MRI of the Urethra in Women With Lower Urinary Tract Symptoms: Spectrum of Findings at Static and Dynamic Imaging

Transcription

1 Women s Imaging Original Research ennett et al. MRI of Urethra in Women Women s Imaging Original Research WOMEN S IMGING Genevieve L. ennett 1 Elizabeth M. Hecht 1 Teerath Peter Tanpitukpongse 1 James S. abb 1 achir Taouli 1 Samson Wong 1 Nirit Rosenblum 2 Jamie. Kanofsky 2 Vivian S. Lee 1 ennett GL, Hecht EM, Tanpitukpongse TP, et al. Keywords: female urethra, MRI, pelvic organ prolapse, women s imaging DOI: /JR Received July 15, 2008; accepted after revision June 11, Department of Radiology, New York University Medical Center, 560 First ve., Ste. HW 202, New York, NY ddress correspondence to G. L. ennett (genevieve.bennett@med.nyu.edu). 2 Department of Urology, New York University Medical Center, New York, NY. CME This article is available for CME credit. See for more information. JR 2009; 193: X/09/ merican Roentgen Ray Society MRI of the Urethra in Women With Lower Urinary Tract Symptoms: Spectrum of Findings at Static and Dynamic Imaging OJECTIVE. The purpose of our study was to determine the findings at both static and dynamic MRI in women with a clinically suspected urethral abnormality. MTERILS ND METHODS. MRI of the urethra was performed in 84 women with lower urinary tract symptoms using multiplanar T2-weighted turbo spin-echo and unenhanced and contrast-enhanced gradient-echo sequences. dynamic true fast imaging with steady-state free precession sequence was performed during straining in the sagittal plane. Images were evaluated by two radiologists for urethral pathology and pelvic organ prolapse. MRI findings were correlated with clinical symptoms using the Fisher s exact and Mann-Whitney tests. RESULTS. Urethral abnormalities were found in 10 of 84 patients (11.9%), including two urethral diverticula, five Skene s gland cysts or abscesses, and three periurethral cysts. Thirty-three patients (39.3%) were diagnosed with pelvic organ prolapse, of whom 29 (87.9%) were diagnosed exclusively on dynamic imaging. In 29 of 33 patients with prolapse (87.9%), the urethra was structurally normal. MRI showed 13 cystoceles and 17 cases of urethral hypermobility not detected on physical examination. Patients with a greater number of vaginal deliveries, stress urinary incontinence, frequency of voiding, and voiding difficulty were statistically more likely to have anterior compartment prolapse (p < 0.05). CONCLUSION. Including a dynamic sequence permits both structural and functional evaluation of the urethra, which may be of added value in women with lower urinary tract symptoms. Dynamic MRI allows detection of pelvic organ prolapse that may not be evident on conventional static sequences. T he clinical diagnosis of structural abnormalities of the female urethra, such as urethral diverticulum and Skene s gland abscess, may be challenging because these abnormalities are often associated with a wide range of nonspecific clinical symptoms and often are not detectable at physical examination [1, 2]. The advantages of MRI for diagnosis of urethral abnormalities in women with lower urinary tract symptoms have been well established [3 6]. Compared with conventional imaging methods, such as voiding cystourethrography and double-balloon catheter urethrography, MRI offers a noninvasive method of evaluating the female urethra that requires no patient preparation. High-resolution multiplanar MRI permits visualization of detailed urethral and bladder anatomy and pathology with excellent soft-tissue contrast. Pelvic floor weakness resulting in anterior compartment prolapse may be associated with lower urinary tract symptoms, such as urinary incontinence. These symptoms may overlap with those of structural abnormalities of the urethra. For instance, a urethral diverticulum may be associated with urinary incontinence due to weakening of the urethral sphincter; however, incontinence may also result from weakening of the pelvic floor support structures, causing bladder descent and urethral hypermobility [7]. Furthermore, pelvic organ prolapse is often multicompartmental [8, 9]. Dynamic MRI using ultrafast sequences and performed during strain maneuvers is an effective and noninvasive method for evaluation of organ prolapse in all three compartments of the pelvic floor [10 23]. Dynamic MRI has been shown to be especially effective in the functional assessment of the urethra in patients with urinary incontinence, allowing detection of bladder neck and urethral motion [7, 24]. The purpose of this retrospective study was to determine the spectrum of imaging 1708 JR:193, December 2009

2 MRI of Urethra in Women findings at both static and dynamic MRI performed in women with lower urinary tract symptoms and a clinically suspected urethral abnormality. Our aim was to determine whether this approach allows a more comprehensive evaluation of the woman with lower urinary tract symptoms through the detection of both structural and functional abnormalities of the urethra and coexisting pelvic organ prolapse. Materials and Methods The institutional review board at our institution approved this HIP-compliant retrospective study and waived informed consent. Patients search of the MRI database at our hospital from March 16, 2001, to December 24, 2007, was performed to identify women who were referred for MRI evaluation of the urethra and who underwent both dynamic and static imaging. Patients with a history of lower urinary tract malignancy were excluded. dynamic sequence was added to the protocol for MRI of the female urethra at our institution in 2001 when we began to perform dynamic pelvic floor imaging. This search yielded a total of 122 patients. For 84 patients, clinical charts were also available for review; therefore, the study population was limited to these 84 patients. The age range was years (mean, 40.1 years). Indications for the MRI examinations were suspected urethral diverticulum (n = 45), recurrent urinary tract infection (n = 16), urinary symptoms including pain or urinary frequency (n = 16), other suspected periurethral mass (n = 5), and incontinence (n = 2). Two patients had undergone prior pelvic floor surgery: one colporrhaphy and one urethral sling. Six patients had undergone hysterectomy. MRI Protocol Patients were imaged using one of three 1.5-T clinical systems (Vision, Symphony, or vanto; Siemens Healthcare) and a torso phased-array coil. In accordance with the routine protocol at our hospital, patients did not undergo bowel preparation, and no intraluminal contrast agent was administered. Each patient was asked to empty her bladder 1 hour before entering the magnet, which typically resulted in the bladder being half full at the time of image acquisition. ll studies included sagittal, axial, and coronal high-resolution T2-weighted turbo spin-echo (TSE) images through the urethra with the following parameters: TR/effective TE, 6,000/116; refocusing flip angle, 180 ; turbo factor, 31; rectangular field of view, mm, depending on the imaging plane; matrix, ; slice thickness, 3 4 mm with an interslice gap of mm, depending on imaging plane; bandwidth, 195 Hz/pixel; no parallel imaging; 35 slices through the urethra and bladder; 2 3 signal averages; average time of acquisition, 4 minutes 40 seconds. xial and coronal imaging planes were prescribed with respect to the urethra. Contrast-enhanced 3D fat-suppressed volumetric interpolated breath-hold examination (VIE) data sets were also acquired before and after administration of a standard weight-based dose (0.1 mmol/ kg, with a maximum of 20 ml) of IV gadopentetate dimeglumine (Magnevist, ayer Health- Care Pharmaceuticals), at 45 and 180 seconds after injection. To evaluate for prolapse, a dynamic true fast imaging with steady-state free precession (true- FISP) sequence was performed before contrast injection. This was a continuous acquisition of a single sagittal slice while the patient alternated every 5 seconds between rest and maximal strain (Valsalva maneuver) with the following parameters: 3.9/1.9; refocusing flip angle, 70 ; matrix, 256; a rectangular field of view optimized to the patient s body habitus ( mm); slice thickness, 8 mm; bandwidth, 673 Hz/pixel; acquisition time per measure, 0.6 second; 90 consecutive measures; acquisition time, 54 seconds. The dynamic sequence was performed at a midline sagittal slice position that best depicted the anatomy of all three pelvic compartments, as prescribed by the technologist on the basis of the multiplanar T2- weighted TSE sequences. If inadequate strain was observed, the dynamic sequence was repeated after additional patient instruction. The dynamic sequence was performed once in 60 patients, twice in 19 patients, three times in four patients, and five times in one patient. In four patients, including the patient in whom it was repeated five times, the acquisition was repeated for technical reasons, including wrap and other artifacts. For the remainder with more than one acquisition, the sequence was repeated because of poor strain effort during the initial image acquisition. Image nalysis ll studies were reviewed retrospectively on a PCS workstation (Sienet, Siemens Healthcare) by two radiologists with 10 and 6 years of experience in interpreting abdominal MRI. The readers had no knowledge of clinical symptoms but did know that the patients were referred for and had undergone urethral imaging, presumably for urinary symptoms. The MRI examinations were reviewed in random order and in consensus. For each study, static images were initially evaluated, followed by review of the dynamic sequence, which is how these studies are interpreted in our clinical practice. Urethral abnormalities were classified according to previously published criteria [3 6]. Using accepted criteria, the presence and degree of pelvic organ prolapse at rest and with strain were also determined. Prolapse was diagnosed when the pelvic organs descended more than 1 cm below the pubococcygeal line, a line extending from the inferior margin of the pubic symphysis to the last joint of the coccyx and representing the level of the pelvic floor [10 14, 19, 20]. Grading of prolapse was based on the distance of a perpendicular line drawn from the pubococcygeal line to the inferior margin of the organ of interest as follows: negative, < 1 cm; mild, < 2 cm; moderate, 2 4 cm; and severe, > 4 cm. cystocele was diagnosed when the bladder neck descended to more than 1 cm below the pubococcygeal line, and urethrocele was diagnosed when the urethra descended to more than 1 cm below the pubococcygeal line. Hypermobility of the urethra refers to inferior descent of the urethra below the pubococcygeal line and rotation from its resting axis resulting from laxity of the urethral supporting structures [12, 24, 25]. Hypermobility of the urethra was defined as horizontal translation of the urethra away from the normal vertical axis, with strain at an angle greater than 30, as defined in the literature [25]. No MR grading system exists for severity of urethral hypermobility. For this study, hypermobility was graded as mild (> 30 and < 45 from the vertical) or (severe > 45 ). rectocele was defined as anterior bulging of the rectal wall greater than 2 cm from a line drawn parallel to the center of the anal canal. Clinical Correlation Clinical charts were available for retrospective review in all 84 patients. ecause these 84 patients were all referred by urologists, clinical symptoms and physical examination findings related to the anterior compartment were specifically examined. Physical examinations were performed by three urologists who perform most urethral and pelvic floor surgery at our medical center. The findings were classified according to aden and Walker [26]. The presence of the following urinary tract symptoms in each patient was recorded: dysuria, urinary frequency, nocturia, recurrent urinary tract infection, stress urinary incontinence, urge incontinence, urgency, and voiding difficulty. The total number of pregnancies, vaginal deliveries, and cesarean sections for each patient was also recorded. Statistical nalysis SS version 9.0 (SS Institute) was used for all statistical computations. The Fisher s exact test was used to evaluate the association of each anterior JR:193, December

3 ennett et al. compartment finding at MRI (cystocele, urethrocele, urethral hypermobility) with each clinical symptom, the number of pregnancies, and type of delivery. n exact Mann-Whitney test was used to compare MRI findings and patient age. n exact Mann-Whitney test also was used to compare women with and without a specific symptom in terms of cystocele, urethrocele, and urethral hypermobility severity. ll reported p values are two-sided and were not subjected to multiple comparison correction. Results were declared significant when associated with a p value less than Comparison was also made between physical examination findings and MRI findings. Patients with cystoceles and urethral hypermobility detected only on MRI or physical examination, on both MRI and physical examination, or on neither MRI nor physical examination were identified. Charts were also reviewed for patient management and findings at pathology. Results Ten (11.9%) of the 84 study patients were found to have an abnormality of the urethra. These included urethral diverticulum (n = 2), Skene s gland cyst or abscess (n = 5), and periurethral or suburethral cyst (n = 3). The two patients with urethral diverticula and the five patients with Skene s gland cyst or abscess underwent surgery with pathologic proof of the findings. For the other patients, there was no surgical correlation. Thirty-three of the 84 patients (39.3%) were found to have pelvic organ prolapse. In four of these patients (12.1%), prolapse was detected on the static, at rest images; however, in 29 patients (87.9%), prolapse was identified exclusively on the dynamic during straining sequence (Figs. 1 5). The dynamic sequence showed an increase in the severity Fig year-old woman undergoing MRI evaluation of possible urethral diverticulum. Patient had previously undergone hysterectomy., xial T2-weighted turbo spin-echo (TSE) image (TR/effective TE, 6,080/116; flip angle, 180 ) shows typical appearance of urethral diverticulum (black arrow) containing several calculi (white arrow). Findings were confirmed at pathology. Curved arrow indicates urethra., Midline sagittal T2-weighted TSE image (6,000/116; flip angle, 180 ) obtained at rest shows no significant prolapse. Solid line represents pubococcygeal line, above which all pelvic organs are located. = bladder, dotted line = urethra, R = rectum. C, Midline sagittal true fast imaging with steady-state free precession image (3.9/1.9; flip angle, 70 ) acquired at maximal strain shows mild prolapse with mild descent of urethra (dotted line) and anorectal junction (arrow) below pubococcygeal line (solid line). Urinary bladder () remains superior in relation to pubococcygeal line. Fig year-old woman undergoing MRI evaluation of urethral pain., xial T2-weighted turbo spin-echo (TSE) image (TR/effective TE, 6,080/116; flip angle, 180 ) shows normal urethra (white arrow) and vaginal wall cyst located posterior to urethra (black arrow)., Midline sagittal T2-weighted TSE image (6,000/116; flip angle, 180 ) obtained at rest shows vaginal wall cyst (arrow) and no prolapse. = bladder, dotted line = urethra, U = uterus, solid line = pubococcygeal line. C, Midline sagittal true fast imaging with steady-state free precession image (3.9/1.9; flip angle, 70 ) obtained at maximal strain shows tricompartment prolapse below pubococcygeal line (solid line). Note hypermobility of urethra (dotted line), which is tilted from normal vertical axis. = bladder, V = vagina, C = cervix; arrow indicates rectum. (See also Fig. S2C, cine loop, in supplemental data at C C 1710 JR:193, December 2009

4 MRI of Urethra in Women of prolapse in all four patients with prolapse detected at rest. The presence and severity of prolapse in each pelvic compartment are summarized in Table 1. Lower Urinary Tract Symptoms and MRI Findings The number of patients with each clinical symptom was as follows: dysuria, n = 48 (57.1%); urinary frequency, n = 50 (59.5%); nocturia, n = 19 (22.6%); recurrent urinary tract infection, n = 31 (36.9%); stress incontinence, n = 9 (10.7%); urge incontinence, n = 6 (7.1%); urgency, n = 34 (40.5%); and voiding difficulty, n = 19 (22.6%). Two patients had both stress and urge urinary incontinence; therefore, there were 13 total patients (15.5%) with any type of incontinence (either stress or urge). The number of patients with Fig year-old woman undergoing MRI evaluation of possible urethral diverticulum., xial T2-weighted turbo spin-echo (TSE) image (TR/effective TE, 6,080/116; flip angle, 180 ) obtained at rest shows Skene s gland cyst (arrow)., Midline sagittal T2-weighted TSE image (6,000/116; flip angle, 180 ) obtained at rest again shows Skene s gland cyst (arrow). No significant prolapse is seen. = bladder, dotted line = urethra. C, Midline sagittal true fast imaging with steady-state free precession image (3.9/1.9; flip angle, 70 ) obtained at maximal strain shows tricompartment prolapse below pubococcygeal line (solid line) and urethral hypermobility. Dotted line denotes urethra, which descends below pubococcygeal line and is tilted from normal vertical axis. = bladder, C = cervix, R = rectum. MRI-detected cystoceles, urethroceles, and urethral hypermobility when each clinical symptom was present or absent is indicated in Table 2. Values for p from Fisher s exact test to evaluate the association of MRI findings with each urinary tract symptom are indicated in Table 3. Patients with stress urinary incontinence were significantly more likely to have cystoceles (p = ) than those without stress urinary incontinence. trend was seen toward more urethroceles (p = ) and urethral hypermobility (p = ) in these patients. Patients with urinary frequency were statistically more likely to have cystoceles (p = ) than those without frequency. There was a trend for patients with any type of urinary incontinence to have cystoceles (p = ) and urethroceles (p = ), and a trend for patients Fig year-old woman undergoing MRI evaluation of possible urethral diverticulum., Midline sagittal T2-weighted turbo spin-echo (TSE) image (TR/effective TE, 6,080/116; flip angle, 180 ) obtained at rest. Urethra is normal. Note mild descent of urethra (dotted line), vagina (V), and anorectal junction (arrow) below pubococcygeal line (solid line). Urinary bladder () is located above pubococcygeal line., Midline true fast imaging with steady-state free precession image (3.9/1.9; flip angle, 70 ) obtained at maximal strain shows increase in severity of tricompartmental prolapse with descent of bladder (), urethra (arrow), cervix (C), and rectum (R) below pubococcygeal line (solid line). Severe urethral hypermobility and funneling of proximal urethra are also noted. (See also Fig. S4, cine loop, in supplemental data at with voiding difficulty to have urethral hypermobility (p = ). The other clinical symptoms did not correlate with MRI findings, as shown in Table 3. Clinical symptoms were also correlated with severity of MRI findings. Women with stress urinary incontinence were statistically more likely to have more severe cysto celes (p = ), urethroceles (p = ), and urethral hypermobility (p = ) than women without stress incontinence. Women with urinary frequency were also statistically more likely to have more severe cystoceles (p = ) than women without frequency. Women with voiding difficulty were statistically more likely to have more severe urethral hypermobility (p = ), and there was a trend for more severe urethroceles (p = ) compared with women without voiding difficulty. C JR:193, December

5 ennett et al. Pregnancy History and MRI Findings Cystoceles were found in eight (16.7%) of 48 women with no prior pregnancy, one (10%) of 10 women with one pregnancy, four (44.4%) of nine women with two pregnancies, and five (50%) of 10 women with three or more pregnancies. When stratified by number of pregnancies (0, 1, 2, or 3), only cystoceles were significantly more likely to occur with increasing number of pregnancies (p = 0.034). However, women with at least two or more pregnancies were significantly more likely than women with fewer than two pregnancies to have cystoceles (p = 0.01) and urethroceles (p = 0.031). There was also a trend for these women to be more likely to have urethral hypermobility (p = 0.062) and rectal descent (p = 0.055). Therefore, the association between pregnancy and MRI findings of prolapse was more significant for women with two or more pregnancies. The number of women with each MRI finding stratified by the number of vaginal deliveries is indicated in Table 4. s the number of vaginal deliveries increased, there was a statically significant increase in the number of cystoceles (p = ), urethral hypermobility (p = ), and rectal descent (p = ), with a trend for the numbers of urethroceles (p = ) and vaginal prolapse (0.0537) to increase. If patients were stratified as having at least two vaginal deliveries, there were significantly more cystoceles (p = ), urethroceles (p = ), urethral hypermobility (p = ), vaginal prolapse (p = ), and rectal descent (p = ) than in patients with less than two vaginal deliveries. No correlation was seen between MRI findings and the number of cesarean sections. Patient ge and MRI Findings statistically significant association was seen between patient age and the presence of cystoceles, urethral hypermobility, and urethroceles. The mean age of patients with an MRI-detected cystocele was 46.9 years (n = 20), versus 37.9 years (n = 64) for patients without a cystocele (p = ). The mean age of patients with urethral hypermobility was 46.4 years (n = 30) versus years (n = 54) for patients without urethral hypermobility (p = ). The mean age of patients with a urethrocele was years (n = 32) versus years (n = 52) for patients without a urethrocele (p = ). This was also true for rectal descent (p = ) and vaginal prolapse (p = ). Physical Examination and MRI Findings MRI and physical examination both detected cystoceles in six patients and were both negative for cystocele in 61 patients. In 13 patients, a cystocele was detected on MRI only (nine mild and four moderate), and in two patients, a cystocele was detected only on physical examination (one mild and one moderate). In 10 patients, MRI and physical examination both detected urethral hypermobility, and in 45 patients, both MRI and physical examination were negative for this finding. In 19 patients, urethral hypermobility was detected only on MRI (12 mild and seven severe), and in seven patients, hypermobility was detected only on physical examination (all mild). Ten patients had both a cystocele and urethral hypermobility detected only on MRI. Fig year-old woman undergoing MRI evaluation of possible urethral diverticulum., Midline sagittal T2-weighted turbo spin-echo image (TR/effective TE, 6,000/116; flip angle, 180 ) obtained at rest shows normal urethra and no evidence of prolapse. Solid line = pubococcygeal line, = bladder, dotted line = urethra, U = uterus, V = vagina, R = rectum., Midline sagittal true fast imaging with steadystate free precession image (3.9/1.9; flip angle, 70 ) obtained at maximal strain shows tricompartment prolapse, marked urethral hypermobility, and moderate cystocele. Solid line = pubococcygeal line, = bladder, dotted line = urethra, C = cervix, arrow = anorectal junction. (See also Fig. S5, cine loop, in supplemental data at Discussion In patients with lower urinary tract symptoms and a suspected urethral abnormality, standard MRI protocols generally include multiplanar high-resolution T2-weighted imaging as well as unenhanced and contrastenhanced T1-weighted imaging. However, dynamic imaging with sequences such as truefisp allows the detection of organ prolapse in the anterior pelvic compartment, which may produce clinical symptoms overlapping those of structural urethral abnormalities. protocol for MRI evaluation of the urethra that includes both static and dynamic imaging permits evaluation of both urethral morphology and function. In this series, only a small percentage (11.9%) of patients with lower urinary tract symptoms were actually found to have a structural abnormality of the urethra. However, 39.3% of patients were diagnosed with prolapse, most cases of which were detected exclusively on the dynamic images acquired with strain. In all patients with prolapse, the anterior compartment was involved. ecause these patients all had lower urinary tract symptoms and most had an otherwise normal urethra, these findings suggest that anterior compartment prolapse contributed significantly to their symptoms. We found that certain symptoms correlated with specific MRI findings. Patients with stress urinary incontinence were more likely to have anterior compartment prolapse that was of greater severity than were women without stress incontinence. This is to be expected because inferior bladder descent and urethral hypermobility are well-described MRI findings associated with stress urinary incontinence [7, 24]. Urinary frequency also was more often associated with cystoceles that were of relatively greater severity. In patients who experienced voiding difficulty, there was a trend toward urethral hypermobility of greater severity. This may be due to kinking of the urethra that can result from severe hypermobility [25]. s expected from previous studies, anterior compartment prolapse was associated with an increased number of pregnancies and vaginal deliveries and increasing patient age [27]. In older patients or patients with a history of multiple vaginal 1712 JR:193, December 2009

6 MRI of Urethra in Women TLE 1: Prevalence and Severity of Organ Prolapse in Each Pelvic Compartment Pelvic Compartment ll Patients With Prolapse deliveries who have clinical symptoms of stress urinary incontinence, urinary frequency, or voiding difficulty, the addition of a dynamic sequence to the MRI protocol is likely to be most valuable. In correlating physical examination findings with MRI findings, we found that in most instances, there was agreement between physical examination and MRI with respect to the presence or absence of prolapse in Patients (n = 84) Patients With bnormal Urethra and Prolapse Patients With Normal Urethra and Prolapse Total 33 (39.3) 4 (4.8) 29 (34.5) Cystocele 20 (23.8) 2 (2.4) 18 (21.4) Mild Moderate Urethrocele 32 (38.1) 4 (4.8) 28 (33.3) Mild Moderate Urethral hypermobility 30 (35.7) 4 (4.8) 26 (31) Mild Severe Vaginal vault 32 (38.1) 4 (4.8) 28 (33.3) Mild Moderate Severe Uterine prolapse 2 (2.4) 0 (0) 2 (2.4) Mild Moderate Cervical prolapse 9 (10.7) 2 (2.4) 7 (8.3) Mild Moderate Rectal descent 31 (36.9) 4 (4.8) 27 (32.1) Mild Moderate Severe Rectocele 9 (10.7) 1 (1.2) 8 (9.5) Mild Moderate Note Data in parentheses are percentages. the anterior compartment. However, some discrepancies were noted, with additional findings more frequently observed at MRI. Therefore, MRI may add valuable information that would go undetected at physical examination but may help to explain patient symptoms. In general, physical examination is most accurate in identifying anterior compartment prolapse versus the other compartments, and previous studies have shown good correlation between physical examination and dynamic MRI in evaluation of this compartment [18, 28]. The observed discrepancy in this study may reflect differences in MRI technique because protocols for MRI evaluation of pelvic prolapse are not standardized. For instance, in a recently published report, the truefisp sequence was found to perform better than the HSTE sequence for the detection of prolapse [29]. ll patients in our series were referred by urologists highly skilled in the detection and staging of pelvic organ prolapse on physical examination; therefore, an even greater role for MRI may be found in the more general setting. In the cases in which the physical examination shows more findings of prolapse, reevaluation of these MRI studies showed poor straining effort by the patient, no doubt contributing to a false-negative MRI result. This is one of the potential pitfalls related to assessment of the pelvic floor by dynamic MRI performed in the supine position. Our study has several limitations. ll patients included were referred for a suspected abnormality of the urethra due to lower urinary tract symptoms. We did not compare our findings with respect to either the urethra or pelvic organ prolapse with those in a normal, asymptomatic age- and parity-matched control population. In a series by Goh et al. [30], dynamic MRI was performed in a group of healthy asymptomatic volunteers. Of 25 women, only three cystoceles (12%) were diagnosed. lthough there was a higher incidence of cystoceles in our patient population (23.8%), comparison with that study is limited because of differences in patient characteristics, such as age and parity. We acknowledge that not all findings of prolapse at MRI may be clinically significant and may not ultimately result in a change in patient management. It is always essential to correlate MRI findings with clinical symptoms. In this study, information regarding physical examination findings was obtained from retrospective chart review and may have been limited, accounting for the increased findings of prolapse in the anterior compartment at MRI; however, a comparison between MRI and physical examination in the detection of prolapse was not the aim of our study. Clinical data were also obtained from retrospective review of patient charts and may also have been limited. prospective study with a comprehensive physical examination and clinical history would be helpful to further validate our findings, as would JR:193, December

7 ennett et al. TLE 2: Correlation of MRI Findings and Clinical Symptoms Symptom comparison with a control group of asymptomatic healthy volunteers. ecause it was not clinically indicated at the time, a comprehensive MRI evaluation Cystocele (%) With Symptom Urethrocele (%) With Symptom of the pelvic floor, including multiplanar dynamic imaging and possibly intraluminal contrast administration, was not performed. This may have resulted in an underestimation Urethral Hypermobility (%) With Symptom bsent Present bsent Present bsent Present ny urinary incontinence a 19.7 (14/71) 46.2 (6/13) 33.8 (24/71) 61.5 (8/13) 32.4 (23/71) 53.8 (7/13) Dysuria 27.8 (10/36) 20.8 (10/48) 41.7 (15/36) 35.4 (17/48) 36.1 (13/36) 35.4 (17/48) Urinary frequency 11.8 (4/34) 32.0 (16/50) 35.3 (12/34) 40.0 (20/50) 29.4 (10/34) 40.0 (20/50) Nocturia 21.5 (14/65) 31.6 (6/19) 35.4 (23/65) 47.4 (9/19) 33.8 (22/65) 42.1 (8/19) Recurrent urinary tract infection 24.5 (13/53) 22.6 (7/31) 37.7 (20/53) 38.7 (12/31) 35.8 (19/53) 35.5 (11/31) Stress urinary incontinence 20.0 (15/75) 55.6 (5/9) 34.7 (26/75) 66.7 (6/9) 32.0 (24/75) 66.7 (6/9) Urge incontinence 21.8 (17/78) 50.0 (3/6) 35.9 (28/78) 66.7 (4/6) 34.6 (27/78) 50.0 (3/6) Urgency 28.0 (14/50) 17.6 (6/34) 42.0 (21/50) 32.4 (11/34) 40.0 (20/50) 29.4 (10/34) Voiding difficulty 26.2 (17/65) 15.8 (3/19) 43.1 (28/65) 21.1 (4/19) 41.5 (27/65) 15.8 (3/19) Note Data in parentheses are number of patients with MRI-detected cystoceles, urethroceles, and urethral hypermobility when each clinical symptom was absent or present. a Patients with either stress or urge incontinence. Two patients had both. TLE 3: Fisher s Exact Test p Values of ssociation of nterior Compartment MRI Findings With Clinical Symptoms Symptom Cystocele Urethrocele Urethral Hypermobility ny urinary incontinence a Dysuria Urinary frequency Nocturia Recurrent urinary tract infection Stress urinary incontinence Urge incontinence Urgency Voiding difficulty Note ll data are p values, which are considered significant if less than significant result implies that the number of women with an MRI finding is significantly higher when the symptom is present. a Patients with either stress or urge incontinence. Two patients had both. TLE 4: Specific MRI Findings Stratified by Number of Vaginal Deliveries MRI Finding No. of Deliveries 0 (52) 1 (9) 2 (7) 3 (9) Cystocele (%) 15.4 (8) 11.1 (1) 57.1 (4) 55.6 (5) Rectal descent (%) 30.8 (16) 22.2 (2) 71.4 (5) 66.7 (6) Rectocele (%) 13.5 (7) 11.1 (1) 14.3 (1) 22.2 (2) Urethrocele (%) 32.7 (17) 22.2 (2) 71.4 (5) 66.7 (6) Urethral hypermobility (%) 28.8 (15) 22.2 (2) 71.4 (5) 66.7 (6) Cervical prolapse (%) 9.6 (5) 11.1 (1) 0.0 (0) 22.2 (2) Uterine prolapse (%) 1.9 (1) 11.1 (1) 0.0 (0) 0.0 (0) Vaginal prolapse (%) 32.7 (17) 22.2 (2) 71.4 (5) 66.7 (6) Note Data in parentheses are number of women. Each p value is from Fisher s exact test to evaluate the association of the number of vaginal deliveries with each MRI finding. p of prolapse in our series. lso, not all patients underwent additional evaluation, such as videourodynamics or surgery, to confirm the findings at dynamic MRI. Finally, because of the retrospective nature of the study, the clinical impact of dynamic MRI findings on patient management and outcome was difficult to determine. lthough such an analysis was beyond the scope of this study, it would be an important subject for further investigation. Despite these limitations, the results of this study show that in women with lower urinary tract symptoms who undergo MRI for evaluation of a suspected urethral abnormality, the addition of dynamic MRI permits detection of pelvic organ prolapse that may not be evident on static at-rest images and that may also go undetected at physical examination. The addition of a sagittal dynamic sequence to the MRI protocol permits more comprehensive evaluation of the anterior pelvic compartment by allowing detection of both structural and functional abnormalities of the urethra. Prolapse in the anterior compartment occurred more frequently and was of greater severity in patients with symptoms of stress urinary incontinence, urinary frequency, and voiding difficulty and also in patients with multiple pregnancies, vaginal deliveries, and age more than 40 years. Therefore, these patients are likely to benefit most from inclusion of a dynamic sequence. Obtaining this clinical information before imaging would help to determine the most appropriate imaging protocol for an individual patient. References 1. Handel LN, Leach GE. Current evaluation and management of female urethral diverticula. Curr 1714 JR:193, December 2009

8 MRI of Urethra in Women Urol Rep 2008; 9: Romanzi LJ, Groutz, laivas JG. Urethral diverticulum in women: diverse presentations resulting in diagnostic delay and mismanagement. J Urol 2000; 164: Hahn WY, Israel GM, Lee VS. MRI of female urethral and periurethral disorders. JR 2004; 182: Hricak H, Secaf E, uckley DW, rown JJ, Tanagho E, Mcninch JW. Female urethra: MR imaging. Radiology 1991; 178: Kim, Hricak H, Tanagho E. Diagnosis of urethral diverticula in women: value of MR imaging. JR 1993; 161: Ryu J, Kim. MR imaging of the male and female urethra. RadioGraphics 2001; 21: Macura KJ, Genadry RR. Female urinary incontinence: pathophysiology, methods of evaluation and role of MR imaging. bdom Imaging 2008; 33: González-rgenté FX, Jain, Nogueras JJ, Davila GW, Weiss EG, Wexner SD. Prevalence and severity of urinary incontinence and pelvic genital prolapse in females with anal incontinence or rectal prolapse. Dis Colon Rectum 2001; 44: Ng CS, Rackley RR, ppell R. Incidence of concomitant procedures for pelvic organ prolapse and reconstruction in women who undergo surgery for stress urinary incontinence. Urology 2001; 57: Fielding JR. Practical MR imaging of female pelvic floor weakness. RadioGraphics 2002; 22: Law YM, Fielding JR. MRI of pelvic floor dysfunction: review. JR 2008; 191[suppl]:S45 S Macura KJ. Magnetic resonance imaging of pelvic floor defects in women. Top Magn Reson Imaging 2006; 17: Pannu HK, Kaufman HS, Cundiff GW, Genadry R, luemke D, Fishman EK. Dynamic MR imaging of pelvic organ prolapse: spectrum of abnormalities. RadioGraphics 2000; 20: Yang, Mostwin JL, Rosensheim N, Zerhouni E. Pelvic floor descent in women: dynamic evaluation with fast MR imaging and cinematic display. Radiology 1991; 179: arbaric ZL, Marumoto K, Raz S. Magnetic resonance imaging of the perineum and pelvic floor. Top Magn Reson Imaging 2001; 12: Stoker J, Halligan S, artram CI. Pelvic floor imaging. Radiology 2001; 218: Unterweger M, Marincek, Gottstein-alame N, et al. Ultrafast MR imaging of the pelvic floor. JR 2001; 176: Gousse E, arbaric ZL, Safir MH, Madjar S, Marumoto K, Raz S. Dynamic half Fourier acquisition, single shot turbo spin-echo magnetic resonance imaging for evaluating the female pelvis. J Urol 2000; 164: Lienemann, nthuber C, aron, Kohz P, Reiser M. Dynamic MR colpocystorectography assessing pelvic-floor descent. Eur Radiol 1997; 7: Lienemann, Fischer T. Functional imaging of the pelvic floor. Eur J Radiol 2003; 47: Kelvin FM, Maglinte DD, Hale DS, enson JT. Female pelvic organ prolapse: a comparison of triphasic dynamic MR imaging and triphasic fluoroscopic cystocolpoproctography. JR 2000; FOR YOUR INFORMTION data supplement for this article can be viewed in the online version of the article at: This article is available for CME credit. See for more information. 174: Comiter CV, Vasavada SP, arbaric ZL, Gousse E, Raz S. Grading pelvic prolapse and pelvic floor relaxation using dynamic magnetic resonance imaging. Urology 1999; 54: Maubon, ubard Y, erkane V, Camezind-Vidal M, Mares P, Rouanet JP. Magnetic resonance imaging of the pelvic floor. bdom Imaging 2003; 28: Macura KJ, Genadry RR, luemke D. MR imaging of the female urethra and supporting ligaments in assessment of urinary incontinence: spectrum of abnormalities. RadioGraphics 2006; 26: ergman, McCarthy T, allard C, Yanai J. Role of the Q-tip test in evaluating stress urinary incontinence. J Reprod Med 1987; 32: aden WF, Walker T. Physical diagnosis in the evaluation of vaginal relaxation. Clin Obstet Gynecol 1972; 15: [No authors listed]. Consensus conference: urinary incontinence in adults. JM 1989; 261: Kelvin FM, Hale DS, Maglinte DD, Patten J, enson JT. Female pelvic organ prolapse: diagnostic contribution of dynamic cystoproctography and comparison with physical examination. JR 1999; 173: Hecht EM, Lee VS, Tanpitukpongse TP, et al. MRI of pelvic floor dysfunction: dynamic true fast imaging with steady-state precession versus HSTE. JR 2008; 191: Goh V, Halligan S, Kaplan G, Healy JC, artram CI. Dynamic MR imaging of the pelvic floor in asymptomatic subjects. JR 2000; 174: JR:193, December