Contrast-enhanced Abdominal CT Research Articles

Impact of Radiation Dose Reduction in Abdominal Computed Tomography on Diagnostic Accuracy and Diagnostic Performance in Patients with Suspected Appendicitis: An Intraindividual Comparison

To determine the intraindividual impact of radiation dose reduction in abdominal computed tomography (CT) on diagnostic performance in patients with suspected appendicitis. This study was approved by the institutional review board. Seventy-five patients who underwent standard contrast-enhanced abdominal CT for suspected appendicitis between 2004 and 2009 were retrospectively included. Low-dose CT reconstructions with 75%, 50%, and 25% of the original radiation dose level were generated by applying realistic reduced-dose simulation. Two blinded, independent readers assessed image quality, signal-to-noise ratio, and diagnostic confidence on each dataset. Diagnostic accuracy for detection of appendicitis and complications were calculated for each reader. Paired univariate tests were used to determine intraindividual differences. Among 75 subjects included in the analysis (57% female, mean age: 41 ± 18 years), the prevalence of histopathologically confirmed appendicitis was 59%. Signal-to-noise ratio and subjective image quality of 50% and 25% reduced-dose CTs were significantly lower than the reference datasets (all P < .005). Appendicitis was correctly identified in all reference and low-dose datasets (sensitivity: 100%, negative predictive value: 100%). Presence of complications was correctly detected in all reference, 75%, and 50% datasets, but was decreased in 25% datasets (sensitivity: 77.8% and negative predictive value: 97.4%). Diagnostic confidence was high for original and 75% datasets, but significantly lower for 50% and 25% datasets (P < .001). Our results indicate that diagnostic accuracy in abdominal CT acquisitions acquired at 75% and 50% of radiation dose is maintained in patients with suspected appendicitis, whereas further reduction of radiation exposition is associated with decreased diagnostic performance.

Expanding the Definition of a Benign Renal Cyst on Contrast-enhanced CT: Can Incidental Homogeneous Renal Masses Measuring 21–39 HU be Safely Ignored?

We aimed to determine the frequency and clinical significance of homogeneous renal masses measuring 21-39 Hounsfield units on contrast-enhanced computed tomography (CT). Subjects 40-69 years old undergoing portal-venous-phase contrast-enhanced abdominal CT from January 1, 2006 to December 31, 2010 with slice thickness ≤5 mm and no prior CT or magnetic resonance imaging were identified (n = 1387) for this institutional review board-approved retrospective cohort study. Images were manually reviewed by three radiologists in consensus to identify all circumscribed homogeneous renal masses (maximum of three per subject) ≥10 mm with a measured attenuation of 21-39 Hounsfield units. Exclusion criteria were known renal cancer or imaging performed for a renal indication. The primary outcome was retrospective characterization as a clinically significant mass, defined as a solid mass, a Bosniak IIF/III/IV mass, or extirpative therapy or metastatic renal cancer within 5 years' follow-up. Eligible masses (n = 74) were found in 5% (63/1387) of subjects. Of those with a reference standard (n = 42), none (0% [95% CI: 0.0%-8.4%]) were determined to be clinically significant. Incidental renal masses on contrast-enhanced CT that are homogeneous and display an attenuation of 21-39 Hounsfield units are uncommon in patients 40-69 years of age, unlikely to be clinically significant, and may not need further imaging evaluation. If these results can be replicated in an independent and larger population, the practical definition of a benign cyst on imaging may be able to be expanded.

Maximum Arterial Contrast Concentrations With Computed Tomography and Left Ventriculography: Implications for Contrast Nephrotoxicity Risk

Contrast nephropathy occurs more frequently after cardiac angiography, which usually includes left ventriculography via direct left ventricular injection, than after contrast-enhanced computed tomography (CT), despite the usually higher intravenous contrast dose used for CT. To determine whether maximum renal arterial contrast concentration is higher after left ventriculography, we assessed this parameter for both procedures. Contrast concentration in abdominal aortic blood during contrast-enhanced CT was measured by performing CT densitometry of aortic blood before contrast, and in the arterial phase, in 100 adults undergoing abdominal CT. Densities were converted to contrast concentrations by scanning water phantoms containing 20 graded concentrations of contrast and comparing their densities to patient data. Because it was impossible to perform CT densitometry during cardiac angiography, aortic contrast concentrations were calculated from standard contrast doses and injection rates with the range of clinically encountered cardiac output rates, assuming ultimate steady state for blood/contrast mixing and normal data distribution. Maximum aortic (and hence renal arterial) concentrations were significantly higher (range, 6.68%-15.90%) after ventriculography than after CT (1.22%-5.80%). Because ventricular injection times are much shorter than published initial-appearance-to-maximum-concentration times after intravenous administration, the rate of change of contrast concentration is also higher after ventriculography than after CT. Higher maximum renal arterial contrast concentration may be responsible for the greater risk of nephropathy after cardiac angiography than after doses for CT. The faster rate of change of renal arterial contrast concentration after ventriculography may also increase the likelihood of renal toxicity. Maximum renal arterial contrast concentration, and/or the rapidity of change of this parameter, may be partly responsible for the risk of nephropathy. Controlling these factors might permit reduction of nephropathy risk; they also suggest avenues of research into the pathophysiology of contrast nephropathy.

Spontaneous isolated dissection of the superior mesenteric artery and aneurysm formation resulting from segmental arterial mediolysis: a case report

BackgroundSpontaneous isolated dissection of the superior mesenteric artery (SMA) can lead to bowel ischemia, aneurysm rupture, or even death. Studies have suggested that mechanical or hemodynamic stress on the vascular wall of the SMA may be a contributor, but its pathogenesis is unclear.Case presentationA 57-year-old Japanese man with a history of untreated hypertension and hyperuricemia was admitted to our hospital with the sudden onset of severe epigastric pain. Laboratory findings showed elevated white blood cell count and C-reactive protein, and contrast-enhanced computed tomography (CT) of the abdomen demonstrated arterial dissection with luminal stenosis and aneurysm formation at the distal portion of the SMA after the branching of the jejunal artery, and intravenous nicardipine was administered. The patient’s epigastric pain resolved spontaneously but recurred on day 6 of his hospital stay. Contrast-enhanced abdominal CT revealed an enlarged aneurysm with wall thinning. Because of the risk of aneurysm rupture, the decision was made to perform aneurysmectomy and bowel resection on day 6. Histologic examinations revealed two separate dissecting lesions: one latent and the other resulting in aneurysm formation. Both lesions showed characteristics of segmental arterial mediolysis (SAM) with lack of arterial media, absence of internal and external elastic laminae and intimal proliferation.ConclusionsHistologic findings in the present case suggest that mechanical or hemodynamic stress on the vascular wall and SAM-related vascular vulnerability may concomitantly contribute to the onset of isolated SMA dissection.

Evaluation of recurrence in gastric carcinoma: Comparison of contrast-enhanced computed tomography and positron emission tomography/computed tomography

AIMTo compare the value of contrast-enhanced abdominal computed tomography (CT) and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for detecting gastric carcinoma recurrence.METHODSWe retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma.RESULTSThe pathological stage of the recurrence group was statistically significantly higher than that of the control group (P < 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Forty-four patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities (P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT (96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT (98% vs 80%, P = 0.035).CONCLUSIONContrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.

CorteXpert: A model-based method for automatic renal cortex segmentation.

This paper introduces a model-based approach for a fully automatic delineation of kidney and cortex tissue from contrast-enhanced abdominal CT scans. The proposed framework, named CorteXpert, consists of two new strategies for kidney tissue delineation: cortex model adaptation and non-uniform graph search. CorteXpert was validated on a clinical data set of 58 CT scans using the cross-validation evaluation strategy. The experimental results indicated the state-of-the-art segmentation accuracies (as dice coefficient): 97.86% ± 2.41% and 97.48% ± 3.18% for kidney and renal cortex delineations, respectively.

Bilateral adrenal myelolipoma: A case report

Myelolipoma is a relatively rare benign tumor composed of mature adipose tissue with variable amounts of hematopoietic element of both the myeloid and the erythroid series. It is usually asymptomatic, and bilateral tumors are unusual. The case is reported of a 62-yr-old male who presented with an ill-defined firm, non-tender, bimanually palpable mass in the right lumbar region, encroaching into right hypochondrium. It showed slight movement with respiration and was intraperitoneal. Contrast enhanced computed tomography (CECT) scan of the abdomen showed bilateral, heterogenous, hypoattenuating lesions with an enhancing rim of soft tissue in the adrenal fossae. At surgery the right sided tumor was treated by adrenalectomy and the left by enucleation of the tumor. Conclusion: Bilateral myelolipoma of adrenal gland is a very rare entity and warrants careful evaluation, by abdominal CECT scan and fat suppressing magnetic resonance imaging (MRI).

Anatomical considerations of the iliac crest on percutaneous endoscopic discectomy using a transforaminal approach

Background ContextPercutaneous endoscopic discectomy is a minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH). It can be performed under local anesthesia and requires a skin incision of only 8 mm, with minimal disruption of the spinal structures including ligaments and muscles. However, performing percutaneous endoscopic discectomy with a transforaminal approach (TF-PED) for the lower lumbar spine is associated with some anatomical problems, such as interference from the iliac crest. This study sought to assess the operability of TF-PED for the lower lumbar spine. PurposeThe purpose of this study was to assess a three-dimensional relationship between the trajectory of TF-PED and the iliac crest, and the operability of TF-PED at the lower lumbar disc levels (L4–L5 and L5–S1) using CT images. Study DesignThis is a retrospective study using 323 multiplanar abdominal computed tomography (CT) scans. Patient SampleWe retrospectively reviewed contrast-enhanced multiplanar abdominal CT scans of 323 consecutive patients (203 male and 120 female) in our hospital from April 2009 to March 2013. The mean age was 66.5 (range 15–89) years old. Outcome MeasuresThe operability of the TF-PED was the outcome measure. Materials and MethodsWe defined the tangent line in the iliac crest and the superior articular process of the caudal spine as the trajectory line of TF-PED, and evaluated the maximum inclination angle of the trajectory of the TF-PED (α angle) at the L4–L5 and the L5–S1 disc levels. Assuming the use of an oblique viewing endoscope at 25°, we defined α angle≥65° as the operability of TF-PED. Results(1) Relationship between iliac crest and disc level: The trajectory of the TF-PED interfered with the iliac crest at L4–L5 in 40.2% (right) and 54.5% (left) of the subjects, and at L5–S1 in 99.7% and 100% of the subjects. (2) The maximum inclination angle of the trajectory of TF-PED: the α angles were 84.3° and 82.3° at the L4–L5, and 56.8° and 55.2° at L5–S1. (3) Laterality of the α angle: At both disc levels, the mean age of the subjects with a laterality of ≥10° was significantly higher than that of subjects with a laterality of <10°. (4) Operability of TF-PED: At L4–L5, TF-PED could be performed in 94.4% and 90.4% of the subjects. In contrast, at L5–S1 the procedure could be performed in 24.1% and 19.2% of the subjects (male: 15.8% and 10.8%, female: 38.3% and 33.3%). ConclusionsFrom the results of this study, the trajectory of TF-PED can be limited by the surrounding anatomical structures. The maximum inclination angle indicated that treatment for the central type of LDH at the L5–S1 disc level was considered more difficult than that at the L4–L5 disc level because of the iliac crest. In the clinical setting, such anatomical particularities can be overcome by using a more perpendicular approach (hand-down technique) with the possible addition of a foraminoplasty. Moreover, we found that we must consider the laterality of the trajectory of TF-PED in terms of the patients' age or sex.

Value of multi-slice spiral CT image texture analysis in diagnosing lymphatic metastasis of rectal cancer

Objective To investigate the value of multi-slice spiral CT image texture analysis in differentiating metastatic (MLN) from non-metastatic lymph nodes (NLN) in patients with rectal cancer. Methods Thirty five patients with rectal cancer who were pathologically confirmed by total mesorectum excision were included retrospectively, with regional lymph nodes (short-axis diameter of larger than 3 mm) found in preoperative CT images. All the patients underwent preoperative abdominal and pelvic dynamic contrast-enhanced CT scan. Regional lymph nodes were identified according to pathological findings, and were divided into MLN and NLN groups. The short-axis diameter, short-to long-axis diameter ratio of lymph nodes were manually measured and calculated, and the texture features, including skewness, kurtosis, variance, entropy and inverse difference moment, were analyzed. The above parameters between MLN and NLN groups were compared using independent sample t test or Mann-Whitney U test. ROC curve analysis was performed regarding the statistically significant parameters and the areas under curve (AUC) were calculated. Multivariate Logistic regression analysis was accomplished to obtain the independent predictive factor of diagnosing regional lymph nodes. Results A total of 68 regional lymph nodes were obtained and consisted of 31 MLNs and 37 NLNs. The short-axis diameter, kurtosis, and entropy of the MLN group were significantly higher than those of the NLN group (all P 0.05). The AUC for distinguishing MLN from NLN of the short-axis diameter, kurtosis and entropy were 0.79, 0.67, and 0.85, respectively. Multivariate logistic regression analysis showed that only entropy (odds ratio= 8.48, 95% confidence interval was 3.01 to 23.92, P<0.01) was screened out as the independent variable, which suggested that the entropy was the unique predictor for characterizing regional lymph nodes of rectal cancer. Conclusion Multi-slice spiral CT images texture analysis can facilitate the accurate differentiation between MLN and NLN in patients with rectal cancer, and especially the entropy has the optimal reference significance. Key words: Rectal neoplasms; Lymphatic metastasis; Tomography, X-ray computed; Texture analysis

Pearls and pitfalls of hepatobiliary and splenic trauma: what every trauma radiologist needs to know.

With the universal acceptance of contrast-enhanced computed tomography (CT) as the imaging modality of first resort in the assessment of blunt abdominal injury, the trauma radiologist must be able to accurately and rapidly identify the range of CT manifestations of the traumatized abdomen. In this article, we lay out the fundamental principles in CT interpretation of blunt trauma to the hepatobiliary system and spleen, including vascular injury, with a focus on technical and interpretive pearls and pitfalls. This review will help radiologists and trainees become more familiar with key aspects of abdominal CT trauma protocol selection, CT-based solid organ injury grading, and the various appearances and mimics of hepatobiliary and splenic injury.

Multi-atlas pancreas segmentation: Atlas selection based on vessel structure.

Automated organ segmentation from medical images is an indispensable component for clinical applications such as computer-aided diagnosis (CAD) and computer-assisted surgery (CAS). We utilize a multi-atlas segmentation scheme, which has recently been used in different approaches in the literature to achieve more accurate and robust segmentation of anatomical structures in computed tomography (CT) volume data. Among abdominal organs, the pancreas has large inter-patient variability in its position, size and shape. Moreover, the CT intensity of the pancreas closely resembles adjacent tissues, rendering its segmentation a challenging task. Due to this, conventional intensity-based atlas selection for pancreas segmentation often fails to select atlases that are similar in pancreas position and shape to those of the unlabeled target volume. In this paper, we propose a new atlas selection strategy based on vessel structure around the pancreatic tissue and demonstrate its application to a multi-atlas pancreas segmentation. Our method utilizes vessel structure around the pancreas to select atlases with high pancreatic resemblance to the unlabeled volume. Also, we investigate two types of applications of the vessel structure information to the atlas selection. Our segmentations were evaluated on 150 abdominal contrast-enhanced CT volumes. The experimental results showed that our approach can segment the pancreas with an average Jaccard index of 66.3% and an average Dice overlap coefficient of 78.5%.

Anatomic variations of inferior mesenteric artery and left colic artery evaluated by 3-dimensional CT angiography: Insights into rectal cancer surgery – A retrospective observational study

ObjectiveTo demonstrate the clinical applicability of 3-dimensional CT angiography (3D-CTA) in evaluating the anatomic variations of inferior mesenteric artery (IMA) and left colic artery (LCA), to help make pre-operative strategies of rectal cancer surgery. Methods188 patients with abdominal and pelvic contrast-enhanced CT scan were retrospectively enrolled and 3D-CTA was reconstructed. The origin and branching patterns of IMA, tracking patterns of LCA, intersectional patterns among IMA, LCA and inferior mesenteric vein (IMV) were examined, and their associations with clinical features were analyzed. ResultsThe origin of IMA was located 42.1 ± 7.7 mm above iliac artery bifurcation, 64.4% within the area of the 3rd lumbar vertebra. 47.3% of LCA arose independently from IMA, 27.1% arose at the root of sigmoid artery (SA), 20.7% shared a common trunk with SA while 4.8% of LCA was absent. As for track of LCA before anastomosis with marginal artery, 53.2% went straight upward while medial to the inner border of left kidney (Type A), 27.1% traveled diagonally across left kidney (Type B) and14.9% went infero-laterally to the lower border of left kidney (Type C). Short IMA trunk was independently associated with type A LCA and lower site of IMA origin. At the horizontal level of IMA origin, 29% of the LCA went distant from IMV, while 71% (21% medial, 50% lateral) were mutually close, and the close type was independently associated with type A LCA. ConclusionPreoperative understanding of the vascular variations and the mutual relationship among LCA, IMA and IMV could be obtained by 3D-CTA, which would further help surgeons to set detailed plans for laparoscopic rectal cancer surgery.

CT for Acute Nontraumatic Abdominal Pain—Is Oral Contrast Really Required?

This study aims to compare the diagnostic performance of abdominal computed tomography (CT) performed with and without oral contrast in patients presenting to the emergency department (ED) with acute nontraumatic abdominal pain. Between December 2013 and December 2014, 348 adult patients presenting to the ED of a large tertiary medical center with nontraumatic abdominal pain were evaluated. Exclusion criteria for the study were history of inflammatory bowel disease, recent abdominal operation and suspected renal colic, abdominal aortic aneurysm rupture, or intestinal obstruction. All patients underwent intravenous contrast-enhanced abdominal CT on a Philips Brilliance 64-slice scanner using a routine abdomen protocol. The study group included 174 patients who underwent abdominal CT scanning without oral contrast, recruited using convenience sampling. A control group of 174 patients was matched to the cohort groups' gender and age and underwent abdominal CT with oral contrast material during the same time period. The patients' medical records were reviewed for various clinical findings and for the final clinical diagnosis. The CT exams were initially reviewed by a senior attending radiologist to determine the exams' technical adequacy and to decide whether an additional scan with oral contrast was required. Two senior radiologists, blinded to the clinical diagnosis, later performed consensus reading to determine the contribution of oral contrast administration to the radiologists' diagnostic confidence and its influence on diagnosing various radiological findings. Each group consisted of 82 men and 92 women. The average age of the two groups was 48 years. The main clinical diagnoses of the pathological examinations were appendicitis (17.5%), diverticulitis (10.9%), and colitis (5.2%). A normal CT examination was found in 34.8% of the patients. There was no significant difference between the groups regarding most of the clinical parameters that were examined. None of the examinations of all of the 174 study group patients was found to be technically inadequate, and therefore no patient had to undergo additional scanning to establish a diagnosis. The consensus reading of the senior radiologists determined that the lack of oral contrast was insignificant in 96.6% of the cases and that contrast material might have been useful in only 6 of 174 study group patients (3.4%). The radiologists found oral contrast to be helpful only in 8 of 174 control group patients (4.6%). There was no significant difference between the clinical and radiological diagnoses in both groups (study group, P = 0.261; control group, P = 0.075). Our study shows that oral contrast is noncontributory to radiological diagnosis in most patients presenting to the ED with acute nontraumatic abdominal pain. These patients can therefore undergo abdominal CT scanning without oral contrast, with no effect on radiological diagnostic performance.

The influence of low concentration iodinated contrast agent and low-dose CT scanning technique combined with body mass index on radiation dose and image quality of upper abdominal CT examinations

Objective To investigate the influence of double technology (low concentration iodinated contrast agent and low-dose scan) combined with body mass index (BMI) on radiation dose and image quality of contrast-enhanced upper abdominal CT examination. Methods One hundred and twenty patients who received upper abdominal enhanced CT examination were randomly divided into 4 groups: group A1, the iodinated contrast agent iodixanol (270 mg/ml), BMI<18.5 kg/m2 and 80 kVp; group A2, the iodinated contrast agent iodixanol (270 mg/ml), 18.5 kg/m2≤BMI≤24.9 kg/m2 and 100 kVp; group B1, the iodinated contrast agent ioversol (320 mg/ml), <18.5 kg/m2 and 120 kVp; group B2, the iodinated contrast agent ioversol (320 mg/ml), 18.5 kg/m2≤BMI≤24.9 kg/m2 and 120 kVp. Image quality was subjectively scored, the objective parameters (noise, CT values of abdominal aorta and liver parenchyma, contrast noise ratio of abdominal aorta and liver parenchyma) were evaluated and radiation dose was recorded. The differences of the indexes between A1 and B1 groups, A2 and B2 groups were compared with Mann-Whitney U test and pared-samples t test. Results All CT images were good. No images with 4 scores were obtained. No significant difference was found between group A1 and B1, between group A2 and B2 (P>0.05). There was no significant difference in contrast noise ratio of liver parenchyma (P>0.05), while significant differences existed in CT values of abdominal aorta and liver parenchyma, contrast noise ratio of abdominal aorta between group A1 and B1 (P<0.05). Significant differences existed in the parameters above mentioned between group A2 and B2, respectively (P<0.05). Radiation dose was lower in group A1 than in group B1 and in group A2 than in group B2 (P<0.05), respectively. Radiation dose was decreased by 40.1%(0.89/2.22) in group A1 than group B1 while radiation dose decreased by 56.9% (3.02/5.31) in group A2 than group B2. Conclusion According to BMI, the low concentration iodinated contrast agent and low-dose scan CT scanning technology could effectively reduce radiation dose and generate ideal images during the contrast-enhanced upper abdominal CT examination. Key words: Tomography, X-ray computed; Radiation dosage; Contrast media; Body weight

Non-occlusive mesenteric ischemia localized in the transverse colon: a case report

BackgroundNon-occlusive mesenteric ischemia (NOMI) is ischemia of the mesentery that is caused by hypoperfusion or vasospasm without any thrombosis. NOMI is difficult to diagnose by physical examination alone. Although angiographic examination of the superior mesenteric artery (SMA) is the usual diagnostic method used, it is an invasive examination. Usually, a long range of the bowel becomes discontinuously necrotic in NOMI. Here, we report a rare case of NOMI localized in the transverse colon that was diagnosed by computed tomography (CT) angiography which is a minimally invasive examination.Case presentationA 72-year-old woman was referred to our hospital for further treatment of abdominal pain that developed 1 day before presentation. Contrast-enhanced abdominal CT scan revealed attenuated enhancement of the transverse colon. CT angiography showed SMA irregularities due to vasospasm. The middle colic artery could not be detected by CT angiography. No occlusion due to thrombus or embolism in the SMA and superior mesenteric vein was observed. Based on the findings, NOMI was suspected, and emergency laparotomy was performed, which revealed a segmentally necrotic transverse colon. The necrotic bowel was resected, and stomas were created.ConclusionThe presence of hypotension in the patient necessitated the use of CT angiography, which proved very useful in the early diagnosis of the present case. Thus, if intestinal ischemia is suspected, even in case of a short segment, CT angiography should be performed.

IPMC術後に吻合腸管の進行性狭窄を来した再発膵癌の1例

A 73-year-old man with fever and upper abdominal pain was admitted for acute cholangitis. He had undergone pancreaticoduodenectomy for intraductal papillary mucinous carcinoma (IPMC) 19 years before and stent placement for the stenosis of the anastomosed intestinal 2 months before. Contrast-enhanced abdominal computed tomography (CE-CT) on admission revealed a thickened wall of the small intestine surrounding the stent with the dilated main pancreatic duct, and a tumor of the remnant pancreas was suspected. Stent exchange for cholangitis was failed because the enteroscope could not reach the stenotic portion. Fever and upper abdominal pain were relieved by administration of antibacterial drugs. Ultrasonography (US) revealed the wall thickening of the anastomosed intestine and percutaneous biopsy of the lesion showed adenocarcinoma. CE-CT and US suggested remnant pancreatic cancer with invasion to the anastomosed intestine. Surgical treatment could not be selected due to extension of the tumor to the retroperitoneum, and chemotherapy was performed.

Endoscopic ultrasound: a promising approach for the diagnosis of pancreatic pseudoaneurysm

Pancreatic pseudoaneurysm converted from a pancreatic pseudocyst is rare but may cause fatal hemorrhage. We report a 42-year-old man with pancreatic pseudocyst in the pancreatic tail which was found by computed tomography in other hospital was referred to our hospital for endoscopic ultrasound(EUS) guided drainage. However, examination by EUS of the pancreas identified a pseudoaneurysm at the level of the pancreatic body, which was represented by a well-defined, 3.5-cm maximal diameter echogenic lesion containing an anechoic area of 1.5 cm with flow detected by Doppler. We immediately terminated the procedure and the patient remained hemodynamically stable. A pseudoaneurysm in the pancreatic tail was detected on contrast-enhanced abdominal computed tomography (CT), which communicated with the splenic artery. A coil embolization of the splenic artery was successfully performed with a favorable outcome. Follow-up contrast-enhanced abdominal CT revealed that the pseudoaneurysm was no longer present. Timely and accurate diagnosis has a great influence on the prognosis of patients with pancreatic pseudoaneurysm. With development of EUS, We do believe that EUS is being an alternative option for the diagnosis of pancreatic pseudoaneurysm.

Evaluation of Adverse Events and Imaging Quality in Contrast-Enhanced Abdominal CT Using Generic CT Contrast Developed in South Korea: A Multicenter Prospective Observational Study

Evaluation of Adverse Events and Imaging Quality in Contrast-Enhanced Abdominal CT Using Generic CT Contrast Developed in South Korea: A Multicenter Prospective Observational Study

Biliary and pancreatic ductal dilation in patients on methadone maintenance therapy.

To determine whether the diameter of intrahepatic and extrahepatic bile ducts and pancreatic ducts in patients on methadone maintenance therapy is increased when compared with control subjects. Between January 1, 2000 and March 15, 2013, a total of 97 patients (mean age 49.9, range 22-79, 65 male, 32 female) were identified who were receiving chronic methadone maintenance therapy (MMT) when they underwent imaging with abdominal MRI or a contrast-enhanced abdominopelvic CT. A group of 97 consecutive non-MMT control patients (mean age 51.4, range 21-86, 45 male, 52 female) who underwent imaging with abdominal MRI or contrast-enhanced abdominopelvic CT were identified. Patients with known pancreaticobiliary pathology that may confound biliary ductal measurements were excluded. Blinded interpretation was performed, documenting the diameters of the intrahepatic and extrahepatic bile ducts and pancreatic ducts. Descriptive statistics were performed. Patients on MMT demonstrated increased bile duct diameter, with an average increase in duct diameter of 2.39mm for the common bile duct (p <0.001; 95% CI 1.88-2.90mm), 1.43mm for the intrahepatic bile ducts (p <0.001; 95% CI 1.12-1.74mm), and 0.90mm for the pancreatic duct (p <0.001; 95% CI 0.64-1.16mm). No statistically significant correlation was found between ductal diameters and the daily dose of methadone. Patients on methadone maintenance therapy demonstrate significantly increased intra- and extrahepatic bile duct and pancreatic duct diameter when compared with controls. There was no correlation between the dose of methadone and ductal diameter.

Anti-NMDA receptor encephalitis presenting as an acute psychotic episode misdiagnosed as dissociative disorder: a case report.

BackgroundIn 2005, “anti-N-methyl-d-aspartate (NMDA) receptor encephalitis,” a syndrome with prominent psychiatric symptoms, memory loss, decrease in level of consciousness, and central hypoventilation, was described in young women with ovarian teratomas and antibodies against an antigen highly expressed in the hippocampus. This report highlights the growing need for increased awareness among psychiatrists and other relevant medical professionals about this under-diagnosed disorder, which should be considered in differential diagnoses.Case presentationA 19-year-old female with no psychiatric history presented to a district general hospital with acute psychosis, emotional lability, memory deficit, fluctuating behavioral changes such as wandering and babbling, and seizure. She was admitted to the hospital with a provisional diagnosis of dissociative disorder. Soon after admission, she developed aspiration pneumonia and was intubated for mechanical ventilation. She was transferred to our hospital for further assessment and admitted to the intensive care unit for ventilation. Laboratory test results were unremarkable, but her EEG showed non-specific slowing with no epileptiform activity, and brain computed tomography (CT) and MRI also showed no remarkable findings. Cerebrospinal fluid (CSF) analysis showed an elevated white blood cell count (15 cells/hpf; 70 % lymphocytes), and blood serum and CSF samples tested positive for NMDA receptor antibodies. Abdominal contrast-enhanced CT revealed an ovarian teratoma, which was subsequently removed laparoscopically. Postoperative immunotherapy (steroids, intravenous immunoglobulin, and plasmapheresis) led to gradual improvement. On day 25 of hospitalization, neuropsychological assessment demonstrated that overall, she had returned to her premorbid level of functioning. Her condition substantially improved over several months of cognitive rehabilitation, and she was eventually discharged on day 75.ConclusionsAnti-NMDA receptor encephalitis, a form of autoimmune encephalitis, is commonly associated with tumors and often misdiagnosed. Diagnosis can be confirmed by detecting NMDA receptor antibodies in the patient’s serum or CSF. Management can be achieved with immunosuppressive therapy and tumor resection.