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Biomedical subjects

L M Freeman

Publications and source records attributed to L M Freeman.

At least 91 records · Page 5Linked to original sources
PubMed1981

Scintigraphic features of cavernous transformation of the portal vein.

A case of portal vein obstruction with cavernous transformation is presented, in which findings on both Tc-99m-sulfur colloid and HIDA liver scintigrams suggested the diagnosis. These findings included a focal hyperconcentration of colloid on the former and notching of the common bile duct as well as "draping" of the right hepatic duct on the latter. All of these findings were shown at angiography and surgery to be secondary to extensive venous collateral vessels related to portal vein obstruction.

Abscess↗
PubMed1981

Spectrum of 99m-Tc-IDA cholescintigraphic patterns in acute cholecystitis.

Cholescintigraphy with 99m-Tc labeled iminodiacetic acid (IDA) derivatives has proved to be extremely reliable in the evaluation of suspected acute cholecystitis. The major diagnostic feature of the study is the presence (cystic duct patency) or absence (cystic duct obstruction) of gallbladder visualization. Secondary findings include degree and rate of liver uptake, visualization and caliber of the intrahepatic and common bile ducts, and the presence of intestinal activity as well as rapidity of biliary tract-to-bowel transit of the radiotracer. Various combinations of these secondary parameters result in a spectrum of cholescintigraphic patterns which can assist in determining the cause of the patient's acute clinical problem.

Acute Disease↗
PubMed1980

Role of 99mTc-IDA cholescintigraphy in evaluating biliary tract disorders.

Technetium-99m IDA cholescintigraphy has provided a new, noninvasive means of visualizing biliary tract function. It has become the procedure of choice in patients with suspected acute cholecystitis because of its ability to most accurately detect functional obstruction or patency of the cystic duct as opposed to ultrasound's ability to detect only anatomic changes such as the presence of calculi or a thickened gallbladder wall. These latter findings are more important in establishing the diagnosis of chronic cholecystitis where ultrasound shares a position of prime importance with the oral cholecystogram. Tc-99m IDA cholescintigraphy has also been particularly useful in evaluating bile leaks, biliary-enteric anastomosis patency and the post-cholecystectomy patient with recurrent pain. In the patient with cholestasis, ultrasound is usually the procedure of choice since it establishes whether or not ductal dilatation is present and frequently can determine the cause of obstruction. Cholescintigraphy has played an ancillary role in many cases by demonstrating the level of partial obstruction, but it does not have the anatomic resolution to visualize the cause of obstruction. Occasionally, in the evaluation of cholestasis, cholescintigraphy has proven to be the only modality which has identified the presence of acute common duct obstruction or localized intrahepatic ductal obstruction. All in all, Tc-99m IDA cholescintigraphy has had a dramatic impact upon hepatobiliary diagnosis.

Abdominal Injuries↗
PubMed1980

The evaluation of ischemic heart disease thallium-210 with comments on radionuclide angiography.

Coronary artery disease causing myocardial ischemia and infarction is the leading cause of death in America. Methods that can be used to diagnose and follow the response to therapy of coronary artery disease or its effect on myocardial ischemia should help control the morbidity and mortality of ischemic heart disease. The use of ECG monitoring is less sensitive and specific for ischemia than thallium (TI) imaging or the use of radionuclide angiography (RNA). In large patient populations, the findings of a positive ECG and TI or RNA study will be highly predictive for the presence of coronary artery disease, while negative test results make the disease unlikely. A combined approach to the patient with possible ischemic heart disease is presented.

Cardiac Catheterization↗
PubMed1980

Serendipity in technetium-99m dimethyl iminodiacetic acid cholescintigraphy: diagnosis of nonbiliary disorders in suspected acute cholecystitis.

Technetium-99m dimethyl iminodiacetic acid cholescintigraphy has contributed significantly to the diagnosis of acute and chronic biliary tract disorders. Yet attention should also be focused on the other structures visualized during the blood pool, hepatocyte, renal excretory, and intestinal phases of the study. Nonbiliary pathology was detected in 42 of 294 patients (14.3%) studied for suspected acute cholecystitis. The serendipitous detection of previously unsuspected abnormalities assisted in directing further work-up from suspected biliary disease and towards the real source of the patient's acute problem in 28 cases (9.5%).

Acute Disease↗
PubMed1980

Myocardial visualization on a perfusion lung scan.

Myocardial activity was noted on a lung scan performed following the i.v. administration of Tc-99m macroaggregated albumin. The patient had primary pulmonary hypertension with a right-to-left shunt through a functionally patent foramen ovale.

Adult↗
PubMed1979

Thallium-201 myocardial scintigraphy in patients with triple-vessel disease and ischemic exercise stress tests.

Thirty patients with triple-vessel coronary artery disease proven by angiography, symptomatic angina and a positive ECG stress test were evaluated with thallium-201 (201TI) scintigraphy. Twenty patients also had aortocoronary saphenous vein bypass surgery; 15 of them had repeat noninvasive evaluation. Seventy percent of these patients showed ischemia by 201TI scintigraphy, of which one-half returned to normal after surgery. Postoperative reversion of the ECG stress test together with 201TI stress/reperfusion imaging correlated well with the completeness of surgical revascularization. We could not explain the prevalence (80%) of infarcts detected by 201TI in this group, of which 76% could be anatomically correlated to epicardial scars. The positivity of infarcts by 201TI exceeded that predicted by previous history of infarction, Q waves on resting ECG or ventriculographic akinesis. These observations suggest that 201TI scintigraphy is a useful noninvasive tool in the follow-up and understanding of patients with coronary heart disease. These conclusions also support the concept that 201TI stress imaging need not have the identical connotation as the ECG stress test.

Adult↗
PubMed1979

Rapid and accurate diagnosis of acute cholecystitis with 99mTc-HIDA cholescintigraphy.

Technetium-99m dimethyl acetanilide iminodiacetic acid (HIDA) cholescintigraphy was performed on 90 patients with suspected acute cholecystitis. Visualization of the gallbladder established patency of the cystic duct and excluded the diagnosis of acute cholecystitis in 50 of 52 patients. Nonvisualization of the gallbladder with visualization of the common bile duct was diagnostic of acute cholecystitis in 38 patients, all subsequently proven at surgery. The observed accuracy of this procedure is 98% and specificity is 100%. The false negative rate is 5% and false positive rate is zero. Technetium-99m-HIDA has many advantages which make it the procedure of choice in evaluating a patient for suspected acute cholecystitis. It is a rapid, simple, safe examination which provides functional as well as anatomic information about the hepatobiliary system in individuals with a serum bilirubin level up to 8 mg/100 ml.

Acetates↗
PubMed1979

Demonstration of traumatic bile leakage with cholescintigraphy and ultrasonography.

Technetium-99m HIDA cholescintigraphy and ultrasonography are noninvasive, safe, simple procedures that can document the presence, location, and extent of a bile leak. Early detection of posttraumatic or postoperative biliary tract disruption can significantly reduce morbidity and mortality. The possibility of biliary tract disruption should be considered in any patient who has had blunt or penetrating abdominal trauma. In two cases reported, the new hepatobiliary radiotracer 99mTc dimethyliminodiacetic acid (HIDA) was quite useful in detecting such leaks. Sonography was particularly useful in detecting small intra- or perihepatic bile collections which no longer communicate with the biliary tree. An active bile leak at a surgical anastomosis may also be documented by 99mTc-HIDA cholescintigraphy and can yield information of potential prognostic importance. Serial cholescintigraphy is also useful in evaluating the response to medical or surgical treatment.

Aged↗
PubMed1979

Computer-assisted static/dynamic renal imaging: a screening test for renovascular hypertension?

Computer-assisted static/dynamic renal imaging with [197Hg] chlormerodrin and [99mTc]pertechnetate was evaluated prospectively as a screening test for renovascular hypertension. Results are reported for 51 patients: 33 with benign essential hypertension and 18 with renovascular hypertension, and for 21 normal controls. All patients underwent renal arteriography. Patients with significant obesity, renal insufficiency, or renoparenchymal disease were excluded from this study. Independent visual analyses of renal gamma images and time-activity transit curves identified 17 of the 18 patients with renovascular hypertension; one study was equivocal. There were five equivocal and three false-positive results in the essential hypertension and normal controls groups. The sensitivity of the method was 94% and the specificity 85%. Since the prevalence of the renovascular subset of hypertension is approximately 5%, the predictive value is only 25%. Inclusion of computer-generated data did not improve this result. Accordingly, this method is not recommended as a primary screening test for renovascular hypertension.

Adult↗
PubMed1978

Is the anterior bone scan necessary in the diagnosis of osseous metastases?

Bone imaging studies of 1650 patients with known or strongly suspected extraosseous malignancies were reviewed to determine whether a completely negative posterior view was sufficient to exclude metastatic disease. Of 708 negative posterior images, 27 (3.4%) were positive for metastasis on anterior views. All of the anterior lesions were in the sternium, sternoclavicular joints and first four ribs. When the posterior view is positive, further views may be unnecessary. Negative or equivocal posterior images necessitate anterior views of the thoracic cage.

Bone Neoplasms↗