John Mathews

Bone imaging in the diagnosis of fractures of the femur and pelvis in the sixth to tenth decades.

A review was made of the records of 24 consecutive trauma patients (aged 55-94 years) who had under gone radiographic examinations and a positive bone image of the femur or pelvis. There was considerable discordance between the radiographs and the bone images. Initially, 25% of the radiographs were interpreted as positive. Even after additional radiographs and retrospective review, only 38% of the x-ray studies were positive. Bone imaging was a useful adjunct in these patients, both to confirm or exclude suspected fractures and to detect occult fractures. The necessity of delaying bone imaging for several days after the trauma was discussed.

Pulmonary Ventilation/Perfusion and Reverse Mismatches in an Infant

A male infant, with bronchopulmonary dysplasia and ventilator dependence, had lung ventilation (Xe-133 gas) and perfusion (Tc-99m MAA) imaging performed. The examination revealed a region that was ventilated but not perfused (mismatch) and a separate area that was perfused but not ventilated (reverse mismatch). The basis of both abnormalities is suspected to be related to bronchopulmonary dysplasia, atelectasis and/or mechanical ventilation. Ventilation/perfusion mismatches and reverse mismatches can occur in the same patient.

Liver function tests. A study in patients with imaging-demonstrated metastases.

Thirty-eight consecutive patients with liver scan evidence of hepatic metastases (and confirmation by other modalities) had blood levels of lactate dehydrogenase and alkaline phosphatase performed within two weeks. In 38% of the patients with small liver metastases, both alkaline phosphatase and lactate dehydrogenase were in the normal range. Even with large metastases present (one or more lesions over 2.5 cm in diameter), 19% of the patients had both enzyme tests within the normal range. Despite the lower cost of these enzyme assays, they failed to detect hepatic metastases in an appreciable portion of our patients.

Technetium-99m MDP demonstration of neoplastic lesions involving bone and adjacent soft tissues

Four patients are presented with malignant tumors involving both bone and adjacent soft tissue. In each of these neoplasms (two representing adenocarcinoma of the prostate, and one each of squamous cell carcinoma of lung and chondrosarcoma), the lesions were detected by accumulation of Tc-99m MDP. Involvement of both bone and soft tissue was confirmed by CT examination or surgery. It is probable that the lesions originated in bone and then extended to soft tissue.

Rapid response of intrasplenic lesions to steroids in non-Hodgkin's lymphoma.

A 70 year old woman had a [99mTc]sulfur colloid liver/spleen scan that showed splenomegaly and multiple intrasplenic defects. The lesions failed to concentrate radiogallium. Thirteen days later, after being on steroid therapy, the spleen had decreased in size and the lesions were only barely apparent. The intrasplenic process, due to non-Hodgkins lymphoma, was thus markedly sensitive to steroids. It is uncertain if such rapid regression can be employed as a prognostic indicator in non-Hodgkins lymphoma and suggests the need for further monitoring. The differential diagnosis of the rapid response of intrasplenic lesions to steroids is a limited one, and likely includes sarcoidosis.