Ring sign on enhanced magnetic resonance image of myocardial abscess

Description of Clinical Presentation: A 22-year-old male primarily diagnosed with acute promyelocytic leukemia, undergoing post-remission consolidation therapy, was admitted in March, 2017 with relapsed leukemia. While being treated with arsenic trioxide, the patient developed neutropenic fever syndrome . Surgical treatment was contraindicated due to septic embolisms and right retinal abscess shown in the preoperative cerebral magnetic resonance study. Tissue culture from right vitrectomy was positive for Aspergillus.

Diagnostic Techniques and Their Most Important Findings: Findings of the transthoracic and transesophageal echocardiograms were suggestive of mycotic vegetations, and right ventricle and aortic root abscesses. Following treatment, ultrasound showed that previously found abscesses remained . The patient was referred to our department to further complete study with cardiac magnetic resonance (CMR), that showed several myocardial ring like lesions in the PSIR LGE sequence.

Learning Points from this Case: A myocardial abscess (MA) is a suppurative infection of the myocardium, endocardium,

native or prosthetic valve tissue 1. MAs in most cases occur as complications of either infective endocarditis (IE) or sepsis 2. For the last decades echocardiography has been the cornerstone of its diagnostic imaging techniques. Nevertheless, the sensitivity of transesophageal echocardiography for detection of MA is of 48% 3. On the other hand, cardiac magnetic resonance imaging (MRI) is a non-invasive supplementary diagnostic method with high temporal and spatial resolution, making it suitable in patients with diagnostic difficulties. MRI is already relevant in IE by influencing clinical decisions through the detection of cerebral complications 4–7. Characteristic descriptive imaging findings or signs suggestive of other IE complications by MRI, particularly, those of cardiac abscesses, on the other hand, remain poorly defined in the current literature. On the basis of the underlying anatomopathological processes leading to abscess organization, it is reasonable to foresee a nodular image with a gadolinium contrast-enhanced peripheral ring at delayed CMR. In line with both liver and brain abscess findings (8,9), a contrast-enhanced delayed ringlike surrounding central hypointensity at CMR would be thought to represent the abscess peripheral capsule and its pus collection, respectively. Accordingly, Ryu et al and Suksaranjit et al have previously described a similar pattern in perivalvular abscess cases 10, 11.

Two chamber PSIR image showing several non contiguous foci of LGE in the inferior and anterior walls, one of them with a distinctive ring like pattern (blue arrow)
A similar ring like focus (blue arrow) was seen at the inferior wall in the basal SAX PSIR image.