ABSTRACT
La diferenciación entre abscesos y metástasis cerebrales en pacientes con algún grado de inmunosupresión y con neoplasias hematológicas resulta en ocasiones difícil. Los estudios funcionales como la tomografía de emisión de fotón único (SPECT) y la tomografía por emisión de positrones (PET) son herramientas diagnósticas eficaces para este propósito. Presentamos el caso de una paciente con diagnóstico de leucemia mieloide crónica en crisis blástica a quien se le informó múltiples abscesos cerebrales; diagnóstico basado en que no existió captación de 99mTc - MIBI en SPECT cerebral y en la buena respuesta al tratamiento antimicrobiano en ocasión en que los estudios de tomografía computarizada (TC) cerebral y resonancia magnética (RM) cerebral no fueron concluyentes. Teniendo en cuenta los resultados de la SPECT se decidió postergar el esquema de quimioterapia, ya que esta podría desencadenar complicaciones probablemente fatales en la paciente.
The differentiation between brain abscess and brain metastasis in patients with some grade of immune suppression and hematological neoplasm is difficult in some situations. Functional studies like Single-Photon Emission Tomography (SPECT) and Positron Emission Tomography (PET) are useful for this purpose. We present the case of a patient with diagnosis of chronic myelogenous leukemia in blast crisis that a diagnosis of brain abscess was made. The diagnosis had a base in 99mTc - MIBI brain SPECT did not show MIBI uptake and the good treatment response to antibiotics when brain CT scan and MRI were not conclusive. Attending to the SPECT result, chemotherapy was postponed because of probably fatal complications in this patient with brain abscess.
ABSTRACT
OBJECTIVES: The role of coronary collateral circulation in protecting myocardium after the occlusion of a supplying artery has long been debated. Recent date show that the coronary collateral circulation may partially prevent ischemia and preserve myocardial contractile function. The purpose of this study was to evaluate the relation between the grades of collateral circulation and perfusion scores of 99mTc-Heart SPECT in patients with totally coronary occlusion. METHODS: We studied 44 patients with totally coronary occlusion who had been hospitalized at Kyung Hee University hospital between October, 1989 and May, 1994, Patients were classified into two groups; Group 1: patients with angina pectoris (n=21), Group 2: patients with myocardial infarction (n=23). Angiographic collateral circulation was graded from 0 to 3: 0=none, 1=filling of side branch only, 2=partial filling of the epicardial segment, 3=complete filling of epicardial segment. The perfusion score of dipyridamole stress 99mTc-MIBI Heart SPCET was analyzed with angiographic findings. Resting and stress echocardiography were analyzed to identify left ventricular wall motion abnormalities. RESULTS: 1) When LAD was totally occluded, there were hishevcrgree of collateral circulations from RCA in group 1 and group 2. When RCA was totally occluded, there was higherdesree of collateral circulation from LAD in group 1 and group 2. 2) The degree of collateral development was higher in group 1 than in group 2 (2.5+/-0.7 vs. 1.8+/-1.0, p<0.05). 3) In 99mTc-MIBI Heart SPECT, there was no significant difference of perfusion score at stress but perfusion score was significantly higher in group I than in group 2 at rest. 4) In 99mTc-MIBI Heart SPCET, there was no difference of perfusion score between totally coronary occlusion territories in group 1 and more than 50% coronary artery stenotic territories in group 1 and group 2. 5) In stress echocardiography, ten of the 13 patients showed normal LV wall motion at rest, but 9 of these 10 patients showed LV wall motion abnormalities at stress in group l. In group 2, all 10 patients showed LV wall motion abnormalities at rest and 3 of these patients showed more aggravation of LV wall motion abnormalities. CONCLUSION: Collateral circulation in angina patients can prevent myocardial ischemia and preserve myocardial function at rest, but not at exercise. Collateral circulation in patients with myocardial infarction cannot preserve myocardial function at rest. and exercise. Dipyridamole stress 99mTc-MIBI Heart SPECT is one of the indirect quantification methods to evaluate collateral development and coronary flow reserve.
Subject(s)
Humans , Angina Pectoris , Arteries , Collateral Circulation , Coronary Occlusion , Coronary Vessels , Dipyridamole , Echocardiography, Stress , Heart , Ischemia , Myocardial Infarction , Myocardial Ischemia , Myocardium , Perfusion , Tomography, Emission-Computed, Single-PhotonABSTRACT
Objectives : 201Tl - chloride, 99mTc - MIBI, 99mTc(V) - DMSA SPECT has been used in distinguishing lung cancer from benign lesion. To compare the diagnostic efficacy of SPECT with these tumor - seeking agents, we performed three consecutive SPECT using 201Tl, 99mTc - MIBI, 99mTc(V) - DMSA in same subjects with a solitary pulmonary lesion. Methods : SPECT was carried out at 10min and 3hr for 201Tl after injection of 2 mCi, and 2hr for 99mTc - MIBI and 99mTc(V) - DMSA after injection of 20mCi, respectively, in 37 patients with a solitary pulmonary lesion(27 lung cancer and 10 benign diseases). In patients showing visual uptake on lesion site, we obtained the lesion - to - bakground(target lesion/contralateral normal lung) uptake ratio from transverse slice for each radionuclide and also calculated the retention index for 201Tl. Results : The diagnostic sensitivity of 201Tl, 99mTc - MIBI and 99mTc(V) - DMSA SPECT to lung cancer was 100%, 96% and 73%, and the specificity was 40%, 70% and 70%, respectively. The low specificities for these agents were mainly due to high positive uptake in patients with active pulmonary tuberculosis. There were no significant differences in uptake ratios and retention index between malignant and benign lesions, and among the histologic types of lung cancer Conclusion : 201Tl and 99mTc - MIBI showed higher sensitivity than 99mTc(V) - DMSA for detecting lung cancer, but was of limited usefulness in distinguishing lung cancer from benign lesion due to low specificity, especially in area with a high prevalence of active pulmonary tuberculosis.
Subject(s)
Humans , Lung Neoplasms , Lung , Prevalence , Sensitivity and Specificity , Succimer , Tomography, Emission-Computed, Single-Photon , Tuberculosis, PulmonaryABSTRACT
Objectives : 201Tl - chloride, 99mTc - MIBI, 99mTc(V) - DMSA SPECT has been used in distinguishing lung cancer from benign lesion. To compare the diagnostic efficacy of SPECT with these tumor - seeking agents, we performed three consecutive SPECT using 201Tl, 99mTc - MIBI, 99mTc(V) - DMSA in same subjects with a solitary pulmonary lesion. Methods : SPECT was carried out at 10min and 3hr for 201Tl after injection of 2 mCi, and 2hr for 99mTc - MIBI and 99mTc(V) - DMSA after injection of 20mCi, respectively, in 37 patients with a solitary pulmonary lesion(27 lung cancer and 10 benign diseases). In patients showing visual uptake on lesion site, we obtained the lesion - to - bakground(target lesion/contralateral normal lung) uptake ratio from transverse slice for each radionuclide and also calculated the retention index for 201Tl. Results : The diagnostic sensitivity of 201Tl, 99mTc - MIBI and 99mTc(V) - DMSA SPECT to lung cancer was 100%, 96% and 73%, and the specificity was 40%, 70% and 70%, respectively. The low specificities for these agents were mainly due to high positive uptake in patients with active pulmonary tuberculosis. There were no significant differences in uptake ratios and retention index between malignant and benign lesions, and among the histologic types of lung cancer Conclusion : 201Tl and 99mTc - MIBI showed higher sensitivity than 99mTc(V) - DMSA for detecting lung cancer, but was of limited usefulness in distinguishing lung cancer from benign lesion due to low specificity, especially in area with a high prevalence of active pulmonary tuberculosis.