RSNA | Journals

Journal Highlights

The following are highlights from the current issues of RSNA's two peer-reviewed journals.

This article meets the criteria for 1.0 AMA PRA Category 1 Credit™.

Infected (Mycotic) Aneurysms: Spectrum of Imaging Appearances and Management

Infected aneurysm of the thoracoacromial artery in an 82-year-old man with methicillin-sensitive S aureus septic arthritis.
Oblique gray-scale (a) and color Doppler (b) sonograms show a 3.5-cm complex hypoechoic mass (arrows in a) adjacent to the right humeral head (H); the mass has turbulent flow on the color Doppler image. There is no significant perianeurysmal soft tissue. (c) Pulsed Doppler sonogram obtained at the aneurysm neck shows a "to-and-fro" waveform with high-velocity antegrade flow into the aneurysm during systole (arrow) and high-velocity bidirectional flow out of the aneurysm during diastole (arrowhead). The bidirectional waveform in diastole is due to turbulent flow. (d) Coronal contrast-enhanced fat-suppressed T1-weighted MR angiogram shows the aneurysm (arrow) arising from the acromial branch (arrowhead) of the right thoracoacromial artery. Selective catheterization of the acromial branch artery for embolization was unsuccessful. Ultrasound-guided percutaneous embolization with steel coils and 100 units of thrombin was performed, resulting in complete exclusion of the aneurysm from the parent artery.

(RadioGraphics 2008;28:1853-1868) © RSNA, 2008. All rights reserved. Printed with permission.

Although not common, infected aneurysms have a high mortality rate if not properly treated. State-of-the-art imaging techniques such as multidetector CT and MR imaging are fast replacing conventional angiography as minimally invasive methods for detecting infected aneurysms and providing vascular mapping to facilitate treatment planning.

In an article in the November-December issue of RadioGraphics (RSNA.org/radiographics), Wai-Kit Lee, M.B.B.S., F.R.A.N.Z.C.R., and colleagues discuss imaging methods used to assess infected aneurysms, list features of infected aneurysms at CT, MR imaging and ultrasound and describe the treatment options.

The authors specifically address these imaging features of infected aneurysms:

• Lobulated vascular mass

• Indistinct irregular arterial wall

• Perianeurysmal edema

• Perianeurysmal soft-tissue mass

Specifically, the article examines aneurysms found in the aorta, peripheral arteries, cerebral arteries, visceral arteries and arteries to other organs.

"The key to a successful outcome in this uncommon but difficult to manage entity is early diagnosis and aggressive treatment," the authors conclude. "Early diagnosis requires a high index of clinical suspicion and awareness by the radiologist of the spectrum of imaging appearances, especially early changes."

Incidental Adrenal Lesions: Principles, Techniques, and Algorithms for Imaging Characterization

A 17-cm left adrenal cyst in 43-year-old woman.

(a) Sagittal ultrasound image shows a complex cyst with marked internal echoes (arrow). (b) Axial contrast-enhanced CT scan shows slightly thickened wall (short arrow) and cyst with mixed components (long arrow). Owing to the cyst's complex nature, percutaneous biopsy was performed to exclude cystic neoplasm; results confirmed benign adrenal cyst.

While almost all incidental adrenal lesions (IALs) in patients without a known primary cancer are benign, characterization of IALs in patients with cancer is essential to predict prognosis of the primary disease, assess staging and direct therapy.

In a review article in the December issue of Radiology (RSNA.org/radiology), Giles W.L. Boland, M.D., and colleagues evaluate the anatomic and physiologic imaging principles used for differentiating adrenal masses, present available imaging techniques and recommend an imaging algorithm that can guide the radiologist toward the correct diagnosis.

High test specificity is the crux of adrenal imaging, according to the researchers. Techniques addressed include:

• Morphologic imaging: CT and MR imaging

• Lipid-sensitive imaging techniques: CT and MR imaging

• CT techniques including CT densitometry and CT histogram analysis

• MR imaging techniques including chemical shift

• Perfusion imaging of the adrenal glands: CT washout scans

Also analyzed are imaging features of cortical adenoma, metastasis, myelolipoma, lymphoma, adrenal carcinoma, pheochromocytoma, hemorrhage, cyst, neuroblastoma, ganglioneuroma, hemangioma and hemangiosarcoma and granulomatous disease.

While the importance of adrenal imaging methods continues to evolve, the researchers found that "CT contrast medium washout tests offer the highest test sensitivity and specificity for IAL characterization."