E1711. Not for the Faint of Heart: Cardiac Sarcoidosis Imaging Techniques and Findings
  1. Jane Ball; LSUHSC New Orleans
  2. Ricky Declet; LSUHSC New Orleans
  3. Mae Igi; LSUHSC New Orleans
  4. Raman Danrad; LSUHSC New Orleans
Cardiac sarcoidosis (CS) most often results in conduction abnormalities, ventricular arrhythmias, and heart failure in clinically active disease. These critical manifestations affect approximately 5% of patients with sarcoidosis though up to 25% of persons with sarcoidosis may have clinically silent cardiac involvement. CS cannot be reliably diagnosed clinically. While endomyocardial biopsy is the gold standard for diagnosis, it may lack sensitivity due to sampling error because of the patchy or focal myocardial infiltration of the sarcoidosis. No imaging study alone can meet criteria for diagnosis of cardiac sarcoidosis. Contrast enhanced magnetic resonance imaging (MRI) and Technetium-99m-tetrofosmin (Tc-99m-tetrofosmin) single positron emission computed tomography (SPECT) and Fluorodeoxyglucose F-18 PET (FDG PET) appear to be the most sensitive imaging studies for cardiac sarcoidosis and tend to correlate with disease activity. Other imaging studies which aid in the diagnosis include Thallium-201 and Gallium-67 scintigraphy. The radiologist plays a critical role in the evaluation of suspected CS and in treatment response follow-up.

Educational Goals / Teaching Points
The aims of this presentation are to describe how best to image suspected cardiac sarcoidosis and to enable radiologists and trainees to answer questions about the various modalities available to aid in the workup and to interpret the examinations confidently. Specific educational goals include, 1) Enumerate the clinical manifestations of cardiac sarcoidosis to aid in patient selection for imaging evaluation. 2) Discuss the different imaging modalities available for suspected sarcoidosis and limitations of each modality. 3) Review where imaging fits in the diagnostic criteria of cardiac sarcoidosis and how it can assist with treatment plans. 4) Present cases demonstrating the imaging findings associated with CS to prepare the exhibit viewers to interpret their own examinations.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
These cases from our institution present examples of cardiac sarcoidosis through nuclear medicine Tc-99m-tetrofosmin SPECT or Cardiac MRI’s used as surrogate for scar detection as well as examinations using FDG PET to detect metabolic activity. Active sarcoidosis is demonstrated as increased activity FDG PET with corresponding lack of scar on Tc-99m-tetrofosmin SPECT. For cardiac MRI, patchy and/or focal late gadolinium enhancement of the mid portion of the myocardium coupled with zones of thinking and segmental myocardial wall motion abnormalities are commonly seen in cardiac sarcoidosis. Gallium- 67 scintigraphy demonstrates accumulation in areas of active inflammation and examples from the literature will be included.

The three primary manifestations of cardiac sarcoidosis are conduction abnormalities, ventricular arrhythmias, and heart failure. These manifestations cause significant morbidity and mortality for patients. Radiologists are critical members of the treatment team for patients with suspected or confirmed cardiac sarcoidosis because dedicated cardiac imaging serves in the diagnosis and management phases of patient care.