Rotator cable: MRI study of its appearance in the intact rotator cuff with anatomic and histologic correlation.

OBJECTIVE: The purpose of this study was to define and correlate the appearance of the rotator cable on MRI with arthroscopy, band-saw cadaveric sections, and histology. MATERIALS AND METHODS: Two cadaveric shoulders underwent 3-T MRI, band-sawing, and histologic evaluation. Three readers evaluated the MRI for the presence of the cable, and the same readers and a pathologist reviewed the macroscopic and microscopic specimens for a structure that corresponded to the cable. Cadaver 1 underwent arthroscopic evaluation to evaluate for the presence of a cable. Seventy consecutive shoulders that underwent 1.5- or 3-T MRI were also reviewed for the presence of the cable and evaluation of its characteristics (location, thickness, and width). RESULTS: A linear band of hypointense signal intensity was found along the undersurface of the supraspinatus and infraspinatus tendons on both cadaveric MR images, which correlated to a linear band of tissue in the same location on macroscopic and microscopic evaluation and linear thickening along the cuff articular surface on arthroscopy consistent with the cable. The cable was seen in 74.3% of the MRI studies in both sagittal and coronal planes with a mean (± SD) distance of the cable from the medial margin of the enthesis of 1.33 ± 0.27 cm, a mean width of the cable of 1.24 ± 0.31 cm, and a mean thickness of 0.19 ± 0.05 cm. CONCLUSION: The rotator cable is a structure that can be consistently seen on gross anatomic and histologic analysis, arthroscopy, and MRI in the intact rotator cuff. Familiarity with the typical location and morphology of the cable may allow easier characterization of disease that can involve the cable, such as rotator cuff tears.

CT colonography in senior versus nonsenior patients: extracolonic findings, recommendations for additional imaging, and polyp prevalence.

PURPOSE: To retrospectively evaluate the frequency of recommendations for additional imaging (RAIs) for important extracolonic findings and polyp prevalence among a cohort of seniors (age ≥ 65 years) and nonseniors (age < 65 years) undergoing low-dose computed tomographic (CT) colonography. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant retrospective study. Four hundred fifty-four patients (204 nonseniors: mean age, 52 years; 250 seniors: mean age, 69 years) underwent CT colonography at an outpatient facility. Cases were prospectively reported by one of four abdominal radiologists with expertise in CT colonography. The dictated reports were reviewed to determine the frequency of polyps (≥6 mm), the number of extracolonic findings, and the number of RAIs generated. The Fisher exact test was used to compare the percentage of seniors and nonseniors with at least one reported polyp, with at least one extracolonic finding, as well as the frequency of RAIs. RESULTS: The percentage of patients with at least one reported polyp was 14.2% (29 of 204) for the nonsenior group and 13.2% (33 of 250) for seniors, which was not significantly different (P = .772). The percentage of patients with at least one extracolonic finding was 55.4% (113 of 204) for nonseniors and 74.0% (185 of 250) for seniors (P < .0001). The percentage of patients in which an RAI was suggested was 4.4% (nine of 204) for nonseniors and 6.0% (15 of 250) for seniors, which was not significantly different (P = .450). CONCLUSION: Extracolonic findings were more frequent in seniors than in nonseniors; however, there was no significant difference in the frequency of RAIs between the two groups. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102144/-/DC1.

Sex-specific normalized reference values of heart and great vessel dimensions in cardiac CT angiography.

OBJECTIVE: Published cardiac CT angiography (CTA) reference measurements for the cardiac chambers, aorta, and pulmonary artery (PA) are incomplete and compromised by study population, coronary artery disease (CAD), or its risk factors. The purpose of our study was to establish sex-specific normalized ranges of cardiac chamber size, wall thickness, ejection fraction (EF), and aorta and PA diameter on cardiac CTA in a population without CAD or its risk factors. MATERIALS AND METHODS: Seventy-six patients (38 men and 38 women) without known diabetes; hypertension; smoking history; or evidence of structural heart, vascular, or coronary artery diseases underwent 64-MDCTA. Obtained left atrial (LA) size, left ventricular (LV) volumes, LV wall thickness, thoracic aorta, and PA diameter measurements were normalized to body surface area (BSA). RESULTS: There were statistically significant differences noted between men and women for all measured left-sided heart and great vessel measurements. After normalization to BSA, only chamber dimensions and ascending aorta and left PA sizes remained significantly different. Selected normalized measurements for men versus women, respectively, include LA area, 10.6 ± 2.1 versus 12.3 ± 2.1 cm²/m²; LV end-diastolic size, 72.4 ± 15.1 versus 60.9 ± 13.3 mL/m²; EF, 67% ± 7% versus 72% ± 8%; aortic sinus, 1.6 ± 0.2 versus 1.7 ± 0.2 cm/m²; ascending aorta, 1.4 ± 0.2 versus 1.6 ± 0.2 cm/m²; descending aorta, 1.1 ± 0.1 versus 1.2 ± 0.1 cm/m²; main PA, 1.3 ± 0.1 versus 1.4 ± 0.1 cm/m²; right PA, 1.1 ± 0.1 versus 1.1 ± 0.2 cm/m²; and left PA, 1.0 ± 0.1 versus 1.1 ± 0.1 cm/m². CONCLUSION: Cardiac CTA measurements of the left cardiac chambers, thoracic aorta, and pulmonary arteries were established for a population without CAD or its risk factors.

Fully automatic segmentation of the brain from T1-weighted MRI using Bridge Burner algorithm.

PURPOSE: To validate Bridge Burner, a new brain segmentation algorithm based on thresholding, connectivity, surface detection, and a new operator of constrained growing. MATERIALS AND METHODS: T1-weighted MR images were selected at random from three previous neuroimaging studies to represent a spectrum of system manufacturers, pulse sequences, subject ages, genders, and neurological conditions. The ground truth consisted of brain masks generated manually by a consensus of expert observers. All cases were segmented using a common set of parameters. RESULTS: Bridge Burner segmentation errors were 3.4% +/- 1.3% (volume mismatch) and 0.34 +/- 0.17 mm (surface mismatch). The disagreement among experts was 3.8% +/- 2.0% (volume mismatch) and 0.48 +/- 0.49 mm (surface mismatch). The error obtained using the brain extraction tool (BET), a widely used brain segmentation program, was 8.3% +/- 9.1%. Bridge Burner brain masks are visually similar to the masks generated by human experts. Areas affected by signal intensity nonuniformity artifacts were occasionally undersegmented, and meninges and large sinuses were often falsely classified as the brain tissue. Segmentation of one MRI dataset takes seven seconds. CONCLUSION: The new fully automatic algorithm appears to provide accurate brain segmentation from high-resolution T1-weighted MR images.