Prashant Jolepalem

Use of SPECT/CT with 99mTc-MDP Bone Scintigraphy to Diagnose Symptomatic Os Acromiale

Os acromiale is an anatomic variant that in rare cases can cause pain. 99mTc-methylene diphosphonate bone scintigraphy with SPECT/CT can play an important role in diagnosing this clinical entity. We present a male football player with shoulder pain secondary to a symptomatic os acromiale, and we demonstrate the findings on bone scanning with limited SPECT/CT that diagnosed this important clinical abnormality.

The Role of Scintigraphy in Confirmation of Suspected Brain Death

We present a case illustrating how cerebral perfusion scintigraphy can be used to assist in crucial medical decision making in the intensive care setting for patients who are maintained on life support but are clinically suspected to have brain death. Cerebral perfusion scintigraphy can confirm brain death but cannot be used to diagnose it. 99mTc-HMPAO and 99mTc-ethylcysteinate dimer are the preferred imaging agents since they cross the blood–brain barrier.

The Evaluation of Cardiac Sarcoidosis with 18F-FDG PET

Cardiac involvement in sarcoidosis is associated with poor prognosis. 18F-FDG PET can detect the presence of cardiac sarcoidosis, assess disease activity, and serve as a means to monitor treatment response in patients with cardiac sarcoidosis.

The Appearance of Congenitally Corrected Transposition of the Great Arteries on Myocardial Perfusion Imaging

We present a case of incidentally discovered congenitally corrected transposition of the great arteries (ccTGA), initially seen on stress–rest myocardial perfusion imaging (MPI). ccTGA has a characteristic appearance on MPI, which reflects the functional alterations associated with this condition.

Implications of Ambient Glucose Variation on the Target-to-Background Ratio of Hepatic Tumors By 18 FDG-PET Imaging

Objectives: To investigate the effects of ambient glucose on quantitative analysis of hepatic tumors on 2-deoxy-2-(18F)-fluoro-D-glucose (18FDG) positron emission tomography (PET) and to establish a method for glucose correction. Patients and Methods: Eighty-six patients with hepatic lesions identified on 18FDG PET/computed tomography (CT) were analyzed. The serum glucose level (Glc) was recorded prior to imaging, and the maximum standardized uptake value (SUV) in the hepatic tumors and the average SUV in normal liver were determined. The inverse relationship of SUV to glucose can be defined as d (SUV)/d (Glc) = g*SUV/(Glc), where g is the glucose sensitivity. Simulations using glucose level from 70 to 250 mg/dl were performed to evaluate the effects of Glc on the maximum SUV of malignant hepatic lesions and normal liver. Results: By logarithmic transformation and linear regression, g for metastasis was significantly higher than that for normal liver (−0.636 ± 0.144 vs. −0.0536 ± 0.0583; P = 0.00092). Simulation studies showed that the SUV in malignant lesions will decrease rapidly when Glc level is >120 mg/dl, while background liver remains relatively constant up to 250 mg/dl. Conclusion: The tumor FDG uptake is much more sensitive to ambient glucose level variation than the background liver. Therefore, correction by the glucose sensitivity factor will result in more accurate SUV measurements and make semi-quantitative analysis of 18FDG PET scans more reliable.

Radiation Therapy–Induced Phrenic Neuropathy Mimicking Metastasis to the Diaphragmatic Crus on 18F-FDG PET/CT

Benign unilateral uptake in the diaphragmatic crus is a relatively uncommon finding on 18F-FDG PET/CT that can mimic the appearance of malignancy in patients with known cancer, as illustrated in this patient with neuroendocrine carcinoma. It is important for the PET interpreter to recognize this finding and attribute it to benign uptake based on the patient’s history and symptoms at the time of the scan. Correlation with the findings of other available imaging modalities is also important to characterize focal uptake in unusual locations.

Semantic Dementia Diagnosed by F-18 FDG PET/MRI: Co-registered Images

We report a case of a 61-year-old male who presented with a sudden change in mental status. From a psychiatric standpoint, his symptoms were consistent with a bipolar disorder. A neurology consult raised suspicion for vascular dementia, given the sudden onset of symptoms; however, the magnetic resonance angiography (MRA) was unremarkable. The magnetic resonance imaging (MRI) had findings that were suggestive of both vascular and frontotemporal lobe dementia based on parenchymal atrophy and a lacunar infarct near the thalamus. However, by co-registering the magnetic resonance images with a subsequent fluorine-18 Fluorodeoxyglucose positron emission tomography (F-18 FDG PET), and combining the functional data with the anatomic appearance, the diagnosis was narrowed to semantic dementia, which is one of the lesser known subtypes of frontotemporal lobe dementia (FTD).

Radiographically Occult Latent Radiogenic Osteosarcoma Uncovered on Tc-99m Methylene-diphosphonate Bone Scintigraphy

We present a case of a 70-year-old male who was referred for a technetium-99m methylene-diphosphonate bone scan for mild left hip pain and an elevated alkaline phosphatase level of 770 units/L. No additional information was provided and the patients history was limited due to a language barrier. We were able to ascertain that the patient had a remote history of prostate cancer, which had been treated with radiation. Originally, we felt the bone scan was compatible with Pagets disease; however, further work-up revealed the presence of osteosarcoma, which was potentially radiation-induced.

67Ga Scintigraphy in the Evaluation of Postsurgical Low Back Pain

FIGURE 2. 99mTc-MDP bone scan (A) in anterior and posterior projections showing mild activity at L3. More intense uptake is incidentally seen at compression deformity surrounding T11. 67Ga-citrate scan (B) at 24 and 48 h in posterior projection shows progressively increasing uptake in mid lumbar spine. FIGURE 1. Plain film (A) and axial CT scan of L3 (B) showing inferior endplate erosion and evidence of periostitis (arrows).

Mediastinal masses in nuclear medicine studies: A diagnostic algorithm.

There are multiple reasons for an anterior mediastinal mass. In this case, we discuss possible etiologies and offer an algorithm to narrow the differential diagnosis. When the mass cannot be diagnosed radiographically, the next step in imaging is a physiologic assessment with radionuclide modalities.