Matthias Dennler, DECVDI, PD, Dr: No financial relationships to disclose
Keynote message
The cross sectional imaging modalities CT and MRI represent promising possibilities for further examinations of cardiological patients. Under no circumstances will there be any competition with the established modalities in the foreseeable future. The presentation is intended to show in which situations the cross sectional modalities can contribute additional information. The radiologists are much more dependent on the close cooperation of the cardiologists in order to formulate an exact question for the examination. This is essential in order to choose the appropriate modality and to develop the examination protocol.
The whole heart can be imaged in several phases of the cardiac cycle. Nevertheless, the modalities CT and MRI in veterinary medicine do not unconditionally fulfil all the criteria of the ‘gold standard’. The complex movement of the myocardium in a combination of contracting, shortening and wringing out in a cardiac cycle poses huge challenges for diagnostic imaging. Especially on the right side, the complex anatomy of the heart creates quite some difficulties. Most importantly, there is a risk of underestimating the values of stroke volume based on morphologic images.
CT examinations of the heart only take a short time. The spatial resolution is currently not achieved by any other modality. Since the modality is dependent on the use of contrast media, it is worth devoting some time to the injection technique. CT is a valuable source of information in malformations and problems of cardiac architecture. Information about the myocardium can also be obtained, particularly with recent developments in CT technology. However, an outstanding advantage of computed tomography is the examination of the entire cardiovascular system.
The excellent soft tissue contrast is responsible for the success of cMRI in humans. Thanks to the ability to quantify flow, information can be obtained, that can otherwise only be measured using Doppler examinations. Nevertheless, information about the regional contractility of the myocardium is eminently important because even a diseased heart can maintain ejection fraction for a long time. MR examinations take a long time. This is a disadvantage for the cardiological patient. This makes it all the more important to have a narrowly defined indication and clinical question.
Patients must be anaesthetised for the examination in the cross-sectional imaging modalities. This is the biggest limitation for use on cardiology patients. The same patients need to be asleep for interventional procedures. There, safe protocols are widely accepted for the cardiology patient.
Learning Objectives:
realize that close cooperation between specialists is fundamentally important for successful examinations of the cardiac patient with cross sectional modalities such as CT and MRI.
understand the advantages and disadvantages of modalities CT and MRI in cardiology patients.
comprehend why neither CT nor MRI fullfills the criteria of a gold standard in veterinary cardiac patients.
