Julie Bykowski

ACR Appropriateness Criteria Head Trauma

Neuroimaging plays an important role in the management of head trauma. Several guidelines have been published for identifying which patients can avoid neuroimaging. Noncontrast head CT is the most appropriate initial examination in patients with minor or mild acute closed head injury who require neuroimaging as well as patients with moderate to severe acute closed head injury. In short-term follow-up neuroimaging of acute traumatic brain injury, CT and MRI may have complementary roles. In subacute to chronic traumatic brain injury, MRI is the most appropriate initial examination, though CT may have a complementary role in select circumstances. Advanced neuroimaging techniques are areas of active research but are not considered routine clinical practice at this time. In suspected intracranial vascular injury, CT angiography or venography or MR angiography or venography is the most appropriate imaging study. In suspected posttraumatic cerebrospinal fluid leak, high-resolution noncontrast skull base CT is the most appropriate initial imaging study to identify the source, with cisternography reserved for problem solving. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three 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.

Hearing preservation and vestibular schwannoma: intracochlear FLAIR signal relates to hearing level.

Objectives This study aimed to evaluate the relationship between cochlear signal on fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) sequences and hearing in patients undergoing hearing preservation surgery for vestibular schwannoma (VS) and to demonstrate a new classification system to be used in imaging evaluation of patients with VS. Methods A search of archived surgical cases at a single institution between January 1, 2006, and January 1, 2012, revealed 51 patients who underwent hearing preservation surgery for VS. Tumor size, patient age and sex, and preoperative and postoperative pure-tone average (PTA) and speech discrimination score (SDS) were recorded. Cochleae on the affected side were examined on preoperative FLAIR sequences and classified as limited hyperintensity (LH) or extensive hyperintensity (EH). Results Mean patient age was 51 years, and mean tumor size was 1.3 cm. Preoperative FLAIR sequences were classified into LH (n = 36) and EH (n = 15) categories. Preoperative PTA and SDS were 29.5 dB (SD, 16.7), 90% (SD, 14) and 40.6 dB (SD, 13.8), 80% (SD, 25) for LH and EH, respectively. On univariate analysis, preoperative PTA was superior in the LH group (p = 0.04). There was a trend toward superior preoperative SDS and postoperative PTA in the LH group, but these differences were not statistically significant (p = 0.08 and p = 0.06, respectively). Conclusion The current study is the first to demonstrate a distinct association between cochlear FLAIR signal and pretreatment hearing levels in patients with VS. A new classification system for evaluating cochlear FLAIR signal is proposed. Improvement in FLAIR sequences will allow further investigation of this association.

Variant carotid origin of left anterior inferior cerebellar artery mimicking infarct on angiography

A case is presented of a rare anterior inferior cerebellar artery variant, originating from the internal carotid artery. This mimicked a cerebellar infarct on vertebral angiography of a patient who presented with dysmetria and gait imbalance. It is important for the neuroradiologist and neurointerventionist to be aware of common and unusual cerebellar arterial anatomic variants to avoid incorrect diagnoses, as well as understand possible implications for surgery and interventional therapies.

ACR Appropriateness Criteria® Myelopathy

Patients presenting with myelopathic symptoms may have a number of causative intradural and extradural etiologies, including disc degenerative diseases, spinal masses, infectious or inflammatory processes, vascular compromise, and vertebral fracture. Patients may present acutely or insidiously and may progress toward long-term paralysis if not treated promptly and effectively. Noncontrast CT is the most appropriate first examination in acute trauma cases to diagnose vertebral fracture as the cause of acute myelopathy. In most nontraumatic cases, MRI is the modality of choice to evaluate the location, severity, and causative etiology of spinal cord myelopathy, and predicts which patients may benefit from surgery. Myelopathy from spinal stenosis and spinal osteoarthritis is best confirmed without MRI intravenous contrast. Many other myelopathic conditions are more easily visualized after contrast administration. Imaging performed should be limited to the appropriate spinal levels, based on history, physical examination, and clinical judgment. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three 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.

Imaging Analysis of Ménière’s Disease

Advances in magnetic resonance imaging have recently allowed the demonstration of endolymphatic hydrops (EH) in human subjects. Ménière’s Disease (MD) is diagnosed based on a constellation of symptoms and can be corroborated with a variety of clinical tests. Prior to the current era, however, EH in MD could only be directly visualized on postmortem human temporal bone studies. Imaging techniques using both intratympanic and intravenous contrast have progressed with the help of animal models, and imaging protocols for evaluation of EH in humans continue to evolve as image resolution and post-processing techniques improve. Although the clinical implications of these imaging modalities seem promising, the details of the specific applications of MR imaging of EH remain to be elucidated.

ACR Appropriateness Criteria® Tinnitus

Tinnitus is the perception of sound in the absence of an external source. It is a common symptom that can be related to hearing loss and other benign causes. However, tinnitus may be disabling and can be the only symptom in a patient with a central nervous system process disorder. History and physical examination are crucial first steps to determine the need for imaging. CT and MRI are useful in the setting of pulsatile tinnitus to evaluate for an underlying vascular anomaly or abnormality. If there is concomitant asymmetric hearing loss, neurologic deficit, or head trauma, imaging should be guided by those respective ACR Appropriateness Criteria® documents, rather than the presence of tinnitus. Imaging is not usually appropriate in the evaluation of subjective, nonpulsatile tinnitus that does not localize to one ear. 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.

Chronic sialadenitis with sialolithiasis associated with parapharyngeal fistula and tonsillolith

Sialolithiasis is a common salivary pathology, suggested to affect over 1% of the population by postmortem studies. An uncommon complication of sialadenitis and sialolithiasis is the formation of fistulous tracts to other cervicofacial compartments. Submandibular gland sialocutaneous and sialo-oral fistulae have been sparsely described, but a sialo-pharyngeal fistula manifesting as a tonsillolith has yet to be described. We present an unusual case of a 35-year-old male presenting with recalcitrant neck pain and a presumed tonsillolith in the background of chronic submandibular sialadenitis, subsequently demonstrating a salivary fistula through the parapharyngeal space. We offer a thorough review of the literature to highlight the possibility of migratory sialolithiasis and its complications.

E-019 Preoperative cortical localization by magnetic source imaging for endovascular treatment of arterial venous malformations in eloquent brain tissue

Introduction Preoperative localization of functionally eloquent brain tissue helps plan and tailor the extent of endovascular embolization and surgical resection of AVMs. Combined magnetoencephalography and MR data can be used to localize functional somatosensory, auditory, and motor cortical organization. Materials and Methods Retrospective review of all AVMs treated (both endovascular and surgical) at our institution over the past 2 years. We identified 4 cases of AVMs involving eloquent cortical brain tissue with associated magnetic source imaging for localization of cortical organization. Case records were reviewed for patient outcome and impact of cortical organization localization of treatment and management. Results Combined magnetoencephalography and MR data had a high degree of reliability in localizing motor cortex in areas adjacent to and incorporated by AVMs. Localization of motor cortex affected AVM treatment plans focusing on preservation of motor cortex function. Conclusion Functional mapping of the cortex is indispensable for optimal treatment of AVMs involving eloquent brain tissue. The cases outlined demonstrate the capability of preoperative spatiotemporal functional brain mapping using MEG.