Patricia C. Davis

Nonaccidental Pediatric Head Injury: Diffusion-weighted Imaging Findings

OBJECTIVEDiffusion-weighted imaging (DWI) reveals nonhemorrhagic posttraumatic infarction hours to days before conventional computed tomographic scanning or magnetic resonance imaging (MRI). We evaluated the diagnostic utility of DWI in children with nonaccidental head trauma. METHODSThe medical records and imaging examinations obtained between January 1998 and May 2000 for all children less than 2 years of age with presumed or suspected nonaccidental head injury were reviewed retrospectively. Twenty children who had undergone DWI within 5 days of presentation were included in the study. Computed tomographic scans, conventional MRI sequences, and DWI combined with apparent diffusion coefficient (ADC) maps were evaluated. RESULTSEleven girls and nine boys (median age, 5 mo) were studied. Eighteen children had presumed nonaccidental head trauma, and two children had suspected nonaccidental head trauma. Of the 18 children with presumed nonaccidental trauma, 16 (89%) demonstrated abnormalities on DWI/ADC, as compared with neither of the two children with suspected nonaccidental trauma. In 13 (81%) of 16 positive cases, DWI revealed more extensive brain injury than was demonstrated on conventional MRI sequences or showed injuries not observed on conventional MRI. DWI combined with ADC maps allowed better delineation of the extent of white matter injury. DWI/ADC abnormalities in the nonaccidental head-injured children were likely to involve posterior aspects of the cerebral hemispheres, with relative sparing of the frontal and temporal poles. Severity on DWI correlated significantly with poor outcome (P < 0.005). CONCLUSIONDWI has broad applications in the early detection of infarction in children with nonaccidental head injury and enhances the sensitivity of conventional MRI. In the patients in this study, early DWI provided an indicator of severity that was more complete than any other imaging modality. The use of DWI may help to identify children at high risk for poor outcome and to guide management decisions.

Intracranial aneurysms in infants and children

Background. The diagnosis and imaging of pediatric aneurysms has changed since the advent of MR and MRA. Objective. To update the literature on pediatric aneurysms and better define the appropriate work-up of childhood aneurysms in 1997. Materials and methods. Retrospective review of 21 children (12 boys, 9 girls) with 25 aneurysms from three institutions over a 20-year period was performed. Imaging studies were mixed and included CT (19 patients), MR (11 patients), MRA (6 patients) and angiography (18 patients). Results. Eighteen of 25 aneurysms were congenital saccular, 6 were mycotic, and 1 was post-traumatic. Of these, 44 % were in the posterior circulation. Nine aneurysms arose from distal arterial branches. Forty percent were large (between 1–2.5 cm) and 16 % were giant (> 2.5 cm). CT and MR showed hemorrhage, and frequently revealed the aneurysms as a focal mass with or without enhancement and flow void. Six children had MRA which revealed aneurysms in four patients. All patients with MRA had corresponding conventional angiography. Conclusion. Characteristics of pediatric aneurysms include diversity of type, increased incidence in the posterior fossa, peripheral location, and large size. CT, MR and MRA are useful in the diagnosis with conventional angiography essential for preoperative planning.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part III. Reliability of a standardized MRI evaluation of Alzheimer's disease

The Consortium to Establish a Registry for Alzheimers Disease (CERAD) has developed procedures for standardized imaging and reporting of magnetic resonance (MR) findings in Alzheimers disease (AD) for use by neuroradiologists in multiple medical centers using a variety of MR equipment and field strengths. After initial pretesting, we revised the protocol, expanded the summary rating scale to seven points, and added more illustrations. Fourteen participating neuroradiologists evaluated 28 MR scans of elderly patients, giving us the basis for judging interrater agreement. We obtained acceptable intraclass correlations (>0.79) for rating the size of the lateral and third ventricles and the temporal horn. Less satisfactory intraclass correlations occurred when rating other areas, including (1) global atrophy of the brain (0.70); (2) dilatation of the sulci of the temporal lobe (0.66); (3) frequency, location, and severity of white matter lesions (0.77); (4) sylvian fissure enlargement (0.70); and (5) cerebral sulcal dilatation (0.64). We also saw considerable variation in the reporting of cortical and lacunar infarcts. Despite careful design of the rating methodology and readings by experienced neuroradiologists, we did not find satisfactory interrater agreement for interpreting MR findings in elderly subjects. These findings may explain the difficulties encountered in applying similar subjective rating techniques that meet with success at one institution to multicenter studies. More objective and reproducible procedures are needed for interpretation of neuroimaging findings of AD in multicenter studies.

Intraventricular Primary Cerebral Neuroblastoma in Adults: Report of Three Cases

Primary cerebral neuroblastoma most often occurs in the cerebral parenchyma in children. When it occurs in adults, it is also described as an intraparenchymal neoplasm. We report three cases of primary cerebral neuroblastoma in adults presenting as an intraventricular mass.

ACR Appropriateness Criteria® on Low Back Pain

Acute low back pain with or without radiculopathy is one of the most common health problems in the United States, with high annual costs of evaluation and treatment, not including lost productivity. Multiple reports show that uncomplicated acute low back pain or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Guidelines for recognition of patients with more complicated status can be used to identify those who require further evaluation for suspicion of more serious problems and contribute to appropriate imaging utilization.

Moyamoya disease in the United States

The epidemiology and radiological features of Moyamoya disease (MMD) in the US were investigated. This study encompassed 98 cases; 26 were newly collected from eight US institutions and 72 were previously reported in the US literature. The patients ranged in age from 6 months to 67 years with age peaks in the first, third and fourth decades. MMD was seen in various ethnic groups and females were more commonly involved (71%) than males. A specific etiology could not be determined in most cases but arteriosclerosis and use of oral contraceptives were occasional associations. On angiography and/or magnetic resonance angiography (MRA), carotid arterial stenosis or occlusion was seen bilaterally in 95 cases (97%) and unilaterally in three. On MR or MRA, internal carotid steno-occlusive lesions were well demonstrated in all cases but Moyamoya collateral vessels (MMVs) were visualized in only 65% of the patients. MMVs in the basal ganglia and thalami were best demonstrated on T1 weighted images. Parenchymal lesions were seen in all patients and were often bilateral. With advances in MR techniques and increasing awareness of diagnostic guidelines, MMD will be diagnosed more frequently than before in the US.

ACR Appropriateness Criteria Sinonasal Disease

Imaging of sinonasal pathology may occur for assessment of rhinosinusitis or mass lesions. Rhinosinusitis is prevalent in up to 16% of the US population with annual economic burdens estimated at 22 billion dollars. Rhinosinusitis is characterized as acute or chronic based on symptom duration; if four or more episodes occur annually, the term recurrent acute rhinosinusitis (RARS) is used. In acute uncomplicated rhinosinusitis when inflammatory change remains in the paranasal sinuses and nasal cavity, imaging may not be required. Distinction between viral or bacterial rhinosinusitis is a clinical diagnosis, and imaging should be interpreted in conjunction with clinical and endoscopic findings. Sinus CT imaging is appropriate per clinical judgment in associated complications including headache, facial pain, swelling, orbital proptosis, or cranial nerve palsies. In maxillary sinusitis, teeth may require assessment because 20% may be odontogenic in origin. MRI may be complementary in aggressive infections with intraocular/intracranial complications, invasive fungal sinusitis, or sinonasal masses. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Effective adjuvant chemotherapy for advanced nasopharyngeal carcinoma in children : A final update of a long-term prospective study in a single institution

Purpose: The purpose of this study was to determine the efficacy and toxicity of a doxorubicin/eyclophosphamide-based chemotherapy and local radiation therapy in children with locally advanced or metaslatic nasopharyngeal carcinoma (NPC). Patients and Methods: Twelve patients aged 6 to 20 years old were treated with a chemotherapy regimen comprised of vincristine (1.5 mg/m2) and doxorubicin (45 mg/m2) on day 1 and cyclophosphamide (210 mg/m2) and 5-fluorouracil (240 mg/m2) on days 1 to 5. Chemotherapy was administered every 3 weeks for 1 to 2 years. Radiotherapy to the primary site (59 to 68 Gy) and to the neck (59 to 66 Gy) was given before or after 2 to 4 courses of chemotherapy. Results: All patients achieved a complete response 4 to 16 months from the start of therapy (median 7 months). Nine patients have remained tumor free from 2 to 21 years (median 11 years) from diagnosis. One child was lost to follow-up and one died of tuberculosis; both were disease-free. One child developed a secondary osteosarcoma in the left mandible. Chemotherapy caused grade 4 neutropenia and thrombocytopenia in four patients. There were no therapy-related deaths and the most common late effect of therapy was neck fibrosis, which was observed in all patients. We conclude that the chemotherapy and radiotherapy regimen used in this study is highly effective for children and adolescents with locally advanced NPC and is associated with tolerable toxicity.

Optic Nerve Hypoplasia: Absence of Posterior Pituitary Bright Signal on Magnetic Resonance Imaging Correlates With Diabetes Insipidus

PURPOSE Magnetic resonance imaging has been used to examine children with optic nerve hypoplasia for pituitary abnormalities who may be at risk for anterior pituitary hormonal deficiencies. We correlated the sellar and optic pathway anatomic findings on magnetic resonance imaging in children with optic nerve hypoplasia with findings from their endocrinologic and ophthalmologic examinations to determine whether magnetic resonance imaging findings predict anterior and posterior pituitary dysfunction. METHODS A retrospective review identified five children with optic nerve hypoplasia and endocrinopathy who also underwent high resolution volumetric magnetic resonance imaging. RESULTS All children had severe bilateral optic nerve hypoplasia and anterior pituitary hormone deficiencies. Three children had no recognizable intrasellar or ectopic posterior pituitary bright spot on magnetic resonance imaging; all had clinical evidence of diabetes insipidus. Two patients with a recognizable but ectopic posterior pituitary did not have diabetes insipidus. CONCLUSION Children with optic nerve hypoplasia and no recognizable posterior lobe of the pituitary gland on magnetic resonance imaging are at risk for both anterior and posterior pituitary dysfunction, whereas those with a posterior lobe on magnetic resonance imaging appear to have intact posterior pituitary function.

ACR Appropriateness Criteria® on Cerebrovascular Disease

Stroke is the sudden onset of focal neurologic symptoms due to ischemia or hemorrhage in the brain. Current FDA-approved clinical treatment of acute ischemic stroke involves the use of the intravenous thrombolytic agent recombinant tissue plasminogen activator given <3 hours after symptom onset, following the exclusion of intracerebral hemorrhage by a noncontrast CT scan. Advanced MRI, CT, and other techniques may confirm the stroke diagnosis and subtype, demonstrate lesion location, identify vascular occlusion, and guide other management decisions but, within the first 3 hours after ictus, should not delay or be used to withhold recombinant tissue plasminogen activator therapy after the exclusion of acute hemorrhage on noncontrast CT scans. MR diffusion-weighted imaging is highly sensitive and specific for acute cerebral ischemia and, when combined with perfusion-weighted imaging, may be used to identify potentially salvageable ischemic tissue, especially in the period >3 hours after symptom onset. Advanced CT perfusion methods improve sensitivity to acute ischemia and are increasingly used with CT angiography to evaluate acute stroke as a supplement to noncontrast CT. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.