David A. Bloom

PET FDG studies of Wilms tumors.

PURPOSE Wilms tumor is the most common renal neoplasm in children. The diagnosis is usually suggested by anatomic imaging and established by biopsy or resection. The principal roles of functional imaging have been the search for skeletal metastases and evaluation of renal function. We hypothesized that, like many tumors, Wilms tumors could concentrate 18F-FDG and that evaluation of the metabolic activity of these neoplasms might prove clinically useful. MATERIALS AND METHODS Three patients with known or suspected Wilms tumors underwent positron emission tomography (PET) with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) scanning (four scans). A patient with a single Wilms tumor was studied once at the time of diagnosis. The two patients with bilateral Wilms tumors were studied during therapy. RESULTS Uptake of FDG was present in the Wilms tumor studied at diagnosis, and in one of the tumors in each of the patients with bilateral disease studied during therapy. In all three cases, the results of the PET scans influenced therapeutic decisions. CONCLUSION PET FDG scanning may be useful for the management of selected patients with Wilms tumors.

Caroli's disease diagnosed in a child by MRCP

We describe a case of Carolis disease associated with a choledochal cyst and autosomal recessive polycystic kidney disease in a child whose diagnosis was confirmed with magnetic resonance cholangiopancreatography (MRCP), after initial abnormalities were seen by ultrasonography. Invasive procedures such as liver biopsy or endoscopic retrograde cholangiopancreatography (ERCP) were, therefore, not necessary. Recent radiological advances in the diagnosis of Carolis disease with particular emphasis on MRCP are discussed.

Unusual presentation of osteoid osteoma mimicking osteomyelitis in a 27-month-old infant

Osteoid osteoma is an uncommon, benign disorder of bone that is most often encountered in school-age children and in adolescents. It is quite rare in children under the age of 3 years. We report a case of osteoid osteoma with unusual clinical and imaging features in a 27-month-old toddler who presented with a limp and swelling of the right knee. Initial clinical evaluation, plain films, and computed tomography (CT) were strongly suggestive of chronic osteomyelitis involving the distal right femoral metadiaphysis. The appearance on nuclear medicine bone scan, however, was typical of osteoid osteoma. A biopsy of the lesion was taken and histological examination confirmed the diagnosis of osteoid osteoma. The misleading clinical and imaging features in this case are discussed.

MR angiography in the evaluation of a renovascular cause of neonatal hypertension

Neonatal hypertension occurs in 2% of all infants and it is caused by renovascular abnormalities in 70% of these infants. The gold standard for diagnosing renovascular disease is conventional renal angiography. However, in neonates the procedure is not commonly used because of its invasive and technically challenging nature. MRI and MR angiography (MRA) are less invasive yet reliable means of detecting renovascular disease in adults. There is minimal literature on the use of MRI/MRA in neonatal hypertension. We report a neonate with hypertension secondary to a renovascular abnormality in which MRI/MRA was helpful in uncovering segmental renal artery stenosis. The infant underwent partial nephrectomy with subsequent resolution of his hypertension. Further studies are needed to validate the use of MRI/MRA in the evaluation of neonatal hypertension.

Correlation of cystographic bladder morphology and neuroanatomy in boys with posterior urethral valves

Purpose. We have observed a difference in the radiographic appearance of the body of the bladder (trabeculated) and its base (smooth) in boys with severely obstructing posterior urethral valves. We wanted to determine if (1) this was a reproducible finding and (2) there was an anatomic and/or physiologic explanation for it. Materials and methods. We reviewed the initial voiding cystourethrogram in 47 boys with severe posterior urethral valves. The interureteric ridge was used as the division between the body and base of the bladder. The presence of trabeculation for each region was recorded. Results. Ages ranged from 1 day to 6 years at the time of initial cystographic evaluation (median 14 days). The body of the bladder was trabeculated and the base smooth in 72 % (34 patients). In the remaining patients, both the body and base were smooth. In no patient was the base trabeculated. Conclusions. The cystographic morphology of the urinary bladder in boys with posterior urethral valves can be explained by its neuroanatomy. The body of the bladder, which contracts during voiding because of parasympathetic (cholinergic) stimulation, becomes trabeculated. The bladder base relaxes during voiding due to sympathetic (alpha adrenergic) stimulation and remains smooth. Thus, this difference in the cystographic appearance of the two parts of the urinary bladder reflects the normal innervation and the mechanics of micturition in boys with urethral obstruction.

Congenital piriform fossa sinus tract presenting as an asymptomatic neck mass in an infant

BackgroundA 5-month-old girl with an asymptomatic left-sided neck mass was demonstrated by ultrasound and upper gastrointestinal series (UGI), and confirmed at surgery, to have a congenital piriform fossa sinus tract (CPFST) that communicated with an intrathyroidal cyst.ObjectiveTo demonstrate a case of CPFST presenting as an asymptomatic neck mass. Nearly all cases of CPFST present with infection or pain, making this case unique.Materials and methodsCase report and review of the literature.ConclusionsCPFST with an associated cyst should be added to the differential diagnosis of asymptomatic cystic neck masses in infants, especially if the cyst is intrathyroidal by ultrasound.

Paratesticular rhabdomyosarcoma with metastatic encasement of the abdominal aorta

Paratesticular rhabdomyosarcoma is a rare but aggressive malignancy in children and adolescents. Prognosis is related to initial tumor resectability as well as staging of the disease based on tumor invasiveness, tumor bulk, nodal disease and metastases. We report the unusual presentation of paratesticular rhabdomyosarcoma with metastatic extension through the inguinal canal and encasement of the abdominal aorta. These features portend a poor prognosis given their association with a greater stage of disease and unresectable nature at presentation. Delayed surgical resection follows a regimen of chemotherapy and radiation therapy in such cases of extensive disease. Encasement of the abdominal aorta has been shown to increase presurgical risk for intraoperative vascular injury when related to other malignancies, but its role in relation to metastatic paratesticular rhabdomyosarcoma has not been investigated. Also, rhabdomyosarcoma should be considered in the differential diagnoses of tumors that demonstrate encasement of the abdominal aorta.

Image-guided Percutaneous Drainage in the Pediatric Population: A Primer for Radiologists

Image-guided percutaneous drainage is an excellent minimally invasive method for dealing with infectious complications in the pediatric population. A thorough understanding of drainage procedures in children can often lead to improved patient outcomes. Indications for percutaneous drainage will be reviewed, including abscesses related to appendicitis, post-surgical abscess formation, and abscesses related to Crohns disease. This pictorial essay will help the radiologist better understand the common etiologies of abscesses in children that may require percutaneous drainage, the special considerations for catheter placement, patient preparation, and anesthesia or sedation issues unique to the pediatric population.

Occult Colonic Duplication

Duplication of the gastrointestinal (GI) tract is a rare congenital malformation, with an incidence of 1 in 4000 to 5000 live births. It can affect any portion of the alimentary tract and may be primarily thoracic, thoracoabdominal, or abdominal. Duplications most commonly affect the ileum, followed by the esophagus. It involves the colon less frequently, accounting for approximately 4% to 18% of all cases. When the colon is affected, the cecum is the most common location. The duplication can be either cystic or tubular. The clinical presentation of colonic duplication (CD) is variable and nonspecific, and thus it represents a diagnostic and therapeutic challenge. Although it can be diagnosed using a contrast enema (CE), we describe the case of a newborn who presented with ileal atresia, whose initial CE demonstrated a microcolon only, and a repeat CE at age 5 months showed a tubular communicating distal CD.