Low-Energy Virtual Monochromatic Dual-Energy Computed Tomography Images for the Evaluation of Head and Neck Squamous Cell Carcinoma: A Study of Tumor Visibility Compared With Single-Energy Computed Tomography and User Acceptance.

OBJECTIVE: Dual-energy computed tomography (CT) 40-keV virtual monochromatic images (VMIs) have been reported to improve visualization of head and neck squamous cell carcinoma, but a direct comparison to single-energy CT (SECT) is lacking, and there is debate regarding subjective user preference. We compared 40-keV VMIs with SECT and performed a subjective evaluation of their utility and acceptability for clinical use. METHODS: A total of 60 dual-energy CT and 60 SECT scans from 2 different institutions were evaluated. Tumor conspicuity was evaluated objectively using absolute and relative attenuation and subjectively by 3 head and neck specialists and 3 general radiologists. RESULTS: Tumors had significantly higher absolute and relative attenuation on 40-keV VMIs (P < 0.0001). Subjectively, the 40-keV VMIs improved visualization, with substantial (κ, 0.61-0.80) to almost perfect (κ, 0.81-1) interrater agreements. CONCLUSIONS: The 40-keV VMIs improve tumor visibility objectively and subjectively both by head and neck specialists and general radiologists.

Percutaneous US-guided renal biopsy: a retrospective study comparing the 16-gauge end-cut and 14-gauge side-notch needles.

PURPOSE: Assess glomerular yield and safety profile of two different types of needles for percutaneous ultrasound-guided kidney biopsy. MATERIALS AND METHODS: Over 24 months, 121 ultrasonographic ultrasound-guided renal biopsies were performed on native kidneys of 121 adults: 66 with 16-gauge, 29-mm end-cut (BioPince) needles and 55 with 14-gauge, 1.9-mm side-notch (Tru-Cut) needles. RESULTS: The mean number of complete glomeruli harvested per biopsy was 21.0 and 19.3, respectively, and the mean number of core samples required to obtain a satisfactory biopsy was 1.8 and 2.6, respectively. The ratio of glomeruli harvested to core samples needed with the end-cut needle was 58% greater than that with the side-notch needles (11.7 vs 7.4, respectively; difference of 4.3; 95% confidence interval: 2.0, 6.8). Procedures performed with end-cut needles were associated with fewer major complications (1.5% vs 7.3% with side-notch needles). CONCLUSIONS: Compared to the 14-g Tru-cut needle, the 16-g end-cut needle provided better glomerular yield per core sample, required fewer cores for satisfactory tissue specimen, and resulted in fewer major complications.

Value of pre-operative breast MRI for the size assessment of ductal carcinoma in situ.

OBJECTIVE: To retrospectively evaluate the accuracy of pre-operative breast MRI and mammography in determining the size of ductal carcinoma in situ (DCIS) compared with the histopathological results. METHODS: 79 patients [mean age: 56.5 (standard deviation 10.2) years] with pathologically proven DCIS (79 lesions) obtained a bilateral mammogram and a pre-operative contrast-enhanced MRI. The accuracy of MRI and mammography to detect tumour size were estimated and compared, using histopathological size as the gold standard, on the subjects with measurements with both modalities (n = 60). RESULTS: MRI detected 67 (85%) lesions, mammography detected 72 (91%) and both modalities detected 60 (76%). Median DCIS size detected by mammography vs MRI was smaller (1.55 vs 1.65 cm). Out of these 60 cases, compared with the histopathological size, the accuracy of MRI and mammography was 0.66 and 0.56, respectively (p = 0.045). MRI showed better accuracy than mammography for younger patients (age ≤ 50 years, p = 0.003). For tumour nuclear grade, there was a statistically significant difference for the intermediate level, with higher accuracy for MRI (p = 0.03). CONCLUSION: MRI was more accurate than mammography in DCIS size assessment when visible, particularly in lesions of intermediate grade and in patients less than 50 years of age. ADVANCES IN KNOWLEDGE: Breast MRI may help in management of DCIS of intermediate grade and in females less than 50 years of age.