7T MR of intracranial pathology: Preliminary observations and comparisons to 3T and 1.5T.

PURPOSE: There have been an increasing number of studies involving ultra-high-field 7T of intracranial pathology, however, comprehensive clinical studies of neuropathology at 7T still remain limited. 7T has the advantage of a higher signal-to-noise ratio and a higher contrast-to-noise ratio, compared to current low field clinical MR scanners. We hypothesized 7T applied clinically, may improve detection and characterization of intracranial pathology. MATERIALS AND METHODS: We performed an IRB-approved 7T prospective study of patients with neurological disease who previously had lower field 3T and 1.5T. All patients underwent 7T scans, using comparable clinical imaging protocols, with the aim of qualitatively comparing neurological lesions at 7T with 3T or 1.5T. To qualitatively assess lesion conspicuity at 7T compared with low field, 80-paired images were viewed by 10 experienced neuroradiologists and scored on a 5-point scale. Inter-rater agreement was characterized using a raw percent agreement and mean weighted kappa. RESULTS: One-hundred and four patients with known neurological disease have been scanned to date. Fifty-five patients with epilepsy, 18 patients with mild traumatic brain injury, 11 patients with known or suspected multiple sclerosis, 9 patients with amyotrophic lateral sclerosis, 4 patients with intracranial neoplasm, 2 patients with orbital melanoma, 2 patients with cortical infarcts, 2 patients with cavernous malformations, and 1 patient with cerebral amyloid angiopathy. From qualitative observations, we found better resolution and improved detection of lesions at 7T compared to 3T. There was a 55% raw inter-rater agreement that lesions were more conspicuous on 7T than 3T/1.5T, compared with a 6% agreement that lesions were more conspicuous on 3T/1.5T than 7T. CONCLUSION: Our findings show that the primary clinical advantages of 7T magnets, which include higher signal-to-noise ratio, higher contrast-to-noise ratio, smaller voxels and stronger susceptibility contrast, may increase lesion conspicuity, detection and characterization compared to low field 1.5T and 3T. However, low field which detects a plethora of intracranial pathology remains the mainstay for diagnostic imaging until limitations at 7T are addressed and further evidence of utility provided.

Dermatofibrosarcoma Protuberans: Update on the Diagnosis and Treatment.

Dermatofibrosarcoma protuberans (DFSP) is a slow growing, low- to intermediate-grade dermal soft-tissue tumor. It has a high local recurrence rate but low metastatic potential. It is characterized by a uniform spindle cell arrangement, classically with a storiform pattern and CD34 immunoreactivity. The histomorphology and immunophenotype overlap with a broad range of other neoplasms. The standard treatment is complete surgical excision. The surgical procedures include wide local excision (WLE) with tumor free margins, Mohs micrographic surgery (MMS) and amputation. Unresectable DFSPs are treated with radiation therapy and/or targeted therapy. DFSP has characteristic t(17; 22) (q22; q13), resulting in a COL1A1- PDGFB fusion transcripts in more than 90% of DFSPs. Molecular detection of the gene rearrangement or fusion transcripts is helpful for the diagnosis of patients with atypical morphology and for screening candidates for targeted therapy with tyrosine kinase inhibitors. The aims of the present review are to update the clinical presentation, tumorigenesis and histopathology of DFSP and its variants for diagnosis and differential diagnosis from other benign and malignant tumors, to compare the advantages and drawbacks of WLE and MMS, to propose the baseline for selecting surgical procedure based on tumor's location, size, stage and relationship with surrounding soft tissue and bone structures, and to provide a biologic rationale for the systemic therapy. We further propose a modified clinical staging system of DFSP and a surveillance program for the patients after surgical excision.

Imaging for headache: what the neuroradiologist looks for.

In this article, computed tomography and magnetic resonance imaging anatomy and pathology of sinus disease is discussed, specifically relating to facial pain, rhinogenic headache, and sinus outflow obstruction. Findings commonly seen in acute, chronic, infectious, and inflammatory sinusitis are illustrated, with additional examples of secondary intracranial and orbital involvement, and more aggressive infectious and neoplastic processes.

Imaging in cutaneous oncology: radiology for dermies.

An overview of currently available imaging modalities is presented. Indications for imaging in cutaneous nonmelanoma skin cancers, selection of the most appropriate and cost-effective study, limitations, and risks are discussed. Finally, representative cases are discussed with emphasis on choice of imaging study for preoperative staging and treatment planning.

The magnetic resonance imaging profile of occult intracranial violations as a result of sinus surgery.

INTRODUCTION: Intracranial injury is a well-described complication of sinus surgery. Although such complications are typically associated with catastrophic morbidity, the neurological sequelae may be subtle and even unrecognized during the postoperative period. Magnetic resonance imaging (MRI), which can distinguish intracranial hemorrhage and injury, may provide a means for the accurate assessment of atypical presentations of occult intracranial complications. OBJECTIVE: To describe the MRI profile of occult intracranial complications that result from unrecognized skull base violation during sinus surgery. METHOD: Retrospective chart review. RESULTS: Two patients, who had endoscopic sinus surgery performed elsewhere, underwent postoperative MR for further evaluation of headache. The available medical records, as well as the patient's personal reports, suggested that no intraoperative cranial base compromise had occurred. Both MRIs showed abnormal signal intensity in the brain parenchyma adjacent to the floor of the anterior cranial fossa; these findings are consistent with traumatic injury presumably from the surgical procedure. Neither patient developed postoperative cerebrospinal fluid rhinorrhea, and neither patient experienced focal neurological deficits. CONCLUSION: New-onset and/or atypical headache after sinus surgery may be associated with occult intracranial injury. MRI may serve as the diagnostic means for this occult intracranial violation. Significant incongruity may exist between patient symptoms and the objective MR evidence that can suggest serious intracranial injury. MRI signal patterns can provide both temporal and anatomical cues about the specific injury.