Magnetic resonance imaging in assessment of stress urinary incontinence in women: Parameters differentiating urethral hypermobility and intrinsic sphincter deficiency

Table 1 Characteristics of participants according to continent vs incontinent status

Characteristics	Continent volunteersn = 10	Incontinent patientsn = 21	P value
1Age (yr)	45.1 (13.6)	54.4 (11.8)	0.0610
2Race
White	5 (50)	14 (67)
Black	5 (50)	6 (29)
Other	-	1 (4)
1BMI index	29.98 (7.0)	29.95 (6.6)	0.9915
1Parity, n births	1.5 (1.2)	1.9 (1.2)	0.3329
2Vaginal, n	11 (65)	39 (90)
2C-section, n	4 (24)	2 (5)
2Nullipara, n	2 (12)	2 (5)
2OB Trauma, n	0 (0)	11 (52)	< 0.0014
2Hormones, n	0 (0)	5 (24)
2Hysterectomy, n	2 (2)	8 (38)
3Urethra wall thickness
Ant total, mm	0.47 (0.43-0.50)	0.59 (0.33-0.84)	0.5161
Ant striated muscle, mm	0.17 (0.13-0.2)	0.21 (0.12-0.29)	0.5467
Ant smooth muscle, mm	0.30 (0.3-0.3)	0.38 (0.20-0.55)	0.5055
Post total, mm	0.40 (0.36-0.43)	0.39 (0.36-0.42)	0.7713
Post striated muscle, mm	0.11 (0.08-0.13)	0.09 (0.08-0.11)	0.3180
Post smooth muscle, mm	0.29 (0.26-0.31)	0.29 (0.27-0.32)	0.7952
3Urethral sphincter length
Total, cm	3.67 (3.45-3.88)	3.77 (3.47-4.06)	0.6432
Length, suprapubic, cm	3.03 (2.59-3.46)	2.95 (2.65-3.24)	0.7361
3Urethra mobility angle	53 (19.6-86.6)	65 (50.1-80.2)	0.4116
3Bladder neck descent
Total, cm	1.98 (0.73-3.23)	2.56 (1.96-3.15)	0.3158
Rest, above PCL, cm	1.42 (0.43-2.41)	1.51 (1.16-1.85)	0.8195
Strain, below PCL, cm	0.56 (0.99-2.12)	1.05 (0.46-1.63)	0.4272
2Funneling, n	1 (10)	11 (52)	0.184
3Retropubic distance to urethra, mm	5.2 (4.19-6.20)	5.0 (4.16-5.92)	0.8259
3Pubo-vaginal distance
Right, cm	1.81 (1.59-2.02)	1.59 (1.47-1.70)	0.0372
Left, cm	1.87 (1.72-2.01)	1.67 (1.53-1.79)	0.0475
2Normal vaginal shape, n	7 (70)	8 (40)	0.128
3Puborectalis muscle thickness
Right, mm	3.4 (2.6-4.1)	3.8 (1.8-3.0)	0.4903
Left, mm	3.9 (2.9-4.9)	4.7 (3.7-5.5)	0.2748
1Puborectalis muscle length
Right, cm	1.81 (0.30)	1.59 (0.24)	0.037
Left, cm	1.87 (0.21)	1.67 (0.28)	0.048
3Puborectalis angle
Right, °	21 (17-24)	25 (21-28)	0.0781
Left, °	23 (19-27)	24 (19-28)	0.7323
2Periurethral ligament status
Intact/symmetric, n	7 (70)	4 (20)	0.0154
Disrupted, n	3 (30)	16 (80)

¹Data are presented as mean (standard deviation);

²Data are presented as number of cases (%);

³Data are presented as mean (95%CI); P value of t-test;

⁴Fisher’s exact test. BMI: Body mass index; PCL: Pubococcygeal line; OB: Obstetric trauma to include episiotomy; Ant: Anterior; Post: Posterior.

Table 2 Predictive value statistics and corresponding 95%CI for urethral hypermobility diagnosis for both suprapubic urethra sphincter length and bladder neck funneling (present/absent)

Urethral hypermobility diagnosis - suprapubic urethra sphincter length and bladder neck funneling1	Estimate 95%CI
Sensitivity	100.0% (66.4%, 100%)2
Specificity	88.9% (51.8%, 99.7%)
Positive predictive value	90.0% (55.5%, 99.7%)
Negative predictive value	100.0% (63.1%, 100.0%)2

A total of 18 incontinent women were included in the analysis.

¹ROC = 0.944;

²One-sided 97.5% CI.

Table 3 Probability of urethral hypermobility diagnosis, alternative propensity scores, and covariate and outcome values

Predicted probability of urethral hypermobility	Score	FunnelingY = 1,n = 0	Suprapubicurethral sphincterlength (cm)	UH = 1ISD/mixed = 0
0.008	-4.77	1	1.8	0
0.020	-3.84	1	2.1	0
0.027	-3.53	1	2.2	0
0.027	-3.53	1	2.2	0
0.065	-2.6	1	2.5	0
0.149	-1.67	1	2.8	0
0.193	-1.36	1	2.9	0
0.377	-0.43	1	3.2	0
0.529	0.19	1	3.4	1
0.587	0.38	0	2.3	1
0.605	0.5	1	3.5	1
0.659	0.69	0	2.4	1
0.925	2.55	0	3.0	1
0.925	2.55	0	3.0	0
0.969	3.48	0	3.3	1
0.969	3.48	0	3.3	1
0.969	3.48	0	3.3	1
0.996	5.65	0	4.0	1

UH: Urethral hypermobility; ISD: Intrinsic sphincter defects.