Unusual Thymic Hyperplasia Mimicking Lipomatous Tumor in an Eight-Year-Old Boy with Concomitant Pericardial Lipomatosis and Right Facial Hemihypertrophy

We report a case of thymic hyperplasia accompanied by pericardial lipomatosis and right facial hemihypertrophy in an 8-year-old boy. On imaging studies, the hyperplastic thymus had prominent curvilinear and nodular fatty areas simulating a fat-containing anterior mediastinal mass, which is an unusual finding in children. To our knowledge, this is the first report on a child with a combination of thymic hyperplasia, pericardial lipomatosis, and right facial hemihypertrophy. The radiologic findings are presented with a brief discussion.

Balloon Dilatation for Corrosive Esophageal Strictures in Children: Radiologic and Clinical Outcomes

OBJECTIVE: We retrospectively evaluated the effectiveness of the esophageal balloon dilatation (EBD) in children with a corrosive esophageal stricture. MATERIALS AND METHODS: The study subjects included 14 patients (M:F = 8:6, age range: 17-85 months) who underwent an EBD due to a corrosive esophageal stricture. The causative agents for the condition were glacial acetic acid (n = 9) and lye (n = 5). RESULTS: A total of 52 EBD sessions were performed in 14 patients (range 1-8 sessions). During the mean 15-month follow-up period (range 1-79 months), 12 patients (86%) underwent additional EBD due to recurrent esophageal stricture. Dysphagia improved after each EBD session and oral feeding was possible between EBD sessions. Long-term success (defined as dysphagia relief for at least 12 months after the last EBD) was achieved in two patients (14%). Temporary success of EBD (defined as dysphagia relief for at least one month after the EBD session) was achieved in 17 out of 52 sessions (33%). A submucosal tear of the esophagus was observed in two (4%) sessions of EBD. CONCLUSION: Only a limited number of children with corrosive esophageal strictures were considered cured by EBD. However, the outcome of repeated EBD was sufficient to allow the children to eat per os prior to surgical management.

Clinical Application of Liver MR Imaging in Wilson's Disease

OBJECTIVE: To determine whether there is a correlation between liver MR findings and the clinical manifestations and severity of liver dysfunction in patients with Wilson's disease. MATERIALS AND METHODS: Two radiologists retrospectively evaluated MR images of the liver in 50 patients with Wilson's disease. The Institutional Review Board approved this retrospective study and informed consent was waived. MR images were evaluated with a focus on hepatic contour abnormalities and the presence of intrahepatic nodules. By using Fisher's exact test, MR findings were compared with clinical presentations (neurological and non-neurological) and hepatic dysfunction, which was categorized by the Child-Pugh classification system (A, B and C). Follow-up MR images were available for 17 patients. RESULTS: Contour abnormalities of the liver and intrahepatic nodules were observed in 31 patients (62%) and 25 patients (50%), respectively. Each MR finding showed a statistically significant difference (p < 0.05) among the three groups of Child-Pugh classifications (A, n = 36; B, n = 5; C, n = 9), except for splenomegaly (p = 0.243). The mean age of the patients with positive MR findings was higher than that of patients with negative MR findings. For patients with Child-Pugh class A (n = 36) with neurological presentation, intrahepatic nodules, surface nodularity, and gallbladder fossa widening were more common. Intrahepatic nodules were improved (n = 8, 47%), stationary (n = 5, 29%), or aggravated (n = 4, 24%) on follow-up MR images. CONCLUSION: MR imaging demonstrates the contour abnormalities and parenchymal nodules of the liver in more than half of the patients with Wilson's disease, which correlates with the severity of hepatic dysfunction and clinical manifestations.

Imperforate Anus: Determination of Type Using Transperineal Ultrasonography

OBJECTIVE: This study was designed to assess the usefulness of transperineal ultrasonography (US) for the determination of imperforate anus (IA) type. MATERIALS AND METHODS:From January 2000 to December 2004, 46 of 193 patients with an IA underwent transperineal US prior to corrective surgery. Sonographic findings were reviewed to identify the presence of internal fistulas and to determine "distal rectal pouch to perineum (P-P)" distances. IA types were determined based on the sonographic findings, and the diagnostic accuracy of transperineal US was evaluated based on surgical findings. RESULTS: Of the 46 patients, 17 patients were surgically confirmed as having a high-type IA, three patients were confirmed as having an intermediate-type IA and 26 patients were confirmed as having a low-type IA. The IA type was correctly diagnosed by the use of transperineal US in 39 of the 46 patients (85%). In 14 of the 17 patients with a high-type IA, internal fistulas were correctly identified. All cases with a P-P distance > 16 mm were high-type IAs and all cases with a P-P distance < 5 mm were low-type IAs. CONCLUSION: Transperineal US is a good diagnostic modality for the identification of internal fistulas in cases of high-type IA and for defining the IA level.

Power Doppler Imaging in Acute Renal Vein Occlusion and Recanalization: a Canine Model

OBJECTIVE: To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model. MATERIALS AND METHODS: We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified. RESULTS: We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant. CONCLUSION: The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion.

Radiological Spectrum of Hepatic Mesenchymal Hamartoma in Children

OBJECTIVE: A hepatic mesenchymal hamartoma is an uncommon benign tumor in children and little is known about the spectrum of its radiological features. The purpose of this study is to describe the spectrum of radiological features of a hepatic mesenchymal hamartoma in children. MATERIALS AND METHODS: Thirteen children with a pathologically confirmed hepatic mesenchymal hamartoma (M:F = 7:6; mean age, 3 years 2 months) were included in our study. Ultrasonography (US) was performed in nine patients including color and power Doppler US (n = 7). CT scans were performed in all patients. We evaluated the imaging findings of the hepatic mesenchymal hamartomas and the corresponding pathological features. RESULTS: Each patient had a single tumor (mean diameter: 13 cm [1.8-20 cm]). On CT and/or US, four patients (31%) had a "multiseptated cystic tumor", five patients (38%) had a " mixed solid and cystic tumor", and four patients (31%) had a "solid tumor." The septa of the cystic portion were thin in the multiseptated cystic tumors and irregularly thick in the mixed solid and cystic tumors as seen on US. On a post-contrast CT scan, solid portions or thick septa of the tumors showed heterogeneous enhancement. The amount of hepatocytes was significantly different among the three tumor groups according to the imaging spectrum (p = 0.042). CONCLUSION: A hepatic mesenchymal hamartoma in children can show a wide spectrum of radiological features, from a multiseptated cystic tumor to a mixed solid and cystic tumor, and even a solid tumor.

Congenital Absence of the Portal Vein Presenting as Pulmonary Hypertension

Congenital absence of the portal vein (CAPV) is a rare malformation in which intestinal and splenic venous flow bypasses the liver and drains directly into the systemic circulation via a congenital portosystemic shunt. We describe two cases of CAPV presenting as pulmonary hypertension that were initially suspected as primary pulmonary hypertension. However, subsequent ultrasonography and CT detected the absence of a portal vein and the presence of a portosystemic shunt. Pulmonary hypertension is a recognized complication of liver disease and portal hypertension. However, these two cases illustrate that CAPV may result in pulmonary hypertension without liver disease or portal hypertension.

MR findings in Acute Disseminated Encephalomyelitis in Children

PURPOSE: We reviewed the distribution of lesion and the characteristics of the MR findings of acute disseminated encephalomyelitis (ADEM) in children. We evaluated the differences in the imaging findings and the clinical outcomes between the patients with deep gray matter involvement and the patients without deep gray matter involvement. MATERIALS AND METHODS: We retrospectively reviewed the 62 MR examinations of 21 patients who were discharged with the clinical diagnosis of ADEM. The patients were aged from 13 months to 12 years old (mean age: 4.5 years). Follow-up MR examinations were done one to 5 times (mean: 3 times) for 2 weeks to 4 years (mean: 3 months) after the initial examination. We compared the signal intensity on T2WI, the enhancement and residue on the MR images and the clinical outcomes between the patients with deep gray matter involvement and the patients without deep gray matter involvement. RESULTS: A total of 21 patients had white matter abnormalities on their initial MR. Fifteen patients (71%) had foci of increased signal intensity on T2WI in the deep gray matter: thalamus (n=15), globus pallidus (n=14) and putamen (n=10). On the follow-up images, all patients showed decreased signal intensity and enhancement of their lesion. We could not find the significant differences in signal intensity, enhancement and residue on the MRIs and also the clinical outcomes between the patients with deep gray matter involvement and the patients without deep gray matter involvement (<.05). CONCLUSION: There were no significant differences in the characteristics of the imaging and the clinical outcomes between the ADEM patients with deep gray matter involvement and those ADEM patients without deep gray matter involvement.

Differentiation of Hyperplastic from Metastatic Lymph Nodes Using a Lymph Node Specific MR Contrast Agent Gadofluorine M

PURPOSE: We wanted to evaluate the value of a lymph node specific MR contrast agent, Gadofluorine M, for the differentiation of hyperplastic and metastatic lymph nodes. MATERIALS AND METHODS: This study included thirty-one rabbits. In ten rabbits, an injection of egg yolk or feces of rat into the calf muscles induced hyperplasia of the lymph node. In sixteen rabbits, metastasis of the lymph node was induced by implantation of VX2 tumor. Five rabbits were normal control models. We acquired the T1-, T2-weighted and SPGR coronal imaging before enhancement with 1.5 T MR. After injection of Gadofluorine M (5 micromol/mL, total amount: 4 mL) interstitially into the interdigital skin fold of the hind limb, we acquired the SPGR coronal imaging at 15, 30, 60 and 90 minutes. We calculated the signal-to-noise ratios on the sequential images, and we recorded the number, size and location of the popliteal and iliac lymph nodes. Three readers assessed the state of the lymph nodes according to the pattern of enhancement: they were deemed hyperplastic nodes when totally enhanced and as metastatic nodes when there was no or partial enhancement. We also compared the imaging patterns with the histopathological results. RESULTS: Among the 26 hyperplasia- or metastasis-induced rabbits, two rabbits were excluded because of failure to be enhanced. Histopathologic evaluation of the 24 rabbits detected one hundred seventeen lymph nodes: forty-six lymph nodes in nine hyperplasia-induced rabbits and seventy-one (metastasis in twenty-eight) lymph nodes in fifteen metastasis-induced rabbits. Out of one hundred two lymph nodes that were larger than 5 mm in size, MR enabled us to detect one hundred one lymph nodes (99.1%). The means of sensitivity, specificity, and the positive and negative predictive values for the diagnosis of lymph node metastasis by three readers were 97.6% (82/84), 98.2% (215/219), 95.3% (82/86), and 99.1% (215/217), respectively (p < 0.05). CONCLUSION: Interstitial MR lymphography using Gadofluorine M showed excellent results in differentiating hyperplastic from metastatic lymph nodes.

Metanephric Adenoma of the Kidney in an Infant: A Case Report

Metanephric adenoma is a rare tumor of the kidney that has been reported mostly in adults. Despite its rarity, metanephric adenoma should be included in any differential diagnosis of solid renal masses in children, especially because of its benign nature and benign clinical course allowing for nephron sparing surgery. We report a case of metanephric adenoma, presented as a solid renal mass in a 14-month-old boy, and discuss the histologic basis of the imaging features of this entity.

Evaluation of the Intraspinal Enhancement for Medulloblastoma on MR Imaging

PURPOSE: The purpose of this study was to analyze the enhancement pattern of the spinal cord for patients with medulloblastoma, and to correlate the enhancement pattern with cerebrospinal fluid (CSF) tumor seeding. MATERIALS AND METHODS: We retrospectively reviewed 84 MR images, including the initial and follow-up studies after chemotherapy or radiation therapy, of 25 patients with medulloblastoma who were aged from 2 to 13 years. We analyzed the spinal leptomeningeal enhancement pattern on the MR images. The leptomeningeal enhancement patterns were categorized into three types: Type I, fine or discontinuous linear enhancement, and type II, continuous linear or nodular enhancement, and type III, intradural mass formation. We correlated the enhancement pattern on MRI with the results of CSF cytology at the initial and follow - up examinations after treatment. RESULTS: Of total 25 patients, type I enhancement was observed for 14 patients. Twelve patients were negative on the initial CSF cytology and 2 patients were positive. On the follow-up MR studies, 14 patients showed no change or only a slight decrease of enhancement, and all were negative on the follow-up CSF cytology. Type II enhancement patterns were observed in seven patients, and all of them were positive on the initial CSF cytology. On follow-up MR study, one patient revealed an increased enhancement with the positive result on the follow-up CSF cytology, and six patients had decreased enhancement on the follow-up MR studies with negative conversion on the follow-up CSF cytology. Type III enhancement patterns were observed in four patients and all of them were positive on the initial CSF cytology. All four patients with intradural mass formations revealed progression of the lesions on follow-up MR studies, and all of them were positive on the follow-up CSF cytology. CONCLUSION: Type II and III enhancement patterns always represented CSF seeding and a type I enhancement pattern had a low probability of metastasis.

Small Airway Disease after Mycoplasma Pneumonia in Children: HRCT Findings and Correlation with Radiographic Findings

PURPOSE: To assess the high-resolution CT (HRCT) findings of small airway abnormalities after mycoplasma pneumonia and correlate them with the findings of chest radiography performed during the acute and follow-up phases of the condition. MATERIALS AND METHODS: We retrospectively evaluated HRCT and chest radiographic findings of 18 patients with clinical diagnosis of small airway disease after mycoplasma pneumonia (M:F=8:10, mean age: 8.3 years, mean time interval after the initial infection; 26 months). We evaluated the lung parenchymal and bronchial abnormalities on HRCT (n=18). In addition, presence of air-trapping was assessed on expiratory scans (n=13). The findings of HRCT were correlated with those of chest radiography performed during the acute phase of initial infection (n=15) and at the time of CT examination (n=18), respectively. RESULTS: HRCT revealed lung parenchymal abnormalities in 13 patients (72%). A mosaic pattern of lung attenuation was noted in ten patients (10/18, 56%), and air-trapping on expiratory scans was observed in nine (9/13, 69%). In nine of 14 (64%) with negative findings at follow-up chest radiography, one or both of the above parenchymal abnormalities was observed at HRCT. In four patients (27%), parenchymal abnormalities were seen at HRCT in areas considered normal at acute-phase chest radiography. Bronchiectasis or ateclectasis was observed in eight (44%) and four (22%) patients, respectively, at HRCT. The CT features of Swyer-James syndrome such as a unilateral hyperlucent lung with reduced lung volume and attenuated vessels were noted in two patients (11%). CONCLUSION: HRCT can clearly demonstrate lung parenchymal and bronchial abnormalities of small airway disease after mycoplasma pneumonia in children.

Clinical Image Evaluation of Mammograms: A National Survey

PURPOSE: The goal of this study was to survey the overall quality of mammographic images in Korea. MATERIALS AND METHODS: A total of 598 mammographic images collected from 257 hospitals nationwide were reviewed in terms of eight image quality categories, namely positioning, compression, contrast, exposure, sharpness, noise, artifacts, and examination identification, and rated on a five-point scale: (1=severe deficiency, 2=major deficiency, 3=minor deficiency, 4=good, 5=best). Failure was defined as the occurrence of more than four major deficiencies or one severe deficiency (score of 1 or 2). The results were compared among hospitals of varying kinds, and common problems in clinical image quality were identified. RESULTS: Two hundred and seventeen mammographic images (36.3%) failed the evaluation. Poor images were found in descending order of frequency, at The Society for Medical Examination (33/69, 47.8%), non-radiology clinics (42/88, 47.7%), general hospitals (92/216, 42.6%), radiology clinics (39/102, 38.2%), and university hospitals (11/123, 8.9%) (p<0.01, Chi-square test). Among the 598 images, serious problems which occurred were related to positioning in 23.7% of instances (n=142) (p<0.01, Chi-square test), examination identification in 5.7% (n=34), exposure in 5.4% (n=32), contrast in 4.2% (n=25), sharpness in 2.7% (n=16), compression in 2.5% (n=15), artifacts in 2.5% (n=15), and noise in 0.3% (n=2). CONCLUSION: This study showed that in Korea, 36.3% of the mammograms examined in this sampling had important image-related defects that might have led to serious errors in patient management. The failure rate was significantly higher in non-radiology clinics and at The Society for Medical Examination than at university hospitals.

Radiological Findings after Endoscopic Incision of Ureterocele

PURPOSE: Endoscopic incision of ureterocele is considered a simple and safe method for decompression of urinary tract obstruction above ureterocele. The purpose of this study was to evaluate the radiological findings after endoscopic incision of ureterocele. MATERIALS AND METHODS: We retrospectively reviewed the radiological findings ultrasonography (US), intravenous urography, and voiding cystourethrography(VCU)] in 16 patients with ureterocele who underwent endoscopic incision (mean age at surgery, 15 months; M: F=3:13; 18 ureteroceles). According to the postoperative results, treatment was classified as successful when urinary tract obstruction improved without additional treatment, partially successful when medical treatment was still required, and second operation when additional surgical treatment was required. RESULTS: Postoperative US (n=10) showed that in all patients, urinary tract obstruction was relieved: the kidney parenchyma was thicker and the ureterocele was smaller. Intravenous urography (n=8), demonstrated that in all patients, urinary tract obstruction and the excretory function of the kidney had improved. Postoperative VCU indicated that in 92% of patients (12 of 13), endoscopic incision of the ureterocele led to vesicoureteral reflux(VUR). Of these twelve, seven (58%) showed VUR of more than grade 3, while newly developed VUR was seen in five of eight patients (63%) who had preoperative VCU. Surgery was successful in four patients (25%), partially successful in three (19%), and a second operation-on account of recurrent urinary tract infection and VUR of more than grade 3 during the follow-up period was required by nine (56%). CONCLUSION: Although endoscopic incision of a ureterocele is a useful way of relieving urinary tract obstruction, an ensuing complication may be VUR. Postoperative US and intravenous urography should be used to evaluate parenchymal change in the kidney and improvement of urinary tract obstruction, while to assess the extent of VUR during the follow-up period, postoperative VCU is required.

Usefulness of Non-ionic, Low Osmolar Contrast Agent (Reyon Iopamidol(R) 300 and Iversion(R) 320) for IVU (Intravenous Urography),Angiography and CT: An Experimental Study in Normal Rabbits

PURPOSE: To compare the diagnostic efficacy of domestically synthesized contrast materials (Reyon Iopamidol(R) 300 and Iversion(R) 320) used for IVU, CT, and abdominal angiography in normal rabbits with that of previously used products (Ultravist(R) 300 and Optiray(R) 320). MATERIALS AND METHODS: A total of 60 rabbits were divided into six groups of ten. In the first group, IVU was performed using Reyon Iopamidol(R) 300 and Ultravist(R) 300, while in the second, abdominal angiography involved the use of Iversion(R) 320 and Optiray(R) 320. For three-phase spiral CT, Reyon Iopamidol(R) 300 was used for group 3, Ultravist(R) 300 for group 4, Iversion(R) 320 for group 5, and Optiray(R) 320 for group 6. The degree of contrast enhancement seen on aortography and IVU was evaluated subjectively by two radiologists who reached a consensus while unaware of the names of the contrast materials. On CT, attenuation expressed in Hounsfield Units(HU) was measured using the regions of interest (ROIs) facility in each anatomic region during the early and delayed phases. Adverse events including death occurred during the investigation. RESULTS: There were no significant differences in the degree of contrast enhancement between Reyon Iopamidol(R) 300 and Ultravist(R) 300, as used for IVU, and between Iversion(R) 320 and Optiray(R) 320, as used for angiography. With two exceptions, abdominal CT revealed no significant differences in the degree of contrast enhancement of most anatomic structure. The exceptions were greater enhancement of the portal vein with Ultravist(R) 300 than with Reyon Iopamidol(R) 300 during the delayed phase, and greater enhancement of the aorta with Optiray(R) 320 than with Iversion(R) 320 during the delayed phase. In no rabbit was adverse reaction observed. CONCLUSION: For IVU, angiography and abdominal CT in normal rabbits, Reyon Iopamidol(R) 300 and Iversion(R) 320 provide contrast enhancement comparable to that provided by Ultravist(R) 300 and Optiray(R) 320. In order to evaluate the diagnostic efficacy of these new agents in diseased tissue and in human subjects, further studies are needed.

Olfactory neuroblastoma: CT and MR Findings

PURPOSE: The purpose of our study was to determine the CT and MR imaging features of olfactory neuroblastomas in 15 patients. MATERIALS AND METHODS: Fifteen patients with pathologically proven sinonasal olfactory neuroblastomas were included in this study. MRI was performed in 12 cases, and CT in 11, while eight patients underwent both MRI and CT. Features analyzed included the extent of the tumor at the time of presentation, its size and enhancement pattern, erosion or destruction of bony structures adjacent to the tumor, and intratumoral cystic areas. Metastasis to regional lymph nodes of head and neck area was also evaluated. RESULTS: In all patients, the epicenter of primary tumor was the superior nasal cavity or ethmoid sinuses. In 14 patients, the wall of the nasal cavity including the lamina papyracea was involved, while in 13 there was invo l vement of the cribriform plate. Intracranial tumor extension was demonstrated in nine patients, and intracranial frank mass formation in four. On MR, eight of 12 masses showed low signal intensity on T1-weighted images, while in 11 cases, T2-weighted images revealed iso- or high intensity. In 11 patients, the tumor showed a prominent enhancement pattern on post-contrast enhanced images, while CT scans showed tumor enhancement in all 12 patients. CONCLUSION: Olfactory neuroblastomas generally invade the paranasal sinuses and or-bit,and are at Kadish stage B or C at the time at which symptoms suggest the need for a hospital visit. Intracranial tumor extension of the tumor is frequent, but mass formation large enough to be detected radiologically is seen in less than half of all cases.

Hepatocellular Carcinoma with Bile Duct Involvement: Computed Tomographic (CT) Findings

PURPOSE: To describe the radiologic features of computed tomography(CT) in hepatocelluar carcinoma(HCC) with bile duct involvement. MATERIALS AND METHODS: We retrospectively analyzed the two phase spiral CT findings of 31 patients in whom HCC with bile duct invasion (n=28) or compression (n=3), was diagnosed. Eight of these underwent follow-up CT after transarterial chemoembolization. We analyzed the size, type, location, enhancement pattern, and lipiodol retention of parenchymal and intraductal masses, as well as their and lymphadenopathy. RESULTS: In all patients with bile duct invasion, single or multiple masses were demonstrated in the bile ducts. Intraductal masses showed the same enhancement characteristics as the parenchymal mass (kappa 0.550, p < .001), and were contiguous to this mass. In 14 of 28 patients, intraductal masses filled the peripheral intrahepatic bile ducts and extended to the common bile ducts. In the other 14, the parenchymal mass extended to the area of the porta hepatis and then directly invaded the large ducts. In nine of the 28 patients, there was a hypoattenuated cleft between the intraductal mass and ductal wall. In six, a parenchymal mass was not apparent (n = 2), or was smaller than 2cm (n = 4). In five of eight patients (62.5%), follow-up CT after transarterial chemoembolization showed compact or partial lipiodol retention within the intraductal mass. In patients with bile duct compression, perihilar lymph nodes were noted along with the dilated intrahepatic duct but no intraductal mass was demonstrated in the duct. CONCLUSION: Hepatocellular carcinomas cause bile duct dilatation either by direct invasion or by extrinsic compression of the bile duct with surrounding enlarged nodes. For the diagnosis of this condition, CT is helpful.

MR Imaging of Growth Plate Injury in Rabbit: Development of Bony Bridge and Pathologic Correlation

PURPOSE: To evaluate the MR findings of a development of bony bridge within tunnels drilled across growth plates after injury in immature rabbits, and to correlate the MR and pathological findings. MATERIALS AND METHODS: In 19 young rabbits, a growth-plate injury model was constructed in the distal femur by longitudinal drilling with a 5-mm drill. Coronal scans with T1-weighted, T2-weighted fast spin-echo, gradient echo, and gadolinium enhanced T1-weighted sequences were obtained immediately, and at 1, 2, 3, and 4 weeks, and 3, 6 months, postoperatively. Each group underwent pathologic examination, and the signal intensity, shape, and enhancement pattern of the drill holes were assessed. All results were correlated with pathologic findings. RESULTS: During the early period, the signal intensity of the defect site varied due to hemorrhage and inflammatory reaction in the lesion, becoming isointense to that of metaphyseal marrow on all sequences during the late period (3 and 6 months). Pathologically, it corresponded to replacement of the osseous bridge with fatty marrow. The new bone formation shown by pathologic examination to be present in the periphery of the defect during the first week corresponded to the vertical dark rim seen on MR images. It appeared during that week and became more distinct, thickening gradually until the fourth week. Enhancement was absent or faint on follow-up immediately after surgery, inhomogenous and seen in half the rabbits at week 1, and maximal and homogenous at weeks 2 and 3. In had decreased by week 4, and was absent at months 3 and 6. These findings corresponded to the changes in transphyseal vascularity across the drill hole revealed by pathologic examination. CONCLUSION: The contrast enhancement demonstrated by defective growth plate may indicate the development of vascularity throughout the plate, a phenomenon which precedes the formation of a bony bridge after trauma.

Disseminated BCG Infection in a patient with Severe Combined Immunodeficiency

Disseminated mycobacterial infection after bacillus Calmette-Guerin (BCG)vaccination is a very rare disorder, occurring mostly in patients with immunologic deficiency. We report a case of disseminated BCG infection in a 16-month-old girl with severe combined immunodeficiency. Plain radiographs showed multiple osteolytic lesions in the femora, tibiae, humerus, and phalanges. Abdominal sonography and CT scanning revealed multiple nodules in the spleen, and porto-caval lymphadenopathy.

Disseminated BCG Infection in a patient with Severe Combined Immunodeficiency

Disseminated mycobacterial infection after bacillus Calmette-Guerin (BCG)vaccination is a very rare disorder, occurring mostly in patients with immunologic deficiency. We report a case of disseminated BCG infection in a 16-month-old girl with severe combined immunodeficiency. Plain radiographs showed multiple osteolytic lesions in the femora, tibiae, humerus, and phalanges. Abdominal sonography and CT scanning revealed multiple nodules in the spleen, and porto-caval lymphadenopathy.