A 20-day-old neonate was brought with history of poor feeding and difficulty in breathing.
Echocardiography showed enlarged heart with a large Ventricular Septal Defect with bidirectional, predominantly left-to-right shunt; dilated Left Ventricle, dilated Right Ventricular Outflow and Pulmonary Trunk. Left Ventricular Outflow, Ascending Aorta and Aortic Arch were not adequately visualized.
The child was sent for an MDCT Aortogram to rule out Coarctation.
Technical details for those interested:
The scan was done with 5 ml of non-ionic iodinated intravenous contrast (the baby weighed 2.5 kg) followed by 5 ml saline flush in a dual-head injector. Ideally we ought to have used an intravenous cannula in a leg vein, but our NICU nurses could only get a vein in the left forearm, so there is opacification of the left brachiocephalic vein and the Superior Vena Cava.
Scan time 2.41 seconds.
Radiation Dose: DLP 40 mGy.cm (0.69 mSv).
Oblique Axial and Sagittal multiplanar reformatted images confirmed the presence of a large VSD and dilated RV Outflow.
3D Volume Rendered images showed classical post-ductal Coarctation of Aorta (coloured arrows in the following images).
Note: I found that the greyscale VRT images showed better detail than the colour images.
Compare the last image with this image from suggested reading #1.
Diagnosis: Large Ventricular Septal Defect with Coarctation of Aorta (Tubular Hypoplasia).
In classic coarctation, the narrowing is located just distal to the left subclavian artery. Coarctation at or immediately proximal to the left subclavian artery is rare and compromises that vessel. An aberrant right subclavian artery may arise at or below the coarctation. An external indentation that involves all but the ventral portion of the coarctation corresponds internally to the ridge. The aorta just distal to the coarctation is typically dilated. Uniform narrowing of the aortic arch (tubular hypoplasia) can be more frequently observed in neonates. A localized coarctation and tubular hypoplasia may coexist or may occur independently.
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