Cardiovascular Magnetic Resonance (CMR)

  

 

 

Last update of the new text02.01.2015

 

 

  Indroduction

Cardiovascular Magnetic Resonance (CMR) is the Rolls Royce of non invasive cardiology. Despite its huge promises, it is a clinical failure. CMR is an expensive car in the Garage, rarely indicated in ambulatory medicine.

However things may change, here you will read what might be the perspectives.

Further, I will update you on all the work I have done around CMR since 1998 and provide you with many fascinating cases collected over the past years during my work at the Rodiag Radiological Institute in Olten and now at the Bürgerspital in Solothurn.

Finally, I hope to be able to give some informations about the future of cardiovascular imaging for cardiologists in Switzerland who perform cardioradiology and their interaction with radiologists and radiocardiologists.

 

  Indications for CMR

In subjects able to tolerate high magnetic fields (> 95% of the population), CMR offers unique opportunities to image the heart and the thoracic vessels.

Indications for imaging include all major issues in cardiovascular medicine with the exception of morphologic changes of heart valves (nodules, endocarditis), whereas important indications for TEE can be reliably performed also in the MRI scanner, including congenital disease of the heart and the large vessels, shunt calculations, assessment of the aorta (including plaque measurements, intramural hemorrhage, site of false lumen entry). Important advantages of CMR over TEE and MSCT are the non invasive approach and the absence of radiation burden. For coronary vessel imaging, by now, CMR did however not hold it's promises and we have to admit, that the accuracy of 16-64 slice MSCT is better.

 

  Chest Vessel Angiography Contrast based angiography of the chest is a very valuable tool for the assessment of variate pathologies in the chest. The images are usually 1.5 thick (coronal view) and acquired within one breath hold (25 seconds). A small bolustracking allows for accurate timing of the acquisition sequence and helps to differentiate different vessels in the chest (e.g. pulmonary angiogram vs angiography of the aorta). The large field of view allows for imaging even of the main vessels in the abdomen, e.g. renal arteries. View some interesting examples of CMR Angiography.
 

 

 Scientific Work

 

Since 2000, a number of interesting studies could be performed at the Rodiag Radiology Institute in Olten.

 

 

CMR coronary flow during adenosin challenge

 

In this study published in Circulation in 2002 we looked at coronary flow reserve in subjects who had undergone a coronary connector implantation at the Inselspital Bern under the direction of the known Prof. Thierry Carrel. Flow reserve was determined in a few patients using adenosin infusion. Flow was quantified using FLOW Software from www.medis.nl. view more images here

 

 

Eplerenone and reduction of left ventricular mass - 4 E

study

In this study published in Circulation in 2003 Betram Pitt and co-workers looked at the regression of left ventricular hypertrophy comparing different drug regimens using either eplerenone or enalapril or combinations in a Phase III drug trial. I participated in this trial (4 patients contributed) together with Prof. Otto Hess (3 patients contributed) and PD Jürg Schwitter from Zurich (3 patients contributed.

 

 

Casereport on coarctation of the Aorta in a young man

 

Herein we report on a case of coarctation, where we have chosen rather to operate than to dilate the stenosis. The case report was published together with the fameous Prof. Thierry Carrel, Inselspital, Bern.  

 

 

Casereport on Arrhythmogenic Right Ventricular Dysplasia

 

Herein we report on a rare case of ARVD with left heart invovlement. In collaboration with the Inselspital Bern and the fameous Prof. Hugo Saner.  

 

 

Other multicenter study participations

 

In 2003 we included 1 patient in the Telmar study, which looked at left ventricular regression using telmisartan. Because of complicated inclusion criteria, European patients were difficult to find and the study was stopped in Europe.

Again with Prof. Mathias Friedrich from Berlin we recruited 3 patients for the "Normal MASS on MRT European multicenter study"

 

 

Effect of endurance training on LV remodeling post myocardial infarction

 

This is an ongoing study in collaboration with the Inselspital Bern (JP Schmid, M. Noveanu, M. Romanens, H. Saner). Results are still beeing collected at different sites. Remodeling is measured by CMR 3 times during the study. Other variables include the course of proBNP over time.

 

  My Lifetime Experience with CMR

Since I have started with CMR in 1997, I have gathered experience from over 450 patients referred for a CMR study at the Rodiag Radiology Institute in Olten. Further, more than 150 subjects were imaged for local or multicenter studies during the past years. Further, I have trained technological assistants, namely Mss Andrea Reidshammer from Graz, Austria. Another great co-worker is Mss Claudia Mueller, which has also gathered quite a lot of experience with CMR. The assistance of Radiologists was never required for CMR purposes, however, some times it was good to have them around, when incident findings appeared in extracardiac structures of the chest.

From Mai to November 2005, I could get some CMR experience with 3 Tesla imaging using a Philips scanner. However, since sequences still gave some unpredictable results, I think, that we should wait fore better sequences, before this technology should become applicable more widely.

 

 

Cases

 

I have published more than 20 cases on Kardiolab which reflect the vast range of diagnostic challanges, that I have encoutered during the past years. Several cases were presented at the annual echocardiography meetings organized by Prof. Michel Zuber, Prof. Paul Erne in Lucerne, the latest case having been presented in January 2006. Two of the cases presented in Lucerne have also been published in "Kardiovaskuläre Medizin". Cases

 

 

 Presentation

 

View my last presentation on CMR held at the Sanitas hospital in April 2005: Presentation

 

 

CMR myocardial Perfusion

 

Although CMR holds great promise for the assessment of coronary artery disease, especially with respect to the detection of ischemia, there are many drawbacks to apply this technique in many patients and I am afraid, that the market for CMR ischemia detection is not as large, as some CMR cardiologists would like it to be.

The advantages of CMR myocardial perfusion are the absence of radiation and a comparable diagnostic performance to other non-invasive imaging studies, such as stress echo and myocardial perfusion SPECT.

The disadvantages are as follows:

1. Many patients can be assessed in ambulatory medicine using exercise ECG or exercise echocardiography. Only when these widely available techniques fail to give appropriate answers, CMR may be used.

2. There are no outcome date on CMR perfusion

3. The lack of outcome data is important because of the poor specificity of CMR perfusion in the heart.

4. Exercise perfusion is not possible. Adenosin should however only be used in subjects who are not able to exercise. Therefore, one may prefer to use exercise SPECT instead of adenosin CMR, since exercise more accuarately addresses real life medicine (where ischemia occurs during exercise, e.g. also due to changes in coronary tone due to vasospastic events, which cannot be assessed by adenosin).

5. Not all scanners can be used for CMR perfusion. In some, the sequences are not yet state-of-the-art and give erroneous results.

6. The ideal protocol for CMR perfusion is still not defined. Addition of delayed imaging may improve diagnostic accuracy.