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Genetic skeletal disorders comprise two broad categories, including skeletal dysplasia and dysostosis. Skeletal Please check if edit to sentence starting “Skeletal dysplasia refers…” is okay. dysplasia refers to a heterogeneous group of conditions in which there is a widespread disturbance of bone and cartilage growth, beginning during the early stages of fetal development and evolving throughout life, while dysostoses comprise conditions that occur as a result of embryonic morphogenic defects and individual bones are affected singly or in combination. Despite Please check if edit to sentence starting “Despite recent advances…” is okay. recent advances in imaging, genetic skeletal disorders are difficult to diagnose due to a number of factors, including the large number of genetic skeletal disorders and their phenotypic variability with overlapping features, lack of precise molecular diagnosis for many disorders, and lack of a systematic approach. It is important to realize that a radiological diagnosis of genetic skeletal disorder depends on an overall pattern of skeletal abnormalities rather than a single radiological sign, alone or in combination, and to make good use of diagnostic information from representatives of other disciplines, including clinicians, molecular biologists, and pathologists.

To review imaging features of fibrous hamartoma of infancy (FHI), focusing on ultrasonography (US) findings. We retrospectively reviewed pediatric patients who were diagnosed with pathologically confirmed FHI in two children’s hospitals from 2004 to 2013. Imaging features of US, Doppler US, and magnetic resonance imaging (MRI) were evaluated. Thirteen pediatric patients (M:F = 7:6; age 5–22 months, mean 11.3 months) were included. Mean lesion size was 3.2 cm (range, 0.7–8.0 cm). The tumors were located in the back (n = 4), scrotum (n = 2), scalp, shoulder, axilla, forearm, intergluteal cleft, inguinal area, and thigh. US was performed in 11 patients. With the exception of two scrotal masses, all masses were located in the dermal and subcutaneous layer. All masses demonstrated heterogeneous hyperechogenicity with a “serpentine pattern” of intervening hypoechoic portions in the hyperechoic mass. The margins were ill-defined (n = 9) or lobulated (n = 2). Doppler US was performed in nine patients and showed no (n = 6) or minimal (n = 3) vascularity. MRI was performed in five patients and the masses showed heterogeneous signal intensity with the presence of fat on T1- and T2-weighted images. FHI is a tumor that is typically located in the dermal and subcutaneous layer in young children less than 2 years old and presents as a heterogeneously hyperechoic mass with a “serpentine pattern” and ill-defined or lobulated margin on US and no remarkable vascularity on Doppler US.

Background: Preterm birth is known to be associated with risks of impaired nephrogenesis. Objectives: To determine the normal range of renal sizes at birth in preterm infants as well as their short-term postnatal renal growth, to assess the correlation between initial renal size and growth parameters at birth and to compare the initial and serial renal sizes between appropriate-for-gestational-age (AGA) and small-for-gestational-age (SGA) preterm infants. Methods: Initial ultrasonography (US) was prospectively performed in 125 preterm infants within the first 72 h of life and every 2 weeks thereafter until a postmenstrual age (PMA) of 37 weeks was reached. Correlation between renal size and growth parameters was investigated. Renal lengths of AGA and SGA preterm infants were compared with those of age-matched fetuses described in the literature. Results: The renal sizes at birth in preterm infants are presented. Multiple regression analysis showed the strongest correlation between initial renal size and birth weight (p < 0.0001). Initial renal lengths of AGA infants were not significantly different from those of age-matched fetuses at ≥30 weeks' gestational age (GA), whereas those of SGA infants were significantly smaller at ≥28 weeks' GA. Serial renal lengths of SGA infants were significantly smaller than fetal renal lengths at ≥30 weeks' GA. Conclusion: With US, the normal range of initial renal sizes of AGA preterm infants was defined according to GA. In contrast to AGA infants, SGA infants showed smaller initial renal sizes and no significant catch-up growth until a PMA of 37 weeks.

Many females who are heterozygous for ornithine carbamoyltransferase (OTC) deficiency are asymptomatic or intermittently symptomatic with great phenotypic variability. Therefore, the diagnosis of this condition is occasionally a challenge and is often delayed. A 12-year-old girl who was initially diagnosed as having attention deficit-hyperactivity disorder (ADHD) became comatose and developed right-sided hemiparesis during her psychiatric admission. Brain magnetic resonance imaging indicated diffuse but extensive swelling in the left hemisphere with multiple lesions suggestive of an old infarction. Repeated evaluations revealed hyperammonemia and orotic aciduria, and she was diagnosed as having an OTC deficiency. Genetic analysis revealed a heterozygous mutation of N47I in the X-linked OTC gene. Her mental status and hemiparesis improved after hyperammonemia treatment. Here, we report a rare case of a manifestating female carrier with severe symptoms of OTC deficiency masquerading as ADHD.

Alveolar soft part sarcoma (ASPS), a rare soft tissue malignant neoplasm, frequently metastasizes to the brain. However, primary intracranial ASPS is extremely rare. We present a case of primary intracranial ASPS arising from the cerebellopontine angle (CPA) without demonstrable systemic lesions.An 11-year-old girl presented with a recurrent tumor in the right CPA after a partial resection and radiation therapy (RT). Near-total resection with a minimal tumor left in the jugular foramen was performed. The pathological diagnosis was ASPS. There was no evidence of primary extracranial tumors. She underwent adjuvant chemotherapy and gamma knife surgery. At 29 months after the second surgery, magnetic resonance imaging revealed multifocal enhancing lesions at the prepontine cistern, right CPA and medulla oblongata, despite intensive treatment. However, extracranial metastasis was not noted. This case suggested a poor outcome of primary intracranial ASPS, similar to extracranial ASPS.

We describe a case of a large intra-articular ossifying mass of the ankle joint in a 12-year-old boy who sustained a severe ankle twisting injury at 6 years of age. The mass is presumed to be the result of secondary synovial osteochondromatosis originated from a fractured osteochondral fragment of the medial tubercle of the posterior process of the talus. The mass could be differentiated from os trigonum syndrome, Trevor disease and primary synovial osteochondromatosis based on its location, size and radiologic and histological features.

We present the case of a 9-year-old boy with a non-germinomatous germ cell tumor (NGGCT) in the pineal gland that exhibited a fulminant course following chemo- and radiotherapy. After the detection of the tiny cerebellar enhancing nodule at the end of chemo- and radiotherapy, tumor seeding progressed rapidly into the entire cisternal space. We herein report a rare case of NGGCT with fulminant clinical course of concomitant cerebellar seeding, with review of literature.

Intracranial germ cell tumors (GCTs) frequently take an insidious clinical course before diagnosis. To date, clinical latency has been discussed in the context of germinoma in the suprasellar area and basal ganglia.In this study, we classified the clinical latency of intracranial GCTs into three categories and described their characteristics in order to understand the full spectrum of the phenomenon.In a cohort of 181 patients with intracranial GCTs, 17 patients had a delayed diagnosis of more than 3 months (90 days) from the initial brain magnetic resonance imaging to the definitive GCT diagnosis. Clinical records and radiological data of the patients were reviewed.The patients with a delayed diagnosis were categorized into three groups according to their tumor location: suprasellar (nine patients), basal ganglia (six patients), and pineal (two patients). Initial symptomatology corresponded with the tumor location: central diabetes insipidus for the suprasellar group, hemiparesis for the basal ganglia group, and precocious puberty for the pineal group. The overall survival of patients with germinoma and delayed diagnosis was significantly shorter than that of patients who were diagnosed within 3 months (P = 0.002).Clinical latency and delayed diagnosis are not restricted to germinomas in the suprasellar area and basal ganglia; they are canonical features of intracranial GCTs including pineal non-germinomatous GCTs. Early detection and proactive diagnosis of these tumors are required because diagnosis delay may negatively influence patient survival.

Infantile myofibromatosis, a rare mesenchymal disorder that develops in early childhood, is classified by the number of lesions that occur: solitary or multicentric. Involvement of the CNS is unusual in either type. Infantile myofibromatosis in the spine is exceptional, and most published cases represent a secondary invasion. Here, the authors report on an 8-month-old girl presenting with weakness below the ankle and an intraspinal mass extending from T-6 to the conus. The patient underwent only partial surgical removal of the lesion, and the pathology was confirmed as infantile myofibromatosis. After the operation, weakness in the lower extremities gradually improved; however, she could not walk at the time of the final follow-up. On follow-up MRI performed 19 months after the operation, the residual lesion remained unchanged with decreased enhancement.

Routine immediate postoperative brain CT (RIPO CT) has advantages and disadvantages. The present study was performed to know the extent of gain by RIPO CT in the aspect of immediate postoperative patient care in pediatric patient population and according to the disease entity and surgical procedure. We reviewed 910 cases of pediatric brain surgery performed from January 2008 to March 2010 who had RIPO CT. The value of each examination was graded according to the impact of the CT findings on the decision making processes on postoperative patient care or on the understanding of postoperative patient’s status: level I (urgent surgical procedures are necessary), level II (high level of attention should be paid because of possible urgent surgical procedure in near future), level III (RIPO CT is useful for understanding of postoperative change of patient’s status), and level IV (no significant gain). The number of patients in each level was evaluated, and proportions of levels according to disease entity and surgical procedure were compared. In total, the proportion of each level of I to IV was 0.4%, 4.9%, 3.5%, and 91.2%, respectively. The group of brain tumors, especially those who have malignant or highly vascular tumors, showed significantly higher value of RIPO CT. Cases of traumatic epidural hematoma and intracerebral hemorrhage revealed significantly high proportion of level II although no case underwent reoperation. The results of present study may be useful for making policy of “selective” application of immediate postoperative brain CT according to the patient conditions. Also the use of immediate postoperative brain CT can be decided in individual cases by considering disease entity and surgical procedure.

Clinical features, images, complications, treatments, and prognosis of 10 children with congenital portosystemic shunt (CPSS) were reviewed. Nine children were diagnosed with intrahepatic shunts while one presented with extrahepatic shunt. CPSS was detected by prenatal ultrasonography in four infants. Three infants presented with galactosemia without an enzyme deficiency. Two children presented with mental retardation and attention deficit hyperactivity disorder. Pulmonary hypertension developed in two patients. Spontaneous closure occurred in four infants with intrahepatic shunts including patent ductus venosus. The shunts were closed using transcatheter embolizations in four patients with intrahepatic shunts. Conclusion: Intrahepatic shunts may close spontaneously. Transcatheter embolization is effective for the treatment of symptomatic intrahepatic shunts.

Sinus pericranii is a rare venous anomaly, which shows abnormal communication between the intracranial and extracranial venous systems. Sonograms of sinus pericranii in 4 children were retrospectively reviewed to evaluate the following imaging findings: the overall sonographic appearance, change in size and shape, Doppler flow pattern, and associated anomalies. All 4 patients had irregularly shaped anechoic lesions with lobulating and bulging contours. They all showed intracranial and extracranial venous communication through a calvarial defect. Two patients had changes in the sizes and shapes of the lesions, and 2 patients had bidirectional turbulent flow on Doppler images. Two patients had isolated sinus pericranii, and the other 2 were associated with Crouzon syndrome. By identifying a venous scalp mass with intracranial and extracranial venous communication and changes in its size, shape, and venous flow pattern, radiologists will be able to make a definitive diagnosis of sinus pericranii by using gray scale and Doppler sonography.

Background: Compressive force across the growth plate may cause retardation and even arrest of physeal growth. The purpose of this study was to investigate histologic changes, metabolic changes in terms of glycosaminoglycan (GAG) concentration, and contrast-enhanced micro-computed tomography (CEMCT) fi ndings of physeal cartilage in a rabbit model of physeal damage caused by excessive compression. Methods: Compressive forces were applied via external fi xators for two weeks to the growth plates of distal femurs and proximal tibiae of right hind-legs in 8-week-old rabbits. Left hind-legs remained intact and were used as controls. Forty-four bone specimens containing growth plates of distal femurs or proximal tibiae were harvested one week (n = 12) and four weeks (n = 32) after surgery, and examined for histologic fi ndings (H&E staining) and GAGs quantifi cation in physeal cartilage. After incubation in an ionic contrast material for 48 hours, specimens were scanned by CEMCT, and the pixel values of physeal cartilage were measured. Results: CEMCT showed a thin, highly attenuated line parallel to the growth plate in compressed specimens harvested at four weeks after surgery, which was found to be transversely connected trabecular bone. In these specimens, GAG content in physeal cartilage was signifi cantly lower, and CEMCT pixel values of physeal cartilage were signifi cantly higher than in the specimens from the contralateral control side. Conclusions: Excessive compressive force applied to growth plates produces altered histologic features and metabolic function in terms of decreased GAG content in physeal cartilage, changes that can be demonstrated by CEMCT.

Purpose To determine whether meniscal deformation and displacement on magnetic resonance imaging (MRI) are associated with tears by use of arthroscopic findings as a standard of reference in children with discoid lateral meniscus (DLM). Methods We reviewed MRI scans and intraoperative videos of 69 consecutive patients (79 knees) treated arthroscopically for suspicious DLM tears. The mean age at surgery was 10.9 years (range, 4.3 to 17.6 years). Signal changes and morphologic changes (deformation or displacement) of DLM on magnetic resonance (MR) images were graded by 2 independent observers using our modifications of previously described classification schemes, and then the grades were determined by consensus of the observers. Meniscal tears were assessed by an observer, blinded to the MRI studies, based on arthroscopic findings. Signal changes and morphologic changes of DLM on MR images were correlated with tears. Results Tears were found more frequently in menisci showing morphologic changes on MR images ( P = .001). Of the 25 menisci with a grade 3 signal change (linear or band-like signal intensity extending to the superior or inferior meniscal surface), 24 had tears, and a horizontal cleavage was the most commonly associated tear type. Of the 50 menisci with a grade 1 (dot-like intrameniscal signal change), grade 2 (linear or band-like intrameniscal signal change), or diffuse signal change, 34 were morphologically changed on MR images, and 29 of these (85%) were torn, whereas 9 of the 16 menisci (56%) not morphologically changed were torn ( P = .036). Conclusions Preoperative MRI evaluations based on signal intensities do not accurately predict the presence of a DLM tear in children, except when a DLM shows a grade 3 signal change. Meniscal deformation or displacement observed on preoperative MR images suggests a higher risk of meniscal tears, even in menisci with signal changes other than grade 3 changes. Level of Evidence Level IV, therapeutic case series.

Purpose The aim of the present study was to describe the gadolinium-enhanced magnetic resonance imaging (MRI) features of temporomandibular joints (TMJs) in children with arthritis. These findings would facilitate the early diagnosis of disease and/or relapse. Materials and Methods In the present retrospective study, 2 pediatric radiologists reviewed consecutive MRI scans of the TMJs of children with a definitive diagnosis of juvenile idiopathic arthritis (JIA), including oligoarthritis, polyarthritis, and juvenile psoriatic arthritis. For each MRI scan, specific criteria were evaluated, including the condylar head, condylar fossa, articular eminence, disk shape and position, joint effusion, synovium, intra-articular space, and jaw motion. Results A total of 48 patients with mean age of 11.2 years who had been diagnosed with JIA were reviewed. The most common abnormal findings (in order of frequency) were erosion of the condylar head (n = 38), synovial enhancement (n = 35), articular surface flattening (n = 20), abnormalities in jaw motion (n = 26), intra-articular space enhancement (n = 20), subchondral sclerosis of articular eminence (n = 12), joint effusion (n = 9), deformed/displaced disk in the open or closed position (n = 9), bone marrow edema (n = 8), sclerosis of fossa (n = 3), sclerosis of head (n = 3), and the presence of osteophytes (n = 1). Comparing each category of MRI findings, no significant gender differences were found. Conclusions Children with JIA who have undergone MRI of their TMJs typically present with more than 1 abnormal radiographic finding consistent with synovitis. Although the presence or absence of each MRI finding did not differ among the arthritis types, bilateral synovial enhancement and bilateral condylar head articular surface flattening were more common in JIA than in juvenile psoriatic arthritis. These findings suggest that MRI should play an important role in the diagnosis and assessment of TMJ involvement in children with JIA.

Synovium is the thin membranous lining of a joint. It produces synovial fluid, which lubricates and nourishes the cartilage and bone in the joint capsule. Synovial diseases in children can be classified as normal structures as potential sources of pathology (synovial folds: plicae, infrapatellar fat pad clefts), noninfectious synovial proliferation (juvenile idiopathic arthritis, hemophilic arthropathy, lipoma arborescens, synovial osteochondromatosis, pigmented villonodular synovitis, reactive synovitis), infectious synovial proliferation (pyogenic arthritis, tuberculous arthritis), deposition disease (gouty arthropathy), vascular malformation, malignancy (metastasis) and intra-/periarticular cysts and cyst-like structures. Other intra-articular neoplasms, such as intra-articular synovial sarcoma, can mimic synovial disease in children.

To compare the clinical and imaging features of posttransplantation lymphoproliferative disorder (PTLD) in pediatric patients who underwent hematopoietic cell transplantation with those in pediatric patients who underwent liver transplantation.This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The authors retrospectively reviewed the medical records and images of 552 hematopoietic cell transplant recipients and 195 liver transplant recipients. PTLD was histopathologically confirmed in 17 of the patients who underwent hematopoietic cell transplantation and 27 of the patients who underwent liver transplantation. The overall frequency, clinical course, histopathologic type, and imaging findings of PTLD were compared between the two patient groups by using the Fisher exact test.The overall frequency of PTLD was 3% (17 of 552 patients) after hematopoietic cell transplantation (12% [nine of 75 patients] after umbilical cord blood transplantation) and 14% (27 of 194 patients) after liver transplantation. PTLD occurred within 6 months of transplantation in 14 of the 17 hematopoietic cell recipients (82%) and 11 of the 27 liver recipients (41%) (P = .012). Histopathologic examination revealed monomorphic disease in 11 of the 17 hematopoietic cell recipients (65%) and eight of the 27 liver recipients (30%) (P = .031). The abdomen was the most common site of involvement in both groups. Extraabdominal PTLD developed in 12 of the 17 hematopoietic cell recipients (71%) and five of the 27 liver recipients (19%) (P = .002). Although 15 of the 17 patients with hematopoietic cell transplantation-related PTLD (88%) exhibited responses after treatment, the overall mortality rate was 35% (six of 17 patients). All 27 patients with PTLD after liver transplantation improved after treatment and remain alive.PTLD after umbilical cord blood transplantation occurred as frequently as liver transplantation-related PTLD. Compared with liver transplantation-related PTLD, PTLD after hematopoietic cell transplantation is characterized by an earlier onset, a higher proportion of malignant monomorphic disease, and a worse outcome.

Legg-Calvé-Perthes disease (LCP) is thought to be associated with ischemic events in the femoral head. However, the types and patterns of reperfusion after these ischemic events are unclear.We therefore determined whether (1) there would be any age-related diffusion changes; (2) diffusion-weighted MR imaging would reveal ischemic damage; and (3) diffusion changes are correlated with prognostic MR findings in patients with LCP.We prospectively performed conventional, perfusion, and diffusion-weighted MR imaging studies in 17 children with unilateral LCP. We then measured the apparent diffusion coefficient (ADC) values in the epiphysis and the metaphysis, and compared them with those of the contralateral normal side. Based on perfusion MR imaging, we assessed reperfusion to the epiphysis as either periphyseal or transphyseal. We studied T2-signal intensity changes in the metaphysis and the presence of focal physeal irregularity. We correlated diffusion changes with reperfusion to the epiphysis, T2-signal intensity change, and focal physeal irregularity.Normal diffusion decreased with age. In LCP hips, epiphyseal diffusion increased early and remained elevated through the healing stage. Six of the 17 patients who had a metaphyseal ADC greater than 50% over the normal side had 13 times greater odds of having an association with transphyseal reperfusion to the epiphysis. The increase of metaphyseal ADC also was associated with an increased T2-signal intensity in the metaphysis and presence of focal physeal irregularity.Diffusion-weighted MR imaging can be used as a complimentary modality to evaluate ischemic tissue damage with a potential prognostic value in patients with LCP.

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.

Objective The purpose of this study was to examine the clinical applicability of Doppler sonography by evaluating Doppler sonographic findings in an experimental rabbit model of necrotizing enterocolitis (NEC). Methods Necrotizing enterocolitis was experimentally induced using a combination of endotoxin, hypoxia, and cold stress in 23 rabbits. Doppler sonography was performed to obtain the Doppler spectrum of the superior mesenteric artery. From the flow profile, the peak systolic velocity (PSV) and resistive index (RI) were calculated at 5 time sessions: initial and 1 to 2, 3 to 4, 5 to 6, and 20 to 24 hours. Animals were divided into 2 groups based on pathologic NEC scores (NEC-positive [NEC+] group versus NEC-negative [NEC-] group). Differences between the groups with regard to RI and PSV values were evaluated for each time session. Results Comparison of RI and PSV values between the NEC+ and NEC- groups revealed a significant increase in the PSV in the NEC+ group during the 1- to 2-hour session (P = .0199). Comparison of RI and PSV differences revealed a significant increase in RI and PSV differences in the NEC+ group during the 1- to 2-hour session (P = .0095 and .0013, respectively). In the other time sessions, there was no difference between the groups. Conclusions The NEC+ group showed a significant increase in the PSV and RI during the 1- to 2-hour period.

Objective: To determine whether there is a correlation between liver MR find-ings and the clinical manifestations and severity of liver dysfunction in patientswith Wilson’s disease.Materials and Methods: Two radiologists retrospectively evaluated MRimages of the liver in 50 patients with Wilson’s disease. The Institutional ReviewBoard approved this retrospective study and informed consent was waived. MRimages were evaluated with a focus on hepatic contour abnormalities and thepresence of intrahepatic nodules. By using Fisher’s exact test, MR findings werecompared with clinical presentations (neurological and non-neurological) andhepatic dysfunction, which was categorized by the Child-Pugh classification sys-tem (A, B and C). Follow-up MR images were available for 17 patients.Results: Contour abnormalities of the liver and intrahepatic nodules wereobserved in 31 patients (62%) and 25 patients (50%), respectively. Each MR find-ing showed a statistically significant difference ( p < 0.05) among the three groupsof Child-Pugh classifications (A, n = 36; B, n = 5; C, n = 9), except forsplenomegaly ( p = 0.243). The mean age of the patients with positive MR find-ings was higher than that of patients with negative MR findings. For patients withChild-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%), oraggravated (n = 4, 24%) on follow-up MR images.Conclusion: MR imaging demonstrates the contour abnormalities andparenchymal nodules of the liver in more than half of the patients with Wilson’sdisease, which correlates with the severity of hepatic dysfunction and clinicalmanifestations. ilson’s disease or progressive hepatolenticular degeneration is an autoso-mal recessive disorder of copper metabolism (1). The gene that causesWilson’s disease, located at chromosome 13 band q14.3, is known tocode for a copper-transporting P-type ATPase (2-4). A mutation of the gene associ-ated with Wilson’s disease results in deficient biliary excretion of copper, leading toexcessive copper accumulation in many tissues. Copper accumulation occurs mainly inthe liver, but also in the brain, cornea, and kidney (1-5). The principal clinical manifes-tations of Wilson’s disease are either hepatic or neurological disease (6, 7). Ultrasound (US), CT, and MR findings of the liver in Wilson’s disease usually reflectnonspecific hepatic injury including fatty infiltration, acute hepatitis, chronic activehepatitis, and cirrhosis (8-12). In advanced Wilson’s disease, nodular infiltrationssuggesting the presence of copper-containing nodules and contour abnormalities consis-Jung-Eun Cheon, MD

Moyamoya disease is a chronic, occlusive cerebrovascular disorder involving the distal internal carotid artery and/or the proximal portion of the anterior and middle cerebral arteries (ACAs and MCAs, respectively). Moyamoya disease is characterized by the extensive development of collateral pathways. The first pathway is known as the “basal moyamoya,” and includes an abnormal dilation of the perforating arteries and a true neoangiogenesis around the circle of Willis. Other collateral pathways may occur via pial-to-pial anastomoses from other less compromised territories, particularly the posterior circulation, or in more advanced cases, via a dural-to-pial collateral pathway, which is known as the “vault moyamoya.” These collateral networks seemingly provide an alternative route of cerebral perfusion in moyamoya disease [1–3].

Congenital abnormalities of the portal venous system are rare. There are few radiological descriptions of intrahepatic portosystemic venous shunt detected in the perinatal period. We report a congenital portosystemic shunt that was detected by US and treated with coil embolisation in the neonatal period.

OBJECTIVE. The purpose of this study was to evaluate retrospectively the CT and sonographic features in nine children with pathologically proven inflammatory myofibroblastic tumors of the abdomen.CONCLUSION. Although inflammatory myofibroblastic tumors occur in various sites and the imaging characteristics are variable, tumors showed different imaging patterns that were dependent on the site at which the tumor had originated.

Congenital esophageal stenosis (CES) can be associated with esophageal atresia/tracheoesophageal fistula (EA/TEF). Because there are a variety of degrees of obstruction and symptoms of CES, it is frequently difficult to make a pre- and post-operative diagnosis of the distal CES associated with EA/TEF.To evaluate the clinical and radiologic features of congenital esophageal stenosis associated with esophageal atresia/tracheoesophageal fistula.We retrospectively reviewed postoperative esophagograms and medical records of 187 children (107 boys, 80 girls) who had primary repair of EA/TEF from 1992 to 2009 at our institution. We evaluated the incidence of CES, clinical findings, radiologic features and management of CES in these children.CES was diagnosed in 22 of 187 EA/TEF children (12%); one child had double CES lesions, for a total of 23 lesions. Ten of those 22 children (45%) had presented with significant symptoms of esophageal obstruction. The diagnosis of CES was delayed in 10 children (45%) until 1-10 years of age. On esophagogram, CES (n = 23) was located in the distal esophagus (n = 20, 87%) or mid-esophagus (n = 3, 13%). The degree of stenosis was severe (n = 6, 26%), moderate (n = 10, 43%), or mild (n = 7, 30%). Eight children, including two with unsuccessful esophageal balloon dilatation of CES, were treated surgically. Histologic examination revealed tracheobronchial remnant (n = 7) or fibromuscular hyperplasia (n = 1). One child with surgically treated CES developed achalasia at the age of 3 years 9 months.Esophagography after EA/TEF repair should be performed with a high index of suspicion for the presence of distal CES, because the diagnosis and adequate management of CES can often be delayed.

Nonalcoholic fatty liver disease (NAFLD) is becoming more frequently diagnosed as the prevalence of obesity in children increases rapidly. The aim of this study was to investigate the correlation of clinical findings with histopathologic features in children with NAFLD. We reviewed the clinical data and liver histology results of children with biopsy-proven NAFLD at Seoul National University Hospital. NAFLD was classified as simple steatosis, type 1 nonalcoholic steatohepatitis (NASH), characterized by ballooning degeneration and perisinusoidal fibrosis, or type 2 NASH, characterized by portal inflammation and portal fibrosis. Among 80 total patients, 84% were male. All patients were obese or overweight. Insulin resistance was present in 96% of children. Perisinusoidal fibrosis was noted in 45% of children and portal fibrosis was noted in 77%. Simple steatosis was present in 22% of children, type 1 NASH in 34%, and type 2 NASH in 44%. No differences were found among NAFLD subtypes or NAFLD activity score with regard to sex, blood pressure, or levels of aminotransferase, fasting lipid, or insulin. Children with NASH were older and had higher body mass index than those with simple steatosis. Patients with type 2 NASH had higher body mass index and advanced fibrosis compared with patients with type 1 NASH. Obesity and older age are associated with development of NASH. Type 2 NASH is the most common form and associated with a greater severity of obesity and advanced fibrosis.

The purpose of our study was to determine whether CT provides additional information for children with a suspected residual foreign body in the airway after bronchoscopy.We reviewed the CT findings and medical records of nine patients (five girls and four boys; mean age, 17.9 months) who underwent CT between March 1999 and February 2007 for the evaluation of a clinically suspected residual foreign body in the airway after bronchoscopy. We evaluated the location and pattern of bronchial obstruction and associated parenchymal abnormalities on CT. CT findings were compared with a second bronchoscopy in five patients. The remaining four patients were followed clinically. Association between CT findings and results on second bronchoscopy was evaluated with Fisher's exact test.CT after bronchoscopy (n = 9) showed bronchial obstruction in eight patients with focal complete (n = 3), diffuse (n = 3), or combined type (n = 2) bronchial obstruction. These obstructions were not seen at chest radiography. CT revealed unilateral or lobar emphysema (n = 6), atelectasis (n = 6), and consolidation (n = 1). The remaining one patient showed no abnormality on CT. A second bronchoscopy (n = 5) confirmed the focal complete bronchial obstruction at CT (n = 3) as retained foreign body fragments (n = 2) or mucus plug (n = 1) and the combined type at CT (n = 2) as retained foreign body fragments, granulation tissue, and edema of the bronchus (n = 1) or retained foreign body fragments, granulation tissue, and mucus plug (n = 1). There was a significant association between CT findings of type of bronchial obstruction and intrabronchial obstructive lesion on the second bronchoscopy (p = 0.036).CT after bronchoscopy can provide additional information regarding the presence and pattern of bronchial obstruction in children with a suspected residual foreign body.

With the increasing application of intra-arterial chemotherapy (IAC), new side-effects are encountered. We describe two children with proximal femoral osteosarcoma who developed focal myositis of the abdominal wall musculature after IAC. In both cases, myositis presented as abdominal pain and mimicked acute abdomen. US demonstrated asymmetrical thickening of abdominal-wall musculature in the right lower abdomen. This diagnosis should be considered when evaluating the patient with unexplained abdominal pain and a history of IAC.

Pilomyxoid astrocytoma is a recently identified variant of pilocytic astrocytoma. We studied 11 circumscribed astrocytomas with focal (n=5) or diffuse (n=6) pilomyxoid features and compared them with 17 pilocytic astrocytomas from the hypothalamic/chiasmatic region in children. In one patient, a tumor that recurred after initial surgery had changed from pure-form pilomyxoid astrocytoma to the mixed form. The presence of a pilomyxoid area was associated with shorter survival. Next, we compared the comprehensive genome copy number changes in the pilomyxoid astrocytoma (n=4) with those in pilocytic astrocytoma (n=6) cases by array-based comparative genomic hybridization. The number of lost clones was larger in pilomyxoid astrocytoma than in pilocytic astrocytoma. Clones located in chromosome 8q24.3 were frequently gained in pilocytic astrocytoma (four of six) and in pilomyxoid astrocytoma (one of four). Clones located in 9p24.3 and 15q26.3 were lost in all of the pilomyxoid astrocytomas and in five of the pilocytic astrocytomas. Those in 8p23.3 showed a copy number loss in three of the pilomyxoid astrocytomas and four of the pilocytic astrocytomas. The frequency of copy number changes was significantly different between pilomyxoid astrocytoma and pilocytic astrocytoma in 47 (3.6%) clones, 20 of them having been located in 2p, 10 in 2q, and 11 in 3q. An unsupervised hierarchical clustering analysis classified the cases into three clusters: one pilomyxoid astrocytoma patient into one cluster, two pilomyxoid astrocytoma patients into another cluster, and six pilocytic astrocytoma patients and one pilomyxoid astrocytoma patient into the third cluster. In conclusion, the presence of mixed-form pilomyxoid astrocytoma, the acquisition of pilocytic astrocytoma features in a recurrent tumor in pure-form pilomyxoid astrocytoma, and the above results of the genome-wide gene copy number analysis suggest that pilomyxoid astrocytoma might be a pathologically and genetically related, aggressive variant of pilocytic astrocytoma with partially different genetic alterations.

Aim To investigate the imaging and clinical findings of central nervous system (CNS) atypical teratoid/rhabdoid tumours (AT/RTs) in children. Materials and methods The computed tomography (CT) and magnetic resonance imaging (MRI) findings and clinical records of 16 children with CNS AT/RTs were retrospectively reviewed. Tumour location, size, composition, enhancement pattern, peritumoural oedema, signal intensity (SI) on MRI and CT attenuation were evaluated. Results A total of 17 lesions from 16 patients (median age 2.3 years, age range 0.7–15 years) were included in the evaluation. Tumour location was infratentorial for 11 lesions and supratentorial for six lesions. The mean diameter of the largest dimension for a tumour was 4 cm. The tumour was mainly solid in 65% of cases, and solid and cystic or cystic and solid in 35% of cases. The solid component of the tumours had a homogeneous iso SI (n = 15) on T2-weighted MRI images and iso SI (n = 14) on T1-weighted images. Moderate to strong enhancement of the solid component was noted in most cases. In spite of a large tumour size, peritumoural oedema was minimal or mild except in four cases. Rapid growth of the tumour was demonstrated in three cases. Seven patients died from tumour progression, with a mean survival time of 8.4 months (range 2–12 months). Conclusion Although the AT/RTs had non-specific imaging findings, the tumours tended to be large in size, have iso SI on T1 and T2-weighted MR images with prominent enhancement, and relatively mild peritumoural oedema. Rapid growth of the tumour was seen during the follow-up period.

Central skull base tumours are rare in children. To characterize the imaging features of central skull base lymphoma in children to aid its diagnosis. The authors reviewed the CT findings (available in three patients) and MR findings (available in four patients) in four patients (three boys, one girl; age 2–12 years) with pathologically proven lymphoma (two with Burkitt lymphoma, two with B-cell lymphoma) involving the central skull base. Tumour location and extent, MRI signal intensities, noncontrast CT attenuation, patterns of enhancement, and changes in adjacent structures were evaluated. All four tumours involved the sphenoid bone. In three patients, the tumour extended to the ethmoid sinus and both cavernous sinuses. All lesions were isointense solid masses on T2-weighted images and showed avid enhancement, except for one lesion with a focal necrosis. All tumours were associated with adjacent dural thickening. Non-contrast CT showed highly attenuating masses and permeative bone destruction in the central skull base. Lymphoma involving the central skull base in children is visualized as an isointense mass on T2-weighted MRI with marked contrast enhancement and adjacent dural thickening, and as a highly attenuating mass on noncontrast CT with permeative or erosive bone destruction patterns.

Patients with complex congenital heart defects palliated by connecting the systemic veins directly to the pulmonary circulation are known to develop hepatopulmonary syndrome (HPS). Although rare, HPS can develop following the Fontan operation. To present and analyse the CT findings of HPS in patients with a Fontan circulation. From May to December 2005, six patients with HPS following the completion of a Fontan circulation were evaluated. CT findings were reviewed and were compared with angiographic findings. All six patients showed unilateral involvement. All patients except one had inferior vena cava (IVC) interruption with azygos continuation. CT scans showed abnormal vascular dilatation in one lung, and properly demonstrated the anatomy causing the hepatic venous blood to flow preferentially into one lung. These CT findings correlated well with the angiography findings. HPS that develops after the Fontan procedure is typically unilateral and is often associated with IVC interruption and azygos or hemiazygos continuation. CT demonstrates dilatation of pulmonary vessels in the affected lung and may be able to demonstrate the underlying anatomical cause for the predilection of hepatic venous flow to the contralateral lung.

To prospectively evaluate the accuracy of hepatic artery diameter and hepatic artery diameter-to-portal vein diameter ratio for ultrasonographic (US) diagnosis of biliary atresia, with cholangiographic or clinical information as reference standard.Institutional review board approval and informed consent were obtained. US was performed in 68 neonates and infants with cholestatic jaundice (mean age, 61 days; male-to-female ratio, 38:30). Biliary atresia (n = 38) was confirmed with cholangiography, and hepatitis (n = 30) was diagnosed with clinical (n = 24) or cholangiographic (n = 6) findings. Diameter of the right hepatic artery was measured with US. Right hepatic artery diameter-to-right portal vein diameter ratio was measured to determine relative enlargement of the hepatic artery. As a control group, 17 neonates and infants (mean age, 67 days; male-to-female ratio, 12:5) without jaundice underwent US of the porta hepatis. Statistical analysis was performed to compare US parameters among three groups with one-way analysis of variance. Optimal cutoff values of the hepatic artery diameter and hepatic artery diameter-to-portal vein diameter ratio for biliary atresia diagnosis were obtained with receiver operating characteristic analysis.The diameter of the right hepatic artery in biliary atresia group (1.9 mm +/- 0.4 [standard deviation]) was significantly larger than that in the hepatitis (1.4 mm +/- 0.3) and control (1.2 mm +/- 0.2) groups (P.001). Hepatic artery diameter-to-portal vein diameter ratio in the biliary atresia group (0.52 +/- 0.12) was larger than that in hepatitis (0.40 +/- 0.07) and in control (0.40 +/- 0.10) groups (P.001). Optimum cutoff values for diagnosis of biliary atresia were 1.5 mm (sensitivity, 92%; specificity, 87%; accuracy, 89%) for hepatic artery diameter and 0.45 for hepatic artery diameter-to-portal vein diameter ratio (sensitivity, 76%; specificity, 79%; accuracy, 78%).Measurement of hepatic artery diameter can be helpful in the US diagnosis of biliary atresia.

Objective: To investigate the usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion MRI for the evaluation of femoral head ischemia. Materials and Methods: Unilateral femoral head ischemia was induced by selective embolization of the medial circumflex femoral artery in 10 piglets. All MRIs were performed immediately (1 hour) and after embolization (1, 2, and 4 weeks). Apparent diffusion coefficients (ADCs) were calculated for the femoral head. The estimated pharmacokinetic parameters (Kep and Ve from two-compartment model) and semi-quantitative parameters including peak enhancement, time-to-peak (TTP), and contrast washout were evaluated. Results: The epiphyseal ADC values of the ischemic hip decreased immediately (1 hour) after embolization. However, they increased rapidly at 1 week after embolization and remained elevated until 4 weeks after embolization. Perfusion MRI of ischemic hips showed decreased epiphyseal perfusion with decreased Kep immediately after embolization. Signal intensitytime curves showed delayed TTP with limited contrast washout immediately post-embolization. At 1−2 weeks after embolization, spontaneous reperfusion was observed in ischemic epiphyses. The change of ADC (p = 0.043) and Kep (p = 0.043) were significantly different between immediate (1 hour) after embolization and 1 week post-embolization. Conclusion: Diffusion MRI and pharmacokinetic model obtained from the DCE-MRI are useful in depicting early changes of perfusion and tissue damage using the model of femoral head ischemia in skeletally immature piglets. Index terms: Diffusion-weighted imaging; Dynamic contrast enhanced MRI; Femoral head ischemia

Moyamoya disease is a unique cerebrovascular disorder characterized by idiopathic progressive stenosis at the terminal portion of the internal carotid artery (ICA) and fine vascular network. The aim of this review is to present the clinical application of quantitative digital subtraction angiography (QDSA) in pediatric moyamoya disease. Using conventional angiographic data and postprocessing software, QDSA provides time-contrast intensity curves and then displays the peak time (Tmax) and area under the curve (AUC). These parameters of QDSA can be used as surrogate markers for the hemodynamic evaluation of disease severity and quantification of postoperative neovascularization in moyamoya disease.

To evaluate prospectively the hemodynamic state of the left renal vein with Doppler ultrasonography (US) and venography in pediatric patients with varicocele to assess the "nutcracker phenomenon."The institutional review board considered this study ethically sound, and parental informed consent was obtained for all subjects. Doppler US of the left renal vein was performed in 27 consecutive boys with varicocele (age range, 7-15 years; mean, 11.9 years) and in 20 boys without varicocele as control subjects (age range, 7-17 years; mean, 11.4 years). Doppler US was used to evaluate left renal vein diameters and peak velocities in the proximal left renal vein near the renal hilum and in the left renal vein between the aorta and superior mesenteric artery (aortomesenteric portion). The diameter ratios and peak velocity ratios between two sites were obtained. For statistical comparison of results, the t test was used. Left renal venography and renocaval pressure measurement were performed in 13 patients with varicocele. The Fisher exact test was used to evaluate the associations between the nutcracker phenomenon (renocaval pressure gradient/=3 mm Hg) and the development of collateral veins.The diameters of the proximal left renal vein and the peak velocities in the aortomesenteric portion of the left renal vein were significantly different between the varicocele group and the control group (P.001). The diameter ratios (5.7 +/- 1.8 [standard deviation]) and peak velocity ratios (5.2 +/- 2.6) in patients with varicocele were significantly higher than those in control subjects (3.5 +/- 1.0 and 3.1 +/- 0.8, respectively) (P.005). According to findings at left renal venography (n = 13), 10 patients (77%) met the criteria for the nutcracker phenomenon. The nutcracker phenomenon was significantly associated with the development of collateral veins (P = .035).Doppler US and venography of the left renal vein can show hemodynamic changes of the left renal vein and depict the presence of the nutcracker phenomenon in pediatric varicocele.

Optic gliomas may unpredictably stabilize or progress. Prognosis was known to be better in patients with neurofibromatosis 1 (NF1) than those with non-NF1. The confusion over management is caused, at least in part, by the uncertain disease course of the tumor. We report here a 13-year-old girl presented with a 1-month history of a gradual decline of vision in her left eye. She was diagnosed by clinical examination and magnetic resonance imaging as having a left optic-nerve glioma and was followed by serial magnetic resonance imaging over 3 years. She and her family did not show any stigmata of NF1. Approximately 3 years after the onset of her symptoms, visual acuity, color testing, and visual fields have markedly improved with tumor regression by magnetic resonance imaging. The possibility of spontaneous regression of an optic-nerve glioma should be considered even in the planning of treatment for a non-NF1 patient with this tumor.

We sought to determine whether torsed testis viability can be evaluated by ultrasonography (US) including power Doppler US in an experimental model of acute testicular torsion.Eighteen rats underwent unilateral 540 degrees testicular torsion and contralateral orchiopexy. Gray-scale and power Doppler US were performed 24 hours later. We evaluated echogenicity, intratesticular vascular flow, and testis size. Echogenicity and intratesticular vascular flow were quantitatively analyzed by using a visual scale and computer-based analysis. After US, detorsion was performed in torsed testes, and 6 days after detorsion testes were excised to determine testicular viability, which was determined using gross and microscopic findings. US findings before detorsion were correlated with testicular viability.At US performed 24 hours after testicular torsion, all viable testes (n = 7) were homogeneous and isoechoic versus contralateral testes. In nonviable testes (n = 11), lower (82%) and heterogeneous (73%) echogenicities were seen on gray-scale US. Intratesticular vascular flow was preserved in 86% of viable testes. In nonviable testes, no intratesticular vascularity was observed in 82%, and intermittent, peripheral blood flow was detected in the remaining 18%. Intratesticular focal lesions were observed in 45% of nonviable testis. Quantitative analysis showed a statistically significant difference between viable and nonviable testes in terms of testicular echogenicity and intratesticular vascular flow.Preoperative US including power Doppler examination can predict testicular viability in testicular torsion. Echogenicity of nonviable testes was found to be hypoechoic and inhomogeneous. Power Doppler examination showed no or intermittent peripheral blood flow in nonviable testes.

MRI and FDG-PET may predict the histological grading of paediatric brain-stem gliomas.To assess MRI findings and metabolic imaging using FDG-PET of brain-stem gliomas based on histological grading.Included in the study were 20 paediatric patients (age 3-14 years, mean 8.2 years) with brain-stem glioma (five glioblastomas, ten anaplastic astrocytomas and five low-grade astrocytomas). MR images were assessed for the anatomical site of tumour origin, focality, pattern of tumour growth, and enhancement.All glioblastomas were located in the pons and showed diffuse pontine enlargement with focally exophytic features. Eight anaplastic astrocytomas were located in the pons and demonstrated diffuse pontine enlargement without exophytic features. Low-grade astrocytomas were located in the pons, midbrain or medulla and showed focally exophytic growth features and peripheral enhancement. In 12 patients in whom FDG-PET was undertaken, glioblastomas showed hypermetabolic or hypometabolic lesions, anaplastic astrocytomas showed no metabolic change or hypometabolic lesions and low-grade astrocytomas showed hypometabolism compared with the cerebellum.MRI findings correlated well with histological grading of brain-stem gliomas and MRI may therefore predict the histological grading. FDG-PET may be helpful in differentiating between anaplastic astrocytoma and glioblastomas among high-grade tumours.

To assess the magnetic resonance (MR) features of fat graft interposition in experimentally induced growth plate injury, to correlate these features with histologic findings, and to compare the growth disturbances of fat-grafted and nonfat-grafted growth plate injuries.The growth plate injury model was created in 20 skeletally immature rabbits. In 14 rabbits, a bilateral growth plate defect was made in the medial half of the proximal tibia. The defect of the right tibia was filled with autologous fat; the left tibia was left empty. In another 6 rabbits, a unilateral growth plate defect was created with (n = 3) or without (n = 3) fat graft interposition in the right tibia. MR imaging was performed at 2, 4, and 12 weeks postoperatively using a 1.5-T MR unit. T1-weighted images, T2-weighted images, gradient echo images, and contrast-enhanced T1-weighted images were obtained in the coronal plane. The authors evaluated the MR features of the growth plate defects with or without fat graft, and the remaining growth plate. The length and angulation of the grafted tibia were compared with those of the nonfat-grafted tibia. RESULTS At 2 weeks postoperatively, the grafted area showed low signal intensity mixed with high signal intensity (71%) on T1-weighted imaging. At 2 weeks, most of the growth plate defect in the control animals showed low signal intensity in all image sequences. At 4 weeks, most of the grafted area showed low signal intensity on T2-weighted imaging. A bone bridge was revealed in 15% of the grafted tibia and in 62% of the control animals at 4 weeks. On gradient echo images, high signal intensity of the remaining growth plate was preserved in grafted tibias, but in the control animals this became invisible 4 weeks postoperatively. At 12 weeks, most of growth plate defect area became isointense on all image sequences in grafted tibia and in the control animals. Histologically, the fat-grafted area was replaced by fibrous connective tissues with thin, trabecular bone formation. Growth plate defects of the control animals were filled with mature fatty marrow with trabecular bone formation. The varus angle and medial length of the tibia were significantly different between fat-grafted tibias at 4 weeks and 12 weeks postoperatively.MR imaging was helpful for evaluating growth plate modifications and subsequent changes after fat graft interposition. Fat graft interposition had a role in reducing growth disturbance in growth plate injury.

Dysmyelinating diseases, or leukodystrophies, encompass a wide spectrum of inherited neurodegenerative disorders affecting the integrity of myelin in the brain and peripheral nerves. Most of these disorders fall into one of three categories-lysosomal storage diseases, peroxisomal disorders, and diseases caused by mitochondrial dysfunction-and each leukodystrophy has distinctive clinical, biochemical, pathologic, and radiologic features. Magnetic resonance (MR) imaging has become the primary imaging modality in patients with leukodystrophy and plays an important role in the identification, localization, and characterization of underlying white matter abnormalities in affected patients. MR imaging has also been extensively used to monitor the natural progression of various white matter disorders and the response to therapy. Although the MR imaging features of leukodystrophy are often nonspecific, systematic analysis of the finer details of disease involvement may permit a narrower differential diagnosis, which the clinician can then further refine with knowledge of patient history, clinical testing, and metabolic analysis.

Background: Mycobacterial osteomyelitis involving only the epiphysis of a long bone is extremely rare, and its clinical and radiographic features remain unclear. The purpose of this study was to characterize mycobacterial epiphyseal osteomyelitis and to identify differences between its features and those reported for epiphyseal osteomyelitis caused by bacteria or unidentified pathogens. Methods: We retrospectively reviewed the cases of eight children (five males and three females) who presented at a median age of nineteen months (range, twelve to twenty-five months). Clinical findings were compiled. Radiographs and magnetic resonance imaging (MRI) were used to determine local spread of the abscess outside the epiphysis during the disease course. At the time of the latest follow-up evaluation, the presence of limited joint mobility or growth disturbance was determined. Physeal damage was evaluated with use of MRI. Results: Pathogens were identified through multiplex polymerase chain reaction. Mycobacterium bovis bacille Calmette-Guerin (BCG, Tokyo-172 strain) was identified in four patients; Mycobacterium tuberculosis, in three patients; and nontuberculous mycobacterium, in one patient. The lesion was located at the distal femoral epiphysis in six patients, at the proximal tibial epiphysis in one patient, and at the proximal humeral epiphysis in one patient. The abscess was confined to the epiphysis at the time of initial presentation but, over time, extended outside the epiphysis in seven cases. The lesion was initially located in the cartilaginous epiphysis in two patients, which could be diagnosed only on MRI. Seven patients worsened despite surgical drainage and medication, and five required additional surgery. At follow-up at a mean of 4.1 years (range, 1.3 to 7.8 years), focal physeal damage was evident in five patients, and clinical growth disturbance was evident in one patient. Conclusions: In contrast to the reported benign features of epiphyseal osteomyelitis caused by bacteria or unidentified pathogens, mycobacterial epiphyseal osteomyelitis seems to have an unfavorable clinical course that tends to lead to physeal damage. MRI is useful for early diagnosis of a cartilaginous lesion and evaluation of abscess spread and physeal damage. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

We report a 13-year-old girl with an unusual, complex bronchopulmonary foregut malformation. The malformation included extralobar pulmonary sequestration and a duplication cyst of mixed bronchogenic and oesophageal type. Preoperative CT and MRI demonstrated the cystic and solid portions of the mass and indicated an aberrant vascular supply, suggesting the possibility of bronchopulmonary foregut malformation and several other differential diagnoses. A direct communication between the cyst and the bronchus of the sequestrated lung was found on pathological examination. This unusual combination of an extralobar pulmonary sequestration and a foregut cyst points to a common embryological pathogenesis.

Rationale and Objectives Ultrasonography (US) has a potential role in the diagnosis of osteomyelitis. The purpose of this study was to determine the characteristic sonographic features of acute osteomyelitis and correlate them with pathologic findings. Materials and Methods An experimental model of acute osteomyelitis was produced in the tibiae of 20 rabbits. Daily US and plain radiography were performed for 2 weeks. The authors evaluated periosteal reaction, subperiosteal fluid collection, and soft-tissue changes seen with US. A hypoechoic band and a hyperechoic line lying along the cortex were considered positive signs of subperiosteal fluid collection and periosteal reaction, respectively. The findings of periosteal reaction were compared for US and radiography, and pathologic findings were also correlated. Results The most common sonographic finding was a hypoechoic band along the cortex (21 [75%] of 28 tibiae), usually associated with a linear periosteal reaction (20 [71%] of 28). This juxtacortical abnormal echogenicity corresponded to periosteal elevation with loose fibrovascular connective tissue and granulation, associated with subperiosteal abscess formation. The periosteal reactions were detected with US before they were seen on radiographs. The periosteum showed gradual thickening during the disease process. In 50% of infected tibiae, inflammation or abscess formation was observed in the surrounding soft tissue. Conclusion US readily demonstrates juxtacortical abnormal echogenicity and soft-tissue infection related to acute osteomyelitis. The abnormal echogenicity correlated well with the pathologic findings of periosteal reaction and subperiosteal abscess.

Meningioangiomatosis is a rare, benign neoplastic disorder involving the cortex and leptomeninges. The pathological findings are characterised by proliferation of meningothelial cells and leptomeningeal vessels and calcifications within the mass. We experienced two cases of pathologically confirmed meningioangiomatosis, one as a solitary cortical mass with calcification and the other as a cortical lesion manifested as extensive intracranial haemorrhage. On MRI, the first case showed an isointense cortical mass in the left frontal lobe and homogeneous enhancement on the contrast-enhanced study. The second case showed a target-like lesion with a peripheral dark signal rim on T2-weighted images accompanied by extensive haemorrhage in the adjacent frontal lobe and lateral ventricles.

To characterize computed tomographic (CT) findings of thoracic actinomycosis.Chest CT scans and radiographs obtained in 22 patients with histopathologically proved thoracic actinomycosis were retrospectively reviewed. All patients were immunocompetent; they were aged 12-73 years (mean, 42.6 years; 14 male, eight female). CT findings were correlated with histopathologic findings in nine patients who underwent surgery (lobectomy [n = 8] or segmental resection [n = 1]).All of the lesions were unilateral, with an average diameter of 6.5 cm (range, 2-12 cm). Patchy air-space consolidation (n = 20) or a mass (n = 2) was seen on CT scans. Fifteen (75%) of the 20 patients with air-space consolidation had central areas of low attenuation (5-30 mm in diameter) within the consolidation. Thirteen of the 15 patients underwent contrast medium-enhanced CT. Ten (77%) of the 13 patients showed ring-like rim enhancement. Adjacent pleural thickening was seen in 16 patients (73%). At histopathologic examination, central low-attenuation areas at CT were seen as microabscesses with sulfur granules or a dilated bronchus that contained inflammatory cells and Actinomyces colonies. Peripheral enhancement of the low-attenuation areas was wall of the microabscess or surrounding parenchyma composed of granulation tissue rich in vascularity.Findings of chronic segmental air-space consolidation that contained low-attenuation areas with peripheral enhancement or adjacent pleural thickening at CT were suggestive of thoracic actinomycosis.