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% Ϯ 1.3% (volume mismatch) and 0.34 Ϯ 0.17 mm (surface mismatch). The disagreement among experts was 3.8% Ϯ 2.0% (volume mismatch) and 0.48 Ϯ 0.49 mm (surface mismatch). The error obtained using the brain extraction tool (BET), a widely used brain segmentation program, was 8.3% Ϯ 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. SEGMENTATION OF THE BRAIN is an important preprocessing step in neuroimaging applications. Total brain volumes and subsequent brain atrophy estimation in patients suffering from various pathologies, including traumatic injury, multiple sclerosis, or dementia, are useful estimates of brain injury and its response to treatment (1,2). Brain segmentation is the initial step in studies of the global and regional brain shape and volume (3-7). These studies are taking place with increasing frequency in research on normal brain development during childhood, normal aging, and neurological and psychiatric disorders. Coregistration of functional brain data with high-resolution MR or computed tomography (CT) images is another area that benefits from brain segmentation (8,9). There is little nonbrain tissue signal in functional imaging such as positron emission tomography (PET), single-photon emission CT (SPECT), or functional MRI (fMRI), whereas structural MR images may contain high signal intensity from nonbrain tissue. As a result, most multimodality registration algorithms work best when processing of structural data is restricted to brain voxels. Segmentation of the brain is also a key step in cortical surface modeling and visualization.The tedious and expensive nature of manual outlining of the brain provided the impetus for the development of several automated and semiautomated skullstripping systems. Several sophisticated algorithms have been developed and extensively tested in recent publications (10 -14). These programs have greatly reduced the amount of time needed to segment brain tissue compared to manual extraction. However, the majority of algorithms include ventricular and subarachnoid cerebro...

Cardiac CTA measurements of the left cardiac chambers, thoracic aorta, and pulmonary arteries were established for a population without CAD or its risk factors.

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102144/-/DC1.

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.

Introduction We aimed to determine whether a unique, ultra high-field 7 Tesla (T) MRI scanner could detect occult cartilage and meniscal injuries in asymptomatic female dancers. Materials and Methods This study had institutional review board approval. We recruited eight pre-professional female dancers and nine non-athletic, female controls. We scanned the dominant knee on a 7T MRI scanner using a 3D-FLASH sequence and a proton density, fast spin-echo sequence to evaluate cartilage and menisci, respectively. Two radiologists scored cartilage (International Cartilage Repair Society classification) and meniscal (Stoller classification) lesions. We applied two-tailed z- and t-tests to determine statistical significance. Results There were no cartilage lesions in dancers or controls. For the medial meniscus, the dancers compared to controls demonstrated higher mean MRI score (2.38±0.61 vs. 1.0±0.97, p<0.0001) and higher frequency of mean grade 2 lesions (88% vs. 11%, p<0.01). For the lateral meniscus, there was no difference in score (0.5±0.81 vs. 0.5±0.78, p=0.78) in dancers compared to controls. Discussion Asymptomatic dancers demonstrate occult medial meniscal lesions. Because this has been described in early osteoarthritis, close surveillance of dancers’ knee symptoms and function with appropriate activity modification may help maintain their long-term knee health.