Cognitive Fusion vs. Software-Assisted Fusion

brain vs ai

Prostate cancer is very treatable during the early stages, when progression is slow and patients are often asymptomatic. Once it reaches more advanced stages, it can quickly metastasize, dropping survival rates down to 10%. In recent years, the pre-biopsy MRI has played a crucial role in the early detection of prostate cancer. Adopted as a first-line diagnostic tool, it identifies targets, or regions of interest (ROIs), for biopsy. Targeted biopsies are most commonly performed using cognitive fusion or software-assisted fusion methods. In-bore is another technique, but it’s less popular due to its limited accessibility.1

Cognitive Fusion

The cognitive fusion biopsy procedure is inexpensive and quick, but the learning curve can be slow and long. The setup requires no specialized equipment, except for the additional screen to display the MRI. It requires the urologist to read the MRI or interpret the reports from the radiologist prior to performing the biopsy. Guided by transrectal ultrasound, the urologist visually estimates where the targets are on the ultrasound image before taking a sample. Because the orientation of the prostate can be different between the two images, and the prostate can deform during the ultrasound scan, this makes cognitive fusion more complex. The accuracy is highly dependent on the operator’s understanding of prostate anatomy and proficiency in reading ultrasound and MRI sequences.1

Software-Assisted Fusion

Software-assisted fusion biopsies come with upfront costs and longer procedural times, but the procedure is “simple” and the cost of learning is low. In addition to the ultrasound, the setup requires a fusion biopsy device, like the Fusion Bx. After the MR images are uploaded to the fusion system, the urologist places landmarks and contours the ultrasound image. The fusion software will then transpose the MR images onto the live ultrasound. Depending on the type of image registration, some systems (yes, the Fusion Bx) can even account for prostate deformation. Now, the urologist is guided by a 3D reconstruction of the prostate, showing the ROIs and the projected needle path. Since lesions are identified by the software, the accuracy relies less on professional experience.1

Cognitive Fusion vs. Software Assisted Fusion

Both cognitive fusion and software-assisted fusion have their pros and cons in terms of ease of use, but more importantly, which one is better at detecting cancer? The National Institute for Health and Care Excellence (NICE) in the UK seeks to answer this question in the IP7-PACIFIC Trial. The trial will compare cognitive fusion with software-assisted fusion, using a variety of different fusion systems, including the Fusion Bx. The outcome will determine which method is adopted by the NHS. Existing evidence is inconclusive as all studies were considered biased, lacking data, or too small of a population size.2 Generally, though, the majority of studies showed no significant difference in detection rates.1,2,3 Some suggest software-assisted fusion has an advantage in identifying smaller, low-grade cancers and better targeting accuracy.1,2,3 All things being equal, there’s no denying cognitive fusion leaves more room for subjective errors. The difference in approaches can be compared to drawing versus tracing. To make a realistic sketch, one requires mastery to translate a 3D object onto a page whereas the other is as simple as following a line. The reduced learning curve of software-assisted fusion lowers the barrier for novices, ultimately making targeted biopsies more accessible.

The Fusion Bx was designed to do just that; provide accurate, efficient and accessible prostate cancer care. To minimize training, the software automatically guides users through the simple 4 step workflow. A counterbalance holds the probe steady, so physicians don’t have to, reducing the need for additional assistance. Automatic motion compensation and freehand-like access to the prostate are just a couple of the features that make the Fusion Bx a cost effective and easy-to-learn system for MRI-targeted biopsies. Contact us at to learn more about the benefits of the Fusion Bx.

1 Liang, L., Cheng, Y., Qi, F., Zhang, L., Cao, D., Cheng, G., & Hua, L. (2020). A Comparative Study of Prostate Cancer Detection Rate Between Transperineal COG-TB and Transperineal FUS-TB in Patients with PSA ≤20 ng/mL. Journal of Endourology, 34(10), 1008–1014.

2 CRD & CHE Technology Assessment Group. (2022). CRD/CHE University of York External Assessment Group report: MRI fusion biopsy in people with suspected prostate cancer. In NICE (No. 135477). University of York.

3 Wysock, J. S., Rosenkrantz, A. B., Huang, W. C., Stifelman, M. D., Lepor, H., Deng, F. M., Melamed, J., & Taneja, S. S. (2014). A Prospective, Blinded Comparison of Magnetic Resonance (MR) Imaging–Ultrasound Fusion and Visual Estimation in the Performance of MR-targeted Prostate Biopsy: The PROFUS Trial. European Urology, 66(2), 343–351.