Rath, Tanya J.

ABSTRACT Background Medial sural artery perforator (MSAP) flaps are favored in head and neck reconstruction for skin paddle pliability, pedicle length, and low donor site morbidity. We sought to characterize MSA vascular branching patterns based on the Dusseldorp et al. classification system using pre‐operative lower extremity computed tomography angiogram (CTA). Methods We conducted a retrospective review of 153 scans from 78 patients who underwent CTA prior to head and neck reconstruction at our institution. Primary data points included MSA branching pattern, branch dominance, and vessel depth. Results The type IIa branching type was most prevalent and the MSA lateral branch most frequently dominant, and they were significantly related to one another. There was no significant difference in depth between branching patterns. Conclusions Lower extremity CTA provides valuable insight to vascular anatomy for MSAP flap harvest. The type IIa and IIb types may be associated with lateral and medial MSA dominance, respectively.

Objective To determine the frequency and accuracy of diffusion restriction (DR) of the retina and/or optic nerve (ON) detection on standard brain magnetic resonance diffusion-weighted imaging (DWI-MRI) in patients presenting with acute non-arteritic central retinal artery occlusion (CRAO). Methods This is a retrospective case-control study that includes all consecutive patients presenting to our tertiary academic center from 2013-2021 with acute non-arteritic CRAO (cases) or acute ischemic stroke syndrome (controls, age and gender-matched) that had brain MRI performed within 14 days from symptom onset. Two neurology residents (junior and senior), a vascular neurologist, and two neuroradiologists, blinded to the site of CRAO, independently reviewed the brain MRIs to assess for the presence of retina and ON DR. The consensus agreement between the two neuroradiologists was used to perform sensitivity and specificity analyses and calculate inter-rater reliability (prevalence-adjusted bias-adjusted kappa coefficient). Results A total of 128 patients with acute non-arteritic CRAO (mean (SD) age 69 (14) years; 50% female; median time from CRAO to DW-MRI 2 days (IQR 1-5)) and 128 age and gender-matched controls with acute cerebral ischemia were included. After the neuroradiologist consensus, DR was correctly identified in the retina or ON in 51/128 (39.8%) CRAO cases, retina alone 27.3%, ON alone 24.2%, and both retina and ON 11.7%, with almost perfect neuroradiologists’ inter-rater reliability for retina (K = 0.91) and ON (K = 0.83). Among controls, the retina DR was identified in 1/128 (0.8%) and ON DR in 5/128 (3.9%). The sensitivity, specificity, positive predictive value, and negative predictive value were 28.1%, 99.2%, 97.3%, and 58.0% for retina DR, and 27.3%, 96.1%, 87.5%, and 56.9% for ON DR. Conclusions Though experienced neuroradiologists identified retina and ON DR with excellent inter-rater reliability, these are infrequent findings in real world CRAO practice, with excellent specificity but limited sensitivity. Prospective studies with larger cohort of patients, optimization of standardized orbit DWI-MRI protocols are needed to facilitate a more accurate and reliable identification of retina and ON DR in acute CRAO.

Objective: To assess whether diffusion restriction (DR) of the retina and optic nerve (ON) can be accurately and reliably identified on standard stroke protocol brain magnetic resonance diffusion-weighted imaging (DWI-MRI) in patients presenting with acute non-arteritic central retinal artery occlusion (CRAO). Background: Retinal DR (RDR) and ONDR in patients with acute non-arteritic CRAO have been described with various diagnostic accuracies and often identified by experienced neuroradiologists with fair inter-rater agreement. Methods: This retrospective case-control study included patients that presented to our academic center from 2013-2021 with acute non-arteritic CRAO or acute cerebral ischemia (controls, age and gender-matched) and had brain MRI performed within 14 days from symptom onset. Two neuroradiologists, blinded to the site of CRAO and diagnosis, independently reviewed MRI of CRAO cases and controls to assess for the presence of RDR and ONDR. Their inter-rater agreement was calculated (prevalence and bias- adjusted kappa coefficient) and their final consensus was used to perform sensitivity and specificity analyses. Results: We included 128 patients with CRAO (mean age 69 years; 50% males; median time from CRAO to MRI 2 days (IQR 1-5)) and 128 matched controls with acute cerebral ischemia (mean age 68 years; 51% males). After neuroradiologists’ consensus, DR was correctly identified in the retina or ON in 51/128 (39.8%), retina alone 35/128 (27.3%), ON alone 31/128 (24.2%), both retina and ON 15/128 (11.7%), with excellent inter-rater agreement for retina (K=0.91) and ON (K=0.83). There were no cases of RDR or ONDR in the control group. After neuroradiologists’ consensus, sensitivity, specificity, PPV and NPV were 28.1%, 100%, 100%, and 58.2% for RDR and 27.3%, 100%, 100%, and 57.9% for ONDR. Conclusion: Though RDR and ONDR can be identified with excellent interrater reliability, they are infrequent findings and their role in diagnosing acute CRAO is unclear. Observational prospective studies with large cohort of patients, optimization of dedicated and standardized orbit DWI-MRI protocols, and education of neurology and neuroradiology providers are needed to facilitate more accurate identification of RDR and ONDR in hyperacute CRAO.

Objective: To develop a methodology for the measurement of balloon dilation (BD) effects on Eustachian Tube (ET) structure using Computerized Tomography (CT) images. Methods: The BD of the ET was performed on three cadaver heads (five ears) through the nasopharyngeal orifice. The axial CT images of the temporal bones were obtained before dilation, while an inflated balloon was in the lumen of ET, and after balloon removal in each ear. Utilizing Dicom images captured by the ImageJ software 3D volume viewer function, the anatomical landmark coordinates of the ET were matched with their pre- and post-dilation counterparts, and the longitudinal axis of the ET was captured with serial images. The histograms of the regions of interest (ROI) and three different lumen width and length measurements were obtained from captured images. The densities of air, tissue, and bone were determined with histograms as a baseline to determine the BD rate as a function of increased air in the lumen. Results: The small ROI box included the area of prominently dilated ET lumen after BD and best represented the visually obvious changes in the lumen, compared to the ROIs that extended the wider areas (longest and longer). Air density was the outcome measure for comparison with each corresponding baseline value. The average increase in air density in the small ROI was 64%, while the longest and long ROI boxes showed 44 and 56% increases, respectively. Conclusion: This study describes a method to image the ET and quantify the outcomes of BD of the ET using anatomical landmarks.

OBJECTIVE Improper embryological development of the clivus, a bony structure that comprises part of the skull base, can lead to a clival canal defect. Previously thought to be a benign condition, clival canals have been reported to be associated with meningitis and meningoceles. In this review, the authors sought to present an unpublished case of a patient with a clival canal defect associated with meningitis and to evaluate all other reported cases. METHODS In October 2020, a search of PubMed, Web of Science, and Scopus was conducted to identify all cases of clival canals reported from January 1, 1980, through October 31, 2020. RESULTS Including the case presented herein, 13 cases of clival canals, 11 in children (84.6%) and 2 in adults (15.4%), have been identified. Of the pediatric patients, 5 (45.5%) had an associated meningocele, and 8 (72.7%) had meningitis. Nine of the 13 patients (69.2%) had defects that were treated surgically, 5 (38.5%) by a transnasal approach and 4 (30.8%) by a transoral approach. Two patients (15.4%) were treated with drainage and antibiotics, 1 patient (7.7%) was treated solely with antibiotics, and 1 patient (7.7%) was not treated. In the literature review, 8 reports of clival canals were found to be associated with meningitis, further contributing to the notion that the clival canal may be an overlooked source of recurrent infection. In several of these cases, surgical repair of the lesion was curative, thus preventing continued episodes of meningitis. CONCLUSIONS When a patient has recurrent meningitis with no clear cause, taking a closer look at clival anatomy is recommended. In addition, if a clival canal defect has been identified, surgical repair should be considered a safe and effective primary treatment option.

There is a wide spectrum of head and neck cartilaginous lesions which include both neoplastic and nonneoplastic processes. Cartilaginous tumors of the head and neck are uncommon, posing a diagnostic challenge. Benign cartilaginous tumors that may occur in the head and neck include chondroma, chondroblastoma, chondromyxoid fibroma, osteochondroma, and synovial chondromatosis. Chondromesenchymal hamartoma is a rare non-neoplastic cartilaginous lesion that is included for the 1first time in the new WHO classification and radiologically can mimic a tumor. Malignant cartilaginous tumors include chondrosarcoma and chondroid variant of chordoma. Characteristic tumor locations, internal chondroid matrix calcification, and typical T2 hyperintense signal secondary to high-water content within the extracellular matrix of the hyaline cartilage are useful imaging features that narrow the differential diagnosis and help in diagnosing these diseases. This article presents a narrative review of the anatomy of the head and neck cartilaginous structures, discusses the current knowledge and imaging spectrum of benign and malignant cartilaginous tumors and tumor-like lesions of the head and neck.