Pulmonary hypertension MRI

, Richard Channick, M.D.; Assistant Editor(s)-in-Chief: Ralph Matar

Cardiac MR
Due to the important prognostic indicators of the function of the right ventricle in patients with PAH. Cardiac MR is performed in some patients to:

1-Accurately evaluate the size, morphology and function of the right ventricle. MRI has similar abilities to those of echocardiography in the diagnosis and treatment of patients with pulmonary hypertension.

2-Detect shunts contributing to pulmonary hypertension. 3-Detect acute and chronic pulmonary thromboembolic disease.

4-Distinguish between the pulmonary vasculature and mediastinal adenopathy when used with contrast enhancement.

5-Also used for follow-up of right heart hemodynamics for follow-up purposes.

Poor right ventricular function is indicated by the following according to the ACCF/AHA 2009 Expert consensus document on pulmonary hypertension:
 * 1) Stroke volume ≤25ml/m^2.
 * 2) Right ventricular end-diastolic volume ≥84ml/m^2( Most appropriate marker of right ventricular failure in the follow-up.)
 * 3) Left ventricvular end-diastolic volume ≤40ml/m^2


 * MRI has similar abilities to those of echocardiography in the diagnosis and treatment of patients with pulmonary hypertension.


 * Pulmonary artery stiffness measured by relative cross sectional area change ≤16% also has implications on mortality rate.

MRI Limitations include:
1- Inability to perform breath hold.

2-Claustrophobia.

3- Incompatible hardware such as neurostimulators, cochlear implants, aneurysm clips, cardiac pacemakers and defibrillators.

4- Limited availability and cost.

5- Difficulty in assessing PA pressures.