ABSTRACT
OBJECTIVE: The study was designed to assess the significance of the interoperator variability in the estimation of functional parameters for four nuclear medicine procedures. MATERIALS AND METHODS: Three nuclear medicine technologists with varying years of experience processed the following randomly selected 20 cases with diverse functions of each study type: renography, renal cortical scans, myocardial perfusion gated single-photon emission computed tomography (MP-GSPECT) and gated blood pool ventriculography (GBPV). The technologists used the same standard processing routines and were blinded to the results of each other. The means of the values and the means of differences calculated case by case were statistically analyzed by one-way ANOVA. The values were further analyzed using Pearson correlation. RESULTS: The range of the mean values and standard deviation of relative renal function obtained by the three technologists were 50.65 +/- 3.9 to 50.92 +/- 4.4% for renography, 51.43 +/- 8.4 to 51.55 +/- 8.8% for renal cortical scans, 57.40 +/- 14.3 to 58.30 +/- 14.9% for left ventricular ejection fraction from MP-GSPECT and 54.80 +/- 12.8 to 55.10 +/- 13.1% for GBPV. The difference was not statistically significant, p > 0.9. The values showed a high correlation of more than 0.95. Calculated case by case, the mean of differences +/- SD was found to range from 0.42 +/- 0.36% in renal cortical scans to 1.35 +/- 0.87% in MP-GSPECT with a maximum difference of 4.00%. The difference was not statistically significant, p > 0.19. CONCLUSION: The estimated functional parameters were reproducible and operator independent as long as the standard processing instructions were followed.
Subject(s)
Gated Blood-Pool Imaging/statistics & numerical data , Observer Variation , Radioisotope Renography/statistics & numerical data , Tomography, Emission-Computed, Single-Photon/statistics & numerical data , Clinical Competence , Heart/diagnostic imaging , Humans , Kidney Cortex/diagnostic imaging , Reproducibility of Results , Stroke Volume/physiologyABSTRACT
Examples of Ga-67 and Tl-201 scans in AIDS patients performed at St. Vincent's Hospital and Medical Center of New York are presented. Use of these methods is the adopted approach at this institution in AIDS patients for localizing sites of tumor or infection involvement. A Ga-67 scan is the most common nuclear medicine examination performed on AIDS patients. Sequential Tl-201 and Ga-67 scans have a role in differentiating Kaposi's sarcoma from malignant lymphoma and opportunistic infections. For intracranial lesions, Tc-99m MIBI or Tl-201-201-201-201 chloride can differentiate malignant from benign inflammatory lesions.
Subject(s)
AIDS-Related Opportunistic Infections/diagnostic imaging , Acquired Immunodeficiency Syndrome/diagnostic imaging , Gallium Radioisotopes , Neoplasms/diagnostic imaging , Radiopharmaceuticals , Thallium Radioisotopes , AIDS Dementia Complex/diagnostic imaging , Abdomen/diagnostic imaging , Brain Neoplasms/diagnostic imaging , Diagnosis, Differential , Humans , Lymphoma, AIDS-Related/diagnostic imaging , Mycobacterium avium-intracellulare Infection/diagnostic imaging , Pneumonia, Pneumocystis/diagnostic imaging , Radionuclide Imaging , Sarcoma, Kaposi/diagnostic imaging , Technetium Tc 99m SestamibiABSTRACT
We report our experience with coincidence detection imaging of 18F-fluorodeoxyglucose (FDG) using a dual-head gamma camera. Scanning of the pelvis and abdomen of a patient with recurrent colorectal carcinoma showed recurrent disease in the pelvic floor and the base of the urinary bladder and metastatic disease in the retroperitoneal space of the pelvis. Although the tumor involving the bladder and pelvic floor was detected by CT and magnetic resonance imaging (MRI), metastatic spread to the retroperitoneal nodes on the left side was detected only by 18F-FDG imaging. Based on the ultrasound, CT, MRI and cystoscopy, a local recurrence of cancer was presumed in our patient. An exploratory laparotomy was performed to resect the tumor in its entirety. At the time of surgery, the retroperitoneal metastasis in the pelvis was confirmed. Had the findings of the coincidence detection imaging study been considered, the patient would have been spared the surgical procedure.
Subject(s)
Adenocarcinoma/diagnostic imaging , Colorectal Neoplasms/diagnostic imaging , Fluorodeoxyglucose F18 , Neoplasm Recurrence, Local/diagnostic imaging , Radiopharmaceuticals , Aged , Colorectal Neoplasms/pathology , Gamma Cameras , Humans , Lymphatic Metastasis/diagnostic imaging , Male , Neoplasm Invasiveness , Radionuclide Imaging , Urinary Bladder Neoplasms/diagnostic imagingABSTRACT
BACKGROUND: AIDS patients are susceptible to opportunistic gastrointestinal infections including ascending cholangitis and cholecystitis, especially if CD4 count is < 200. Incidence of acalculous cholecystitis has not been reported previously. PURPOSE: We aim to evaluate the incidence of acalculous cholecystitis in AIDS patients and to identify causative organisms and mortality rate following cholecystectomy. MATERIALS AND METHODS: We reviewed the files of 46 patients in order to meet the objectives of this study. RESULTS: CD4 counts were < 200 in 31 patients and > 200 in 15 patients. HIDA imaging was performed in 31 patients; in 8, the CD4 count was > 200 and all had calculous cholecystitis. The gallbladder was visualized in 3 patients for a sensitivity of 63% and no organisms were found in the gallbladder specimens. In 23 patients, the CD4 count was < 200; the gallbladder was visualized in 5 patients for a HIDA sensitivity of 78%; 16 (52%) had acalculous cholecystitis; and 15 had calculous cholecystitis. In acalculous cholecystitis, Cryptosporidium was found in six cases, cytomegalovirus (CMV) in six cases, and fungus, yeast, tuberculosis, and mycobacterium avium intracellular each in one case. The thirty day mortality rate was 18%; 5 of 28 who underwent open cholecystectomy died within 30 days, 4 of them with a CD4 count < 200. There was no mortality in the 26 patients who underwent laparoscopic cholecystectomy. CONCLUSION AND RECOMMENDATIONS: (1) Because of the high incidence of 52% of acalculous cholecystitis in AIDS patients with a CD4 count < 200, we recommend using intravenous cholecystokinin if the gallbladder is visualized on hepatobiliary scintigraphy in order to determine gallbladder ejection fraction and exclude acalculous cholecystitis. (2) Laparoscopic rather than open cholecystectomy should be the surgical procedure of choice in AIDS patients especially if the CD4 count is < 200.
Subject(s)
Acquired Immunodeficiency Syndrome/complications , CD4 Lymphocyte Count , Cholecystitis/diagnostic imaging , Technetium Tc 99m Lidofenin , AIDS-Related Opportunistic Infections/diagnostic imaging , AIDS-Related Opportunistic Infections/microbiology , AIDS-Related Opportunistic Infections/surgery , Acquired Immunodeficiency Syndrome/immunology , Acute Disease , Cholecystectomy , Cholecystitis/complications , Cholecystitis/microbiology , Cholecystitis/surgery , Cholelithiasis/complications , Cholelithiasis/diagnostic imaging , Gallbladder/diagnostic imaging , Humans , Radionuclide Imaging , Retrospective Studies , Sensitivity and SpecificityABSTRACT
The aim of this study was to compare 201Tl-chloride and 99Tc(m)-sestamibi (MIBI) SPET brain imaging for differentiating brain lymphoma from other intracranial lesions in AIDS patients. Both studies were performed on the same day in 17 AIDS patients with intracranial enhancing lesions on either CT or MRI. Eleven patients underwent brain biopsy and six patients were followed clinically. We calculated the radiopharmaceutical uptake ratio of the lesion to that on the contralateral side with the guidance of CT or MRI findings. Ratios of 1.5 or more were considered to represent malignant lesions and ratios < 1.5 were considered to represent benign lesions. Biopsy revealed four cases of lymphoma, four cases of toxoplasmosis and two cases of progressive multi-focal leukoencephalopathy; one biopsy yielded necrosis. Both the MIBI and 201Tl studies yielded no false-negative cases of lymphoma (sensitivity 100%). Of the 13 non-lymphoma cases, the 201Tl studies showed seven true-negative cases (specificity 54%) and the MIBI studies showed nine true-negative cases (specificity 69%). The biopsies of the false-positive cases (toxoplasmosis) showed a pattern of healing after medical treatment. We conclude that MIBI is more helpful than 201Tl because of higher specificity and equal sensitivity. The medical treatment of toxoplasmosis is a cause of false-positive 201Tl and MIBI studies.
Subject(s)
Acquired Immunodeficiency Syndrome/complications , Brain Neoplasms/diagnostic imaging , Brain/diagnostic imaging , Lymphoma, AIDS-Related/diagnostic imaging , Radiopharmaceuticals , Technetium Tc 99m Sestamibi , Thallium Radioisotopes , Tomography, Emission-Computed, Single-Photon/methods , AIDS-Related Opportunistic Infections/diagnostic imaging , AIDS-Related Opportunistic Infections/pathology , Acquired Immunodeficiency Syndrome/diagnostic imaging , Biopsy , Brain Neoplasms/diagnosis , Brain Neoplasms/etiology , Brain Neoplasms/pathology , Cerebral Hemorrhage/complications , Cerebral Hemorrhage/diagnosis , Cerebral Hemorrhage/diagnostic imaging , Diagnosis, Differential , False Negative Reactions , Lymphoma, AIDS-Related/diagnosis , Lymphoma, AIDS-Related/pathology , Magnetic Resonance Imaging , Prospective Studies , Thallium , Tomography, X-Ray Computed , Toxoplasmosis, Cerebral/diagnostic imaging , Toxoplasmosis, Cerebral/etiology , Toxoplasmosis, Cerebral/pathologySubject(s)
Bone Marrow/pathology , Granulocyte Colony-Stimulating Factor/adverse effects , Radiopharmaceuticals , Technetium Tc 99m Medronate , Acquired Immunodeficiency Syndrome/drug therapy , Blood , Bone Marrow/diagnostic imaging , CD4 Lymphocyte Count , Humans , Hyperplasia , Knee Joint/diagnostic imaging , Leukopenia/drug therapy , Pelvic Bones/diagnostic imaging , Radionuclide Imaging , Spine/diagnostic imaging , Whole-Body CountingABSTRACT
We report an unusual finding in an AIDS patient who presented with a large mediastinal mass and multiple lymphadenopathy. A sequential thallium and gallium scan to specify the nature of the mediastinal mass was requested. The early thallium images, acquired 15 min after the intravenous injection, showed no uptake in the mass. The delayed images 2 hr later showed intense thallium uptake. A gallium scan performed 48 hr later also showed intense gallium uptake in the mediastinal mass. Biopsy from the inguinal lymph node confirmed the presence of large-cell diffuse noncleaved malignant lymphoma. This case raises questions about the optimum time of imaging for thallium in high-grade lymphoma, whether delayed imaging is essential, about previous reports of low sensitivity of thallium in undifferentiated lymphoma and about the mechanism of thallium uptake in this type of tumor.