Small Bowel Obstruction Caused by Peritoneal Immunoglobulin G4-Related Disease Mimicking Carcinomatosis: Case Report

We hereby report a case of diffuse pelvic peritoneal involvement by immunoglobulin G4-related disease (IgG4-RD). Numerous pelvic masses and nodules showing delayed enhancement on enhanced abdominal CT were found to congregate in the pelvic organs of a 57-year-old female presenting with intestinal subocclusion. The differentiation between peritoneal IgG4-RD and pelvic peritoneal carcinomatosis was only made by histopathology and immunohistochemistry performed after surgical resection. Autoimmune pancreatitis represents the historical prototype of IgG4-RD, but the spectrum of manifestations involving various organs has expanded during the last decade. In this report, we shortly review this clinical entity.

Follicular Dendritic Cell Sarcoma of the Abdomen: the Imaging Findings

Follicular dendritic cell sarcoma is a rare neoplasm that originates from follicular dendritic cells in lymphoid follicles. This disease usually involves the lymph nodes, and especially the head and neck area. Rarely, extranodal sites may be affected, including tonsil, the oral cavity, liver, spleen and the gastrointestinal tract. We report here on the imaging findings of follicular dendritic cell sarcoma of the abdomen that involved the retroperitoneal lymph nodes and colon. It shows as a well-defined, enhancing homogenous mass with internal necrosis and regional lymphadenopathy.

Renal Hypoperfusion Associated with Splenorenal Shunts in Liver Cirrhosis

PURPOSE: To determine whether spontaneous a splenorenal shunt can be used as an imaging predictor of early renal hemodynamic changes in patients with cirrhosis. MATERIALS AND METHODS: The study included 82 cirrhotic patients and 41 control subjects. Three-phase CT was performed and CT attenuation values (Hounsfield units) of the renal cortex in three phases were measured to evaluate renal perfusion. Likelihood ratio tests for trend were conducted for age, presence of ascites, and Child's grade. RESULTS: The mean CT attenuation values of the renal cortex in cirrhotic patients were significantly lower than the values of control subjects in three phases: 153.3 +/- 37.9 versus 173.3 +/-25.2 in the arterial phase, 172.6 +/- 41.0 versus 197.6 +/- 26.5 in the portal phase and 136.9 +/- 26.0 versus 152.7 +/- 20.0 in the delayed phase, respectively. The mean CT attenuation value of cortices in patients with renal hypoperfusion was 119.9 +/- 11.8 in the portal phase. Child's class C (aOR: 58.4, 95% CI: 3.6-956.2; p < 0.01) and the presence of a renal shunt (aOR: 7.5, 95% CI: 1.8-30.5; p < 0.01) were associated with renal hypoperfusion. The incidence of renal hypoperfusion was associated with Child's grade (trend: p < 0.01), and not with the grade of ascites or age. CONCLUSION: A dilated spontaneous splenorenal shunt may be a risk factor for renal hypoperfusion in cirrhosis.

The Optimal Parameter for Radiation Dose in Pediatric Low Dose Abdominal CT: Cross-sectional Dimensions versus Body Weight

PURPOSE: To investigate the best parameter between cross-sectional dimensions and body weight in pediatric low dose abdominal CT. MATERIALS AND METHODS: One hundred and thirty six children consecutively underwent weight-based abdominal CT. The subjects consisted of group 1 (79 children, weight range 10.0-19.9 kg) and group 2 (57 children, weight range 20.0-39.9 kg). Abdominal cross-sectional dimensions including circumference, area, anteroposterior diameters and transverse diameters were calculated. Image noise (standard deviation of CT density) was measured by placing a region of interest in the posterior segment of the right hepatic lobe on a CT image at the celiac axis. The measured image noise was correlated with the cross-sectional abdominal dimensions and body weight for subjects in each group. RESULTS: In group 1 subjects, area, circumference, transverse diameter, anteroposterior diameter, and body weight showed a significant positive correlation with image noise in descending order (gamma = 0.63, 0.62, 0.61, 0.51, and 0.49; p<0.0001). In group 2 subjects, transverse diameter, circumference, area, anteroposterior diameter, and body weight showed a significant positive correlation with image noise in descending order (gamma = 0.83, 0.82, 0.78, 0.71, and 0.71; p<0.0001). CONCLUSION: Cross-sectional dimensions such as area, circumference, and transverse diameter showed a higher positive correlation with image noise than body weight for pediatric low dose abdominal CT.

The Short-Term Effects of Balloon-Occluded Retrograde Transvenous Obliteration, for Treating Gastric Variceal Bleeding, on Portal Hypertensive Changes: a CT Evaluation

OBJECTIVE: We wanted to evaluate the short-term effects of balloon-occluded retrograde transvenous obliteration (BRTO) for treating gastric variceal bleeding, in terms of the portal hypertensive changes, by comparing CT scans. MATERIALS AND METHODS: We enrolled 27 patients who underwent BRTO for gastric variceal bleeding and they had CT scans performed just before and after BRTO. The pre- and post-procedural CT scans were retrospectively compared by two radiologists working in consensus to evaluate the short-term effects of BRTO on the subsequent portal hypertensive changes, including ascites, splenomegaly, portosystemic collaterals (other than gastrorenal shunt), the gall bladder (GB) edema and the intestinal wall edema. Statistical differences were analyzed using the Wilcoxon signed rank test and the paired t-test. RESULTS: Following BRTO, ascites developed or was aggravated in 22 (82%) of 27 patients and it was improved in two patients; the median spleen volumes increased from 438.2 cm3 to 580.8 cm3, and based on a 15% volume change cut-off value, splenic enlargement occurred in 15 (56%) of the 27 patients. The development of new collaterals or worsening of existing collaterals was not observed in any patient. GB wall edema developed or was aggravated in four of 23 patients and this disappeared or improved in five; intestinal wall edema developed or was aggravated in nine of 27 patients, and this disappeared or improved in five. Statistically, we found significant differences for ascites and the splenic volumes before and after BRTO (p = 0.001 and p < 0.001, respectively) CONCLUSION: Some portal hypertensive changes, including ascites and splenomegaly, can be aggravated shortly after BRTO.

Non-contiguous Multi-organ Involvement of an Inflammatory Myofibroblastic Tumor: A Case Report

An inflammatory myofibroblastic tumor (IMT) is relatively rare quasineoplastic lesion. An IMT usually presents as a single mass within a single organ or sometimes as multifocal lesions within a single anatomic region. An IMT involving noncontiguous multi-organs within different anatomic regions is extremely rare. We present a case of an aggressive IMT that involved the musculoskeletal system and multiple abdominal visceral organs.

Gossypiboma in the Abdomen: A Case Report

Gossypiboma is retained surgical sponge or swab. We experienced a case of gossypiboma resulting from a retained surgical sponge, which had been left in intraperitoneal cavity for 4 years after appendectomy. Abdominal CT scan revealed a non-calcified soft tissue mass with wall enhancement. We thought this lesion was an abscess or hematoma. So we tried to perform aspiration and drainage guided by ultrasonography. Ultrasonography showed illdefined hyperechoic stripe with strong posterior acoustic shadow within the mass, which has hypoechoic fibrous capsule. We could not puncture the lesion with aspiration needle due to its hardness, and the mass was removed by surgery. We report a case of gossypiboma confirmed by surgery, which was suspected by ultrasonographic feature and difficulty in puncture of mass.

Comparison of Two-dimensional CT with Virtual Gastrography Using Multi-detector CT in the Diagnosis of Early Gastric Cancer

PURPOSE: We compared the performance of virtual gastrography (VG) using multi-detector (MDCT) with two-dimensional (2D) CT in the diagnosis of early gastric cancer (EGC). MATERIALS AND METHODS: We performed conventional gastroscopy and MDCT examination after gaseous distension of the stomach in 50 consecutive patients who were confirmed as EGC by surgery and endoscopic mucosal resection. Unenhanced images were obtained in the prone position and contrast enhanced images were obtained in the supine position. Contrast enhanced imaging was done 70 seconds after intravenous injection of 150 mL of ionic contrast material at the rate of 3 mL/sec. 2D CT and VG images were analyzed by two radiologist with consensus to assess the location and gross morphologic type of EGC. Crosstabs were used to determine the diagnostic accuracy of EGC on 2D CT and VG. RESULTS: The diagnostic specificity for 50 patients with EGC was significantly higher with VG (72%) than with 2D CT (88%) (p<0.05). VG depicted EGC in eight patients (type I = 1; type IIa = 3; type IIb = 1; type IIc = 2; type IIa + IIc = 1) that were missed on the 2D CT. The lesions were located in the antrum (n = 6), angle (n = 1), and body (n = 1). However, VG frequently misdiagnosed EGCs of type IIb (n = 4), IIc (n = 1), and III (n = 1), as well as the location at the angle (n = 3), antrum (n = 1), and body (n = 1). CONCLUSION: VG showed excellent result in the detection of EGC compared with 2D CT. However, it had limitations in the diagnosis of EGC type IIb or gastric angle tumor.

CT Differentiation of Periappendiceal Inflammation with Appendicitis and Pelvic Inflammatory Disease in Woman with Right Lower Quadrant Pain

PURPOSE: We wanted to determine the usefulness of the computed tomography (CT) findings for making the diagnosis between periappendiceal inflammation (PAI) with appendicitis and pelvic inflammatory disease (PID) for the women presenting with right lower quadrant pain. MATERIALS AND METHODS: We retrospectively analyzed the CT findings of 83 women with right lower quadrant pain: PAI in 36 and PID in 47 patients. We reviewed the CT images, including the appendiceal diameter and the enhancing wall thickening, the cecal thickening, the location of the appendix, thickening of the right anterior renal fascia, abscess, mesenteric fatty infiltration, ascites, heterogeneous uterine enhancement and paralytic ileus. Statistical analysis was performed by using the t-test for the diameter of appendix, and the x2 test or Fisher's exact test for the CT findings. RESULTS: The mean diameter of the appendix was 11.0+/-3.4 mm for the PAI subjects and it was 6.7+/-2.0 mm for the PID subjects (p<0.0001). Wall thickening of the appendix was more commonly detected in PAI (25 subjects, 69%) than in PID (15 subjects, 32%) (p=0.0007). Thickening of the right anterior renal fascia was more commonly detected in PAI (18 subjects, 50%) than in PID (7 subjects, 15%). Cecal thickening, ascitis, heterogeneous uterine enhancement and paralytic ileus were not significantly different between PAI and PID. Abscess and mesenteric fatty infiltration were more frequently detected in the RLQ, and in the abdomen or pelvic cavity in PAI and PID, respectively (p<0.05). There was no significant difference in the distribution of ascites between the diseases. CONCLUSION: The CT findings of the appendiceal diameter, enhancing wall thickening and thickening of the right anterior renal fascia are useful for making the diagnosis of PAI. The abdominal and pelvic distributions of abscess and mesenteric fatty infiltration are highly suggestive findings of PID.

Retrospective Evaluation of Acute Appendicitis Incorrectly Diagnosed on CT

PURPOSE: The purpose of our study was to retrospectively evaluate the CT images of patients suffering with surgically proven appendicitis to determine the causes of missed diagnoses. MATERIALS AND METHODS: We reviewed the pathology reports of the patients with surgically proven appendicitis from two hospitals during a 3-year period. Thirty-seven such cases with a misdiagnosis were identified and they served as our misdiagnosed group (17 females and 20 males, mean age: 58 years, age range 15-68 years). These were cases that were misdiagnosed on preoperative abdominal CT. All 57 patients in the control group (30 females and 27 males, mean age: 44 years, age range: 21-78 years) had undergone laparotomy for acute appendicitis and they had been correctly diagnosed preoperatively on CT. Two abdominal radiologists evaluated the following items from all 94 CT examinations: 1) an abnormal appendix, 2) periappendiceal fat inflammation, 3) pericecal extraluminal fluid, 4) pericecal extraluminal air, 5) appendicolith, 6) cecal wall thickening, 7) small bowel dilatation, and 8) the pericecal fat content. Statistical analysis was performed using a Chi-squared test and Fisher's exact test. RESULTS: Any abnormal appendix was not visualized, even retrospectively, in 27 (73%) of the 37 patients from the misdiagnosed group, whereas it was not visualized in 13 (23%) of the 57 patients in the control group (p=0.001). Of the patients who had been misdiagnosed, inflammation of the pericecal fat was observed in 21 patients (57%) as compared to 50 (88%) patients in the control group (p=0.001). Pericecal fluid and air were noted in 15 (41%) and 9 (24%) patients, respectively, in the misdiagnosed group and in 19 (33%) and 14 (25%) patients, respectively, in the control group, (p=0.477 and p=0.901, respectively). Appendicolith was found in 3 (8%) misdiagnosed subjects and in 10 (18%) of the controls (p=0.001). Focal cecal wall thickening was noted in 14 (38%) misdiagnosed patients and in 28 (49%) control patients (p=0.28). Small bowel dilatation was noted in 5 (14%) and 4 (7%) patients in the misdiagnosed and control groups, respectively (p=0.477). The numbers of patients showing abundant pericecal fat were 3 (8%) in the misdiagnosed group and 25 (44%) in the control group (p=0.001). CONCLUSION: The main causes of missed diagnosis of acute appendicitis on CT are: non-visualization of an abnormal appendix and a lower index of suspicion by the radiologist. Knowledge of the aforementioned factors may help to avoid the misdiagnosis of appendicitis and so improve the diagnostic accuracy.

CT Findings of Cystic and Solid Masses of the Mesentery

CT remains the optimal imaging modality for diagnosing cystic and solid masses in the mesentery. CT may provide important information regarding the lesion? location, size and shape, the presence and thickness of a wall, the presence of septa, calcifications or fat, and the involvement of adjacent structures. Although percutaneous imaging-guided or surgical biopsy is often necessary to guide medical management, analysis of the CT features along with the clinical history may be helpful in differentiating mesenteric masses, including cystic lesions and primary neoplasms arising from the mesenchymal tissues or the secondary metastatic lesions. CT is useful not only for detecting cystic and solid mesenteric masses, but also for helping physicians become familiar with the features of various mesenteric masses for accurate diagnosis and treatment.

CT Findings of Cystic and Solid Masses of the Mesentery

CT remains the optimal imaging modality for diagnosing cystic and solid masses in the mesentery. CT may provide important information regarding the lesion? location, size and shape, the presence and thickness of a wall, the presence of septa, calcifications or fat, and the involvement of adjacent structures. Although percutaneous imaging-guided or surgical biopsy is often necessary to guide medical management, analysis of the CT features along with the clinical history may be helpful in differentiating mesenteric masses, including cystic lesions and primary neoplasms arising from the mesenchymal tissues or the secondary metastatic lesions. CT is useful not only for detecting cystic and solid mesenteric masses, but also for helping physicians become familiar with the features of various mesenteric masses for accurate diagnosis and treatment.

Differentiation Between Mass-forming Type Peripheral Cholangiocarcinoma and Hepatic Abscesses: Application of Artificial Neural Networks to CT Images

PURPOSE: To determine which CT findings are useful for differentiating cholangiocarcinomas (CC) from hepatic abscesses and also to determine whether artificial neural networks (ANNs) improve radiologists' performance. MATERIALS AND METHODS: CT findings of 51 patients with mass-forming type CC and 70 patients with hepatic abscesses were analyzed with morphologic, enhancing and other ancillary findings by three radiologists with differing levels of expertise independently. ANNs were constructed using statistically significant CT findings derived from the analyses. The performances of the ANNs and the radiologists were evaluated using receiver operating characteristic analysis. RESULTS: CT findings of rim-like enhancement, lymphadenopathy, capsular retraction, focal bile duct dilatation and a solid component were significant features of CC (p< 0.05). Findings of a clustered sign, multilayered enhancement, sharp margin, round shape, and air-biliary gram were significant features of hepatic abscesses. The ANNs showed better performance (AZ=0.9673, 98.0%, 97.1%, and 97.5%, respectively) than the resident (AZ=0.898, 78.4%, 81.4%, 80.2%) (p<0.05) in differentiating between the two diseases: (AZ, sensitivities, specificities, and overall accuracies). However, there were no significant differences in the diagnostic performance of the ANNs and the two board-certified radiologists. CONCLUSION: Several CT findings are useful in differentiating CC from hepatic abscesses and ANNs may improve the performance of a radiologist with little experience.

CT Findings of Gastrointestinal Stromal Tumor versus Lymphoma of the Small Intestine

PURPOSE: To compare CT features of gastrointestinal stromal tumors (GIST) with those of lymphomas in the small intestine. MATERIALS AND METHODS: CT findings of 11 pathologically confirmed GIST patients and 10 lymphoma patients were retrospectively reviewed. CT findings were analyzed with regard to location, size, margin, growth patterns, internal character, enhancement, invasion, vascular encasement, lymphadenopathy, intestinal obstruction and ascites. RESULTS:An extraluminal mass was present in 82% (9/11) of the GIST patients versus 30% (3/10) of the lymphoma patients. Circumferential wall thickening was observed in 80% (8/10) of the lymphoma patients (p.05). CONCLUSION: Features revealed by CT scans are highly useful in differentiating GIST from lymphoma of the small intestine. Extraluminal growth and internal necrosis or gas are more common in patients with GIST compared with lymphoma. CT features of circumferential wall thickening and associated lymphadenopathy are more common in patients with lymphoma.

Assessment of Mesenteric Vascular Steno-occlusive Lesion in Acute Mesenteric Ischemia: Comparison between CT Angiography and Digital Subtraction Angiography

PURPOSE: Acute mesenteric ischemia (AMI) is one of the most dramatic abdominal emergencies. The most common cause of AMI is a thrombo-embolism of the mesenteric artery or vein. The aim of this study was to evaluate the feasibility of CT angiography for evaluating mesenteric vascular steno-occlusive lesion in AMI. MATERIALS AND METHODS: Fifteen patients with clinically and angiographically proven AMI underwent a two-phase CT. The CT angiographic images were reconstructed using a 3D rendering algorithm, such as the maximum intensity projection and volume-rendering. All the CT angiographic images were reviewed with respect to stenosis or occlusion of mesenteric vessel by the consensus of two radiologists, and were correlated with the findings of digital subtraction angiography. RESULTS:Digital subtraction angiography (DSA) visualized 60 mesenteric vessels including the superior mesenteric artery (n=15) and vein (n=15), and the inferior mesenteric artery (n=15) and vein (n=15). DSA showed steno-occlusive lesions in 16 mesenteric vessels (13 superior mesenteric arteries, two superior mesenteric veins, and one inferior mesenteric artery). CT angiography detected steno-occlusive lesions in 16 mesenteric vessels (12 superior mesenteric arteries, one superior mesenteric vein, and three inferior mesenteric arteries). The sensitivity, specificity, and accuracy of CT angiography for evaluating mesenteric vascular steno-occlusive lesion were 87.5%, 95.4%, and 93.3%, respectively. CONCLUSION: CT angiography is an useful adjunct to abdominal CT in an AMI setting on account of its ability to detect the causes of AMI such as a steno-occlusive lesion of the mesenteric vessel.

Extragastrointestinal Stromal Tumor Presenting a Large Multilocular Cystic Mass Arising from the Greater Omentum: A Case Report

Extragastrointestinal stromal tumor (EGIST) has been reported to occur only rarely, and the cases of this disease appearing as cystic masses are also known to be very infrequent. Along with a review of the related articles, we report here on a case of EGIST arising from the omentum that was seen as a multiloculated large cystic mass with multiple thick septa and a solid component.

Cystic Changes in Intraabdominal Extrahepatic Metastases from Gastrointestinal Stromal Tumors Treated with Imatinib

OBJECTIVE: This study was undertaken for the purpose of describing the CT features of intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors in patients who were treated with imatinib. MATERIALS AND METHODS: Eleven patients with intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors, who were treated with imatinib between May 2001 and December 2003, were included in this study. The clinical findings and CT scans were retrospectively reviewed. The metastatic lesions were assessed according to the location, size (greatest diameter), attenuation, and the enhancing pattern before and after imatinib treatment. RESULTS: Prior to the treatment, the sizes and attenuation values of the metastatic lesions ranged from 5 to 20 cm and from 63 to 131 H, respectively. The metastatic lesions showed a heterogeneous enhancement pattern on the contrast-enhanced CT scans. After the treatment, the metastatic lesions became smaller in all 11 patients, and the corresponding attenuation value ranged from 15 to 51 H. The metastatic lesions became homogeneous and cystic in appearance on the follow-up CT scans, mimicking ascites. CONCLUSION: Intra-abdominal extra-hepatic metastases of patients with gastrointestinal stromal tumors treated with imatinib may appear as well-circumscribed cystic lesions on contrast-enhanced CT. These metastases are likely to become smaller and resemble ascites, but may persist indefinitely on the follow-up CT.

CT Findings of Congenital Transmesenteric Hernia: Case Report

Transmesenteric hernia occurs usually in adult patients who had history of an abdominal surgery or blunt abdominal trauma. Congenital mesenteric defect is a relatively common cause of internal hernia in children. However, the report of CT findings of congenital transmesenteric hernia is relatively rare. Thus, we report a case of congenital transmesenteric hernia occurring in a 13-year-old girl with intestinal obstructive symptoms, and include the CT findings.

Mucopolysaccharidosis: Abnormal Findings on Abdomen and Chest Excluding Musculoskeletal System

PURPOSE: Mucopolysaccharidosis (MPS) is a lysosomal storage disease that causes tissue distortion and dysfunction due to the infiltration of mucopolysaccharide in connective tissue. The purpose of this study was to evaluate the characteristic findings of abdominal CT and plain chest radiography in patients with MPS. MATERIALS AND METHODS: Sixty-two children with MPS diagnosed by urine analysis were involved in this study; 24 of these underwent abdominal CT and the findings were reviewed by two radiologists, who reached a consensus. Organomegaly was classified as severe, moderate or mild. On chest PA radiographs of 42 of the children, the transverse diameter of the trachea was measured and compared with that of 42 normal controls. Student's t test was used for statistical analysis. RESUTLS: At abdominal CT, hepatomegaly was observed in 22 patients (92%; 2 severe, 15 moderate and 5 mild); and splenomegaly was present in 18 (75%; 2 severe, 4 moderate and 12 mild). Among eight patients (33%) with pancreatic enlargement, one had a severly enlarged pancreas, while in the remaining seven, enlargement was mild. Also present were inguinal hernia (n=15), umbilical hernia (n=12), undulation with thickening of the diaphragmatic crura (n=10), abnormalities related to the male genitalia (n=5) and vascular anomaly (n=3). In MPS patients, the mid-point diameter of the trachea (range, 5.6-9 mm; mean, 6.9 mm) was significantly less than in normal controls (range, 8-14 mm; mean, 10.8 mm) (p<0.001). CONCLUSION: An awareness of the characteristic abnormalities observed at abdominal CT and chest PA radiography can lead to a better understanding of MPS in children.

CT Findings of Small Bowel Metastases From Primary Lung Cancer

PURPOSE: To evaluate the CT findings of small bowel metastases from primary lung cancer. MATERIALS AND METHODS: Of the 1468 patients with primary lung cancer between 1990 and 2000, 13 patients who had metastasis to the small intestine were collected. Of these 13 patients, nine who underwent CT scan were included for analysis. The pathologic diagnoses of primary lung cancer in these nine patients were squamous cell carcinoma in six, adenocarcinoma in two, and large cell carcinoma in one. CT scans were analyzed with regard to the site and patterns (intraluminal mass/bowel wall thickening/bowel implants) of metastatic masses, and the presence or absence of complication such as intussusception, obstruction, or perforation of the small bowel. The medical records of the patients were also reviewed retrospectively for evaluation of presenting abdominal symptom and time interval of metastases from initial diagnosis of lung cancer. RESULTS: Metastatic lesions were distributed throughout the small intestine: the duodenum in five, the jejunum in four, the ileum in six, and both jejunum and ileum in one patient. The size of metastatic masses of small bowel ranged from 1.3 cm to 5.0 cm (mean size, 2.6 cm) On CT, the small bowel was involved with intraluminal masses (mean size, 3.4 cm) in eight patients, diffuse wall thickening (mean thickness, 1.6 cm) in five, and bowel implants (mean size, 2.2 cm) in two. Complications occurred in seven patients, including intussusceptions without obstruction in two patients and with obstruction in two, obstruction without intussusceptions in two, and bowel perforation in one. Of 9 patients, 6 had at least one symptom referable to the small bowel including abdominal pain in 4, anemia in 3, vomiting in 1, and jaundice in 1. Lung cancer and small bowel lesions were detected simultaneously in four patients and the time interval of metastases from initial diagnosis of lung cancer ranged from 10 days to 30 months (median interval, 54 days) in 5 patients. CONCLUSION: CT helps in defining the extent and pattern of small bowel metastases as well as in demonstrating their complication.