Endocarditis

36 year old male with prior history of IVDU and endocarditis, non-compliant with treatment, presents with chest pain. Chest CT shows multiple bilateral lung nodules, mostly peripheral, some with early cavitation. This is classic septic embolism, patient needs blood cultures and echocardiogram, which were obtained. Can spectral CT add anything here?

The images in this case are the exact same oblique axial cut. Note the left lower lobe cavitary nodule. The central cavitation is very well seen as a round hole on the iodine map.

Now look at the tricuspid valve. Nothing much to see on conventional image, but the iodine map and 40 keV mono-energy image show a clear vegetation. This was confirmed on echo, and blood culture grew MRSA.

The lower keV images have significant enhancement of iodine, and therefore increased signal to noise ratio. As seen here, this can help in detection of filling defects in blood pool, such as in the heart.

Conventional CT: Cavitary nodule in left lower lobe. Nothing particularly interesting in the heart.

Iodine density image: Hole in the center of the nodule nicely depicts the cavitation. Small tricuspid valve nodule becomes apparent!

40 keV image also nicely depicts the tricuspid valve vegetation.