Faculty Bibliography

The differential diagnosis of a red and/or pulsatile retrotympanic mass includes aberrant internal carotid artery, persistent stapedial artery (PSA), glomus tympanicum, and dehiscent jugular bulb. By recognizing the features of aberrant internal carotid artery and PSA on high-resolution computed tomography, these entities can be assessed by the radiologist. PSA is further classified by type because each type demonstrates a unique set of imaging features in addition to features common to all types. Although rarely encountered, it is important to reliably and consistently detect these anomalies because failure to do so can lead to disastrous surgical outcomes.

Temporal bone pathologies are challenging to discern because of their small size and subtle contrast. MR imaging is one of the key modalities in evaluating otologic diseases. Current advancement in MR techniques provide multiparametric information for evaluation of these pathologies. The aim of this article is to review state-of-the-art 3-dimensional morphologic and diffusion sequences for otologic MR imaging.

Detection of wooden foreign bodies within the orbit can be difficult on imaging, including computed tomography (CT). When visible, wood appears iso- or hypodense and can mimic air or fat. We report the case of a 3-year-old boy with progressive orbital cellulitis following a penetrating wood injury to the right lower lid. CT imaging revealed a linear hyperdensity contiguous with an orbital abscess. He underwent a right anterior orbitotomy with abscess drainage, during which exploration revealed a 2.3 cm retained wooden foreign body. The appearance of wood as hyperdense on imaging is unusual. In the appropriate context, high clinical suspicion for retained wood should be maintained with any irregularity on CT imaging.

Visual loss can be the result of an abnormality anywhere along the visual pathway including the globe, optic nerve, optic chiasm, optic tract, thalamus, optic radiations or primary visual cortex. Appropriate imaging analysis of visual loss is facilitated by a compartmental approach that establishes a differential diagnosis on the basis of suspected lesion location and specific clinical features. CT and MRI are the primary imaging modalities used to evaluate patients with visual loss and are often complementary in evaluating these patients. One modality may be preferred over the other depending on the specific clinical scenario. Depending on the pattern of visual loss and differential diagnosis, imaging coverage may require targeted evaluation of the orbits and/or assessment of the brain. Contrast is preferred when masses and inflammatory processes are differential considerations. 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.

OBJECTIVE:FSE sequences play key roles in neck MRI despite the susceptibility issues in neck region. Iterative decomposition of asymmetric echoes (IDEAL, GE) is a promising method that separates fat and water images resulting in high SNR and improved fat suppression. We tested how neck tissue contrasts, image artifacts and fat separation as opposed to fat suppression in terms of image quality compare between routine and IDEAL FSE. METHODS:-weighted FSE sequences were applied for neck MRI at 1.5T and 3T. Overall image quality including fat suppression, tissue contrast, image artifacts and lesion conspicuity were subjectively assessed for 20 patients clinically indicated for neck MRI. Quantitative tissue contrast estimates from parotid area were compared between IDEAL and routine FSE for 7 patients. Four patients with oncocytoma were also reviewed to assess benefits of separately reconstructed fat specific image sets. RESULTS:Subjective tissue contrast and overall image quality including image sharpness, fat suppression and image artifacts were superior for IDEAL sequences. For oncocytoma fat specific IDEAL images provided additional information. Objective CNR estimates from a central slice were equivalent for IDEAL and routine FSE at both field strengths. CONCLUSIONS:. However, the objective contrast estimates for parotid gland at isocenter were statistically equivalent for IDEAL and conventional FSE perhaps because at or near isocenter routine FSE works well. Additionally, fat specific IDEAL image sets add to diagnostic specificity for fat deficient lesions.

This article provides a practical overview of head and neck cancers, outlining an approach to evaluating these lesions and optimizing imaging strategies. Recognition of key anatomic landmarks as suggested by American Joint Committee on Cancer (AJCC) tumor, node, metastasis (TNM) criteria is emphasized. Further, the recently updated eighth edition of the AJCC staging manual has introduced some modifications that influence the TNM staging. These modifications are discussed throughout the article to provide an updated review on head and neck cancer.

Evaluation of cranial neuropathy can be complex given the different pathway of each cranial nerve as well as the associated anatomic landmarks. Radiological evaluation requires imaging of the entire course of the nerve from its nucleus to the end organ. MRI is the modality of choice with CT playing a complementary role, particularly in the evaluation of the bone anatomy. Since neoplastic and inflammatory lesions are prevalent on the differential diagnosis, contrast enhanced studies are preferred when possible. The American College of Radiology Appropriateness Criteria are evidencebased 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.