Role of Spectral Doppler Sonography in the Evaluation of Partial Testicular Torsion

Transcription

1 ase Series Role of Spectral Doppler Sonography in the Evaluation of Partial Testicular Torsion Scott assar, MD, Shweta hatt, MD, Harriet J. Paltiel, MD, Vikram S. Dogra, MD Objective. The purpose of this series was to evaluate the role of spectral Doppler and color flow Doppler sonography in the evaluation of partial testicular torsion. Methods. Eight cases of partial testicular torsion, diagnosed on the basis of abnormal spectral Doppler waveforms or abnormal color flow Doppler findings, were retrospectively pooled from 2 teaching hospitals. Results. The age group ranged from 4 to 85 years. Testicles with partial testicular torsion showed variable spectral Doppler patterns, including increased, similar, or decreased amplitude of the arterial waveform relative to the contralateral testicle. Two cases showed reversal of arterial diastolic flow, and 1 case showed diastolic flow variability within the same testicle. Decreased blood flow was observed on color flow Doppler sonography in 7 of the 8 patients. onclusions. Variability of the Doppler waveform when compared with the contralateral testicle and reversal of diastolic blood flow are indirect clues that aid in the diagnosis of partial testicular torsion. Key words: color flow Doppler sonography; partial testicular torsion; sonography; spectral Doppler sonography. Received June 19, 2008, from the Department of Imaging Sciences, University of Rochester School of Medicine, Rochester, New York US (S.., S.., V.S.D.); and Department of Radiology, hildren s Hospital oston, oston, Massachusetts US (H.J.P.). Revision requested June 27, Revised manuscript accepted for publication July 9, ddress correspondence to Vikram S. Dogra, MD, Department of Imaging Sciences, University of Rochester School of Medicine, 601 Elmwood ve, ox 648, Rochester, NY US. vikram_dogra@urmc.rochester.edu Testicular torsion is a twisting of the spermatic cord, which can strangulate blood flow to and from the testicle. lthough it may occur at any age, it most commonly affects boys and young men, approximately 1 per 4000 younger than 25 years. 1 Intravaginal torsion is the most common subtype, accounting for 90% of cases, and it typically occurs between the ages of 12 and 18 years. 2,3 This type of testicular torsion is associated with the so-called bell clapper deformity. Torsion in these cases occurs within the tunica vaginalis, hence the term intravaginal torsion. Testicular torsion is one of many possible causes of acute scrotal pain. The differential diagnosis also includes epididymo-orchitis, torsion of the testicular appendages, and trauma. 4 The ability to rapidly distinguish between these possibilities is necessary given the serious morbidity of testicular ischemia and the need to institute appropriate treatment. When a testicle undergoes torsion, there are salvage rates of near 100% within the first 6 hours, 70% between 6 and 12 hours, and 20% between 12 and 24 hours. 5 Salvage rates after 24 hours are less than 10% by the merican Institute of Ultrasound in Medicine J Ultrasound Med 2008; 27: /08/$3.50

2 Spectral Doppler Sonography of Partial Testicular Torsion In cases of complete testicular torsion of greater than 450, 7 arterial and venous flow are absent in the affected testicle, making a sonographic diagnosis straightforward. Torsion is not necessarily an all-or-nothing occurrence, however, and may be either partial or transient. Figure 1. Normal scrotal sonograms., Gray scale image showing bilateral homogeneous echogenicity of the testicles in a 23-year-old man with right scrotal pain., Normal color Doppler image showing similar bilateral intratesticular blood flow., Normal testicular artery spectral Doppler waveform with a high-flow, low-resistance pattern in a 20-year-old man with left testicular pain. Figure 2. ase 1: 15-year-old boy with 10 hours of acute right testicular pain. Two years earlier, he had similar symptoms and was discharged with the diagnosis of a torsed testicular appendage. He reported no similar symptoms in the interim., Scrotal sonogram showing an enlarged edematous right testicle with diminished flow on color flow Doppler sonography. and, Torsed right testicle showing an increased amplitude of the arterial spectral Doppler waveform () compared with the normal left testicle (). t emergent surgery, the right testicle was torsed 360 but still well vascularized and viable J Ultrasound Med 2008; 27:

3 assar et al In these cases, arterial flow is not necessarily absent. 8 ases of partial torsion present a diagnostic challenge, and the ability of color and power Doppler sonography to definitively diagnose partial testicular torsion remains problematic. Sonographic findings vary depending on the degree of rotation ( ) and the duration of torsion. Spectral Doppler sonography proved beneficial in the detection of partial testicular torsion in a canine model, in which there was enhancement of the diastolic component of the arterial signal at 180 of torsion. 9 Subsequent case reports have shown the usefulness of spectral Doppler sonography in partial testicular torsion. 10,11 We describe 8 cases of partial testicular torsion that were diagnosed on the basis of their color and spectral Doppler patterns. Methods and Techniques This was a retrospective collection of patients with diagnoses of partial testicular torsion from 2 institutions pooled together because of the rarity of this entity. In total, 8 cases were included, 7 of which had surgical confirmation. Scrotal sonography was performed by different sonographers using a variety of ultrasound machines. ll patients were scanned supine with a high-frequency linear transducer ranging from 6 to 14 MHz. In longitudinal and transverse axes, the size, echogenicity, and vascular flow of each testicle and epididymis were compared with the contralateral side (Figure 1). olor Doppler and pulsed Doppler parameters were optimized to display low flow velocities to show blood flow in the testicles and surrounding scrotal structures. Table 1. Summary of Sonographic Findings in Partial Testicular Torsion Presenting Gray Scale olor Flow Spectral Doppler ase ge, y Symptom Findings Doppler Findings Findings Outcome 1 (Figure 2) 15 cute right Enlarged edematous Relatively decreased Increased amplitude 360 torsion reduced testicular pain right testicle right testicular flow of arterial waveform in the operating room (OR) with bilateral orchiopexy 2 (Figure 3) 28 cute-onset Homogeneous and Relatively decreased Decreased amplitude Spontaneously right groin pain equal echogenicity right testicular flow of arterial waveform detorsed in the OR, after weight lifting bilateral orchiopexy 3 (Figure 4) 15 Sudden-onset left Mildly edematous Relatively decreased Decreased amplitude bnormal lie that testicular pain, left testicle with right testicular flow of arterial waveform detorsed spontaneousscrotal swelling, increased relative ly in the OR after nausea, vomiting parenchymal induction of echogenicity anesthesia 4 (Figure 5) 4 Sudden-onset left bnormal transverse Relatively decreased Similar high flow 180 torsion reduced testicular pain lie with a moderate left testicular flow patterns in the OR with bilateral reactive hydrocele orchiopexy 5 (Figure 6) 23 Sudden-onset right Whirlpool sign in the Relatively decreased Similar high flow Urgently reduced by testicular pain right spermatic cord right testicular flow patterns urology, subsequent bilateral orchiopexy 6 (Figure 7) 20 Enlarged tender Mildly edematous Relatively decreased Diastolic flow 180 torsion reduced in left testicle left testicular flow variability within the OR with bilateral the same testicle orchiopexy 7 (Figure 8) 16 Right groin pain Enlarged right Similar flow Reversal of right 360 torsion reduced after sprinting epididymis, large intratesticular in the OR with bihydrocele diastolic flow lateral orchiopexy 8 (Figure 9) 85 Left groin mass 1 Elevated left testicle Relatively decreased Reversal of spermatic Patient was too unwk after with a hetero- left testicular flow cord diastolic flow stable to undergo cystectomy geneous echogenic surgical exploration appearance and and died reactive hydrocele J Ultrasound Med 2008; 27:

4 Spectral Doppler Sonography of Partial Testicular Torsion The transverse view of both testicles with color flow Doppler sonography in a single frame was obtained for evaluating and comparing testicular blood flow (Figure 1). Spectral Doppler tracings from both testicles were compared and evaluated. The normal spectral waveform of the testicular artery and artery supplying the epididymis has a low-resistance, high-flow pattern (Figure 1). dditionally, any variation in spectral Doppler tracings within the same testicle was also evaluated. Figure 3. ase 2: 28-year-old man with acute-onset right testicular pain that radiated to the stomach after a weight-lifting exercise. The echogenicity of both testicles was homogeneous and grossly equal. There was decreased relative flow in the right testicle compared with the left., Spectral Doppler image of the normal left testicle showing a normal low-resistance flow pattern., Spectral Doppler image of the torsed right testicle showing relatively decreased arterial flow. Flow in the epididymis was symmetric bilaterally. t the time of surgical exploration, the right testicle was edematous but detorsed. ilateral orchiopexy was performed. Figure 4. ase 3: 15-year-old boy with left testicular pain, scrotal swelling, nausea, and vomiting. Symptoms began abruptly approximately 5 hours before examination. The pain was described as severe and constant without radiation. Sonography showed a slightly swollen left testicle with increased relative parenchymal echogenicity compared with the right, which became more apparent as the examination progressed., olor Doppler image showing decreased relative flow to the left testicle compared with the right., rterial flow identified on the left; however, the waveform is blunted., Normal contralateral right testicle waveform. t surgery, the left testicle had an abnormal lie and detorsed spontaneously after induction of general anesthesia. The patient underwent bilateral orchiopexy J Ultrasound Med 2008; 27:

5 assar et al ase Descriptions We describe a series of cases of partial testicular torsion in which a combination of gray scale, color Doppler, and spectral Doppler flow patterns was used to make the diagnosis of partial testicular torsion (Table 1 and Figures 2 9). rief histories are included in the figure legends. Discussion In addition to the patient history and physical examination, sonography has become a valuable tool in assisting the clinician in diagnosing the acute scrotum. Gray scale sonography can be used to display the sequelae of testicular ischemia. 12 Early on in testicular torsion, the testicular echogenicity appears normal and homogeneous, but as time progresses, it becomes hypoechoic, indicating infarction. Testicular echogenicity is the best reported predictor of viability. 13 Figure 5. ase 4: 4-year-old boy who was brought to the emergency department after an hour of sudden-onset left testicular pain that began when he jumped off his father s lap., Scrotal sonogram showing an abnormal transverse lie of the left testicle with a moderate reactive hydrocele. LT indicates left testicle; and RT, right testicle., olor Doppler image showing a small amount of blood flow to the left testicle and no substantial flow throughout most of the testicular parenchyma., Power Doppler image showing minimal intratesticular flow. D and E, Left (D) and right (E) spectral Doppler images showing similar high flow patterns. t surgery, 180 torsion was found. D E J Ultrasound Med 2008; 27:

6 Spectral Doppler Sonography of Partial Testicular Torsion Interpretation of color flow Doppler and spectral Doppler waveforms requires an understanding of normal blood flow to the testicles. The normal spectral waveform of the testicular artery and artery supplying the epididymis has a lowresistance, high-flow pattern. The waveform of the cremasteric artery, which supplies the scrotal wall, has a high-resistance, low-flow pattern. 14 Resistance to flow is quantified by the resistive index [(peak systolic flow end diastolic flow)/ peak systolic flow], which in a healthy person is rarely less than Figure 6. ase 5: 23-year-old man with a reported history of right epididymitis 2 years previously who had new sudden-onset right testicular pain. The echogenicity of the testicles was homogeneous and equal. There was a small right hydrocele. and, Unaffected left () and torsed right () spectral Doppler waveforms showing similar high flow patterns., olor Doppler image showing decreased relative flow to the partially torsed right testicle. D and E, Whirlpool sign (arrows) in the right spermatic cord. The testicle was urgently derotated by the urologist. F, Immediate disappearance of the whirlpool sign and return of flow in the right spermatic cord after derotation. Subsequent surgical bilateral orchiopexy was performed. D E F 1634 J Ultrasound Med 2008; 27:

7 assar et al Figure 7. ase 6: 20-year-old man with an enlarged tender left testicle, which scrotal sonography showed to be mildly edematous., olor flow Doppler image of the left testicle showing the presence of intratesticular blood flow and normal spectral Doppler tracings., Variation in the spectral Doppler waveforms in the same testicle, evidenced by different amplitudes of intratesticular arterial waveforms., Transverse view of both testicles in a single image with color flow Doppler sonography providing a better appreciation of the decrease in vascularity of the left testicle. The patient underwent surgery and was found to have partial torsion. Detorsion and orchiopexy were performed. Reprinted with permission from Lin et al. 4 olor Doppler and spectral Doppler sonography are optimized to display low flow velocities to show blood flow in the testis and surrounding scrotal structures. Power Doppler sonography may also be used to visualize intratesticular flow. 7,16 olor Doppler sonography for testicular torsion was initially shown to be 82% sensitive and 100% specific. 17 Subsequent studies have shown sensitivities of 78.6% to 89% and specificities of 77% to 100%. 18 In a rabbit model, color Doppler sonography was eventually proven better than radionuclide imaging. 19 The usefulness of spectral Doppler waveform analysis in the evaluation of the acute scrotum has also been described. 20,21 Despite technological advances and improved operator skill, color Doppler sonography still results in false-negative diagnoses of testicular torsion. The sensitivity of color Doppler sonography remains less than 90%, and many authors have reported false-negative findings Those studies revealed normal flow even though there was testicular torsion, and that was attributed to technical factors and partial torsion. 11,27 This has led to the investigation of many ancillary signs to diagnose torsion. Some of these include evaluating flow in the spermatic cord directly, 28 the whirlpool sign, 29 and a markedly enlarged echogenic and avascular or hypovascular epididymis. 18 The whirlpool sign is a twisting of the spermatic cord at the external inguinal ring. This sign has low sensitivity and high specificity. 4 gray scale evaluation of partial torsion usually yields normal findings, as it did in most of the cases in this series. Intratesticular flow was also consistently present on color flow Doppler sonography. ttempting to assign a resistive index value to establish a diagnostic cutoff is not a practical means for differentiating partially torsed and nontorsed testicles. Resistive indices in normal intratesticular arteries range from 0.48 to 0.75 with a mean of The resistive indices in the partially torsed testicles of this series covered a broad range, and a nominal value above or below which a diagnosis could be confidently made was not possible. This is because it is the abnormality in the waveform itself that points to the underlying abnormality in blood flow to the affected testicle, which is not always represented in the resistive index and thus is not a consistent- J Ultrasound Med 2008; 27:

8 Spectral Doppler Sonography of Partial Testicular Torsion ly reliable indicator of partial torsion. Most of these cases of partial testicular torsion were diagnosed only after careful examination of the morphologic characteristics and amplitude of the spectral Doppler waveform and its appearance relative to the contralateral testicle or a different region within the same testicle. Variability of the amplitude was the most common abnormality, followed by reversal of diastolic flow. summary of the findings is given in Table 1. The true incidence of partial testicular torsion is unknown. Some cases may automatically undergo detorsion; others may be classified as torsion/detorsion; and still others may be presumed complete and taken directly to the operating room without a sonographic evaluation. high index of suspicion for partial testicular torsion must be maintained when evaluating the acute scrotum. spectral Doppler analysis should be performed in the upper, mid, and lower poles of each testicle, preferably with a Doppler angle correction of less than 60 if possible. Subtle variations in the spectral Doppler waveform must be examined in detail when a patient has a classic clinical history, paying particular attention to the symptomatic side. Figure 8. ase 7: 16-year-old boy with 18 hours of right groin pain after a sprinting exercise. The right hemiscrotum was enlarged and tender to palpation. The right epididymis was enlarged, and there was a large hydrocele. and, Transverse sonograms of the right () and left () testicles showing asymmetric resistive indices. The diastolic flow is reduced in the partially torsed right testicle., Transverse sonogram of the inferior pole of a partially torsed right testicle showing diastolic flow below the baseline. Surgical exploration revealed 360 clockwise right testicle torsion, and bilateral orchiopexy was performed. Reprinted with permission from Dogra et al J Ultrasound Med 2008; 27:

9 assar et al Figure 9. ase 8: 85-year-old man with a history of bladder cancer and multiple myeloma who had a left groin mass 1 week after cystectomy., Elevated left testicle with a heterogeneous echogenic appearance and a reactive hydrocele. and, Highresistance blood flow pattern with reversal of diastolic flow in the left () intratesticular vessels and the torsed spermatic cord (). The patient was too unstable to undergo surgical exploration and died before his torsion could be corrected. This will help lead to an appropriate diagnosis of partial testicular torsion, as has been described in the cases of this series. Variability of the Doppler waveform when compared with the contralateral testicle, variability within the same testicle, and reversal of flow are indirect clues that aid in the diagnosis of partial testicular torsion. References 1. arada JH, Weingarten JL, romie WJ. Testicular salvage and age-related delay in the presentation of testicular torsion. J Urol 1989; 142: andocia FJ, Sack-Solomon K. n infant with testicular torsion in the inguinal canal. Pediatr Radiol 2003; 33: Williamson R. Torsion of the testis and allied conditions. r J Surg 1976; 63: Lin EP, hatt S, Rubens DJ, Dogra VS. Testicular torsion: twists and turns. Semin Ultrasound T MR 2007; 28: Patriquin H, Yazbeck S, Trinh, et al. Testicular torsion in infants and children: diagnosis with Doppler sonography. Radiology 1993; 188: Davenport M. of general surgery in children: acute problems of the scrotum. MJ 1996; 312: Lee FT Jr, Winter D, Madsen F, et al. onventional color Doppler velocity sonography versus color Doppler energy sonography for the diagnosis of acute experimental torsion of the spermatic cord. JR m J Roentgenol 1996; 167: Mernagh JR, aco, De Maria J. Testicular torsion revisited. urr Probl Diagn Radiol 2004; 33: Mevorach R, Lerner RM, Greenspan S, et al. olor Doppler ultrasound compared to a radionuclide scanning of spermatic cord torsion in a canine model. J Urol 1991; 145: Dogra VS, Sessions, Mevorach R, Rubens DJ. Reversal of diastolic plateau in partial testicular torsion. J lin Ultrasound 2001; 29: Sanelli P, urke J, Lee L. olor and spectral Doppler sonography of partial torsion of the spermatic cord. JR m J Roentgenol 1999; 172: ird K, Rosenfield T, Taylor KJ. Ultrasonography in testicular torsion. Radiology 1983; 147: Middleton WD, Middleton M, Dierks M, Keetch D, Dierks S. Sonographic prediction of viability in testicular torsion: preliminary observations. J Ultrasound Med 1997; 16: Dogra VS, Rubens DJ, Gottlieb RH, hatt S. Torsion and beyond: new twists in spectral Doppler evaluation of the scrotum. J Ultrasound Med 2004; 23: J Ultrasound Med 2008; 27:

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