Intravesical growth of murine bladder tumors assessed by transrectal ultrasound.

Experimental studies in the therapy of intravesically growing bladder tumors in mice have been hampered by an inability to monitor tumor growth before and during treatment. To establish a repeatable, noninvasive method to monitor the intravesical growth of bladder tumors, MB49 murine bladder tumor cells were instilled into the bladders of syngeneic C57BL/6 mice. Following 3 weeks of growth, the bladders of tumor-bearing and control mice were imaged using a 20 mHz, 6.2 F catheter-based ultrasound transducer inserted rectally. Bladders of tumor implanted and control mice were identified by high resolution endoluminal ultrasound after distension with 0.15 ml. of normal saline. When compared with the results of histologic analysis, transrectal ultrasound (TRUS) accurately identified tumor presence, size, and location.