Faculty Bibliography

OBJECTIVES To assess the cross-sectional area and angle of the internal nasal valve more accurately by reformatting computed tomography (CT) scans of the nasal airway according to a more appropriate orientation than scans traditionally sectioned in the coronal plane and then to compare the results with clinical data on the nasal valve obtained from physical examination. METHODS We performed a retrospective review of the medical records of 24 rhinoplasty patients treated at a private practice facial plastic surgery office affiliated with a tertiary care university hospital. The patients had fine-cut (0.75-mm section) CT scans ordered for nasal airway obstruction or nasal valve compromise at the same institution. These patients were evaluated from January 1, 2000, through December 31, 2010. The previously acquired CT scans were reformatted to obtain sections through the internal nasal valve at a more appropriate orientation. The internal nasal valve cross-sectional area and valve angle were measured through a standardized section (1 cut immediately anterior to the head of the inferior turbinate) from the reformatted scans. The cross-sectional area was also measured through the same point on the traditionally oriented CT scan, and the values were compared. The results from each patient's scan were compared with data from the patient's medical record and analyzed against the patient's preoperative modified Cottle examination findings. RESULTS The CT scans oriented in the reformatted plane through the internal nasal valve provided a narrower valve angle than the traditionally oriented CT scans and more closely approximated the hypothesized true value of the internal nasal valve of 10 degrees to 15 degrees (P < .001). In a comparison of the same-side internal nasal valve angle and cross-sectional nasal valve area between the 2 different CT scan orientations, a statistically significant difference in the internal nasal valve angles between the 2 scan orientations was discovered, but this finding did not reach significance when distinguishing the nasal valve cross-sectional area. Finally, no correlation was found with regard to the preoperative modified Cottle maneuver scores for the internal nasal valve angle and cross-sectional valve area values in either scan orientation. CONCLUSIONS Precise preoperative evaluation of the internal nasal valve is critical to the workup for reconstruction or repair of problems that involve this area. Although tools such as acoustic rhinometry exist to evaluate the cross-sectional area of the nasal valve, many rhinoplasty surgeons do not have access to this expensive equipment. A CT scan with reformatting in the proper plane of the internal nasal valve can provide the surgeon with improved anatomical information to assess that region. With this in mind, however, the surgeon should always perform a thorough preoperative physical examination and treat the patient and his or her symptoms, not the imaging studies, when considering a candidate for a surgical intervention.

PURPOSE: The aim of this study was to use intravoxel incoherent motion diffusion-weighted imaging to discriminate subtypes of renal neoplasms and to assess agreement between intravoxel incoherent motion (perfusion fraction, fp) and dynamic contrast-enhanced magnetic resonance imaging (MRI) metrics of tumor vascularity. SUBJECTS AND METHODS: In this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved prospective study, 26 patients were imaged at 1.5-T MRI using dynamic contrast-enhanced MRI with high temporal resolution and diffusion-weighted imaging using 8 b values (range, 0-800 s/mm). Perfusion fraction (fp), tissue diffusivity (Dt), and pseudodiffusivity (Dp) were calculated using biexponential fitting of the diffusion data. Apparent diffusion coefficient (ADC) was calculated with monoexponential fit using 3 b values of 0, 400, and 800 s/mm. Dynamic contrast-enhanced data were processed with a semiquantitative method to generate model-free parameter cumulative initial area under the curve of gadolinium concentration at 60 seconds (CIAUC60). Perfusion fraction, Dt, Dp, ADC, and CIAUC60 were compared between different subtypes of renal lesions. Perfusion fraction was correlated with CIAUC60. RESULTS: We examined 14 clear cell, 4 papillary, 5 chromophobe, and 3 cystic renal cell carcinomas (RCCs). Although fp had higher accuracy (area under the curve, 0.74) for a diagnosis of clear cell RCC compared with Dt or ADC, the combination of fp and Dt had the highest accuracy (area under the curve, 0.78). The combination of fp and Dt diagnosed papillary RCC and cystic RCC with 100% accuracy, and clear cell RCC and chromophobe RCC, with 86.5% accuracy. There was significant strong correlation between fp and CIAUC60 (r = 0.82; P < 0.001). CONCLUSION: Intravoxel incoherent motion parameters fp and Dt can discriminate renal tumor subtypes. Perfusion fraction demonstrates good correlation with CIAUC60 and can assess degree of tumor vascularity without the use of exogenous contrast agent.

Objective: To test that cerebral atrophy is associated with increased risk for development of chronic subdural haematoma (cSDH), this study performed volumetric analysis of computed tomography (CT) brain scans from patients who were diagnosed with cSDH on subsequent CT scans and their age-matched controls. Methods: Volumetric analysis was performed on CT scans acquired a mean of 209 days prior to cSDH diagnosis in 19 patients. Cerebral atrophy present on these scans was then compared to 76 age-matched control patients randomly selected from cSDH-free subjects. Results: There was a higher degree of atrophy in cSDH patients (n = 19, 14.3% +/- 5.4%) than in age-matched control patients (n = 76, 11.9% +/- 5.5%; p = 0.044). Logistical regression demonstrated that atrophy was found to be a significant predictor of cSDH at all ages (OR = 1.11, 95% CI = [1.01, 1.23], p = 0.05). For younger subjects