| Characteristic | N = 211 |
|---|---|
| Age | 41 (35, 61) |
| BMI | 28 (24, 31) |
| IPSS | 7 (4, 16) |
| Unknown | 5 |
| Voiding Diffuculty | 10 (4, 26) |
| Unknown | 5 |
| Urgency | 8 (0, 33) |
| Unknown | 5 |
| Nocturia | 57 (29, 75) |
| Unknown | 5 |
| Postmicturation | 24 (15, 37) |
| Unknown | 5 |
| Qmax (ml/s) | 17 (12, 29) |
| Unknown | 2 |
| Voiding Time (sec) | 31 (22, 37) |
| Unknown | 2 |
| Voided Volume (ml) | 219 (167, 349) |
| Unknown | 2 |
| Qavg (ml/s) | 7.7 (5.8, 13.6) |
| Unknown | 2 |
| DeltaQ | 10 (6, 15) |
| Unknown | 2 |
| PVR | 136 (44, 237) |
| Unknown | 1 |
| Prostate volume | 25 (21, 38) |
| Unknown | 1 |
| TZ volume | 10 (7, 18) |
| Unknown | 1 |
| BWV | 53 (41, 69) |
| Unknown | 1 |
| BWT | 2.90 (2.58, 3.90) |
| Unknown | 1 |
| VV/(PVR+VV)*100 | 69 (54, 83) |
| Unknown | 3 |
| MRE base (kpa) | 3.60 (3.45, 4.35) |
| Unknown | 2 |
| MRE mid (kpa) | 3.70 (3.55, 4.50) |
| Unknown | 2 |
| MRE mean (kpa) | 3.70 (3.50, 4.35) |
| Unknown | 2 |
| Urethra length | 4.10 (3.78, 4.43) |
| Unknown | 1 |
| kPa*U. length | 14.8 (13.4, 20.0) |
| Unknown | 2 |
| 1 Median (IQR) | |
MR elastography to identify patients with bladder outlet obstruction (BOO)
Statistical analysis
Categorical variables were summarized as counts and percentages, while continuous variables were summarized as means and standard deviations. Spearman correlation coefficients were calculated to assess the relationship between MRE parameters and clinical parameters. A p-value < 0.05 was considered statistically significant. All statistical analyses were performed using R version 4.2.2 (R Foundation for Statistical Computing, Vienna, Austria).
Results for Full Data
Patient characteristics
Patient characteristics and variables are summarized in Table 1.
IPSS & LURN
IPSS and LURN (voiding difficulty, urgency, nocturia, postmicturation) scores were correlated to MRE parameters below.
Uroflowmetry
Uroflowmetry parameters (Qmax, voiding time, voided volume, Qavg, delta Q, PVR, prostate volume, TZ volume, bladder wall volume (BWV), bladder wall thickness (BWT), and voiding volume/PVR) were correlated to MRE parameters below.
LUTS
| Variable | No LUTS, N = 61 | Mild LUTS, N = 91 | Moderate/Severe LUTS, N = 61 | p-value2 |
|---|---|---|---|---|
| Age | 25 (23, 36) | 48 (36, 61) | 62 (55, 65) | 0.008 |
| BMI | 27 (24, 31) | 24 (22, 29) | 34 (30, 41) | 0.044 |
| Qmax (ml/s) | 32 (28, 39) | 16 (10, 21) | 12 (10, 16) | 0.005 |
| Unknown | 0 | 2 | 0 | |
| Voiding Time (sec) | 28 (19, 38) | 31 (28, 42) | 31 (25, 36) | >0.9 |
| Unknown | 0 | 2 | 0 | |
| Voided Volume (ml) | 287 (266, 511) | 219 (178, 416) | 167 (115, 203) | 0.078 |
| Unknown | 0 | 2 | 0 | |
| Qavg (ml/s) | 15.0 (13.3, 15.9) | 8.0 (6.1, 10.8) | 5.8 (4.5, 7.1) | 0.017 |
| Unknown | 0 | 2 | 0 | |
| DeltaQ | 20 (15, 26) | 8 (4, 10) | 6 (6, 9) | 0.012 |
| Unknown | 0 | 2 | 0 | |
| PVR | 151 (59, 256) | 106 (29, 254) | 147 (58, 162) | 0.9 |
| Unknown | 0 | 0 | 1 | |
| Prostate volume | 21 (16, 23) | 27 (22, 50) | 36 (29, 46) | 0.2 |
| Unknown | 0 | 0 | 1 | |
| TZ volume | 7 (5, 8) | 11 (10, 19) | 17 (12, 20) | 0.032 |
| Unknown | 0 | 0 | 1 | |
| BWV | 50 (36, 65) | 55 (44, 69) | 52 (36, 58) | >0.9 |
| Unknown | 0 | 0 | 1 | |
| BWT | 3.00 (2.73, 3.65) | 3.20 (2.40, 3.90) | 2.70 (2.70, 3.00) | >0.9 |
| Unknown | 0 | 0 | 1 | |
| VV/(PVR+VV)*100 | 75 (67, 86) | 70 (49, 81) | 59 (52, 69) | 0.4 |
| Unknown | 0 | 2 | 1 | |
| Urethra length | 3.80 (3.63, 4.05) | 4.10 (3.80, 4.40) | 4.50 (4.40, 4.80) | 0.072 |
| Unknown | 0 | 0 | 1 | |
| kPa*U. length | 13.4 (12.6, 13.9) | 15.4 (13.7, 19.9) | 18.9 (15.2, 20.6) | 0.10 |
| Unknown | 0 | 1 | 1 | |
| MRE base (kpa) | 3.50 (3.35, 3.58) | 3.65 (3.48, 4.53) | 4.20 (3.90, 4.20) | 0.6 |
| Unknown | 0 | 1 | 1 | |
| MRE mid (kpa) | 3.55 (3.50, 3.60) | 4.05 (3.68, 4.70) | 4.30 (4.00, 4.40) | 0.4 |
| Unknown | 0 | 1 | 1 | |
| MRE mean (kpa) | 3.55 (3.50, 3.60) | 3.90 (3.58, 4.45) | 4.30 (4.00, 4.30) | 0.5 |
| Unknown | 0 | 1 | 1 | |
| 1 Median (IQR) | ||||
| 2 Kruskal-Wallis rank sum test | ||||
| Variable | No/Mild LUTS, N = 151 | Moderate/Severe LUTS, N = 61 | p-value2 |
|---|---|---|---|
| Age | 39 (29, 53) | 62 (55, 65) | 0.032 |
| BMI | 25 (22, 29) | 34 (30, 41) | 0.019 |
| Qmax (ml/s) | 28 (16, 29) | 12 (10, 16) | 0.072 |
| Unknown | 2 | 0 | |
| Voiding Time (sec) | 31 (19, 38) | 31 (25, 36) | >0.9 |
| Unknown | 2 | 0 | |
| Voided Volume (ml) | 270 (211, 441) | 167 (115, 203) | 0.058 |
| Unknown | 2 | 0 | |
| Qavg (ml/s) | 12.9 (7.7, 15.7) | 5.8 (4.5, 7.1) | 0.018 |
| Unknown | 2 | 0 | |
| DeltaQ | 13 (8, 15) | 6 (6, 9) | 0.2 |
| Unknown | 2 | 0 | |
| PVR | 125 (33, 268) | 147 (58, 162) | >0.9 |
| Unknown | 0 | 1 | |
| Prostate volume | 23 (21, 29) | 36 (29, 46) | 0.2 |
| Unknown | 0 | 1 | |
| TZ volume | 10 (7, 12) | 17 (12, 20) | 0.15 |
| Unknown | 0 | 1 | |
| BWV | 55 (43, 69) | 52 (36, 58) | 0.8 |
| Unknown | 0 | 1 | |
| BWT | 3.20 (2.55, 3.90) | 2.70 (2.70, 3.00) | 0.7 |
| Unknown | 0 | 1 | |
| VV/(PVR+VV)*100 | 70 (60, 85) | 59 (52, 69) | 0.3 |
| Unknown | 2 | 1 | |
| Urethra length | 3.90 (3.65, 4.20) | 4.50 (4.40, 4.80) | 0.049 |
| Unknown | 0 | 1 | |
| kPa*U. length | 14.1 (12.6, 18.9) | 18.9 (15.2, 20.6) | 0.087 |
| Unknown | 1 | 1 | |
| MRE base (kpa) | 3.50 (3.43, 4.33) | 4.20 (3.90, 4.20) | 0.5 |
| Unknown | 1 | 1 | |
| MRE mid (kpa) | 3.65 (3.53, 4.63) | 4.30 (4.00, 4.40) | 0.8 |
| Unknown | 1 | 1 | |
| MRE mean (kpa) | 3.60 (3.50, 4.33) | 4.30 (4.00, 4.30) | 0.6 |
| Unknown | 1 | 1 | |
| 1 Median (IQR) | |||
| 2 Wilcoxon rank sum test; Wilcoxon rank sum exact test | |||
Excluded Data
Patient characteristics
Patient characteristics and variables are summarized in Table 4.
| Characteristic | N = 171 |
|---|---|
| Age | 40 (35, 59) |
| BMI | 24.7 (22.4, 29.6) |
| IPSS | 6.0 (4.0, 7.0) |
| Unknown | 4 |
| Voiding Diffuculty | 10 (0, 15) |
| Unknown | 4 |
| Urgency | 8 (0, 8) |
| Unknown | 4 |
| Nocturia | 57 (29, 57) |
| Unknown | 4 |
| Postmicturation | 19 (15, 26) |
| Unknown | 4 |
| Qmax (ml/s) | 25 (14, 29) |
| Unknown | 2 |
| Voiding Time (sec) | 31 (23, 37) |
| Unknown | 2 |
| Voided Volume (ml) | 264 (211, 349) |
| Unknown | 2 |
| Qavg (ml/s) | 8.0 (6.4, 13.6) |
| Unknown | 2 |
| DeltaQ | 12 (7, 15) |
| Unknown | 2 |
| PVR | 115 (35, 196) |
| Unknown | 1 |
| Prostate volume | 25 (21, 31) |
| Unknown | 1 |
| TZ volume | 10 (8, 14) |
| Unknown | 1 |
| BWV | 50 (41, 69) |
| Unknown | 1 |
| BWT | 3.00 (2.48, 3.90) |
| Unknown | 1 |
| VV/(PVR+VV)*100 | 69 (59, 85) |
| Unknown | 3 |
| MRE base (kpa) | 3.60 (3.50, 4.35) |
| Unknown | 2 |
| MRE mid (kpa) | 3.70 (3.60, 4.55) |
| Unknown | 2 |
| MRE mean (kpa) | 3.70 (3.55, 4.35) |
| Unknown | 2 |
| Urethra length | 3.90 (3.68, 4.33) |
| Unknown | 1 |
| kPa*U. length | 14.80 (12.85, 19.95) |
| Unknown | 2 |
| ...24 | NA (NA, NA) |
| Unknown | 17 |
| 1 Median (IQR) | |
IPSS & LURN
IPSS and LURN (voiding difficulty, urgency, nocturia, postmicturation) scores were correlated to MRE parameters below.
Uroflowmetry
Uroflowmetry parameters (Qmax, voiding time, voided volume, Qavg, delta Q, PVR, prostate volume, TZ volume, bladder wall volume (BWV), bladder wall thickness (BWT), and voiding volume/PVR) were correlated to MRE parameters below.
LUTS
| Variable | No LUTS, N = 51 | Mild LUTS, N = 91 | Moderate/Severe LUTS, N = 31 | p-value2 |
|---|---|---|---|---|
| Age | 23 (23, 39) | 48 (36, 61) | 59 (49, 68) | 0.048 |
| BMI | 26.3 (23.7, 28.2) | 23.8 (22.1, 28.7) | 29.6 (26.7, 30.7) | 0.5 |
| Qmax (ml/s) | 29 (28, 34) | 16 (10, 21) | 17 (13, 21) | 0.019 |
| Unknown | 0 | 2 | 0 | |
| Voiding Time (sec) | 19 (19, 37) | 31 (28, 42) | 36 (32, 46) | 0.4 |
| Unknown | 0 | 2 | 0 | |
| Voided Volume (ml) | 270 (264, 303) | 219 (178, 416) | 211 (144, 259) | 0.5 |
| Unknown | 0 | 2 | 0 | |
| Qavg (ml/s) | 14.2 (13.0, 15.7) | 8.0 (6.1, 10.8) | 5.5 (3.8, 6.6) | 0.086 |
| Unknown | 0 | 2 | 0 | |
| DeltaQ | 15 (15, 26) | 8 (4, 10) | 10 (8, 15) | 0.032 |
| Unknown | 0 | 2 | 0 | |
| PVR | 125 (37, 177) | 106 (29, 254) | 102 (80, 125) | >0.9 |
| Unknown | 0 | 0 | 1 | |
| Prostate volume | 20 (15, 23) | 27 (22, 50) | 32 (31, 34) | 0.14 |
| Unknown | 0 | 0 | 1 | |
| TZ volume | 6 (5, 8) | 11 (10, 19) | 15 (14, 16) | 0.058 |
| Unknown | 0 | 0 | 1 | |
| BWV | 45 (34, 55) | 55 (44, 69) | 55 (46, 65) | 0.7 |
| Unknown | 0 | 0 | 1 | |
| BWT | 2.80 (2.70, 3.80) | 3.20 (2.40, 3.90) | 3.85 (3.03, 4.68) | >0.9 |
| Unknown | 0 | 0 | 1 | |
| VV/(PVR+VV)*100 | 68 (67, 88) | 70 (49, 81) | 72 (65, 78) | 0.8 |
| Unknown | 0 | 2 | 1 | |
| Urethra length | 3.70 (3.60, 3.90) | 4.10 (3.80, 4.40) | 4.30 (4.05, 4.55) | 0.3 |
| Unknown | 0 | 0 | 1 | |
| kPa*U. length | 13.30 (12.40, 14.00) | 15.40 (13.65, 19.90) | 17.90 (16.55, 19.25) | 0.3 |
| Unknown | 0 | 1 | 1 | |
| MRE base (kpa) | 3.50 (3.50, 3.60) | 3.65 (3.48, 4.53) | 4.05 (3.98, 4.13) | 0.7 |
| Unknown | 0 | 1 | 1 | |
| MRE mid (kpa) | 3.60 (3.50, 3.60) | 4.05 (3.68, 4.70) | 4.20 (4.10, 4.30) | 0.4 |
| Unknown | 0 | 1 | 1 | |
| MRE mean (kpa) | 3.60 (3.50, 3.60) | 3.90 (3.58, 4.45) | 4.15 (4.08, 4.23) | 0.6 |
| Unknown | 0 | 1 | 1 | |
| 1 Median (IQR) | ||||
| 2 Kruskal-Wallis rank sum test | ||||