18F-FDG imaging of the primary breast leiomyosarcoma and follow-up lung metastasis.

A 46-year-old woman presented with a large left breast mass. FDG PET/CT demonstrated a large left breast mass (SUV = 28). Preoperative biopsy showed malignant sarcoma. Modified radical mastectomy was performed. Immunohistochemical analysis using h-caldesmon and smooth muscle actin staining established the diagnosis of primary breast leiomyosarcoma. Despite intensive chemotherapy, 3-month follow-up PET/CT revealed a large lung metastasis suggesting aggressiveness and poor response to chemotherapy. Primary leiomyosarcoma of the breast is extremely rare and difficult to diagnose before excisional surgery because of the need for immunohistochemical staining to confirm the diagnosis.

F-18 FDG PET scan findings in patients with Loeffler's syndrome.

PURPOSE: : This study aimed to evaluate the F-2-fluoro-2-deoxyglucose positron emission tomography (F-18 FDG PET) findings of Loeffler's syndrome and to determine differential features between lung malignancy and Loeffler's syndrome. MATERIALS AND METHODS: : F-18 FDG PET and low-dose chest CT scans were performed to screen for lung cancer. Eleven patients who showed pulmonary lesions on CT scan with peripheral blood eosinophilia were included. PET scans were evaluated by mean and maximum standardized uptake values (SUVs) of abnormalities. CT findings were reviewed and correlated with the PET findings. In all patients, follow-up CT scans and PET scans were done from 1 to 4 weeks after the initial study. RESULTS: : F-18 FDG PET scans identified metabolically active lesions in 9 of 11 patients. Maximum SUVs ranged from 2.8 to 10.6, and mean SUVs ranged from 2.2 to 7.2. The other 2 patients had maximum SUVs of 1.3 and 2.2. Follow-up PET scans showed a decreased degree of initially noted FDG uptakes or migration of the lesion. The CT scan showed nodular lesions with a peripheral halo (n = 6), ground-glass attenuation (n = 4), and consolidation (n = 1). Follow-up CT scans revealed decreased size and extent of the initial lesions in 7 patients and migration in 2 patients. The other 2, who had relatively mild F-18 FDG uptakes, showed complete radiographic resolution of the lesions. CONCLUSIONS: : A single F-18 FDG PET study is not useful in differentiating benign and malignancy in patients with Loeffler's syndrome. Correlation and follow-up of PET and CT scan for the identification of abnormalities and their changes can be helpful for the differentiation between lung malignancy and Loeffler's syndrome.

Factors affecting accuracy of ventricular volume and ejection fraction measured by gated tl-201 myocardial perfusion single photon emission computed tomography.

The electrocardiogram-gated single photon emission computed tomography (SPECT) measurement of left ventricular end-diastolic volume, end-systolic volume and ejection fraction may contain substantial errors. We evaluated whether patient-related factors affect the accuracy of left ventricular volume and ejection fraction measured by gated Tl-201 SPECT. A total of 518 patients without perfusion defects on Tl-201 SPECT or coronary artery disease were studied. Left ventricular volume and ejection fraction were measured from echocardiography and adenosine stress/redistribution gated Tl-201 SPECT using commercially available software packages (QGS and 4D-MSPECT). We identified factors affecting the accuracy of gated SPECT via multiple linear regression analysis of the differences between echocardiography and gated SPECT. Gated SPECT analyzed with QGS underestimated end-diastolic and end-systolic volume, and overestimated ejection fraction, but 4D-MSPECT overestimated all those values (P<0.001). Independent variables associated with increasing the difference in end-diastolic volume between echocardiography and gated SPECT were decreasing left ventricular end-diastolic wall thickness, decreasing body surface area, female sex and increasing end-diastolic volume (P<0.001). Those for end-systolic volume were decreasing left ventricular end-systolic wall thickness, female sex, and decreasing end-systolic volume (P<0.001). Increasing end-systolic wall thickness, male sex and decreasing age were independent determinants associated with an increased difference in ejection fraction (P<0.001). Adenosine stress SPECT showed significantly higher end-diastolic and end-systolic volume values and a lower ejection fraction than did redistribution SPECT (P<0.001). Patient-related factors affect the accuracy of left ventricular volume and ejection fraction measured by gated Tl-201 SPECT. Modification of gated SPECT measurements by taking account of these factors would lead to reduce systemic errors.