suggesting post-ERCP pancreatitis using computed tomography as the criterion standard. METHODS: We prospectively followed 2078 cases. Computed tomography was performed in patients whose serum amylase levels exceeded the institutional upper limit 12 to 24 hours after ERCP. Two expert radiologists blindly assessed the images and judged the presence or absence of pancreatitis. Correlations between serum amylase levels with pancreatitis were investigated using receiver operating characteristic analysis. RESULTS: Amylase levels increased in 416 (23.2%) of 1789 cases included, and 350 cases were analyzed using computed tomography. Post-endoscopic retrograde cholangiopancreatography pancreatitis was diagnosed in 12.0% (214/1789). The cutoff amylase levels for judging pancreatitis after 12 to 24 hours was 2.75 times higher than the institutional upper limit, with an area under the curve of 0.77. CONCLUSIONS: The appropriate cutoff serum amylase level for judging post-ERCP pancreatitis at 12 to 24 hours after ERCP was 2.75 times higher than the institutional upper limit. These results may clarify the definition of post-ERCP pancreatitis.

Difference of computed tomographic characteristic findings between gastric and intestinal gastrointestinal stromal tumors.

PURPOSE: We aimed to compare the computed tomography (CT) imaging differences between gastric and intestinal gastrointestinal stromal tumors (GISTs). MATERIALS AND METHODS: Thirty-eight patients with 38 gastric GISTs and 27 with 31 intestinal GISTs were enrolled. Tumors were classified as small (< 5 cm) or large (≥ 5 cm). Qualitative and quantitative CT imaging characteristics on non-contrast and contrast-enhanced CT were evaluated by two radiologists independently and statistically compared. RESULTS: Early venous return and higher CT number of the draining vein in the arterial phase were more frequent in small-sized intestinal GISTs than in small-sized gastric GISTs (p < 0.001). Small-sized intestinal GISTs demonstrated a wash-out pattern, whereas small-sized gastric GISTs showed a plateau pattern. Contrast enhancement was higher in small-sized intestinal GISTs than in small-sized gastric GISTs (p < 0.001). CT number was inversely proportional to the diameter of intestinal GISTs in both arterial and venous phases but not to that of gastric GISTs. CONCLUSION: Strong enhancement with wash-out pattern and early venous return are characteristic findings of small-sized intestinal GISTs. Radiologists should be aware that CT findings of GISTs have a wide spectrum and may differ according to size and site of origin.

MR Imaging-based Evaluation of Mesenteric Ischemia Caused by Strangulated Small Bowel Obstruction and Mesenteric Venous Occlusion: An Experimental Study Using Rabbits.

PURPOSE: This study assessed the MRI findings of strangulated small bowel obstruction (SBO) and mesenteric venous occlusion (MVO) in a rabbit model using 3T MRI. MATERIALS AND METHODS: Twenty rabbits were included in this study. The strangulated SBO and MVO models were generated via surgical procedures in nine rabbits, and sham surgery was performed in two rabbits. The success of generating the models was confirmed via angiographic, macroscopic, and microscopic findings after the surgical procedure. MRI was performed before and 30 min after inducing mesenteric ischemia. T1-weighted images (T1WIs), T2-weighted images (T2WIs), and fat-suppressed T2WIs (FS-T2WIs) were obtained using the BLADE technique, and fat-suppressed T1WIs (FS-T1WIs) were obtained. The signal intensities of the affected bowel before and after the surgical procedures were visually categorized as high, iso, and low intense compared with the findings for the normal bowel wall on all sequences. Bowel wall thickness was measured, and the signal intensity ratio (SI ratio) was calculated using the signal intensities of the bowel wall and psoas muscle. RESULTS: Angiographic, macroscopic, and microscopic findings confirmed that all surgical procedures were successful. The ischemic bowel wall was thicker than the normal bowel. The bowel wall was thicker in the MVO model (3.17 ± 0.55 mm) than in the strangulated SBO model (2.26 ± 0.46 mm). The signal intensity and SI ratio of the bowel wall were significantly higher after the procedure than before the procedure on all sequences in both models. The mesentery adjacent to the ischemic bowel loop exhibited a high signal intensity in all animals on FS-T2WIs. CONCLUSION: Non-contrast MRI can be used to evaluate mesenteric ischemia caused by strangulated SBO and MVO. FS-T2WIs represented the best modality for depicting the high signal intensity in the bowel wall and mesentery caused by ischemia.

Accuracy, criteria, and clinical significance of visual assessment on diffusion-weighted imaging and apparent diffusion coefficient quantification for diagnosing acute appendicitis.

PURPOSE: To assess the accuracy, criteria, and clinical significance of diffusion-weighted imaging (DWI) signal intensity and apparent diffusion coefficient (ADC) quantification for diagnosing acute appendicitis. METHODS: Fifty-one patients with right lower abdominal pain [uncomplicated appendicitis (n = 25), complicated appendicitis (n = 10), and non-appendicitis (n = 16)] who underwent MR examination were enrolled in this retrospective study. Two radiologists independently measured appendiceal diameter and wall thickness. They assessed whether a wall defect, an abscess, extraluminal air, or an appendicolith was present on axial T2WI; evaluated intensity on DWI using a 5-point scale; and determined the ADC values of the appendix and peri-appendiceal tissue. Statistical analysis was performed to assess imaging findings for the diagnosis of appendicitis and complicated appendicitis. Cut-off values were determined using receiver operating characteristic analysis. RESULTS: For diagnosing acute appendicitis, the accuracy improved from 78.4% using only T2WI to 86.3% using combined T2WI and DWI for reader 1 and from 82.4 to 86.3% for reader 2. For the appendix, the cut-off ADC values that diagnosed appendicitis were 1.41 × 10-3 and 1.26 × 10-3 mm2/s with accuracies of 78.4% and 76.5%, respectively. For the peri-appendiceal tissue, these values of 1.03 × 10-3 and 0.91 × 10-3 mm2/s differentiated between uncomplicated and complicated appendicitis with an accuracy of 97.1%. CONCLUSIONS: Combined DWI and T2WI provided high accuracy for diagnosing appendicitis. The inflamed appendix had lower ADC value than the normal appendix. The peri-appendiceal tissue presenting low ADC value was a notable finding of complicated appendicitis.

Change in hepatic hemodynamics assessed by hepatic arterial blood pressure and computed tomography during hepatic angiography with the double balloon technique.

PURPOSE: To assess the change in hepatic arterial blood pressure (HABP) and computed tomography during hepatic arteriography (CTHA) using the double balloon technique. MATERIALS AND METHODS: Nine patients with hepatocellular carcinoma (HCC) were enrolled. We inserted a 5.2-Fr balloon catheter into the common or proper hepatic artery and a 1.8-Fr microballoon catheter into the lobar or segmental artery feeding the HCC. HABPs were measured with the 1.8-Fr microballoon catheter (usual-HABP), with the 1.8-Fr balloon inflated (B-HABP), and with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-HABP). CTHAs were performed via a 1.8-Fr microcatheter (usual-CTHA), with the 1.8-Fr balloon inflated (B-CTHA selective), with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-CTHA selective), and via the 5.2-Fr catheter with the 1.8-Fr balloon inflated (B-CTHA whole) and with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-CTHA whole). RESULTS: In all cases, B-HABP was lower than usual-HABP. There was a decrease in BB-HABP in comparison with B-HABP in cases with occlusion of the proper hepatic artery. The contrast effect of B-CTHA selective increased in four cases. The contrast effect on B-CTHA whole remained in all cases. CONCLUSION: This technique can be useful in decreasing HABP and collateral blood flow from the adjacent hepatic segment.

Comparison of characteristic computed tomographic findings of gastrointestinal and non-gastrointestinal stromal tumors in the small intestine.

PURPOSE: We aimed to reveal specific findings of gastrointestinal stromal tumors (GISTs) in the small intestine on contrast-enhanced computed tomography (CT) by comparing GISTs with non-GISTs. METHODS: We enrolled 28 patients with 39 GISTs and 20 patients with 22 non-GISTs who underwent enterectomy with a preoperative diagnosis of small intestinal tumor. All lesions were diagnosed by histopathological examination. Two radiologists independently evaluated internal homogeneity, growth pattern, calcification, intratumoral hemorrhage, degeneration, ulceration, and lymphadenopathy and measured the maximum diameter of the tumor and contrast-enhanced CT (CECT) value of the solid portion as well as the diameter and CT value of the feeding artery and drainage vein on CECT in the arterial and venous phases. RESULTS: Intratumoral hemorrhage was seen in 15.4% and 25.6% of GISTs and in 0% and 0% of non-GISTs (p = 0.079 and 0.010), with good interobserver agreement (κ = 0.715). The drainage vein diameter correlated well with the maximum diameter of the tumor (r = 0.744, p < 0.001). The CT value of the solid tumor part in the arterial and venous phases (p < 0.01) and the CT value of the drainage vein in the arterial phase (p < 0.05) were higher for GISTs than for non-GISTs (p < 0.01). CONCLUSIONS: Strong parenchymal enhancement with the peak in the arterial phase and the CT value of the drainage vein in the arterial phase was characteristics findings of GIST compared with non-GISTs. The diameter of the drainage vein was proportional to the maximum diameter of GISTs.

Acute Mesenteric Ischemia: Multidetector CT Findings and Endovascular Management.

Acute mesenteric ischemia is a rare life-threatening condition that accounts for approximately one in 1000 hospital admissions. The mortality rate is 50%-69% owing to the absence of specific symptoms and laboratory data, which makes early detection of this condition difficult. If the use of contrast material is possible, biphasic contrast material-enhanced multidetector computed tomography (CT) is the first-line imaging test for early diagnosis of the disease and for differentiation from other causes of acute abdomen. Multidetector CT can depict mesenteric ischemia, its underlying causes, and its severity. Mesenteric ischemia is classified as either acute or chronic. The causes of AMI include arterial embolism, arterial thrombosis, venous thrombosis, and nonocclusive mesenteric ischemia, among which arterial causes are far more common than venous causes. Recently, endovascular procedures such as thrombolysis, thrombectomy, thrombus fragmentation, and stent placement have been successfully and safely performed when the ischemia is reversible. Online DICOM image stacks are available for this article. ©RSNA, 2018.

Copper-catalyzed nucleophilic trifluoromethylation of benzylic chlorides.

Reactions of primary and secondary benzylic chlorides with trifluoromethyltrimethylsilane in the presence of a catalytic amount of copper(i) thiophene-2-carboxylate (CuTC) have been found to give the corresponding benzylic trifluoromethylated products in good to high yields.