MR imaging of the male and female urethra

Surgery for urethral cancer

Primary urethral cancers represent less than 1% of genitourinary malignancy. Given this is an uncommon disease, there are limited data to guide diagnostic and treatment strategies. Surgical extirpation remains the standard for most patients, with the addition of chemotherapy and radiation therapy in select patients. The surgical approach to urethral cancer depends largely on the location and extent of the tumor.

Active surveillance and radical therapy in prostate cancer: can focal therapy offer the middle way?

INTRODUCTION

Focal therapy for prostate cancer is a radical paradigm shift in the management of men with localised prostate cancer. It involves locating and destroying only the areas of prostate cancer whilst leaving the majority of the prostate untreated. By doing so, it is proposed that side-effects of traditional whole-gland therapies such as impotence, incontinence and rectal toxicity will be significantly reduced and cancer control will be at similar levels.

METHODS AND MATERIALS

A Medline/Pubmed search was conducted between 1 May 1998 and 1 May 2008 using the following terms: 'focal therapy', 'lumpectomy', 'hemiablation', 'laterality', 'multifocal', 'unifocal' and 'index lesion' alongside 'prostate cancer'. Articles were selected for their relevance to this review. Abstracts from international conferences over the last 5 years were also used where appropriate. Authors' personal bibliography was used to supplement the review.

CONCLUSIONS

A number of case series have reported significantly lower incontinence and impotence rates using focal cryoablation and one series on focal HIFU. The reporting quality has been variable and there are currently ongoing clinical trials with IRB approval in the USA and UK. Long term follow-up is required. Focal therapy is an exciting new area of research that could hold great promise for men with localised low to intermediate risk prostate cancer.

Extensive perineal soft tissue disruption with 'open-book' pelvic fracture

We present a case in which direct visualisation of the nature and extent of a perineal soft tissue injury following pelvic trauma was achieved through the use of multi-modality and multi-planar imaging. The case emphasises the importance of a flexible approach to imaging as a problem-solving technique after severe pelvic trauma.

Imaging of the Male Urethra

For imaging of the male urethra, conventional radiographic contrast studies including retrograde urethrography are most commonly utilized. They are best suited for delineating luminal abnormalities of the urethra and thus are commonly used as the primary imaging modality for patients with various urethral abnormalities such as trauma, inflammation, and stricture. More recently, the cross-sectional imaging techniques of ultrasound, computed tomography and magnetic resonance imaging have been utilized increasingly for urethral and periurethral abnormalities. These studies are most valuable as an adjunctive tool in patients with the complex anatomical derangements such as congenital anomalies, posterior (or bulbomembranous) urethral injuries, and with urethral or periurethral tumors. These cross-sectional techniques can be performed during micturition or with retrograde injection of saline or jelly through the urethral meatus to improve visualization of the urethral luminal abnormalities. This article describes imaging techniques, anatomy, and findings of various urethral and periurethral pathology in the male including congenital anomalies, infection/inflammation, stricture, traumatic injury, fistula, tumors, and calculi.

Gray Scale and Color Doppler Sonography With Extended Field of View Technique for the Diagnostic Evaluation of Anterior Urethral Strictures

PURPOSE

We compared the clinical relevance of radio urethrography with that of sonourethrography for evaluating male urethral strictures.

MATERIALS AND METHODS

From 2002 to 2004, 93 men were referred to our institution for urethral strictures. Patients were evaluated by conventional voiding cystourethrography, retrograde urethrography, and gray scale and color Doppler sonourethrography. For sonourethrography the extended field of view technique was used to obtain 1 image of the whole anterior urethra. In all cases the urethra was evaluated cystoscopically or at open surgery. Radio urethrography and sonourethrography findings were compared with cystoscopy or surgery findings.

RESULTS

All strictures were evaluated and treated cystoscopically with visual internal urethrotomy (34%) or at open operation (66%), which allowed comparison of the ability of each study to predict operative stricture length. Sonourethrography correctly identified the stricture and its site in all cases, whereas radio urethrography yielded 2 false-negative results. There was a significant difference between stricture length measured by radio urethrography compared to that measured by sonourethrography (correlation coefficient 0.72 vs 0.92, p<0.005). Mean+/-SD stricture length measured by radio urethrography was 1.5+/-1.3 cm and by sonourethrography it was 2.1+/-0.9 cm. Comparison of radio urethrography and sonourethrography stricture length with operative lengths demonstrated a good correlation in the penile urethra (correlation coefficient 0.91 vs 0.98), whereas a poor correlation was found in the bulbar urethra (correlation coefficient 0.65 vs 0.92).

CONCLUSIONS

Gray scale and color Doppler sonourethrography using the extended field of view technique with a Siemens Sonoline Elegra is a promising tool for defining male urethral strictures. It seems to be superior to radio urethrography for treatment planning.

Significance of fibrosis around and/or at external urinary sphincter on pelvic magnetic resonance imaging in patients with postprostatectomy incontinence

OBJECTIVES

To determine the clinical importance of fibrosis on pelvic magnetic resonance imaging in patients with postprostatectomy incontinence (PPI) due to sphincteric incompetence.

METHODS

Urethral and periurethral fibrosis was determined by pelvic magnetic resonance imaging in patients who did (n = 22) or did not (n = 14) have urinary incontinence after transurethral resection, transvesical prostatectomy, or radical retropubic prostatectomy. The relation between fibrosis and the duration of incontinence, pad weight, symptom score, cystoscopy findings, and urodynamic findings was examined.

RESULTS

Fibrosis was seen in all patients (22 of 22) in the study group and in 4 of 14 patients in the control group (P <0.001). All the patients with severe fibrosis had undergone radical retropubic prostatectomy (P <0.001). Similar to the etiology for incontinence, no relation was found between the severity of fibrosis and the duration of incontinence, pad weight, symptom score, cystoscopy findings, or urodynamic findings. However, the duration of incontinence was shorter in patients with mild fibrosis, clinically.

CONCLUSIONS

The results of our study have shown that the incidence of fibrosis is much greater in patients with PPI than in patients without PPI. Consequently, we believe that fibrosis plays an important role in the development of PPI because it may have a negative effect on external urethral sphincter function.

Magnetic resonance urethrography in comparison to retrograde urethrography in diagnosis of male urethral strictures: is it clinically relevant?

OBJECTIVE

To compare the clinical relevance of retrograde urethrography (RUG) and magnetic resonance (MR) urethrography in evaluating male urethral strictures.

METHODS

Between January and April 2004, 20 men were referred to our institute for management of urethral strictures. The patients were investigated by conventional RUG and multiformat MR urethrography. The patients were examined by urethroscopy under anesthesia to be followed by definitive endoscopic or open operative intervention. The radiologic data were compared by endoscopic as well as operative findings in all the patients.

RESULTS

Ten patients were managed by visual internal urethrotomy (VIU) and two by dilatation under anesthesia; two showed normal urethral caliber. Four patients required open urethral reconstructive procedures. Two patients underwent radical cystectomy and cutaneous diversion because of associated bladder or urethral malignancy. Although overall accuracy for diagnosis of urethral strictures was equal between both modalities (85%), MR urethrography provided extra clinical data in seven patients (35%). It was superior to RUG in judging the urethral stricture length in three patients, diagnosing a urethral tumor in one, detecting associated bladder mass in one, characterizing the site of urethra-rectal fistula in one, and accurately delineating the proximal urethra in the last patient. Unlike RUG, MR urethrography provided adequate information about the degree of spongiofibrosis in all patients.

CONCLUSION

MR urethrography is a promising tool for defining male urethral strictures and can provide extra guidance for treatment planning that cannot be obtained with RUG.

Cross-sectional imaging of the female urethra: technique and results

Clinical assessment of women with urethral symptoms is difficult, necessitating further evaluation with imaging. Urethrography provides limited information on luminal abnormalities of the urethra. Recent advances in ultrasound (US) and magnetic resonance (MR) imaging have dramatically improved evaluation of the female urethra, clarifying findings at physical examination and providing accurate road maps for surgeons. High-resolution transvaginal US, transperineal US, and transurethral US are reliable techniques for diagnosis and characterization of urethral abnormalities. High-resolution multiplanar MR imaging with phased-array pelvic and endovaginal coils demonstrates the urethral anatomy in greater detail. In women with urethral diverticula, US and MR imaging demonstrate the number of diverticula and the location, size, configuration, and possible contents of the sac. Most important, the position of the neck of the diverticulum may be identified for the surgeon. Imaging features do not allow differentiation between histologic subtypes of urethral carcinoma; the diagnosis is established with histopathologic examination. Periurethral cysts do not communicate with the urethra and therefore can often be differentiated from urethral diverticula at endocavitary MR imaging. High-resolution multiplanar US and MR imaging allow comprehensive evaluation of abnormalities of the female urethra.

Pelvic anatomy and MRI

An in-depth knowledge of the anatomy of the pelvis and pelvic sidewall is necessary before a gynaecologist can even contemplate making an initial examination and start management in cases of pelvic pathology or malignancy. This chapter provides basic information on gross pelvic anatomy structures that are of clinical relevance and discusses their correlation with medical imaging, especially magnetic resonance imaging (MRI). MRI is an ideal non-invasive technique in the assessment of normal anatomy and tissue characterization of pelvic pathology. The excellent soft-tissue contrast and the ability to direct multiplanar imaging and to demonstrate blood vessels without the use of intravenous contrast make MRI superior to other imaging modalities in the evaluation of pelvic abnormalities. The anatomical relation of the visceral organs, the differential zonal anatomy of the corpus uteri and the cyclical endometrial changes during the menstrual cycle are well depicted with MRI.

Imaging of urethral disease: a pictorial review

Retrograde urethrography and voiding cystourethrography are the modalities of choice for imaging the urethra. Cross-sectional imaging modalities, including ultrasonography, magnetic resonance (MR) imaging, and computed tomography, are useful for evaluating periurethral structures. Retrograde urethrography is the primary imaging modality for evaluating traumatic injuries and inflammatory and stricture diseases of the male urethra. Sonourethrography plays an important role in the assessment of the thickness and length of bulbar urethral stricture. Although voiding cystourethrography is frequently used to evaluate urethral diverticula in women, MR imaging is highly sensitive in the demonstration of these entities. MR imaging is also accurate in the local staging of urethral tumors.

[Imaging in the management of urinary tract infections]

This review analyzes the role of imaging in the diagnosis, follow-up and management of urinary tract infections. Uncomplicated infection of the urinary tract is frequent and usually resolves rapidly with treatment; in such cases imaging is unnecessary except to exclude dilatation or the existence of an obstacle. Progression towards complex infection often occurs in patients with predisposing factors. Imaging helps in evaluating the extent of the disease; it has a role in the selection of therapy and interventional procedures.

[Value of perineal sonography for diagnosing anterior urethral stenosis]

OBJECTIVES

To determine the value of perineal sonography in the diagnosis of urethral stenosis and evaluation of surrounding fibrosis. Materials and methods. Fifty-eight healthy subjects underwent urethral sonography. Thirty-two patients with suspected urethral stenosis underwent sonography after retrograde distension of the urethra using normal saline and retrograde urethrogram and voiding cystourethrogram.

RESULTS

The mean diameters of the healthy urethra varied from 11 to 15 mm. The mean thickness of normal periurethral tIssue was between 2 and 4mm. Sonography detected 34 stenoses (97.4%). The length of the stenosis was significantly longer at sonography compared to retrograde urethrogram and voiding cystourethrogram. No significant difference was found between both techniques when measuring urethral diameter. In all cases, the thickness of periurethral tIssues was greater at the stenotic level than at a normal level, irrespective of the involved segment. There was no correlation between the thickness of periurethral tIssues and the degree of stenosis.

CONCLUSION

Urethral sonography is a method that permits diagnosis of urethral stenosis and evaluation of periurethral fibrosis. It may replace retrograde urethrogram and voiding cystourethrogram in the diagnosis of post infectious stenosis.

[Female urethral diverticulum. Report of a case]

PURPOSE

We describe the successful repair of a large and complex urethral diverticulum in a female by transvaginal approach. Epidemiology, diagnostic methods, treatments and complications of female urethral diverticula are reviewed.

PATIENTS AND METHODS

A 35-year-old woman with a history of postvoid dribbling, dyspareunia and recurrent urinary tract infections for 4 months was referred. Magnetic resonance imaging demonstrated two fluido-filled collections in the pelvis of 3.5 and 1 cm in size respectively which may be a very large and complex diverticulum, however, Bartholin gland cyst could not be rule out. Cystourethroscopy revealed a urethral diverticulum at 10 mm from the bladder neck with two ostia. It was performed transvaginal diverticulectomy and an anterior vaginal wall flap was placed. The published literature on female urethral diverticula was identified using a Pubmed Medline search and analysed.

RESULTS

Convalescence was unremarkable. Suprapubic cystostomy tube was removed 2 weeks after surgery. The patient regained normal voiding. In the published literature there are no agreement neither in the diagnostic nor in the surgical techniques for female urethral diverticula.

CONCLUSIONS

Urethral diverticula are diagnosed with increasing frequency. However, this entity continues to be overlooked because the symptoms may mimic other disorders. Cystourethroscopy, retrograde urethrograme using a double balloon catheter and recently magnetic resonance imaging may diagnose this disease. The cure rate of urethral diverticula with appropriate surgical management has a range of 86-100%. Complete excision through the anterior vaginal wall is the most successful treatment modality with minimum postoperative complications.

The axial location of structural regions in the urethra: a magnetic resonance study in nulliparous women

OBJECTIVE

To define and quantify the appearance and location of distinct regions of the bladder neck and urethra by using axial magnetic resonance images from healthy, continent, nulliparous women.

METHODS

Seventy-eight asymptomatic, healthy, nulliparous women (mean age 29.2 +/- 5.4 years) volunteered for this study. All women were proven continent on urodynamic examination. Axial proton density magnetic resonance images of the pelvic floor were analyzed at 5-mm intervals. A geometric origin was established at the internal urethral meatus. The presence or absence of each of six structural regions--the bladder base, bladder neck, striated urethral sphincter, compressor urethrae and urethrovaginal sphincter, perineal membrane, and distal urethra--was then noted in each more distal image. The proportion of women in whom a structural region was seen at each 5-mm interval was recorded.

RESULTS

The striated urogenital sphincter was observed at 5-25 mm distal to the bladder base. It was observed 10 and 15 mm below the bladder base in 91% (95% confidence interval [CI] 85%, 98%) and 99% (95% CI 97%, 100%), respectively, of all women. The perineal membrane, marking the distal end of the muscular urethra, was located 20-35 mm distal to the bladder base. The length of the muscular region of the urethra ranged from 20 to 35 mm (mean 24 mm, 95% CI 24, 25 mm).

CONCLUSION

Magnetic resonance images allow the normal appearance and location of urethral and bladder neck structures to be quantified in healthy, continent, nulliparous women.

Comparison of radiographic and sonographic urethrography for assessing urethral strictures

The aim of this study was to compare radiourethrography (RUG) and sonourethrography (SUG) for assessment of urethral strictures and to evaluate whether RUG underestimates stricture length, as has been reported. Fifty-one men with suspected urethral strictures were evaluated by both methods performed consecutively. Stricture lengths and diameters measured by RUG were significantly greater (mean 22%, 30%) than those measured by SUG because of radiographic magnification. Both methods, however, detected a similar percentage lumen reduction and similarly graded stricture severity. Equally significant non-correlation between both methods for length measurements in the bulbar and penile urethra ( p<0.001, R(2)=0.33 and 0.34, respectively) supported radiographic magnification. Previous inaccuracies appear to relate to RUG measurements of the central tight stricture (mean 44% of the entire length in our series), not the full stricture length. Use of sonographic contrast medium intra-urethrally improved the definition of long narrow strictures. The SUG gave information about peri-urethral tissues not provided by RUG. Once radiographic magnification was taken into account, there were no major differences in the assessment of urethral strictures by both methods. With correct measurement methods, RUG does not underestimate stricture length. For full assessment, the combination of RUG and SUG, which gives information about peri-urethral disease, is optimal in many patients.

Endorectal coil magnetic resonance imaging for diagnosis of urethral and periurethral pathologic findings in women

OBJECTIVES

To report our experience with endorectal coil magnetic resonance imaging (ERC-MRI) in the evaluation of female patients with lower urinary tract symptoms (LUTS). We present the results of symptomatic patients who underwent this imaging modality, to better define its use and to try to identify applications relevant to everyday clinical practice.

METHODS

We reviewed retrospectively 140 consecutive patients who presented with LUTS and underwent ERC-MRI between June 1997 and June 2000. Assessment included history, physical examination, urodynamic studies, and other radiologic evaluations (such as voiding cystourethrogram). Patients were divided into five groups on the basis of the main indication for ordering the MRI. The results in the subgroups of patients who had repeat ERC-MRI and transvaginal urethrolysis were also analyzed.

RESULTS

Findings consistent with periurethral fibrosis were detected in 52% of the patients, most frequently in those with symptoms suggestive of, or with urodynamic evidence of, obstruction. Ten percent of the patients were found to have urethral diverticula; in 54% of this group, the diagnosis was made solely by MRI. Repeat ERC-MRI showed either periurethral fibrosis or a urethral diverticulum in most patients (17 of 22). No correlation was observed between the subjective estimate of scar tissue during urethrolysis and the amount determined by the interpretation of the images.

CONCLUSIONS

Our 3-year experience suggests that ERC-MRI may help better define the diagnosis of urethral and periurethral pathologic features in female patients with LUTS. With improved patient selection, ERC-MRI will likely have a role in evaluating women with symptoms difficult to explain by other diagnostic modalities.

[Urinary fistula: update]

The urinary fistulas are not a frequent problem in our urological rutinary work, being the vesicovaginal ones the most common. However, it will be necessary to know them to be able to diagnose and treat them in the best way. In this article we classificate the different urinary fistulas (uro-gynecologicals, uro-vasculars, uro-cutaneous and entero-urinarys), explaining the possible etiologies and the correct management.

Advances in uroradiological imaging

The development of new imaging techniques and the refinement of established methods in uroradiological imaging is proceeding rapidly. In the last few years several important developments have been implemented in the routine diagnostic evaluation of urological patients.A milestone is the recent advent of multidetector helical computed tomography (CT), enabling the radiologist to provide the clinician with high-quality three-dimensional (3-D) reconstructions of the urological organs. Powerful workstations are an indispensable tool in the post-processing of CT and magnetic resonance imaging (MRI)data. Significant advances in imaging were obtained in the fields of oncological imaging (e.g. prostate MRI and spectroscopic imaging), paediatric uroradiology(e.g. MR urography) and the evaluation of stone disease by unenhanced helical CT.

Magnetic resonance imaging for urinary incontinence

Magnetic resonance imaging provides the most accurate, versatile and safe imaging of the pelvic floor. Images can be produced to show sections in any plane and even in three dimensions. The resolution is such that detail as good as that seen in histological sections is possible. Once standardization of data acquisition and patient positioning is agreed we look forward to a new era of increasingly accurate diagnoses of incontinence, allowing tailored management, both surgical and nonsurgical.