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Enlarged mesenteric lymph-nodes in asymptomatic children inand CT examinationRathaus V, Zissin R, Werner M, Meir Medical Center, Israel

Objectives: To determine the prevalence of enlarged mesenteric lymphnodes in asymptomatic children.Methods: We prospectively studied 189 consecutive asymptomaticchildren from the outpatients’ nephrological clinics who were referredto abdominal US. For comparison, we retrospectively reviewed theabdominal CT studies of 99 children, performed following blunt ab-dominal trauma. The children of both groups were divided in foursubgroups according to their ages. The size, the number and themorphology of mesenteric lymph nodes were assessed.Results: On abdominal US, enlarged mesenteric lymph nodes weredetected in 55 of 189 asymptomatic children (29.1%). The longitudinaldiameter of the lymph nodes ranged between 5 to 19 mm. These lymphnodes were arranged in clusters (three to nine in number in a cluster).All the lymph nodes were oval-shaped, flattened, and without anydiscomfort following graded transducer compression. On abdominalCT, enlarged mesenteric lymph nodes were diagnosed in 28 of the 99children (28.3%). These lymph nodes measured more than 5 mm andwere arranged in clusters (three or more in number).Conclusions: The presence of enlarged mesenteric lymph nodes inasymptomatic children of all ages and in both genders is a common,nonspecific finding and should be evaluated only in the appropriatedclinical context.

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Abdominal inflammatory myofibroblastic tumor (inflammatorypseudotumor) mimicking malignant neoplasm in children: Awide spectrum of imaging findingsYoun BJ, Kim WS, Cheon JE, Eo H, Jung AY, Kim I-O, Yeon KM,Seoul National University Hospital, Korea

Inflammatory myofibroblastic tumor (IMT) is rarely encountered inchildren. Abdominal manifestations of IMT have not been well de-scribed previously. We reviewed imaging findings of seven patientswith pathologically confirmed abdominal IMT. Two patients had pre-vious history of chemotherapy after surgical resection of malignanttumor. Four tumors occurred in the liver, two in the mesentery, one inthe duodenum. The IMT involving the mesentery (n � 2) showed ahuge well-defined mass with heterogeneous low echogenicity, whilethe IMT involving the liver (n � 4) showed an ill-defined heteroge-neous low echoic lesion at porta hepatis with intrahepatic bile ductdilatation (n � 2) and a low echoic nodule suggesting metastasis (n �2). The IMT involving the duodenum showed wall thickening of lowechogenicity suggesting lymphoma. It is difficult to distinguish abdom-inal IMT clinically and radiologically from malignant neoplasms suchas lymphoma, sarcoma, or metastasis. Abdominal IMT showed a widespectrum of imaging findings.

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Abdominal sonographic features of hemophagocyticlymphohistiocytosis in childrenLim GY, Lee Y-J, Im S-A, Cho B, Hahn S-T, St. Mary’s Hospital,The Catholic University of Korea, Korea

Objectives: Hemophagocytic lymphohistiocytosis (HLH), a variant ofhistiocytosis, is characterized by an overproduction of cytokines anddiminished immune surveillance. The purpose of this study is toevaluate the abdominal sonographic findings in children with HLH.Methods: Twenty-two abdominal US results of 32 children at presen-tation who received a diagnosis of HLH were reviewed. The patients

ranged in age from 5 months to 15 years. The US findings at thepresentation and follow up periods during therapy were included.Results: Common abdominal US findings included hepatosplenomeg-aly (22), gall bladder thickening (12), and ascites (10). Other uncom-mon findings were increased, coarse hepatic echotexture (10), mesen-teric/periportal adenopathy (five), echogenic periportal focal nodularlesion (one) and nephromegaly with increased renal cortical echoge-nicity (two). Follow-up imaging of above findings were well correlatedwith clinical disease activity.Conclusions: Although abdominal US findings of HLH in children arenonspecific, in the appropriate clinical findings, awareness of USmanifestation may be helpful in differential diagnosis from other dis-orders as well as in monitoring therapy response.

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The usefulness of transperineal ultrasonography in imperforateanusChoi YH, Kim IO, Cheon JE, Kim WS, Yeon KM, Seoul NationalUniversity Hospital, Korea

Objectives: To assess the usefulness of transperineal ultrasonographyin determining the type of imperforate anus (IA).Methods: From January 2000 to December 2004, out of overall 193patients with IA, 46 patients underwent transperineal US prior tocorrective surgery. Sonographic findings were reviewed for the iden-tification of the internal fistula and the measurement of “distal rectalpouch to perineum” distance (P–P distance). Based on these findings,the level of IA was determined. Diagnostic accuracy of US wasevaluated on the basis of the surgical findings.Results: Of the 46 patients, 17 patients were surgically confirmed ashigh-type, three as intermediate-type and 23 as low-type. The level ofimperforate anus was correctly diagnosed with transperineal US in 40out of 46 patients (87%). Two patients with low-type IA were misdi-agnosed as high-type. And the level of IA could not be determined ineach two patients with high- and intermediate-type. All patients withP–P distances of �15 mm were exclusively high-type. All patients withP–P distances of �5 mm were exclusively low-type.Conclusions: Transperineal US is a good diagnostic modality to iden-tify the internal fistula in high-type IA and to define the level of IA.

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Focused abdominal sonography for gastrointestinal complicationsin pediatric bone marrow transplant recipientsLim GY, Shin Y-R, Im S-A, Hahn S-T, St. Mary’s Hospital, TheCatholic University of Korea, Korea

Bone marrow transplantation(BMT) is widely used in the treatment ofhematologic disorders and some solid tumors in children. A widevariety of complications may occur in BMT recipients and are a majorcause of morbidity and death. The gastrointestinal tract is a frequentlyaffected organ after BMT. Gastrointestinal complications include neu-tropenic colitis, CMV enterocolitis, pseudomembranous colitis,GVHD, pneumatosis intestinalis and post-transplantation lymphopro-liferative disease (PTLD). In pediatric age, ultrasonography is used formodality of choice and essential tool for diagnosing these complica-tions in critically ill recipients. We present US features of these manygastrointestinal complications with correlative other abdominal imag-ing, including plain radiography, contrast studies and enhanced CTscans.

Abstracts P271