RESUMO
The technetium-labeled hippuran analog [99mTc]MAG3 was compared with [131I]hippuran in 50 patients using a quantitative renal function protocol that includes: (a) estimation of effective renal plasma flow by a single-injection, single-sample plasma clearance method, (b) determination of relative function of right and left kidney from the initial count rate over each kidney, and (c) comparison of recovered urine activity with plasma disappearance. This protocol is suitable for routine clinical use, and, in fact, has been used heavily at our clinic for a number of years. By slight modification of the formulas, the results obtained with [99mTc]MAG3 agreed well with those using [131I]hippuran. We conclude that [99mTc]MAG3 can be substituted for [131I]hippuran in the quantitative protocol, with the better image quality and lower radiation dose (in abnormals) of a technetium-labeled agent.
Assuntos
Oligopeptídeos , Compostos Organometálicos , Renografia por Radioisótopo , Tecnécio , Humanos , Ácido Iodoipúrico , Circulação Renal , Tecnécio Tc 99m MertiatidaRESUMO
A case of renovascular hypertension is presented in which the [131I]hippuran renogram was initially normal, but became strikingly abnormal upon administration of the angiotensin converting enzyme (ACE) inhibitor captopril. The patient presented with fibromuscular dysplasia of the renal arteries, which was shown by hippuran renography to be functionally significant on the right side. She became normotensive after angioplasty of the right renal artery. Hypertension recurred a year later, at which time the renogram was normal without captopril, but showed functionally significant left renal artery stenosis with captopril challenge. Both the conventional agent, [131I]hippuran, and an experimental new 99mTc-labeled hippuran analog, [99mTc]MAG3, were used. Angiography confirmed progression of disease on the left side, which was successfully treated by angioplasty. Functionally significant unilateral renal artery stenosis was thus demonstrated first on the right side and then, 1 yr later, on the left side, using hippuran and [99mTc]MAG3. Anatomic progression of disease was documented by angiography.
Assuntos
Captopril , Hipertensão Renovascular/diagnóstico por imagem , Radioisótopos do Iodo , Ácido Iodoipúrico , Oligopeptídeos , Compostos Organometálicos , Renografia por Radioisótopo , Tecnécio , Adulto , Feminino , Humanos , Tecnécio Tc 99m MertiatidaRESUMO
Technetium-99m MAG3, a technetium-labeled analog of hippuran, was compared with [131I] hippuran using a simultaneous dual isotope study in 20 patients. The plasma clearance for MAG3 was lower than that of hippuran, but its plasma concentration was higher, resulting in similar rates of excretion and similar renal time-activity curves. Apart from better statistics with the technetium-labeled agent, there were no clinically significant differences in this group of patients.
Assuntos
Ácido Iodoipúrico , Oligopeptídeos , Compostos Organometálicos , Renografia por Radioisótopo , Adulto , Humanos , Tecnécio Tc 99m MertiatidaRESUMO
A patient with a normal DISIDA study underwent a laparotomy that revealed acute cholecystitis. Retrospective review of the DISIDA study showed pericholecystic hepatic activity.
Assuntos
Colecistite/diagnóstico por imagem , Vesícula Biliar/diagnóstico por imagem , Iminoácidos , Fígado/diagnóstico por imagem , Compostos Organometálicos , Idoso , Colecistite/patologia , Feminino , Vesícula Biliar/patologia , Humanos , Cintilografia , Estudos Retrospectivos , Disofenina Tecnécio Tc 99mAssuntos
Doenças Fetais/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Tumor de Wilms/diagnóstico por imagem , Adulto , Feminino , Humanos , Neoplasias Renais/congênito , Neoplasias Primárias Múltiplas/congênito , Gravidez , Radiografia , Tumor de Wilms/congênitoRESUMO
A fistula from the superior mesenteric artery to the duodenum is an extremely rare complication of pancreatic carcinoma. It presents with overwhelming upper gastrointestinal hemorrhage and can lead to death from blood loss.
Assuntos
Carcinoma Intraductal não Infiltrante/complicações , Duodenopatias/etiologia , Fístula/etiologia , Hemorragia Gastrointestinal/etiologia , Fístula Intestinal/etiologia , Artérias Mesentéricas , Neoplasias Pancreáticas/complicações , Angiografia , Duodenopatias/diagnóstico por imagem , Fístula/diagnóstico por imagem , Humanos , Fístula Intestinal/diagnóstico por imagem , Masculino , Pessoa de Meia-IdadeRESUMO
A new renal imaging agent, technetium-99m mercaptoacetyltriglycine (MAG3, mertiatide), is currently undergoing clinical trials. Like iodine-131 orthoiodohippurate (OIH)--and unlike all other available agents--it is avidly secreted by the renal tubules. Fifty patients underwent simultaneous renal imaging studies with I-131 OIH and Tc-99m MAG3. The superior physical properties of the Tc-99m label led to better image quality in all cases, largely due to count rates that were 50-fold better. In two patients, lesions were seen with MAG3 that were not visible with OIH. The biological properties of the two agents were found to be so similar that conventional diagnostic criteria for I-131 OIH could be used for Tc-99m MAG3 with only minor modifications.