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PubMed1993

Patients with persistent elevation of aminotransferases: investigation with ultrasonography, radionuclide imaging and liver biopsy.

Eighty-three patients, submitted for investigation of the liver due to persistently elevated activities of serum aminotransferases were included in a study in order to compare the relative merits of liver biopsy, ultrasound and radionuclide imaging. From the liver biopsy it was found that 45 patients had fatty liver, 14 had cirrhosis and 11 had chronic inflammation, 3 had haemochromatosis and 10 had unspecific changes or normal findings. An investigation with ultrasound yielded pathological findings in 65% of the patients. The sensitivity was highest in patients with fatty liver (82%) and more than 10% fat in the liver always resulted in increased echogenicity. Alterations in the liver due to cirrhosis and chronic inflammation were detected with ultrasound in only 50% and 57% of the cases, respectively. Radionuclide imaging was positive in 44% of the patients with fatty liver. 64% of those with cirrhosis and 21% of the patients with chronic inflammation. It was only possible to distinguish fatty liver from cirrhosis in those patients who had an increase in the size of the spleen (four patients). The study demonstrates that in patients with a persistent elevation of serum aminotransferases ultrasound has a high sensitivity for detecting more than 10% fat in the liver. However, both the ultrasound and a liver scintigram had a rather low sensitivity and a very low specificity for making a diagnosis for this group of patients. With the aid of a liver biopsy it was possible to establish a diagnosis in 90% of the patients.

Adult↗
PubMed1976

The role of radionuclide imaging in disease of the alimentary tract.

The current status of radionuclide imaging studies of the liver, spleen, and pancreas is reviewed. Although current instrumentation and radiopharmaceuticals allow considerably better images than in the past, the overall accuracy of detecting liver metastases remains at 80%. The specificity of detecting hepatic space occupying disease has been enhanced by additional radionuclide studies which reveal the vascular and metabolic properties of the lesion.--The frequency of spleen imaging has increased since 99mTc-labeled colloids have been used. In most instances, it is obtained as a coincidental portion of the liver scintigraphic examination although it has significant primary indications such as in the elucidation of masses in or trauma to the left upper quadrant of the abdomen.--Selenium-75 selenomethionine pancreatic scintigraphy is best performed with serial Anger Camera images. Interfering hepatic activity is best removed by electronic subtraction techniques; if available. Careful attention to patient selection for the procedure is important. The mean true-positive and negative rates are 86% and 20%, respectively.

Humans↗
PubMed1985

Radionuclide imaging of the urinary tract.

This article describes the role of nuclear medicine in the evaluation of the genitourinary tract. The technical aspects of radionuclide imaging (radiopharmaceuticals, radiation dosimetry, instrumentation, and method) are briefly presented, and each of the indications for renal scintigraphy--including the evaluation of differential renal function, hypertension, obstruction, renal transplants, masses, trauma, congenital anomalies, vesicoureteral reflux, and infection--are discussed. The relative advantages and disadvantages of radionuclide imaging with respect to alternative radiographic examinations (such as intravenous urography, ultrasonography, CT, angiography, and magnetic resonance imaging) are emphasized wherever applicable.

Graft Rejection↗
PubMed2004

Radionuclide imaging metabolic activity of brown adipose tissue in a patient with pheochromocytoma.

We describe a patient with extra-adrenal pheochromocytoma and high plasma norepinephrine levels. Radionuclide images of this patient obtained using (18)F-fluorodeoxyglucose and (123)I-metaiodobenzylguanidine revealed bilateral tracer accumulation in the shoulder and lower neck. The regions of radiotracer uptake corresponded to the location of human brown adipose tissue (BAT). Excessive sympathetic stimulation by high circulating catecholamine concentrations augmented the metabolic activity and tracer uptake in the BAT. This study showed that radionuclide imaging can noninvasively visualize human BAT in terms of metabolic and functional activity.

Adipose Tissue, Brown↗
PubMed1980

Cardiac tumours: non-invasive detection and assessment by gated cardiac blood pool radionuclide imaging.

Four patients with cardiac tumours were investigated by gated cardiac blood pool radionuclide imaging and echocardiography. Contrast angiocardiography was performed in three of the cases. Two left atrial tumours were detected by all three techniques. In one of these cases echocardiography alone showed additional mitral valve stenosis, but isotope imaging indicated tumour size more accurately. A large septal mass was detected by all three methods. In this patient echocardiography showed evidence of left ventricular outflow obstruction, confirmed at cardiac catheterisation, but gated isotope imaging provided a more detailed assessment of the abnormal cardiac anatomy. In the fourth case gated isotope imaging detected a large right ventricular tumour which had not been identified by echocardiography. Gated cardiac blood pool isotope imaging is a complementary technique to echocardiography for the non-invasive detection and assessment of cardiac tumours.

Adult↗
PubMedDate not supplied

[Improvement in radionuclide imaging of the adrenals].

The most adequate method of extracting the background in radionuclide images is proposed. The level of the 131I labelled cholesterol in the adrenal glands is detected with the system consisting of the gamma camera and computer. The method represents a solution of an incorrect problem. Variations of the background caused by the effect of the radiopharmaceutical preparation (RPP) in the liver are assumed to be exponential, and that serves as an additional information to reduce the job to the correct, steady problem. The method offers higher accuracy and consistency as compared to the conventional averaging in detecting the level of the RPP absorbed in the adrenal glands.

Adrenal Glands↗
PubMed1977

Computerized cranial tomography and radionuclide imaging in the detection of intracranial mass lesions.

Computerized cranial tomography (CCT) and radionuclide imaging (RI) of the brain are both accurate techniques for detecting intracranial mass lesions. CCT is superior in detecting low-grade gliomas, cystic lesions, parasellar tumors, and brain stem lesions. Overall, CCT detection rates are slightly higher than those with RI, but the use of iodinated contrast media with CCT increases the risk of this examination. There is a significant difference in the generally binary (positive/negative) type of information offered by RI and the more specific information offered by CCT about the pathologic nature of a lesion and its precise location. In the evaluation of patients with suspected intracranial mass lesions, CCT is generally the preferable initial diagnostic test. However, RI may still serve as a satisfactory screening examination in certain well-defined clinical situations.

Brain Abscess↗
PubMed1999

Radionuclide imaging of nonosseous infection.

Nuclear medicine is an important tool in the diagnostic evaluation of patients with a variety of nonosseous infections. In the immunocompetent population labeled leukocyte imaging is the radionuclide procedure of choice, with Gallium imaging reserved for those situations in which the leukocyte study is nondiagnostic or cannot be performed. Fever of unknown origin is caused by infection in less than one-third of cases, and therefore the number of positive leukocyte studies will be relatively low. The negative leukocyte study is also useful, however, as it has been demonstrated that a negative study excludes, with a high degree of certainty, focal infection as the cause of an FUO. In the cardiovascular system, labeled leukocyte scintigraphy is very useful for diagnosing mycotic aneurysms and infected prosthetic vascular grafts, with a sensitivity of about 90%. The specificity of the study is somewhat more variable--false positive results have been described in perigraft hematomas, graft thrombosis, bleeding, and pseudoaneurysms. In the central nervous system, labeled leukocyte imaging can provide important information about the etiology of contrast enhancing brain lesions identified on computed tomography, i.e., distinguishing between neoplasm and infection. In the immunocompromised population, typified by the AIDS patient, Gallium scintigraphy is the radionuclide procedure of choice for diagnosing opportunistic diseases. In the thorax, a normal Gallium scan, in the setting of a negative chest X-ray, virtually excludes pulmonary disease. A negative Gallium scan in a patient with an abnormal chest X-ray and Kaposi's sarcoma study suggests that the patient's respiratory problems are related to Kaposi's sarcoma. Focal pulmonary parenchymal uptake is most often associated with bacterial pneumonia, although Pneumocystis carinii pneumonia can occasionally present in this fashion. Diffuse pulmonary parenchymal uptake of Gallium can be due to numerous causes, but in general, the more intense the uptake, the greater the likelihood that the patient has P. carinii pneumonia. Lymph node uptake is most often due to lymphoma or mycobacterial disease. In the abdomen, Gallium is also useful for detecting nodal disease. but is not reliable for detecting large bowel disease. Labeled leukocyte imaging should be performed when colitis is a concern. Both 18FDG PET and 201Tl SPECT imaging of the brain are useful for distinguishing between central nervous system lymphoma and toxoplasmosis in the HIV (+) patient. On both studies, lymphoma manifests as a focus of increased tracer uptake, whereas toxoplasmosis shows little or no uptake of either tracer.

AIDS-Related Opportunistic Infections↗
PubMed1993

Double-blind placebo controlled randomized trial of indomethacin on urodynamic values measured by radionuclide imaging.

The effect of the prostaglandin synthetase inhibitor, indomethacin on urodynamic values measured by radionuclide imaging was studied in 17 men in a double-blind placebo controlled randomized trial. Measurements were made of voiding time, time for 50% emptying, average flow rate, ejection fraction, post-void residual urine volume, voided volume, and total bladder volume. Statistical analyses indicated no placebo-indomethacin differences between the two groups. Although prostaglandins are thought to contribute to the act of micturition by maintenance of bladder tone and contractility, our studies indicate that a standard dose of the prostaglandin inhibitor, indomethacin, did not affect the voiding component of bladder function. Patients need not discontinue prostaglandin inhibitors and other non-steroidal anti-inflammatory drugs with such effects prior to urodynamic testing.

Aged↗
PubMed1982

Comparison of ultrasonography, computerized tomography, and radionuclide imaging in the diagnosis of acute and chronic cholecystitis.

Seventy-five patients with abdominal pain in the right upper quadrant who were subsequently confirmed operatively and histologically to have acute or chronic cholecystitis underwent radionuclide imaging of the biliary tree, ultrasonography, and/or computerized tomography before operation. fifty-eight of the patients had acute cholecystitis and 17 had chronic cholecystitis and cholelithiasis. Analysis of our data indicates that ultrasonography is an accurate and better screening test than cholescintigraphy in the diagnosis of chronic cholecystitis and cholelithiasis, but it is less accurate in the detection of acute cholecystitis. On the other hand, radionuclide imaging is highly sensitive and specific in the early diagnosis of acute cholecystitis, but it is poor in the diagnosis of chronic cholecystitis and cholelithiasis unless the cystic duct is obstructed. CT scanning is more expensive than ultrasonography but may be extremely helpful in problematic cases such as the diagnosis of the cause in biliary obstruction or in imaging of the pancreas.

Acute Disease↗
PubMed1989

Radionuclide imaging in the evaluation of osteomyelitis and septic arthritis.

Despite controversy over its exact role, radionuclide imaging plays an important role in the evaluation of patients suspected of having osteomyelitis. The differentiation between osteomyelitis and cellulitis is best accomplished by using a three-phase technique using Tc-99m methylene diphosphonate (MDP). Frequently, it is necessary to obtain multiple projections and magnification views to adequately assess suspected areas. It is recommended that a Ga-67 or In-111 leukocyte scan be performed in those cases where osteomyelitis is strongly suspected clinically and the routine bone scan is equivocal or normal. Repeated bone scan after 48 to 72 h may demonstrate increased radioactivity in the case of early osteomyelitis with the initial photon-deficient lesion. In-111 leukocyte imaging is useful for the evaluation of suspected osteomyelitis complicating recent fracture or operation, but must be used in conjunction with clinical and radiographic correlation. The recognition of certain imaging patterns appears helpful to separate osteomyelitis from septic arthritis or cellulitis.

Adult↗
PubMed1995

Diagnosis of uterine abnormalities with radionuclide imaging.

A pelvic hypervascular blush often creates a diagnostic dilemma during radionuclide abdominal imaging studies in females. This blush is shown to be due to uterine vascularity that is more prominent in the secretory and menstrual phases of the menstrual cycle. Significant uterine vascularity in the earlier phases is inappropriate and may be pathologic. Three such cases are presented in which increased uterine vascularity on radionuclide imaging during the proliferative phase either lead to a diagnosis or supported a clinical finding.

Adult↗
PubMed1980

Current status of radionuclide imaging in the management and evaluation of patients with cardiovascular disease.

The current status of radionuclide imaging in the patients with cardiac disease has been reviewed. Currently it is possible to detect acute myocardial infarction, exercise-induced or spontaneous myocardial ischemia and ventricular function during rest or exercise in a relatively noninvasive manner. The recent development of mobile computer/camera systems opened the possibility for the study and evaluation of critically ill patients. Further developments of techniques and instrumentation can be expected in the near future.

Cardiovascular Diseases↗
PubMed1983

Radionuclide image minification can compensate for coarse digitization: concise communication.

Although it is common practice to digitize radionuclide images onto the finest matrix available, their low count densities and poor spatial resolution suggest that quite large pixels should be adequate. Observers find these large pixels visually obtrusive, but minification of the image can reduce this effect. Experiments reported here have investigated how minification (achieved by increasing viewing distance) affects the perceived quality of images digitized onto different sized matrices. Observers' subjective preference for different pixel sizes was measured at various viewing distances using clinical bone images as test patterns. An objective measure of image quality was made by comparing the detectability of computer-generated focal areas of increased activity both in simple noisy backgrounds and in clinical bone images. The results show that a 128 X 128 matrix is adequate when the image is 8 cm2 and is viewed from 1 and 2 m. A finer matrix failed to produce better results.

Bone and Bones↗
PubMed1998

Comparison of different echocardiographic methods with radionuclide imaging for measuring left ventricular ejection fraction during acute myocardial infarction treated by thrombolytic therapy.

The aim of this study was to: (1) compare the usefulness, in clinical practice, of different echocardiographic methods of left ventricular (LV) function determination in patients with a recent thrombolytic-treated acute myocardial infarction (AMI); (2) compare these measurements with the reference method radionuclide imaging; and (3) evaluate the reproducibility of visual estimation of the LV ejection fraction (EF) and the use of the biplane method of discs (Simpson's rule) in clinical practice. Echocardiography and radionuclide imaging were performed within 2 hours of each another, 5 to 8 days after hospital admission. Ninety-six patients (70 men and 26 women) age 64 +/- 9 years (range 45 to 75) were studied. The echocardiographic study was performed by 2 experienced physicians, independently of each another. LV wall motion score index and visual estimation of the EF correlated best with the radionuclide EF (r = 0.72 and r = 0.71), thereafter simply counting the number of affected LV segments (r = 0.67) or atrioventricular plane measurements (r = 0.64). Simpson's rule had low correlation to the radionuclide EF (r = 0.45 to 0.51) and could not be used in approximately half of the patients due to poor identification of endocardial borders. The interobserver coefficient of variation for independent visual echocardiographic estimation of the EF was 10%, for Simpson's rule 18%, and for the radionuclide EF 5%. We conclude that the EF estimated from quantitative echocardiographic volume calculations (Simpson's rule) may differ substantially from radionuclide methods of measuring the EF. However, with experienced sonographers, the LV wall motion score index or visual estimation of the EF had reasonable agreement with the radionuclide EF in most of the patients. Atrioventricular plane measurement is an acceptable alternative.

Aged↗
PubMed1997

Characterization of hepatic adenoma with atypical appearance on CT and MRI by radionuclide imaging.

The appearance of hepatic adenomas on CT and MRI are highly variable because of their varied histopathology, and images of adenomas are at times indistinguishable from those of other hepatic tumors. The authors present two patients with hepatic adenomas with extremely atypical CT and MRI manifestations demonstrating a "nodule-in-nodule" appearance. Radionuclide imaging in both patients showed decreased Ga-67 uptake in the adenomas compared to normal liver, negative colloid (Tc-99m phytate) uptake in the adenomas, and early uptake and subsequent retention of Tc-99m PMT. This correctly characterized the unique histopathologic features of the resected tumors. Radionuclide imaging using a combination of radiotracers may play an important role in aiding the diagnosis of this rare benign tumor, despite variable CT and MRI appearances.

Adenoma, Liver Cell↗
PubMed1983

Radionuclide joint imaging.

Radionuclide joint imaging with the technetium-99m-labeled phosphates is a sensitive technique for the detection of inflammatory articular disease, although it is nonspecific as to the cause of the increased uptake and offers poor resolution in comparison to conventional radiography. There does not appear to be any place for the routine use of joint imaging of the peripheral joints, as there is little evidence that it benefits patient management. Scintigraphy is of benefit in the detection of osteomyelitis, Legg-Perthes' disease, and osteonecrosis, where changes may antedate roentgenologic abnormalities. Technetium-99m-phosphates may have an increasing role in the evaluation of knee and hip prosthetic joint loosening and infection, especially regarding the femoral components. Scintigraphy may be useful in excluding synovitis and allaying concern in selected patients with chronic articular pain in whom a conventional diagnostic evaluation is unrewarding. Attempts have been made to use radionuclide joint imaging to quantitate the degree of synovitis present in individual joints, particularly the sacroiliac joints. To date, reliable methods that distinguish normal from abnormal joints have not been established, although this remains an area of potential usefulness and active research. Scintigraphy with 99mTc-phosphates is useful in the detection of spinal fracture and pseudoarthrosis in individuals with ankylosing spondylitis.

Adult↗