| Abstract|| |
Objectives: To evaluate abnormalities of the male anterior urethra with the help of high resolution ultrasonography and to evaluate the efficacy of sonourethrography as compared to conventional radiographic procedures such as retrograde urethrography (RGU).
Material and Methods: Twenty consecutive patients with a clinical diagnosis of urethral strictures were studied. We performed RGU in all the patients followed by sonourethrography, performed independently by different observers.
We used a P-700 Philips scanner with 7.5 MHz linear array small parts probe for ultrasonography with the patient in a supine position. The urethra was dilated with 5-10 cc of normal saline and the tip of the penis was pinched manually. During scanning the patients were asked to contract the pelvic muscles to prevent the saline solution from escaping into the bladder. The penis was stretched and multiple longitudinal and transverse scans of the urethra were obtained. The procedure was well tolerated by the patients and there were no complications. The findings of RGU were compared with those of sonourethrography.
Results : Twenty patients with a diagnosis of urethral strictures were evaluated. The scans of ten patients (50%) revealed abnormalities of the anterior urethra. Six of these ten revealed strictures in the anterior urethra and three revealed urethritis. One revealed a urethral diverticulum.
Of these six, five revealed strictures on RGU as well as on sonourethrography. The scan of one patient who revealed a normal urethra on RGU, revealed a small 2mm stricture on sonography. The length of the strictures was better demonstrated on sonography in all patients and varied between 2mm and 1cm. Three patients revealed urethritis on RGU, which was appreciated very well on sonourethrography. One patient revealed a diverticulum, which was also well correlated.
Conclusion: Our study revealed that ultrasound was positive in all cases in which RGU showed strictures and in one where RGU was negative. There was no situation where RGU picked up a lesion and ultrasound did not.
Keywords: Sonourethrography, Ultrasound, Anterior urethra
|How to cite this article:|
Pushkarna R, Bhargava SK, Jain M. Ultrasonographic evaluation of abnormalities of the male anterior urethra. Indian J Radiol Imaging 2000;10:89-91
Retrograde urethrography (RGU) is a conventional and standard radiographic procedure for the evaluation of the anterior urethra in men. The limitations of this procedure are well known. The length and depth of strictures are poorly defined. Radiographs provide no information about the extent of periurethral fibrosis and expose a patient to ionizing radiation. In addition, fluoroscopic facilities may be required.
|How to cite this URL:|
Pushkarna R, Bhargava SK, Jain M. Ultrasonographic evaluation of abnormalities of the male anterior urethra. Indian J Radiol Imaging [serial online] 2000 [cited 2020 Feb 29];10:89-91. Available from: http://www.ijri.org/text.asp?2000/10/2/89/30609
Since 1988, many authors have published their work on sonourethrography for the anterior urethra ,,. We would like to report our experience of ultrasound studies in the anterior urethra in men compared with RGU studies.
| Materials and Methods|| |
Twenty patients with a clinical diagnosis of urethral stricture, referred by the Department of Surgery, were studied. We first performed an RGU in all patients and later performed sonourethrography.
We used a standard ultrasound scanner (Philips, India), with 7.5 MHz linear array small parts transducer. After disinfecting the glans penis and urethral meatus, ultrasonic gel was applied over the dorsal surface of the penis. The anterior urethra was dilated with 5-10 cc normal saline, the tip of the penis was pinched manually and multiple longitudinal and transverse scans of the urethra were obtained. During scanning the patient was asked to contract the pelvic muscles to prevent the saline solution from escaping into the bladder. The findings of RGU and sonourethrography were compared.
| Results|| |
Twenty patients with a diagnosis of urethral strictures were evaluated. Nine patients showed abnormalities on RGU in the anterior urethra. One patient whose RGU was normal showed a 2 mm stricture on US [Figure - 1]
The rest of the patients who showed strictures on RGU also had strictures on sonourethrography. There was no situation where RGU picked up a lesion and ultrasound did not. The length of the strictures was better demonstrated on US. The length of the strictures varied between 2 mm and 1cm, proving that sonography is more accurate in determining the presence of strictures in the urethra. Three patients revealed evidence of urethritis on RGU and this was well appreciated on US [Figure - 2]. One patient revealed a urethral diverticulum on RGU, which correlated well with US [Figure - 3].
| Discussion|| |
RGU is a standard imaging technique for visualizing the male anterior urethra, indicated for the evaluation of strictures, diverticulae, fistulae, tumors and trauma. Rapid and forceful injection of contrast medium in RGU may lead to rupture of the mucosal barrier with extravasation of contrast into the systemic circulation with occasional resultant systemic complication such as sepsis and anaphylaxis. Reflex contraction of the pelvic muscle due to forceful injection of contrast may lead to a falsely positive diagnosis of stricture . Strictures are more commonly seen in the anterior urethra, secondary to gonococcal urethritis and trauma. The normal urethral lumen is 4 mm or less in diameter and has small thin walls. A stricture appears as a segment of narrowed lumen with irregularity and thickening of the wall due to fibrosis and scarring.
In 1988, the first ultrasound studies in the anterior urethra in men were described. In their report, the authors believed that US studies were preferable to radiographic studies in the evaluation of patients with suspected anterior urethral strictures ,,.
Our study was done to prove the efficacy of ultrasound in the evaluation of symptoms attributable to strictures. Appropriate evaluation of the urethra was performed by retrograde instillation of 5-10 cc normal saline. As the normal urethral wall and corpus spongiosum are elastic, even at low pressure they are compressible to injection of saline. Corpus spongiosum altered by stricture disease loses its elasticity due to a higher collagen content and therefore is not compressible and causes a reduction of the inner diameter of the urethra. Even small strictures that have no urodynamic effect and are not visible on radiographic examination may be visualized ultrasonically. By dilating the anterior urethra with saline, it could be scanned longitudinally and transversely enabling the length of the stricture, the intra-luminal diameter and the wall thickness to be determined accurately. A study conducted by Heidenreich A. et al reported a 98% sensitivity and 96% specificity for urethral ultrasound in the diagnosis of strictures . In our study ultrasound was positive in all patients in whom RGU showed strictures and in one where RGU was negative. There was no situation where RGU picked up a lesion and ultrasound did not.
We believe that US should be the modality of choice for follow-up of postoperative patients and for the evaluation of patients with urethral symptoms. Merkle W et al have speculated that an internal urethrotomy is less likely to be successful in patients with periurethral cuffing which is seen only on sonography. US is good for the patient for a number of reasons. Multiple examinations are often required and the use of US reduces exposure to radiation. The three dimensional nature of the urethra can be appreciated on US. Soft tissues around the urethra can also be examined. The disadvantage of US of the penile urethra is its inability to visualize the posterior prostatic urethra without a transrectal approach. Fortunately most strictures are seen in the anterior urethra.
Thus US is a simple convenient, rapid, real time study which can be repeated without radiation exposure to the patients. Both cross sectional and longitudinal images can be easily obtained. The procedure is well tolerated by patients.
| References|| |
|1.||McAninch JW, Laing FC, Jeffery B, Jr.: Sonourethrography in the evaluation of urethral stricture: a preliminary report. J Urol 1988; 139: 294-297. |
|2.||Merkle W, Wagner W: Sonography of the distal male urethra - a new diagnostic procedure for urethral strictures: results of a retrospective study. J Urol 1988; 140:1409-1411. |
|3.||Cluck CD, Bundy AL, Fine C, et al : Sonographic urethrogram: comparison to roentgenographic techniques in 22 patients. J Urol 1988; 140: 1404-1408. |
|4.||Edward M, Mullin Lloyd J, Paterson and David, Paulson F. Retrograde urethrogram: diagnostic aid and hazard. J. Urol 1973; 110: 464-466. |
|5.||Heinenreich A, Derschum W, Bonfig R, Wilbert, D.M. Ultrasound in the evaluation of urethral stricture disease: a prospective study in 175 patients. British Journal of Urology. 1994; 74: 93-98. |
Satish K Bhargava
E-3, UCMS & GTB Hospital, Dilshad Garden, Delhi 110095
Source of Support: None, Conflict of Interest: None
[Figure - 1], [Figure - 2], [Figure - 3]