Sindu Sheth

Atlas of sodium fluoride PET bone scans: atlas of NaF PET bone scans.

Sodium fluoride (NaF) is a bone-seeking positron-emitting tracer with high sensitivity and specificity for detection of osseous lesions, particularly osteolytic lesions. We believe that NaF positron emission tomography (PET)/computed tomography (CT) scans can provide a more thorough and conclusive evaluation of bone diseases than conventional Technetium-99m-methylene diphosphonate bone scans. Understanding both normal and pathologic patterns is important for the evaluation and interpretation of these studies. Thus, an atlas of NaF positron emission tomography/computed tomography bone scans demonstrating benign, pathologic, and malignant osseous lesions as well as extraosseous lesions will be invaluable in the correct interpretation and diagnosis of osseous lesions.

Coronary Calcium Score as an Adjunct to Nuclear Myocardial Perfusion Imaging for Risk Stratification Before Noncardiac Surgery

The purpose of this study was to evaluate the added value of coronary artery calcium score (CACS) as an adjunct to myocardial perfusion imaging (MPI) with SPECT for cardiac risk stratification before noncardiac surgery. SPECT MPI is a well-established and widely used tool for preoperative risk stratification before noncardiac surgery. The potential added value of combining SPECT MPI with CACS is unknown. Methods: We included 326 consecutive patients who were referred for SPECT MPI for preoperative cardiac risk assessment before elective noncardiac surgery. All patients underwent an additional low-dose CT scan for CACS and SPECT MPI. Patients were followed up for 40 d after their index surgical procedure, and the occurrence of major adverse cardiovascular events (MACE), including death, myocardial infarction, revascularization, stroke, and sudden cardiac death, was registered. Results: Postoperative MACE occurred in 30 patients (9%). Cumulative MACE rate was highest in patients with abnormal SPECT and high CACS (22%), defined by a cutoff value CACS of 1,314 or more, and lowest in patients with normal SPECT MPI findings and low CACS (5%) (CACS < 1,314). A CACS score of 1,314 or more was independently associated with a higher MACE rate in patients with normal (12% vs. 5%) or abnormal perfusion (22% vs. 12%, P < 0.05 for all intergroup comparisons). Conclusion: SPECT MPI findings and CACS are strong preoperative risk predictors. CACS allows further risk stratification, indicating very low risk when CACS less than 1,314 is associated with normal SPECT MPI findings. Conversely, in patients with abnormal SPECT MPI findings, a CACS of 1,314 or more confers an added value for predicting adverse outcomes.

Intramuscular metastasis of endometrial carcinoma on FDG PET/CT.

We report the F-18 FDG PET/CT appearance of biopsy proven intramuscular metastasis from primary endometrial carcinoma. The patient is a 70-year-old woman initially diagnosed with endometrioid adenocarcinoma, status post total abdominal hysterectomy, bilateral salpingo-oopherectomy and pelvic node dissection. Restaging PET/CT study performed 1 year later demonstrated extensive metastatic disease involving the intramuscular region of the right neck, right kidney, pancreas, left adrenal gland, lungs, lymph nodes, and bone. The lesion in the right neck intramuscular region was subsequently biopsied and interpreted as consistent with metastasis from an endometrial primary. Metastasis to the skeletal muscle from the primary endometrial carcinoma is a rare entity. Knowledge of this rare metastatic site will help the interpreting physician make the correct diagnosis.

Malignant transformation of retroperitoneal inflammatory pseudotumor to undifferentiated high-grade pleomorphic sarcoma on FDG PET/CT.

We report FDG PET/CT appearance of malignant transformation of retroperitoneal inflammatory pseudotumor to pleomorphic sarcoma in a 78-year-old woman. The patient was diagnosed with left retroperitoneal pseudotumor in 2007. She subsequently suffered from recurrent disease and chronic osteomyelitis in the L5 vertebral body in July 2008, status post surgical excision. In November 2009, after the patient developed left groin pain, MRI study of lumbosacral spine and whole-body PET/CT study demonstrated 2 hypermetabolic soft-tissue masses originating from the L5 surgical bed. These masses were subsequently resected and were consistent with pleomorphic sarcoma. Malignant transformation of retroperitoneal pseudotumor to pleomorphic sarcoma is extremely rare.

(18)F-FDG PET/CT imaging of metastatic atypical fibroxanthoma.

We report the F-FDG PET/CT appearance of a metastatic biopsy-proven malignant fibroxanthoma of the ankle. A 41-year-old female patient with a history of scleroderma presented with a fungating mass in the left ankle. Shave biopsy of the overlying skin showed atypical fibroxanthoma (AFX). Staging FDG PET/CT demonstrated a hypermetabolic exophytic soft tissue mass in the left ankle with local extension to bone and widespread metastatic disease including pulmonary parenchyma, nodes, bone marrow, and skeletal muscle. While rare, knowledge of the potential aggressive nature of AFX is important for accurate diagnosis.

Modified Bi-Rads Scoring of Breast Imaging Findings Improves Clinical Judgment.

In contrast with the reporting requirements currently mandated under the Federal Mammography Quality Standards Act (MQSA), we propose a modification of the Breast Imaging Reporting and Data System (Bi‐Rads) in which a concluding assessment category is assigned, not to the examination as a whole, but to every potentially malignant abnormality observed. This modification improves communication between the radiologist and the attending clinician, thereby facilitating clinical judgment leading to appropriate management. In patients with breast cancer eligible for breast conserving therapy, application of this modification brings to attention the necessity for such patients to undergo pretreatment biopsies of all secondary, synchronous ipsilateral lesions scored Bi‐Rads 3‐5. All contralateral secondary lesions scored Bi‐Rads 3‐5 also require pretreatment biopsies. The application of this modification of the MSQA demonstrates the necessity to alter current recommendations (“short‐interval follow‐up”) for secondary, synchronous Bi‐Rads 3 (“probably benign”) image‐detected abnormalities prior to treatment of the index malignancy.

18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging of extra-medullary plasmacytoma of the ovary

Extrameduallary plasmacytoma of ovary is extremely rare. We report a case of involvement of ovary in a treated case of plasmacytoma of 2nd part of duodenum, which was initially thought to be physiological luteal activity. However, follow up whole body FDG PET-CT scan shows appearance of metabolically active soft tissue mass in left adnexal region which confirmed to be extra-medullary plasmacytoma of ovary on histopathology.