Infrared light scanning of the breast.

Transillumination and Infrared Light Scanning (I.L.S.) of the breast were evaluated in a high referral breast clinic over a 15-month period. Seven hundred (700) patients were examined and blindly transilluminated; 101 were biopsied, all had mammography. The study was conducted in two phases: Phase I evaluated transillumination without I.L.S. This included 22 biopsied patients out of 101, with eight carcinomas identified histologically, demonstrating 87 per cent sensitivity and 64 per cent specificity for transillumination, versus 87 per cent and 71 per cent for mammography, and 87 per cent and 57 per cent for examination. Phase II evaluated simple transillumination combined with I.L.S. This included 79 biopsied patients out of 101 with 26 carcinomas identified histologically, demonstrating 96 per cent sensitivity and 74 per cent specificity for transillumination combined with I.L.S. compared to 85 per cent and 72 per cent for mammography and 81 per cent and 73 per cent for examination. Of the 26 Phase II carcinomas identified, two were not felt by examination, and two were neither felt nor read correctly by mammography. I.L.S. of the breast has proven effective in the hands of trained personnel and should be used with routine breast examination or mammography to increase yield of breast pathology.

Subacute and chronic bone infections: diagnosis using In-111, Ga-67 and Tc-99m MDP bone scintigraphy, and radiography.

The usefulness of indium-111 white blood cell scintigraphy in the diagnosis of subacute or chronic bone infection was examined in 21 orthopedic patients. In-111 WBC imaging was compared with gallium-67 and technetium-99m methylene diphosphonate skeletal scintigraphy and bone radiography, all studies being performed within 1 week. In-111 WBC scintigraphy showed no definite advantage over Ga-67 scintigraphy in the identification of chronic bone infection. The two tests had the same sensitivity (80%) and similar specificity (In-111 WBC 75%, Ga-67 83%; difference not significant). Bone radiography had a sensitivity of 60% and a specificity of 67%. A negative Tc-99m MDP bone scintigram ruled out infection (sensitivity 100%), but because of low specificity (25%), final evaluation required performance of Ga-67 or In-111 WBC scintigraphy.

Evaluation of an immunoradiometric assay specific for the CK-MB isoenzyme for detection of acute myocardial infarction.

Clinical evaluation of patient's symptoms, electrocardiographic changes and increased serum enzyme levels, specifically creatine kinase (CK)-MB by electrophoresis, are established as the primary diagnostic indicators for myocardial infarction (MI). Two hundred fifteen patients were evaluated in this study. Of these patients, 102 were admitted to the coronary care unit and 113 were admitted to the emergency room and screened for possible MI. The immunoradiometric assay used in this study was a double antibody "sandwich" technique, which utilizes antibody to the M and B monomers of the CK isoenzymes. This assay is specific for the CK-MB isoenzyme, which is present in increased levels in MI. The intraassay coefficients of variation for 30 samples were 11.7% (mean 4.1 equivalent units [EU]/liter) and 8.4% (mean 15.4 EU/liter) and the interassay coefficients of variation for 30 samples were 11.1% (mean 2.6 EU/liter) and 8.1% (mean 13.6 EU/liter). The diagnostic sensitivity, specificity and accuracy in this study was 100%, respectively. The CK-MB by the immunoradiometric assay was found to be significantly more accurate than electrophoresis and, therefore, a reliable and also technically simpler replacement for electrophoresis.

A sign of symptomatic chronic cholecystitis on biliary scintigraphy.

Five hundred patients with acute right-upper-quadrant pain underwent biliary scintigraphy with 99mTc paraisopropyliminodiacetic acid. One hundred and thirty-four studies were reported normal (both gallbladder and activity in bowel are noted in 1 hr). Of the 134 studies reported as normal, 32 showed intestinal activity before gallbladder visualization during the first hour of the study. Sonography and/or oral cholecystography revealed that 24 patients had gallstones, and eight patients had no demonstrable pathology in the biliary system. Of the 134 studies, 102 showed visualization of the gallbladder before intestinal activity during the first hour of the study. Sonography and/or oral cholecystography showed that 73 patients had normal biliary system. The remaining 29 patients had gallstones. The overall sensitivity of this finding is 45%, the specificity is 90%, and the accuracy is 73%. In this group of symptomatic patients, the appearance of intestinal activity before gallbladder activity on biliary scintigraphy warrants further evaluation of these patients by sonography and/or oral cholecystography.

Biliary scintigraphy in acute pancreatitis.

A prospective study was carried out in 60 patients to determine the efficacy of 99mTc-PIPIDA scintigraphy in differentiating biliary pancreatitis from nonbiliary pancreatitis. Forty patients were classified as having biliary pancreatitis and 20 patients as having the nonbiliary type. Scintigraphic scans were divided into five main types according to the time to visualization of the gallbladder and the time to excretion of 99mTc-PIPIDA into the intestinal tract. Normal scans were obtained on 95% of patients (19/20) with nonbiliary pancreatitis; 22.5% of patients (9/40) with biliary pancreatitis had normal scans. It is concluded that elevated amylase levels together with an abnormal biliary scan, as defined by the criteria presented here, indicate biliary pancreatitis, while a normal scan largely excludes such diagnosis.

Radioimmunoassay of free thyroxine with prebound anti-T4 microcapsules.

Free thyroxine (FT4) may be one of the active throid hormones in contact with target end organs. It is unaffected by alterations in serum protein levels. In most cases, measurement of FT4 reflects an individual's true thyroid function or dysfunction. Previous FT4 assay techniques have been difficult, tedious, indirect, and inaccurate. A rapid, simple, and accurate radioimmunoassay for FT4 has been developed using microencapsulated rabbit anti-T4 antiserum to which I-125 T4 tracer of high specific activity has been complexed. Addition of FT4 standards or unknown samples displaces a proportional amount of I-125 T4 from antibody. Protein-bound T4 is excluded from the reaction by short incubation time and spatial configurations. Specimens representing known thyroid dysfunction were tested using the above procedure. The normal range of FT4 was 0.8-2.4 ng/dl. The mean FT4 for the hyperthyroid group was 6.92 +/- 1.38 (range 4.4-9.6) ng/dl. The mean FT4 for the hypothyroid group was 0.43 +/- 0.37 (range 0.1-1.3) ng/dl, and in pregnancy the mean FT4 was 1.64 +/- 0.44 (range of 1.0-2.2) ng/dl (1).