Computed tomography of the chest in blunt thoracic trauma: results of a prospective study.

BACKGROUND: Computed tomography of the chest (CTC) is more sensitive than conventional roentgenography at detecting blunt thoracic injuries. Its effect on subsequent therapy remains incompletely characterized. METHODS: Nine criteria believed to represent the presence of, or the potential for, significant thoracic injuries were defined, and patients were followed prospectively. Forty consecutive patients had CTC after initial evaluation. Physiologic and anatomic findings were compared, and the effect of CTC on therapy was analyzed. RESULTS: CTC detected 76 injuries not found on plain roentgenograms, and plain roentgenograms detected 25 injuries not visible on CTC scans. Six patients had therapy changes based on CTC findings, five of which involved chest tube modification. The percentage of pulmonary contusion did not predict the need for mechanical ventilation but did correlate with physiologic contusion. CONCLUSIONS: Blunt thoracic injuries detected by CTC infrequently require immediate therapy. If immediate therapy is needed, findings will be visible on plain roentgenograms or on clinical exam. Routine CTC in blunt trauma is not recommended but may be helpful in selected cases.

The prevalence of abnormal magnetic resonance imaging findings in asymptomatic knees. With correlation of magnetic resonance imaging to arthroscopic findings in symptomatic knees.

The purpose of this study was to prospectively evaluate the prevalence of abnormal magnetic resonance imaging scans of the knees of asymptomatic subjects. A prospective analysis of magnetic resonance imaging to arthroscopic findings in symptomatic knees was also performed. The prevalence of meniscal tears found in asymptomatic knees was 5.6% (medial meniscus, 1.9%; lateral meniscus, 3.7%). Other abnormal findings included a prevalence of 1.9% for degenerative changes of the medial femoral condyle and 3.7% both for ganglion cysts and patellofemoral joint articular cartilage degenerative changes. There was also a prevalence of 24.1% of Grade II signal changes of the posterior horn of the medial meniscus. Statistical comparison of our results to previous studies revealed that the magnetic resonance imaging scan readings on the asymptomatic knees in this study were accurate and lesions were correctly identified. We recommend that clinicians match clinical signs and symptoms with magnetic resonance imaging findings before instituting surgical treatment because of a 5.6% prevalence of meniscal tears in the asymptomatic population. The significance of the high percentage of posterior horn medial meniscal Grade II signal changes is unknown.

Isolated fracture-dislocation of the fourth carpometacarpal joint. A report of two cases.

Dislocations and fracture-dislocations of isolated and multiple carpometacarpal (CMC) joints are rare injuries that usually result from the impact of a clenched hand on an immobile object. Various authors have presented combinations of dislocations of any or all of the CMC joints. Isolated fracture-dislocation of the fourth CMC joint, however, is either exceedingly rare or highly underreported. Two cases of isolated fracture-dislocation of the fourth CMC joint are presented here: in both, the appearance of the hand suggested a fracture-dislocation of the CMC joint, and the isolated lesion was confirmed at the time of surgery. Both patients were treated with open reduction and internal fixation and had good results at 2 years.

Value of MR imaging in differentiating benign from malignant soft-tissue masses: study of 95 lesions.

MR imaging has largely replaced CT as the technique of choice for preoperative staging of patients with soft-tissue masses. Whether MR imaging can be used to differentiate benign from malignant masses is controversial. Our experience suggests that MR imaging often can characterize soft-tissue masses accurately. To evaluate this question further, we studied 95 consecutive lesions (50 benign and 45 malignant). Consecutive cases were selected to simulate our clinical practice. Surgical proof was available for all masses except hematomas, for which clinical follow-up confirmed the diagnosis. MR images were interpreted twice by three radiologists. The first review was accomplished without any clinical history and the second review with clinical history. Reviewers were asked to classify the lesion as benign or malignant on the basis of their clinical knowledge and analysis of MR image features (size, lesion margin, signal homogeneity, and neurovascular or bone involvement). Although interpretation varied somewhat because of the experience of the reviewers, the specificity and accuracy of diagnosis averaged 90% for both benign and malignant lesions. Negative predictive value for malignancy averaged 94% among the three reviewers. MR imaging is the technique of choice for identification and characterization of soft-tissue masses. The nature of the lesion (benign vs malignant) can be determined in the majority of cases.

Preoperative staging of rectal carcinoma by computed tomography and 0.15T magnetic resonance imaging. Preliminary report.

A prospective study was done on 34 patients using magnetic resonance imaging (MRI) and computed tomography (CT) preoperatively to stage patients with known rectal carcinoma. The study was done to determine the accuracy and clinical usefulness of CT and MRI. The Thoeni staging method was used. Twenty-four of 30 cases were staged correctly by CT. Sixteen of 27 were staged correctly by MRI. CT detected lymph node metastases in six of 15 cases with one false-positive. MRI detected lymph node metastases in two of 15 patients with one false-positive. CT was the preferred examination, and was useful in some cases. These cases included patients with small tumors who were considered for local excision and patients with extensive disease who were candidates for preoperative or intraoperative radiation treatment. MRI demonstrated extensive disease, as did CT in our later cases.