Hypothermic Cooling Measured by Thermal Magnetic Resonance Imaging; Feasibility and Implications for Virtual Imaging in the Urogenital Pelvis

Abstract

Objective To study the combination of thermal MRI imaging and novel hypothermic cooling, via an Endorectal Cooling Balloon (ECB) to assess the effective dispersion and temperature drop in pelvic tissue to potentially reduce inflammatory cascade in surgical applications. Methods Three male subjects, prior to undergoing robot-assisted radical prostatectomy (RARP), were cooled via an ECB, rendered MRI compatible by for patient safety Prior to ECB hypothermia. MRI studies were performed using a 3T scanner and included T2w anatomical scan for the pelvic structures, followed by a temperature mapping scan. The sequence was performed repeatedly during the cooling experiment while the phase data were collected using an integrated MR-HIFU workstation in real time. Pelvic cooling was instituted with a cooling console located outside the MRI magnet room Results The feasibility of pelvic cooling measured a temperature drop of the ECB of 20–25 degrees in real time was achieved after an initial time delay of 10–15′ for the ECB to cool. The anatomic image of the prostate and NVB and demonstrate cooling at this interface of 10–15 degrees, and that cooling extends into the prostate itself ~ 5 degrees, and disperses into the pelvic region as well. Conclusion An MRI compatible ECB coupled with Thermal MRI is a feasible method to assess effective hypothermic diffusion and saturation to pelvic structures. By inference hypothermia induced rectal cooling could potentially reduce inflammation, scarring and fistula in RP as well as other urologic tissue procedures of HIFU, ERBT, radioactive seed implants, transurethral microwave therapy, and TURP.

A Randomized Control Trial Of Anti-Inflammatory Regional Hypothermia On Urinary Continence During Robot-Assisted Radical Prostatectomy

“…Cooling was initiated at the initiation of the surgical dissection. As noted, we previously demonstrated the cooling effect both by direct temperature measurement as well as MRI assessment of tissue cooling 21 .…”

“…The UroCool (Philips Healthcare Inc.) ECB device was used to achieve regional peri-prostatic hypothermia which had been demonstrated previously 19 – 21 . For those patients randomized to the hypothermia group, device insertion and use was the same as previously described 22 .…”

Feasibility study of a novel rectal cooling system for hypothermic radical prostatectomy in a swine model

“…The minimum temperature around the apex of the prostate was maintained at 10.1℃. Similarly, in a study analyzing thermal MRI in real time while cooling the pelvic cavity with an endorectal cooling ball, the muscle and perirectal tissue were cooled to 8℃ to 10℃, and the penile stalk and surrounding tissues were cooled to 10℃ to 15℃ [ 23 ]. However, we have an excellent system that can maintain the temperature around the apex of the prostate at approximately 10℃ during electrocoagulation.…”