Assessment of prostate volume and morphology can provide valuable information for the clinician related to available procedural options and optimal selection. While some surgical techniques have a broad range of sizes and morphologies that can be utilized, others may have a more limited utilization due to prostate volume limits based on current literature and FDA approval (e.g., WVTT, PUL, TIPD, RWT, IPDCB). Prostate morphology can also be a limiting factor for some surgical techniques due to urethral length, or presence of a median lobe. When evaluating prostate anatomy, imaging studies may offer the ability to measure IPP of the median lobe. IPP ≥1.0 cm was associated with BOO, an unsuccessful TWOC,119 and lower response to ABs.120 The presence of a median lobe not only is associated with BOO and negatively correlated with Qmax, but also can affect surgical eligibility for certain surgical techniques and should be considered in the preoperative planning stage for patients.121-123  Proper prostate volume assessment can be performed using a variety of imaging modalities such as transabdominal ultrasound, TRUS, computed tomography (CT), and MRI. It is not unusual for patients to have already performed prostate-dedicated imaging tests (i.e., workup of elevated PSA, prostate biopsies, surveillance of prostate cancer) or studies done for other purposes that can still be used to calculate prostate volume and be utilized as a part of preoperative evaluation. Imaging studies obtained within 12 months is preferred; however, given that prostate growth rates are 1.6% per year on average, older imaging studies can likely give a reasonably accurate estimate of current volume if that is all that is available.124 DRE is unreliable for prostate volume assessment and should not be the only method to select surgical techniques that are prostate volume dependent.125 Some studies have tried to determine the best imaging modality for prostate volume assessment validating against radical prostatectomy specimen. MRI prostate volume, especially if 3-dimensional (3-D) segmentation is used, seems to correlate very well with pathology specimens with differences around 0.5 cc, while TRUS can underestimate prostate volume.126, 127 When preoperative prostate volumes calculated by TRUS and MRI were compared to radical prostatectomy specimen, TRUS underestimated prostate volume relative to mpMRI with 8% lower volume per cc up to 77.5 cc and 39% lower volume per additional cc >77.5 cc. Transabdominal ultrasound seems to be equivalent in prostate volume assessment when compared to MRI.128 It is important to remember that ultrasound quality and accuracy are operator-dependent and can vary based on experience. The differences in prostate volume based on imaging modalities are not large enough to justify one image modality over another. The clinician should use images already available or assess prostate volume and morphology by obtaining sizing information according to clinician and patient preference. Prostate volume calculations can be performed utilizing cross-sectional image measurements with either one of the two formulas; ellipsoid (prostate volume = [(height x length x width) x 3.14/6], or bullet formula [prostate volume = anteroposterior x longitudinal x transverse x π/4.8]).