Sclerosing polycystic adenosis.

A 25-year-old female presented with a well-defined, painless mass of 1 year's duration in the right parotid gland. MR imaging revealed a relatively well-circumscribed lesion involving the deep and superficial lobes of the right parotid gland. Histologic examination of the resection resulted in a diagnosis of sclerosing polycystic adenosis, a rare benign salivary gland entity of presumed non-neoplastic origin. The clinical, radiographic, and morphologic features of sclerosing polycystic adenosis are discussed.

Late spinal metastases from an isolated pineal region germinoma mimicking a schwannoma.

A 20-year-old male with a prior history of germinoma presented 8 years after the initial diagnosis with progressive lower back pain. The preoperative diagnosis was schwannoma based on the appearances of a tumor in the lumbosacral region on MRI; however, histologically, a germinoma "drop" metastasis was seen. This report emphasizes the need for long-term follow-up in patients with germinoma. In addition, this patient is unusual in that the preoperative assessment favored schwannoma.

Bilateral thalamic lesions.

OBJECTIVE: The purpose of this study was to present the neuroimaging findings and differential diagnosis of bilateral thalamic lesions. CONCLUSION: The limited differential diagnosis of bilateral thalamic lesions can be further narrowed with knowledge of the specific imaging characteristics of the lesions in combination with the patient history.

Radiation dose reduction strategy for CT protocols: successful implementation in neuroradiology section.

PURPOSE: To retrospectively quantify the effect of systematic use of tube current modulation for neuroradiology computed tomographic (CT) protocols on patient dose and image quality. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval, with waiver of informed consent. The authors evaluated the effect of dose modulation on four types of neuroradiologic CT studies: brain CT performed without contrast material (unenhanced CT) in adult patients, unenhanced brain CT in pediatric patients, adult cervical spine CT, and adult cervical and intracranial CT angiography. For each type of CT study, three series of 100 consecutive studies were reviewed: 100 studies performed without dose modulation, 100 studies performed with z-axis dose modulation, and 100 studies performed with x-y-z-axis dose modulation. For each examination, the weighted volume CT dose index (CTDI(vol)) and dose-length product (DLP) were recorded and noise was measured. Each study was also reviewed for image quality. Continuous variables (CTDI(vol), DLP, noise) were compared by using t tests, and categorical variables (image quality) were compared by using Wilcoxon rank-sum tests. RESULTS: For unenhanced CT of adult brains, the CTDI(vol) and DLP, respectively, were reduced by 60.9% and 60.3%, respectively, by using z-axis dose modulation and by 50.4% and 22.4% by using x-y-z-axis dose modulation. Significant dose reductions (P < .001) were also observed for pediatric unenhanced brain CT, cervical spine CT, and adult cervical and intracranial CT angiography performed with each dose modulation technique. Image quality and noise were unaffected by the use of either dose modulation technique (P > .05). CONCLUSION: Use of dose-modulation techniques for neuroradiology CT examinations affords significant dose reduction while image quality is maintained.

Magnetic resonance neurography in children with birth-related brachial plexus injury.

BACKGROUND: Magnetic resonance neurography (MRN) enables visualization of peripheral nerves. Clinical examination and electrodiagnostic studies have been used in the evaluation of birth-related brachial plexus injury. These are limited in their demonstration of anatomic detail and severity of injury. OBJECTIVE: We investigated the utility of MRN in evaluating birth-related brachial plexus injury in pediatric patients, and assessed the degree of correlation between MRN findings and physical examination and electromyographic (EMG) findings. MATERIALS AND METHODS: The MRN findings in 11 infants (age 2 months to 20 months) with birth-related brachial plexus injury were evaluated. A neuroradiologist blinded to the EMG and clinical examination findings reviewed the images. Clinical history, examination, EMG and operative findings were obtained. RESULTS: All infants had abnormal imaging findings on the affected side: seven pseudomeningoceles, six neuromas, seven abnormal nerve T2 signal, four nerve root enlargement, and two denervation changes. There was greater degree of correlation between MRN and physical examination findings (kappa 0.6715, coefficient of correlation 0.7110, P < 0.001) than between EMG and physical examination findings (kappa 0.5748, coefficient of correlation 0.5883, P = 0.0012). CONCLUSION: MRN in brachial plexus trauma enables localization of injured nerves and characterization of associated pathology. MRN findings demonstrated a statistically significant correlation with physical examination and EMG findings, and might be a useful adjunct in treatment planning.

Diagnosis of Chiari III malformation by second trimester fetal MRI with postnatal MRI and CT correlation.

We report a case of Chiari III malformation diagnosed by fetal MRI. Ultrasound (US) performed at a gestational age of 18 weeks demonstrated a posterior skull base cyst. Repeat US at 19 weeks demonstrated neural tissue in the cyst, consistent with an encephalocele. MR imaging at 23 weeks confirmed the presence of an occipital encephalocele, demonstrated additional bony defect in the upper cervical spine, and identified abnormal morphology and position of the brainstem consistent with the diagnosis of Chiari III. Postnatal MRI and CT confirmed the fetal MRI findings and demonstrate the utility of fetal MRI in the early evaluation of songraphically detected posterior fossa abnormalities.

Atypical teratoid/rhabdoid tumor of the velum interpositum presenting as a spontaneous intraventricular hemorrhage in an infant: case report with long-term survival.

Atypical teratoid/rhabdoid tumors (ATRT) of infancy are highly malignant neoplasms that are most common in the first 2 years of life. We present the case of a 3-month-old girl who presented with the acute onset of generalized seizures and was found to have a large spontaneous intraventricular hemorrhage. The blood masked an underlying ATRT of the velum interpositum in the midline of the lateral ventricles and roof of the third ventricle, the first reported case in this location. Serial imaging studies and two ventriculoscopic biopsies were required to establish the diagnosis of the tumor in this unique location and in the midst of an evolving hematoma. After surgical resection, the patient received adjuvant chemotherapy. At 4-year follow-up, the child is neurologically intact, meeting normal developmental milestones, and imaging studies show no evidence of tumor. ATRT were previously associated with an extremely poor prognosis, but more recent evidence with complete surgical resection and adjuvant chemotherapy shows extended survival in some cases, supporting an aggressive and comprehensive approach to give these patients the best chance for a good outcome. Spontaneous brain hemorrhage in a full-term infant requires a diligent and persistent search to rule out an underlying neoplasm.