Home » 2009 » 09-04

Number 09-04 Diagnosing RV dilatation (2)

see also previous case 08-19

Authors:  Sharon L. Roble, MD and Robert C. Gilkeson, MD
Institution:  University Hospitals of Cleveland/Case Western Reserve University School of Medicine, Cleveland, Ohio, USA

Clinical History 
44 y/o female with shortness of breath found to have possible pulmonic stenosis with pulmonic dilatation by echocardiogram.  CMR ordered to evaluate pulmonary artery aneurysm and degree of pulmonic stenosis.

 Transesophageal echocardiogram performed after CMR (Images 6a and b)  confirmed the diagnosis.

Conclusions: 
CMR demonstrates a large secundum atrial septal defect with evidence of right ventricular dilatation and markedly dilated main and left pulmonary artery without evidence of significant pulmonic stenosis.  The finding of a large ASD explains the echocardiographic findings of increased flow across the pulmonic valve (due to left-to-right shunting through the defect) which was mistaken for pulmonic stenosis.  The right-sided dilatation (right atrium, right ventricle and pulmonary artery) are most likely secondary to increased volume and flow over time in the setting of a large secundum atrial septal defect.

 Technical/Images:

1. Image 1:  Steady state free precession (Seimens Avanto, 1.5Tesla) sequence of the right ventricular outflow tract showing markedly dilated main and left pulmonary arteries.
2. Image 2: Steady state free precession (Seimens Avanto, 1.5 Tesla) cine imaging in the coronal plane showing a dilated main pulmonary artery in cross-section.   
3. Image3:  Minimum intensity projection (MIP) in the axial plane showing a markedly dilated main and left pulmonary artery with relative sparing of the right pulmonary artery.
4. Image 4: SSFP cine through the pulmonic valve demonstrating a tricuspid and widely patent pulmonic valve.
5. Image 5:  Steady state free precession sequence in the horizontal long (4-chamber) axis view showing large secundum atrial septal defect with predominantly left-to-right shunting.  Please note dilated right ventricle and atrium. 
6. Image 6a and b: 
7.   Transesophageal echocardiogram at 41 degrees confirms a large secundum atrial septal defect with predominantly left to right shunting.

 References:

1. Cevik C, et al.  A Rae Consequence of Uncorrected Atrial Septal Defect:  Diffuse Pulmonary Artery Aneurysms.  Tex Heart Inst J. 2004; 31: 328-329.
2. Butto F, Lucas RV Jr, and Edwards JE.  Pulmonary Arterial Aneurysm.  A Pathologic Study of Five Cases.  Chest 1987; 91: 237-241.
3. Ugolini P, et al.  Idiopathic Dilatation of the Pulmonary Artery:  Report of Four Cases.  Magnetic Resonance Imaging. 1999; 17: 933-937.