Nand Relan

Diagnosis and monitoring of cardiac sarcoidosis with delayed-enhanced MRI and 18F-FDG PET-CT

A 41-year-old African-American man presented with symptoms of congestive heart failure, which included 4 days of shortness of breath and a 10 lb weight gain over the past 1 week. On admission, the patient’s blood pressure was 118/78 mm Hg, his respiratory rate was 20 breaths/minute. He had a resting heart rate of 118 beats/minute, decreased basilar breath sounds with crackles, and a murmur consistent with mitral regurgitation. Additionally, bilateral occipito-cervical adenopathy was detected. EKG revealed sinus tachycardia with a firstdegree heart block, frequent premature ventricular complexes, and right bundle branch block. Chest radiography showed central pulmonary vascular congestion with bilateral pleural effusions. An echocardiogram showed severely reduced global systolic function. Subsequent biopsy of an occipito-cervical lymph node revealed noncaseating granulomas on pathology, findings which were consistent with a diagnosis of sarcoidosis. During this admission a cardiac MRI was performed with the addition of contrast-enhanced first-pass perfusion followed by delayed-enhanced imaging revealing extensive cardiac sarcoid involvement (Figure 1). On the following day, fasting F-FDG PET-CT scan showed extensive hypermetabolic activity within the left ventricle, as well as the right ventricle; findings compatible with active cardiac sarcoidosis. Whole-body PET-CT imaging revealed extensive systemic sarcoidosis (Figure 2). Following a 3-month course of corticosteroid therapy and optimal medical management for heart failure, the patient returned for follow-up with improved cardiac MRI findings (Figure 3) and near-resolution of F-FDG PET-CT abnormalities (Figure 4). After 9 months of therapy, cardiac MRI showed persistent delayed post-contrast enhancement of both the left and the right ventricles despite significant clinical improvement (Figure 5). At 1-year follow-up, the F-FDG PET-CT remained free of active cardiac sarcoidosis. Additionally, there were no areas to indicate active systemic sarcoidosis. Only small residual right lung nodules were seen on the CT portion of the exam. Detection of cardiac involvement in sarcoidosis is often a difficult task. Myocardial involvement is responsible for many deaths through fatal arrhythmias and congestive heart failure. While these symptoms are identical to those caused by other forms of cardiomyopathy, the diagnosis of cardiac sarcoidosis is important both in terms of treatment and in overall prognosis. To do so, traditional endomyocardial biopsy has proven an insensitive method. Often, as in our patient, the diagnosis of systemic sarcoidosis is first made by peripheral lymph node biopsy, and later, cardiac imaging is performed to evaluate for potential myocardial involvement. Without extracardiac manifestations, the diagnosis of cardiac sarcoidosis can be difficult, especially when the clinical picture may point to other types of cardiac disease. Dedicated fasting cardiac F-FDG PET-CT imaging offers sensitivity comparable to MRI contrastenhanced imaging in the detection of inflammation in cardiac sarcoidosis. Sensitivity of F-FDG PET has been reported to be up to 100%, allowing for early detection of lesions before the appearance of perfusion defects. F-FDG PET imaging, however, suffers from low specificity, which is reported as low as 38.5%. The acquisition of whole-body PET-CT imaging has the advantage of evaluating the extent of systemic disease, data which is not obtainable with MRI. During admission, it was strongly suggested to the patient to have an implantable cardioverter-defibrillator (ICD), but the patient declined placement and agreed to close follow-up. The ICD would have prevented further cardiac MRI imaging because of its electromagnetic interference and potential severe hazardous effects. Clinically at that time, the patient’s respiratory and cardiac symptoms had improved. Continuous electrocardiographic (Holter) monitoring showed underlying From the Department of Radiology, Health Sciences Center, Division of Cardiology, Department of Medicine, Stony Brook University Medical Center, Stony Brook, NY. All authors actively participated in drafting the manuscript and revising critically important intellectual content. Reprint requests: Robert Matthews, MD, Department of Radiology, Health Sciences Center, Stony Brook University Medical Center, L4, Rm 120, Stony Brook, NY 11794-8460; robert.matthews@ stonybrook.edu. J Nucl Cardiol 2012;19:807–10. 1071-3581/

PERSPECTIVES IN PEDIATRIC PATHOLOGY: Basement Membranes in Development

34.00 Copyright 2012 American Society of Nuclear Cardiology. doi:10.1007/s12350-012-9550-9

Head and neck cancers: post-therapy changes in muscles with FDG PET-CT.

The aim of this review is to introduce the reader to the main ECM constituents and to some of their roles in development. The main functions of the ECM during embryogenesis are the production, promotion, and regulation of normal tissue structure. Among the ECM components, LMs have been the most extensively studied in relation to embryo-genesis. Skin and skeletal muscle disorders have been shown to be caused by LM alterations. Additional experiments, e.g., with knockout mice, will help enormously to elucidate the functional significance of many ECM constituents and their involvement in development and disease.

18F-FDG PET-CT: predicting recurrence in patients following percutaneous cryoablation treatment for stage I primary non-small-cell lung cancer.

Background: FDG PET-CT plays a critical role in the management of head and neck cancer patients. After therapy, many patterns of altered physiologic FDG uptake have been recognized. In our institution, we noticed patterns of head and neck muscle uptake that were unique in the post-therapy scans of head and neck cancer patients. Materials and Methods: A total of 32 patients with head and neck cancers who had both pretherapy and posttherapy FDG PET-CT scans were retrospectively analyzed. Regional anatomic muscle groups that had increased PET uptake on either pretherapy or post-therapy scans were identified. Results: On the pretherapy scans, the majority of patients (24/32 patients) did not have increased PET activity in the predefined muscle groups. On the post-therapy scans, the majority of patients (25/32 patients) demonstrated increased uptake in at least 1 head and neck muscle group, with an average of 3 muscle groups per patient. The muscle groups with the greatest frequencies were the prevertebral (50%), the accessory neck (47%), the posterior paravertebral (47%), and the scalene muscles (38%). Relative to pretherapy scans, the mean intensity of the post-therapy elevations corresponded to greater SUVs. Conclusion: FDG PET-CT scan commonly depicts an elevated FDG muscle uptake in all regional anatomic muscle groups in the post-therapy head and neck cancer patient. This uptake should be considered as a consequence of treatment and perhaps changes in altered biomechanics, and not be confused with residual or recurrent neoplastic activity.

Fluorodeoxyglucose PET-CT Findings Following Bone Marrow Harvesting

PurposeThe aim of this study was to understand the imaging features of fluorine-18 fluorodeoxyglucose (18F-FDG) PET-computed tomography (CT) in postcryoablation lung cancer patients that could help predict recurrence. MethodsWe identified 28 patients with 30 lesions treated by means of percutaneous cryoablation for stage I non-small-cell lung cancer. Two experienced nuclear radiologists blindly reviewed baseline images and follow-up 18F-FDG PET-CT scans for a minimum of 24 months, with discrepancy in interpretation resolved by consensus. Nineteen lesions had undergone baseline PET-CT studies, whereas 11 lesions had undergone only baseline CT studies. Follow-up PET-CT studies were analyzed for up to 24 months, whereas the recurrence-free survival analysis was performed for 36 months. ResultsThe average maximum standardized uptake value (SUVmax) at baseline (n=19) was 5.2±3.9 and the average CT area at baseline was 2.2±1.6 cm2. Only the CT area was significantly different between recurring and nonrecurring lesions at baseline (P=0.0028). The Kaplan–Meier survival analysis showed that dichotomizing lesions around 2 cm on CT did not result in a statistically significant survival difference (hazard ratio=1.42, 95% confidence interval: 0.63–2.21). The average SUVmax at first follow-up was 1.9±1.8 for 27 lesions, whereas the average SUVmax of recurrent lesions was 2.2±2.2 and that of nonrecurrent lesions was 1.5±0.3 (P=0.17). Six lesions had SUVmax more than or equal to 2.5 within 24 months, all of which recurred in the ablation zone. Conclusion18F-FDG PET-CT is a valuable tool for determining treatment response and for distinguishing benign from malignant lesions after cryoablation. The CT area was most predictive of future recurrence at baseline, whereas SUVmax more than or equal to 2.5 was most predictive of future recurrence at first follow-up.

Added Value of Including Entire Brain on Body Imaging With FDG PET/MRI

Two patients demonstrated an unusual pattern of intense bone and surrounding soft tissue hypermetabolic uptake in the posterior pelvis on fluorodeoxyglucose positron emission tomography with computed tomography PET-CT scans. After further investigation, we found that both patients underwent uncomplicated autologous bone marrow harvesting several weeks before imaging. These two cases illustrate a distinctive PET-CT appearance following bone marrow harvesting that the radiologist needs to recognize to not confuse the findings with metastatic disease.

Embryonic mesenchymal cells share the potential for smooth muscle differentiation: myogenesis is controlled by the cell's shape

OBJECTIVE FDG PET/MRI examination of the body is routinely performed from the skull base to the mid thigh. Many types of brain abnormalities potentially could be detected on PET/MRI if the head was included. The objective of this study was therefore to identify and characterize brain findings incidentally detected on PET/MRI of the body with the head included. MATERIALS AND METHODS We retrospectively identified 269 patients with FDG PET/MRI whole-body scans that included the head. PET/MR images of the brain were reviewed by a nuclear medicine physician and neuroradiologist, first individually and then concurrently. Both PET and MRI findings were identified, including abnormal FDG uptake, standardized uptake value, lesion size, and MRI signal characteristics. For each patient, relevant medical history and prior imaging were reviewed. RESULTS Of the 269 subjects, 173 were women and 96 were men (mean age, 57.4 years). Only the initial PET/MR image of each patient was reviewed. A total of 37 of the 269 patients (13.8%) had abnormal brain findings noted on the PET/MRI whole-body scan. Sixteen patients (5.9%) had vascular disease, nine patients (3.3%) had posttherapy changes, and two (0.7%) had benign cystic lesions in the brain. Twelve patients (4.5%) had serious nonvascular brain abnormalities, including cerebral metastasis in five patients and pituitary adenomas in two patients. Only nine subjects (3.3%) had a new neurologic or cognitive symptom suggestive of a brain abnormality. CONCLUSION Routine body imaging with FDG PET/MRI of the area from the skull base to the mid thigh may miss important brain abnormalities when the head is not included. The additional brain abnormalities identified on whole-body imaging may provide added clinical value to the management of oncology patients.