Dual-energy CT scanning captures subtle pancreatic masses

LAS VEGAS-The increased speed and improved visualization of dual-energy CT helps pinpoint lesions at an earlier, more treatable stage. Faster and better visualization are the main reasons to use dual-energy CT for the assessment of pancreatic masses, according to a radiologist from the University of Munich.

Dual-energy CT differentiates between tissues based on CT density values.

Anno Graser, MD, outlined the main advantages dual-energy CT provides:

• immediate visualization of mass enhancement;
• ability to calculate virtual unenhanced images; and ability to assess vascular anatomy and involvement.

Dr. Graser offered an explanation of how each of these elements can help pinpoint early-stage masses at the 2008 Stanford University International Symposium on Multidetector-Row CT.

Color coding of the images, for example, draws immediate attention to the areas of mass enhancement. Dual-energy CT clarifies subtle enhancement differences between masses and the normal body of pancreas, based on differences in attenuation.

Graser also mentioned other advanced visualization options with dual-energy CT.

“You can use these (dual-energy) data sets to create curved planar reformatting and 3D image volume rendering, looking at venous anatomy with greater clarity,” he said.

Finally, assessing vascular anatomy and involvement is important when deciding whether a patient is a candidate for surgical resection, he said.

Graser and colleagues have reported successful results with dual-energy CT for characterizing renal and ureteral stones.

In a paper published in Investigative Radiology, they scanned 24 renal calculi, using dual-energy properties to differentiate between uric acid and other calculi (43:112-119, 2008).

They used the following scan parameters:

• tube potentials of 80 kV and 140 kV;
• tube currents of 342 mAs and 76 mAs; and
• collimation of 14 × 1.2 mm2.

According to their results, uric acid, cystine, struvite, and mixed renal calculi could be differentiated from other types of stones on dual-energy CT scans. This information can guide patients into pharmacological treatment, the authors said.

This article is adapted from ONI’s sister publication Diagnostic Imaging (August 2008).