Cardiac MRI in kidney failure can be challenging, however anatomic assessment of the heart and vessels can be readily performed without requirement for intravenous contrast. The information obtained may have value in prognosis and for therapeutic monitoring. Applicable techniques will be reviewed and changes that may be observed in chronic kidney disease (e.g. left ventricular remodelling) will be discussed.
Highlights
· CMR in kidney failure can be challenging, however anatomy of the heart can be readily assessed without the need for contrast agents
· LV remodelling has important prognostic and therapeutic implications
· Non-contrast MRA techniques can be used for vascular assessment
· Understanding how best to deploy the sequences at our disposal is important so the exam can be tailored appropriately to the clinical scenario
Target Audience
Radiologists, technologists and basic scientists with an interest in cardiovascular MRI1. To review how cardiac MR can be used to assess anatomy of the heart in patients with chronic kidney disease, with particular focus on balanced steady state free precession imaging.
2. To review cardiac anatomic findings in CKD including LV remodelling
3. To review vascular assessment in CKD using non-contrast MRA techniques
Cardiovascular disease is the leading cause of mortality in patients with kidney failure. Whilst atherosclerotic risk factors and atherosclerosis are commonly found in patients with kidney failure, outcomes such as sudden cardiac death, heart failure and stroke are disproportionately represented in relation to myocardial infarction in the chronic kidney disease (CKD) population. Left ventricular hypertrophy and fibrosis are strong predictors of cardiovascular outcomes in CKD. Left ventricular mass in particular is an important end point in clinical trials of patients with renal failure. Vascular disease As such, assessment of the cardiovascular system is important for risk stratification. CMR also has potential for treatment monitoring, with LV remodelling observed in end stage renal failure patients, e.g. following arteriovenous fistula creation for haemodialysis.
Cardiac MR provides important insights in this population, including comprehensive anatomic and functional information. With regards to cardiac anatomy, chamber size, valve morphology and myocardial thickness/ mass can be readily assessed without the use of contrast agents. This is mainly achieved with balanced steady state free precession (SSFP) imaging, the workhorse of cardiac MRI. At 3T however, performing SSFP can be more challenging. Sequence adjustments may be required or alternative sequences may need to be performed.
Vascular disease frequently co-exists with CKD, for example it is common in patients with diabetic nephropathy. Vessel anatomy and calibre can also be assessed without contrast. Again, this can be achieved with volumetric balanced steady state free precession imaging, which is flow independent, relying upon the intrinsic T1 and T2 properties of blood for (bright blood) vessel visualisation. Other relatively recent and new techniques have also been described for vascular assessment that do not require contrast, e.g. subtractive and non-subtractive flow dependent techniques, and fast interrupted steady state imaging (FISS).
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