A new technique for imaging microbubble ultrasound contrast agents may be useful in the detection of prostate cancer (PCa) not found by multiparametric MRI, according to a study being presented at the ARRS 2019 Annual Meeting, which is taking place in Hawaii this week. The first in vivo application of contrast-enhanced subharmonic imaging (SHI)  in the prostate, the pilot study was conducted to evaluate contrast-enhanced SHI of the prostate for detection of PCa.

Building on the authors’ previous work demonstrating the effectiveness of contrast-enhanced harmonic imaging (HI) for the detection of prostate cancer, 55 patients referred for prostate biopsy were imaged using conventional grayscale, color, and power Doppler, conventional contrast HI, SHI—a new technique for imaging of microbubble ultrasound contrast agents with up to a 10-fold increase in contrast-to-background signal ratio relative to conventional HI—and flash replenishment in combination with SHI (MIP-SHI).

The results demonstrated contrast-enhanced SHI enhancement in all patients. Detection of PCa using contrast-enhanced SHI included nine of 31 patients with a prior negative MRI or negative MRI-guided biopsy, suggesting SHI may be useful in detection of PCa not found by multiparametric MRI.

“Diagnosis of clinically significant prostate cancer with noninvasive means is a real clinical challenge,” says study author Ethan Halpern, MD. “Although multi-parametric MRI is currently used for this purpose, ultrasound has numerous advantages. Ultrasound systems are portable. Ultrasound studies are far less expensive and more widely available as compared with MRI. Contrast-enhanced ultrasound studies can be performed at the same sitting as the ultrasound-guided biopsy, while mp-MRI requires two visits, one for the diagnostic MR study and a second for the fusion biopsy.”

Halpern continues:“There is no need for a fusion imaging system (additional hardware/software) when using contrast enhanced ultrasound. No additional effort is required to properly register the contrast-enhanced ultrasound diagnostic study with the targeting system for biopsy. Combining contrast-enhanced ultrasound with subharmonic imaging has the potential to provide a new, noninvasive method for diagnosis and characterization of prostate cancer.”