Josephine Rini

Preoperative parathyroid scintigraphic lesion localization: accuracy of various types of readings.

PURPOSE To retrospectively compare the accuracy of various parathyroid scintigraphy readings for single-gland disease (SGD) and multigland disease (MGD) in patients with primary hyperparathyroidism, with histologic analysis as the reference standard. MATERIALS AND METHODS Institutional review board approval was obtained for this HIPAA-compliant study. Records of 462 patients with primary hyperparathyroidism who underwent preoperative imaging with a technetium 99m ((99m)Tc) sestamibi and (99m)TcO4- protocol that consisted of early and late pinhole (99m)Tc sestamibi, pinhole thyroid imaging, image subtraction, and single photon emission computed tomography (SPECT) were retrospectively reviewed. An experienced nuclear medicine physician without knowledge of other test results or of the final diagnoses graded images on a scale from 0 (definitely normal) to 4 (definitely abnormal). Early pinhole (99m)Tc sestamibi images, late pinhole (99m)Tc sestamibi images, subtraction images, SPECT images, early and late pinhole (99m)Tc sestamibi images, all planar images, and all images--including SPECT images--were read in seven sessions. Receiver operating characteristic curves were generated for each session and were used to calculate sensitivity, specificity, and accuracy. RESULTS A total of 534 parathyroid lesions were excised. Of the 462 patients, 409 had one lesion, whereas 53 had multiple lesions. Reading all images together was more accurate (89%, P = .001) than was reading early (79%), late (85%), subtraction (86%), and SPECT (83%) images separately; however, it was not significantly more accurate than reading planar images (88%) or early and late images together (87%). Reading all images was significantly less sensitive in the detection of lesions with a median weight of 600 mg or less than in the detection of lesions with a median weight of more than 600 mg (86% vs 94%, P = .004). Per-lesion sensitivity for reading all images was significantly higher for SGD than for MGD (90% vs 66%, P < .001). Sensitivity of reading all images together in the identification of patients with MGD was 62%. CONCLUSION Reviewing early, late, and subtraction pinhole images together with SPECT images maximizes parathyroid lesion detection accuracy. Test sensitivity is adversely affected by decreasing lesion weight and MGD.

Correlación de los parámetros hematológicos con la captación de FDG en médula ósea y bazo en la PET

Resumen Objetivo Valorar la correlacion existente entre los parametros hematologicos y la captacion de FDG en medula osea (MO) y bazo en la PET. Material y metodos 29 pacientes (pts) con linfoma de Hodgkin remitidos para un estudio inicial con FDG PET antes de comenzar el tratamiento y sin evidencia de afectacion en MO, fueron incluidos en el estudio. En 18 pts sin afectacion esplenica tambien se valoro la captacion de FDG en el bazo. La captacion en MO y bazo se clasifico de acuerdo a una escala visual de tres puntos, y se determino si era homogenea o difusa. Tambien se realizo un analisis semi-cuantitativo por medio de unos indices de captacion obtenidos a traves de unas regiones de interes, en medula osea y bazo, en relacion con otras en pulmon derecho e higado. Se calcularon unos coeficientes de correlacion entre la escala visual y los indices semi-cuantitativos en medula osea y bazo, con las cifras de hemoglobina (Hb), leucocitos y plaquetas en sangre. Resultados En 27/29 pts la captacion de FDG en MO y en 18/18 pts la captacion en bazo fue homogenea. Se objetivo una correlacion directa entre las cifras de leucocitos y la captacion de FDG en MO y bazo. La correlacion era menor y ademas inversa con las cifras de Hb (esto es, cuanto mas baja la Hb mas alta la captacion en MO). Las correlaciones mas bajas se obtuvieron con la cifras de plaquetas. Conclusion Los diferentes parametros hematologicos pueden llegar a afectar la captacion de FDG en MO y bazo. El conocimiento de esta correlacion puede ayudar a la mejor interpretacion de los estudios FDG PET.OBJECTIVE To assess the relationship between various hematologic parameters and bone marrow (BM) and splenic uptake of FDG in PET imaging. MATERIAL AND METHODS 29 patients with Hodgkins disease (HD) referred for baseline FDG PET imaging before treatment and without evidence of bone marrow (BM) involvement were included in the study. Splenic uptake also was analyzed in 18 patients without splenic involvement. BM and splenic activity were visually graded on a 3 point scale. Activity pattern was classified as homogeneous or heterogeneous. Semi-quantitative analysis was also performed by drawing regions of interest (ROI) over the spine and spleen. ROIs also were drawn over right lung and liver. FDG uptake ratios for the spine and spleen in comparison with the lung and liver were generated. Visual scoring of marrow and splenic uptake, and the various ratios were correlated with hemoglobin (Hb), white blood cell (WBC), and platelet counts, and correlation coefficients were calculated. RESULTS In 27/29 patients (93 %) BM and in 18/18 patients (100 %) spleen uptake was diffuse. There was a direct correlation between BM and spleen uptake of FDG with increasing WBC, which was stronger than the inverse correlation seen with Hb (the lower the Hb the greater the uptake). Correlation with platelet counts was weaker. CONCLUSION There is a correlation between hematologic parameters such as Hb, WBC and platelet counts and the uptake of FDG in BM and spleen in PET imaging. Knowledge of this correlation should help to better interpret and understand PET imaging.

Radionuclide bone imaging in Erdheim-Chester disease

Erdheim-Chester disease is a rare sporadic systemic histiocytic disease of unknown etiology that routinely involves the diametaphyseal region of the long bones of the appendicular skeleton. In addition, there is frequent involvement of multiple internal organs producing protean manifestations. Although definitive diagnosis requires histopathologic confirmation, its appearance on bone scintigraphy is virtually pathognomonic of this entity. We report the case of a 53-year-old man with Erdheim-Chester disease who presented with lower extremity bone pain and was found to have the characteristic lesions of this condition on bone scintigraphy.

18F-FDG Uptake in the Anterior Mediastinum. Physiologic Thymic Uptake or Disease?

Purpose: We reviewed 18F-fluorodeoxyglucose (18F-FDG) studies to determine the frequency of thymic visualization, to characterize this uptake to facilitate differentiation from disease, and to ascertain effects of therapy on visualization.Methods: Hybrid positron emission tomography images performed on 14 patients with known or suspected malignancy before therapy, and on six of the patients after treatment, were reviewed. Mediastinal uptake was characterized by location, contour and intensity.Results: Thymic uptake seen in five patients, 13-16-years-old, was characterized by an anterior midline location, regular contours, and a mean uptake ration of 2.5, and involved large glands. In five patients with mediastinal disease, 16-23-years-old, uptake was more posterior and eccentric in location with irregular borders and a mean uptake ratio of 4.3. One patient had anterior (thymic) and posterior (disease) mediastinal uptake. Three patients, 15-22-years-old, without disease and small thymus glands had no uptake. Five patients, including two with baseline uptake, showed no thymic uptake subsequently. One patient, negative initially, had thymic uptake five months after therapy.Conclusions: Thymic 18F-FDG uptake occurs in younger patients, before or after treatment, and is associated with larger glands. Its midline anterior mediastinal location and mild intensity should facilitate discrimination from disease.

Detection of papillary thyroid cancer brain metastasis with FDG-PET/CT.

Abstract:A 70-year-old woman with a history of papillary thyroid carcinoma metastatic to lung and arm muscle previously was treated with total thyroidectomy, pneumonectomy, excision of an intramuscular lesion, and I-131 therapy. Because of an elevated serum thyroglobulin level, she underwent Thyroge