Soft-tissue masses of the locomotor system: comparison of MR imaging with CT.

Abstract

Magnetic resonance (MR) images and computed tomographic (CT) scans of histologically characterized soft-tissue masses of the locomotor system in 35 patients were compared for image contrast, demonstration of bone destruction, and display of extent and anatomic relationships of the masses. Subjective criteria for predicting malignancy were tested. T1 measurements were made in a few cases. Intensities of masses relative to those of fat and muscle in spin-echo T1-weighted and highly T2-weighted images were evaluated for correlation with tissue type. Subjective value of using coronal and sagittal images was assessed. Because of its superior inherent image contrast and its ability to provide direct sagittal and coronal images, MR was better than CT in demonstrating size and extent of most tumors and their relationships to vascular and nonvascular structures. However, bone destruction was more difficult to see with MR. Except for fatty tumors, MR was not helpful in identifying tissue type. Subjective criteria were of limited value in distinguishing benign from malignant lesions. Moreover, there is currently no credible evidence that T1 or T2 measurements are helpful in this regard. Study results suggest that MR is superior to CT in evaluating soft-tissue masses of the locomotor system. If an MR examination is performed, CT may not be necessary in certain cases unless bone involvement is suspected.

Foot-in-mouth disease no April fools' joke.

“…In our study [3] on pretreatment with corticosteroids, 93% of the patients had not had a reaction to contrast material when they had received it previously (3O%) or had never received contrast material before (63%). In this study, patients who had the most severe signs and symptoms were categorized as grade III.…”

“…Despite the general belief and strong feelings on the part of many radiologists that knowledge of the clinical history is extremely important (a study of our own emphasized this point to us [3]), no scientific, objective, and comprehensive data are available to support Dr. Miller's statement that such knowledge of the history "plays a major role in the interpretation of observations. "…”

“…However, such use might require an expenditure of $1 billion each year [1], money that might better be spent on alternative radiologic [2], or other health-related measures. In 1987 [3], we compared the occurrence of reactions to contrast medium in patients pretreated with a two-dose regimen of corticosteroids (32 mg of methylprednisolone given 12 hr and 2 hr before injection of IV contrast medium), patients receiving a single one-dose regimen 2 hr before injection, and patients receiving a placebo with a matching two-dose or one-dose schedule. For all categories of reactions, the two-dose regimen conferred significant protection when compared with the one-dose and placebo regimens.…”

“…Although MR has become valuable in preoperative planning and in the staging of soft-tissue masses, the distinction between a benign and malignant process is not always clear [2][3][4]. MR is excellent for localizing the abnormality and for defining adjacent structures, but diagnostic biopsy is still necessary.…”

“…[3,4]. In i 19,590 arthroscopic surgeries, six penetrating injuries to the popliteal artery occurred, four of which required amputations [3].…”