study of relationships between bladder volume and intravesical prostatic protrusion on transabdominal ultrasound in patients with benign prostatic hyperplasia

Background: Benign prostatic hyperplasia (BPH) is a common cause of lower urinary tract symptoms (LUTS) in ageing men, primarily resulting from bladder outlet obstruction (BOO). Intravesical prostatic protrusion (IPP), assessed by transabdominal ultrasonography, has emerged as a reliable and non-invasive imaging marker reflecting the degree of BOO. However, IPP measurements may vary with bladder volume (BV), and the optimal filling level for consistent evaluation remains uncertain. Objective: To examine the relationships between IPP, BV, prostate volume (PV), postvoid residual urine (PVR), and symptom severity (IPSS) in patients with BPH. Materials and methods: A prospective cohort study was conducted at xxxx, from May to October 2025. Fifty-four men aged ≥50 years with ultrasonographically confirmed BPH underwent four standardised transabdominal ultrasound scans: three for BV, PV, and IPP, and one for PVR. Baseline IPSS was recorded. Pearson correlation and group comparisons were performed, with statistical significance defined as p < 0.05. Results: IPP demonstrated significant positive correlations with PV (p = 0.007) and PVR (p < 0.001), but not with BV (p = 0.762) or IPSS (p = 0.887). Patients with Grade 3 IPP had the largest PV and highest PVR (p = 0.038 and p = 0.016). Conclusion: IPP was significantly associated with PV and PVR but not with IPSS. Measurements were most consistent at bladder volumes of 200–299 mL, underscoring the importance of standardised bladder filling for accurate IPP assessment. Keywords: Benign prostatic hyperplasia, Bladder volume, Intravesical prostatic protrusion, Prostate volume, post-void residual.