Demonstration of coronary venous anatomy using cardiac MRI

Objectives: We sought to evaluate the ability of cardiac MRI to demonstrate the anatomy of the coronary venous system.

Background: Cardiac MRI is useful in the diagnosis and management of patients with impaired left ventricular (LV) function, providing information about anatomy, function, perfusion, and viability. Cardiac resynchronisation therapy (CRT), an established treatment of LV dysfunction, requires the deployment of a left ventricular pacing lead via the coronary sinus to a branch of the cardiac venous system. Knowledge of coronary venous anatomy, and the presence or absence of suitable veins for CRT, may be useful in the management of patients referred for cardiac MRI to investigate heart failure. Although coronary veins can be seen by cardiac CT, they are not routinely demonstrated with conventional cardiac MRI protocols.

Methods: The cardiac MRI scans of 30 patients (21 men; mean age 58.2 (11.1) years) were studied. All scans had been performed on a 1.5 T MR scanner (Gyroscan Intera CV, Philips Medical Systems, Best, the Netherlands), and were requested for assessment of known or suspected ischemic heart disease. All scans were judged suitable for coronary imaging, and performed as part of a comprehensive protocol involving LV function, perfusion and delayed enhancement imaging. A 3D volume stack was acquired, using a single diaphragmatic navigator, using an SSFP sequence with a fat suppression and T2 preparation prepulses (TR/TE/flip angle 4.6/2.3/100; spatial resolution 1.18×1.18×1.80 mm). The scans were commenced after first pass perfusion imaging with intravenous administration of 0.05 mmol/kg of a gadolinium based contrast agent. The sequences were reviewed on a ViewForum Workstation (Philip’s Medical Systems) equipped with a dedicated cardiac analysis package and volume rendering tools. The ability to visualise the coronary sinus (CS), anatomical variants and the presence of an LV branch after volume rendering were recorded. The diameter of the CS ostium on the axial images, and the uninterrupted distance from this point to the most distal demonstrable end of a cardiac vein on the volume rendered image was measured.

Results: Continuous data are presented as mean (standard deviation). The coronary sinus was demonstrated in all patients. The average diameter of the CS ostium was 11.5 (4.2) mm. The mean distance for which continuous vein could be visualised from the ostium of the CS was 81.5 (43.6) mm. An LV branch was demonstrated in 22 (71%) patients and an anterior interventricular branch was seen in 14 (45%) patients.

Conclusions: The anatomy of coronary veins can be reliably imaged by cardiac MRI in a manner similar to CT. This technique may prove a useful addition to the already impressive armamentarium of cardiac MRI for the assessment of patients with left ventricular dysfunction.