Robert T. Morrison

Radioimmunoimaging with 99mTc monoclonal antibodies: Clinical studies

Abstract A technetium-99 m ( 99m Tc) mouse monoclonal anti-hCGbeta antibody fragment labeled according to a novel pretinning method is shown in the present studies to be suitable for the in vivo detection of hCG-secreting and certain non-hCG-secreting human tumours. The advantages of this radiopharmaceutical over other radiolabeled antibody compositions previously described for in vivo tumor detection relate to its improved image quality, lower radiation exposure, and earlier scanning times.

Delayed massive soft tissue uptake of Tc-99m MDP after radiation therapy for cancer of the breast

A patient with a history of breast cancer and known lung metastases was referred for a bone scan to investigate the cause of severe neck and right shoulder pain. The bone scan showed massive uptake of the radiopharmaceutical in the soft tissue surrounding the right shoulder. A review of the patients history indicated that the patient had undergone radiation therapy to the right upper thorax and breast area 14 months previously and an acute radiation dermatitis of the proximal right arm and shoulder had developed. This had long since resolved. Physical examination and plain radiographs of the right shoulder and humerus failed to demonstrated any abnormality.

Comparison of Technetium-99m Pyrophosphate and Technetium-99m Methylene Diphosphonate with Variable Amounts of Stannous Chloride in the Detection of Acute Myocardial Infarction

The authors prospectively compared the ability of Tc-99m pyrophosphate (PYP) and Tc-99m methylene diphosphonate (MDP) to detect acute myocardial infarctions. The agents used were PYP (12 mg) with 3.4 mg of stannous chloride, MDP (10 mg) with 1.0 mg of stannous chloride, and MDP (10 mg) with 3.4 mg of stannous chloride. Imaging was performed on three consecutive days on 34 patients with proven myocardial infarctions, using the same agent on the first and third days of the study and an alternate agent on the second day. Agents were assigned randomly to each of six groups of patients. First images were obtained an average of 3.7 days (range, one to six days) following myocardial infarction. Seventeen of 23 patients (75%) had images positive for acute myocardial infarction with Tc-99m PYP, whereas only two of 21 patients (9.5%) had positive studies with Tc-99m MDP with 3.4 mg of stannous chloride and one of 24 patients (4.2%) had positive studies with Tc-99m MDP and 1.0 mg of stannous chloride. All three myocardial infarctions detected by Tc-99m MDP were extensive and transmural. When MDP and PYP were both positive in the same patient, the apparent size of the myocardial infarction was much smaller with the MDP. It is concluded that MDP can detect only large myocardial infarctions, has poor localization in the infarcted tissue, and varying the stannous chloride content of the preparation does not improve the ability of MDP to detect acute myocardial infarctions.

Multifocal uptake of Tc-99m mebrofenin in dilated liver ductules in a patient with cystic fibrosis.

A patient with cystic fibrosis and a previous cholecystectomy, underwent Tc-99m mebrofenin scintigraphy to rule out hepatobiliary disease. The scan revealed multiple focal collections of radiopharmaceutical within the liver parenchyma. This unusual pattern of multiple focal parenchymal activity may be specific for patients with cystic fibrosis. This is the first time this unusual pattern has been confirmed at autopsy.

Gamma scintigraphy using Tc-99m labeled antibody to human chorionic gonadotropin

A case report is presented describing a 27-year-old woman with invasive trophoblastic hydatidiform mole metastatic to the lung. Gamma scintiscanning, using a polyclonal and monoclonal antibody specific to human chorionic gonadotropin, hCG, and labeled with Tc-99m, is described. The area of the primary lesion in the uterus was demonstrated with both antibodies tested without computer subtraction techniques; metastatic deposits in the lung were detected only with the aid of blood pool subtraction techniques.

Leaking Glenn anastomosis demonstrated by first pass radionuclide angiography.

First pass radionuclide angiography was used to demonstrate a leaking Glenn anastomosis at the superior vena cava-right atrial junction as well as tricuspid atresia and a ligated persistent left superior vena cava. First pass radionuclide angiography may demonstrate anatomic configurations not obvious at cardiac catheterization and can be useful for adults with complicated congenital heart disease, particularly when biplane or multiple view angiography is not possible. Lung perfusion imaging can lead to an incorrect diagnosis of pulmonary embolism if the presence of a Glenn anastomosis in not known.

Fracture of the laryngeal cartilage. An incidental finding on bone scintigraphy.

A patient complaining of headaches and bone pain at multiple sites had Tc-99m MDP scintigraphy performed for possible bone trauma after a motor vehicle accident. Bone imaging revealed a small focal increase in tracer uptake in the area of the laryngeal cartilage. There was some reluctance to place a label on this abnormality because the findings were so unusual. The initial diagnosis was a probable fracture of the laryngeal cartilage. Computed tomography of the neck also demonstrated a fracture but correctly localized it to the thyroid cartilage.