High-Resolution CT Imaging of the Temporal Bone: A Cadaveric Specimen Study.

Objective Super-high and ultra-high spatial resolution computed tomography (CT) imaging can be advantageous for detecting temporal bone pathology and guiding treatment strategies. Methods Six temporal bone cadaveric specimens were used to evaluate the temporal bone microanatomic structures utilizing the following CT reconstruction modes: normal resolution (NR, 0.5-mm slice thickness, 512 2 matrix), high resolution (HR, 0.5-mm slice thickness, 1,024 2 matrix), super-high resolution (SHR, 0.25-mm slice thickness, 1,024 2 matrix), and ultra-high resolution (UHR, 0.25-mm slice thickness, 2,048 2 matrix). Noise and signal-to-noise ratio (SNR) for bone and air were measured at each reconstruction mode. Two observers assessed visualization of seven small anatomic structures using a 4-point scale at each reconstruction mode. Results Noise was significantly higher and SNR significantly lower with increases in spatial resolution (NR, HR, and SHR). There was no statistical difference between SHR and UHR imaging with regard to noise and SNR. There was significantly improved visibility of all temporal bone osseous structures of interest with SHR and UHR imaging relative to NR imaging ( p < 0.001) and most of the temporal bone osseous structures relative to HR imaging. There was no statistical difference in the subjective image quality between SHR and UHR imaging of the temporal bone ( p ≥ 0.085). Conclusion Super-high-resolution and ultra-high-resolution CT imaging results in significant improvement in image quality compared with normal-resolution and high-resolution CT imaging of the temporal bone. This preliminary study also demonstrates equivalency between super-high and ultra-high spatial resolution temporal bone CT imaging protocols for clinical use.

A Comprehensive Review of Cross-Sectional Imaging of the Nasolacrimal Drainage Apparatus: What Radiologists Need to Know.

OBJECTIVE. The purpose of this study is to provide a comprehensive review of the radiographic anatomy and cross-sectional imaging findings of the full gamut of nasolacrimal drainage apparatus diseases, highlighting imaging findings from the different nasolacrimal drainage apparatus surgeries, posttreatment complications, and potential imaging pitfalls. CONCLUSION. Radiologists play a critical role in guiding the management of nasolacrimal drainage apparatus diseases and should be familiar with the anatomy and characteristic imaging findings of commonly encountered nasolacrimal drainage apparatus abnormalities and surgeries.

Degree of Frontal Bone Exposure via Upper Blepharoplasty Incision: Considerations for Frontal Sinus Fracture.

OBJECTIVE: The upper eyelid blepharoplasty incision affords direct access to the frontal bone for skull base surgery and trauma reconstruction with a well-hidden scar. The goal of this study is to quantify frontal bone exposure that can be achieved with an upper eyelid blepharoplasty incision. DESIGN: Anatomic study with human cadaver heads. SETTING: UC Davis Medical Center. SUBJECTS/METHODS: Fourteen human cadaver heads were used to perform 26 upper blepharoplasty approaches. Exposure was measured with virtual planning software to create virtual reference points at the midline of the superior orbital rim. Surgical navigation was used with a 3-dimensionally printed drill model to measure the maximum exposure achievable relative to the virtual reference point at 5 standardized angles. RESULTS: Mean ± SD exposures at medial 60°, medial 30°, 0°, lateral 30°, and lateral 60° were 16.1 ± 1.3 mm, 17.8 ± 1.3, 18.3 ± 1.4, 19.3 ± 1.9, and 20.9 ± 1.9, respectively. Significant differences were detected between exposures at 60° laterally and 60° medially and between exposures 60° laterally and 30° medially ( P < .05). CONCLUSIONS: The upper eyelid blepharoplasty incision provides direct surgical access to the inferior frontal bone. Access was greatest with far lateral extension (mean, 20.9 mm) and most limited with far medial extension (mean, 16.1 mm). Treatment of injuries above this level could be achieved with additional percutaneous incisions for screw placement.

Cost-Effectiveness of Endoscopic Versus Microscopic Transsphenoidal Surgery for Pituitary Adenoma.

BACKGROUND: Endoscopic transsphenoidal surgery (ETPS) has become increasingly popular for resection of pituitary tumors, whereas microscopic transsphenoidal surgery (MTPS) also remains a commonly used approach. The economic sustainability of new techniques and technologies is rarely evaluated in the neurosurgical skull base literature. The aim of this study was to determine the cost-effectiveness of ETPS compared with MTPS. METHODS: A Markov model was constructed to conduct a cost-utility analysis of ETPS versus MTPS from a single-payer health care perspective. Data were obtained from previously published outcomes studies. Costs were based on Medicare reimbursement rates, considering covariates such as complications, length of stay, and operative time. The base case adopted a 2-year follow-up period. Univariate and multivariate sensitivity analyses were conducted. RESULTS: On average, ETPS costs $143 less and generates 0.014 quality-adjusted life years (QALYs) compared with MTPS over 2 years. The incremental cost-effectiveness ratio (ICER) is -$10,214 per QALY, suggesting economic dominance. The QALY benefit increased to 0.105 when modeled to 10 years, suggesting that ETPS becomes even more favorable over time. CONCLUSIONS: ETPS appears to be cost-effective when compared with MTPS because the ICER falls below the commonly accepted $50,000 per QALY benchmark. Model limitations and assumptions affect the generalizability of the conclusion; however, ongoing efforts to improve rhinologic morbidity related to ETPS would appear to further augment the marginal cost savings and QALYs gained. Further research on the cost-effectiveness of ETPS using prospective data is warranted.