Colorectal tumors: an in vitro study of high-resolution MR imaging
Cancer of the colon is one of the more common types of cancer found in the United States. This cancer is primarily treated by surgery. New surgical techniques have been developed that limit loss of function resulting from the tumor removal. However, these techniques require accurate data on the location and depth of the tumors to be removed. This study looked at the possible use of magnetic resonance (MR) imaging to characterize and evaluate the depth of colorectal tumors. Gross evaluation and MR imaging were performed on 17 tumors from 15 surgically removed colorectal specimens. Specimens were also compared in their fresh state and in a fixed state. Results of MR comparing fresh with fixed specimens showed shrinkage in the fixed specimens, but greater contrast between the submucosa and muscle. Depending on the MR technique used, the intestinal wall could be differentiated as up to eight distinct layers. The distinctions arise from differences in signal intensities of the different layers. The signal intensities from the tumors that were studied varied depending on their composition. MR imaging was able to show the depth of the tumors in the wall of the colon. Other information obtained from MR on the characteristics of the tumors correlated well with pathologic findings. These results indicate that MR can be useful in evaluating the stage to which a colorectal tumor has progressed and that MR might be useful in determining the depth and exact location of tumors. This would help lessen the damage to the colon resulting from surgical removal of tumors. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Radiology
Rotator cuff tears: diagnostic performance of MR imaging
The most common cause of shoulder pain is disorders of the rotator cuff, the group of muscles and related tendons and ligaments which form the shoulder. Until recently only standard X-ray of the bones and joint spaces was possible. The present clinical study evaluates the use and promise of magnetic resonance imaging (MRI) to evaluate the bones and soft-tissues of the shoulder joint. With MRI a computer presents anatomic data of the bones and soft-tissues with often surprising clarity. The MR image is formed through the use of an extremely powerful magnet and the interaction of radio waves and, unlike conventional radiologic methods, does not require ionizing radiation (X-ray). The image obtained from MRI examination of the rotator cuff was compared to the results of other radiologic procedures (e.g. arthrography) and to findings at surgery. The ability of MRI to properly evaluate abnormalities of the rotator cuff was a relatively high .91 compared to a score of .71 for arthrography (on a scale of 1.0 maximum). Statistical analysis has shown significant correlation between MRI-determined tears of the rotator cuff and actual measurements determined at the time of surgery. The method shows both excellent sensitivity and specificity for ascertaining the degree of tears of the rotator cuff.
Publication Name: Radiology