Role of Grayscale and Color Doppler Ultrasonography in the Diagnosis and Outcome Analysis of Testicular Torsion

O R I G I N A L A R T I C L E

Role of Grayscale and Color Doppler Ultrasonography in the Diagnosis and Outcome Analysis of Testicular Torsion Chao-Yu Shen1, Mein-Kai Gueng1, Yu-Chi Su1, Tan Lee1,22, San-Kan Lee2,3,4* Background: Ultrasonography (US) plays an important role in helping to differentiate acute epididymo-orchitis from testicular torsion, which is a surgical emergency. Both manifest with acute pain and swelling. Clinical differentiation of these conditions is difficult, with a false-positive rate of nearly 50%, and can result in unnecessary surgical exploration. The purpose of this study was to diagnose and analyze outcomes in patients with suspected testicular torsion by using grayscale and color Doppler US. Patients and Methods: A total of 15 patients with the final diagnosis of testicular torsion confirmed at operation were retrospectively reviewed. Eleven of the 15 underwent grayscale and color Doppler US imaging using a high frequency linear transducer. The four patients who did not undergo US were excluded. All of the US images were analyzed and compared with operating and pathologic results. Results: Color Doppler US revealed a lack of intratesticular blood flow in the affected testis and normal flow within the contralateral testis in all 11 patients. Grayscale US findings varied, and it was found that all three salvage testes appeared homogeneous or had a slightly increased testicular echogenicity on grayscale US. Conclusion: Color Doppler and grayscale US accurately assesses testicular torsion and can reflect the outcome of the affected testis.

KEY WORDS — color Doppler ultrasonography, grayscale ultrasonography, testicular torsion ■ J Med Ultrasound 2005;13(1):26–31 ■

Introduction Testicular torsion can occur at any age, although it is most frequent in adolescent boys. Patients with acute torsion usually present after a sudden

onset of pain followed by nausea, vomiting, and low-grade fever. Physical examination reveals a swollen, tender, and inflamed hemiscrotum. The cremasteric reflex is usually absent, and the pain cannot be relieved by elevating the scrotum.

1

Department of Radiology, Taichung Veterans General Hospital and 2School of Medicine, Chung-Shan Medical University, Taichung, 3Yuanshan and Su-ao Veterans Hospitals, Yilan, and 4Department of Radiology, National Defense Medical Center, Taipei, Taiwan, R.O.C. *Address correspondence to: Dr. San-Kan Lee, Yuanshan Veterans Hospital, 386, Jongguang Road, Yuanshan, Yilan 204, Taiwan, R.O.C. E-mail: [email protected]

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©Elsevier & CTSUM. A Allll rig rights ghts rreserv eservved.

Ultrasonographic Analysis of Testicular Torsion Ultrasonography (US) plays an important role in helping to differentiate acute epididymo-orchitis from testicular torsion, which is a surgical emergency. Both manifest with acute pain and swelling. Clinical differentiation of these conditions is difficult, with a false-positive rate of nearly 50% for diagnosis of testicular torsion based on clinical findings alone, which, therefore, often results in unnecessary surgical exploration [1]. Grayscale US images are nonspecific for testicular torsion [2]; findings vary with the duration and degree of rotation of the spermatic cord. Color Doppler plays an important role in the diagnosis of acute testicular torsion by using the absence of identifiable intratesticular flow for detecting testicular torsion [3,4]. The purpose of this article is to share our experiences of diagnosis and analysis of patients with suspected testicular torsion by using grayscale and color Doppler US.

Patients and Methods From January 2001 to October 2005, 15 male patients (mean age, 15 years; age range, 11–30 years) with the final diagnosis of testicular torsion confirmed at operation were retrospectively reviewed. Eleven of the 15 patients underwent grayscale and color Doppler US imaging using a high frequency linear transducer (7.5–10 MHz) and commercially available US scanners (LOGIQ 500 and LOGIQ

A

B

9 Expert systems, GE Healthcare, Milwaukee, WI, USA). Both affected and unaffected testes were evaluated. Scrotal wall thickness, presence of hydrocele, enlarged epididymis or twisted spermatic cord, testicular size, and echotexture were all carefully evaluated by grayscale US. Intratesticular blood flow was evaluated by color Doppler US. All the US images were analyzed and compared with operating and pathologic results. The four patients who did not undergo US were excluded.

Results Color Doppler US revealed an absence of intratesticular blood flow in the affected testis (Figs. 1A, 2A and 3A) and normal blood flow within the contralateral testis in all 11 patients (Table). The findings of grayscale US of the affected testes varied, including scrotal wall thickening in 11 patients (Figs. 1B and 2B), reactive hydrocele in 10 patients (Fig. 2B), enlarged epididymal head in eight patients (Fig. 2B), heterogeneous testicular echotexture in nine patients (Figs. 2A and 3A), homogeneous testicular echogenicity in two patients (Fig. 1A), and twisted spermatic cord in two patients (Fig. 3B). During operation, eight of the 11 affected testes showed ischemic or necrotic change (Figs. 2C and 3C), and the patients underwent orchiectomy. The other three affected testes showed normal appearance or congestive change (Fig. 1C), and those

C

Fig. 1. Patient 2, with 180° torsion of the left testis and 5 hours’ duration of ischemia, received orchiopexy. (A) On ultrasonography, no blood flow can be detected, but there is homogeneous echogenicity of the left testis. (B) Thickening of the left scrotal wall (white arrow) can be seen, as compared with the unaffected right side. (C) The left testis showed no evidence of hemorrhagic or ischemic change during the operation. J M Med Ult Ultrasound rasoound d 20 005 • V Vol 13 • No 1

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A

B

C

Fig. 2. Patient 5, with 360° torsion of the left testis and 24 hours’ duration of ischemia, received orchiectomy. (A) On ultrasonography, heterogeneous echogenicity of the left testis without intratesticular blood flow is shown. (B) Scrotal wall thickening (black arrow), enlarged hypoechoic epididymal head (white arrow) and reactive small hydrocele (white arrowhead) are also noted in the left scrotum. (C) The testis showed hemorrhagic ischemic change during the operation.

A

B

C

Fig. 3. Patient 7, with 270° torsion of the right testis and 48 hours’ duration of ischemia, received orchiectomy. (A) Heterogeneous echogenicity of the right testis without intratesticular blood flow are noted on ultrasonography. (B) The twisted spermatic cord appeared as an oval homogeneous extratesticular mass with blood flow (white arrow). (C) Hemorrhagic ischemic change of the right testis was noted during the operation. patients only underwent orchiopexy. On review of the initial US images of the 11 patients, we found that all of the three salvage testes appeared homogeneous or had slightly increased testicular echogenicity on grayscale US. One of the three salvage testes (Patient 6) underwent manual detorsion immediately after US diagnosis of testis torsion, and only congestive change of the affected testis was noted during operation. We found that the three salvage testes fell within the boundary lines of 270° of torsion and 6 hours’ duration of ischemia (Fig. 4), which indicates that the testicular salvage rate is highly associated with the degree of torsion and the duration of ischemia. Although Patient 8 was within these boundary lines, his affected left testis showed mild heteroechogenicity on grayscale US and ischemic change was noted during operation.

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Discussion US plays an important role in helping to differentiate acute scrotal pain, especially in patients who are difficult to diagnose clinically [1]. Epididymo-orchitis is a common cause of acute scrotal pain in adolescent boys and adults. On clinical examination, the epididymis can be palpated as an enlarged tender structure, and scrotal pain associated with epididymitis may be present with positive Prehn sign, helping to clinically differentiate it from testicular torsion. Grayscale US findings of acute epididymo-orchitis include an enlarged hypoechoic or hyperechoic (due to secondary hemorrhage) epididymis, testicular enlargement and an inhomogeneous testicular echotexture, and reactive hydrocele or pyocele with scrotal wall thickening are present

L = left; R = right; NIL = absence of intratesticular blood flow; CCW = counterclockwise; CW = clockwise; –* = orchiopexy only without orchiectomy; S/P MD = S/P manual detorsion.

Hemorrhagic infarct Ischemia 270 CCW NIL Yes Mild Heterogeneous L > R Yes L 13 11

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Hemorrhagic infarct Necrosis 360 CCW NIL Yes Mild Heterogeneous L > R Yes L 25 10

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Hemorrhagic infarct Necrosis 360 CCW NIL Yes Mild Heterogeneous L > R Yes L 14 9

72

Hemorrhagic infarct

Hemorrhagic infarct Ischemia

Ischemia 270 CCW

180 CCW NIL

NIL Yes

No Mild

Mild Heterogeneous

Heterogeneous L > R

R > L Yes

Yes 04 L 16 8

R 14 7

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–* Congestion S/P MD NIL No Mild Mildly increased L > R Yes L 13 6

06

Hemorrhagic infarct Ischemia 360 CCW NIL Yes Mild Mildly heterogeneous L > R Yes L 13 5

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–* Ecchymosis 270 CW NIL Yes Mild Mildly increased L > R Yes L 15 4

06

Hemorrhagic infarct Congestion 720 CCW NIL Yes Mild Heterogeneous L > R Yes L 11 3

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–* Unremarkable 180 CCW NIL No No Homogeneous L > R Yes L 30 2

05

Hemorrhagic infarct Gangrene 540 CCW NIL Yes Mild Heterogeneous L > R Yes L 11 1

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Testis echogenicity Testis size Scrotum swelling Duration of ischemia (hr) Age Involved (yr) side Patient

Table. Clinical, ultrasonographic, operative and pathologic data

Presence of hydrocele

Epididymis swelling

Blood flow

Degree of torsion

Operative findings

Pathologic findings

Ultrasonographic Analysis of Testicular Torsion in most cases. These grayscale US findings are nonspecific and not easily distinguishable from testicular torsion. On color Doppler US, increased blood flow to the epididymis and testis indicates hyperemic change of scrotal infection or inflammation. The sensitivity of color Doppler US imaging in detecting scrotal inflammation is nearly 100%. It is the best way to distinguish epididymo-orchitis from testicular torsion [5]. Testicular trauma is not an uncommon cause of acute scrotal pain, and can result in contusion, hematoma, or rupture of the testis. Grayscale US findings in testicular rupture include a heterogeneous testis due to hemorrhage or infarction, poorly defined borders that indicate interruption of the tunica albuginea, scrotal wall thickening, echoic hematocele in an acute stage and fluid– fluid level or septation of hematocele in the late stage. Color Doppler US can demonstrate disruption in the normal capsular blood flow of the tunica vasculosa [6]. Varicoceles usually occur in young adults. Sometimes, it may be present as acute scrotal pain. Although it can be distinguished from testicular torsion by either medical history or physical examination, the additional use of grayscale and color Doppler US will aid further diagnosis. Patients may reveal a palpable scrotal mass that may feel like a bag of worms. The grayscale US features of varicocele include multiples larger than 2 mm hypoechoic, tortuous, tubular structures that are usually best visualized superior or lateral to the testis, but which can extend posteriorly and inferiorly to the testis when enlarged. Color Doppler US reveals low-flow velocities, helping the confirmation of venous flow pattern, with phasic variation and retrograde filling during a Valsalva maneuver [7]. Testicular torsion can occur at any age. Two types of torsion have been described: extravaginal (supravaginal) and intravaginal. Extravaginal testicular torsion is rare, and is seen most often in newborns. Intravaginal torsion occurs most frequently in adolescent boys. The predisposing factors of intravaginal torsion include J M Med Ult Ultrasound rasoound d 20 005 • V Vol 13 • No 1

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Degree of torsion

630 540 450 360 270 1800 90 0 0

6 12 18 24 30 36 42 48 54 60 66 72 78 84

Duration of ischemia (hr)

Fig. 4. Distribution of the 11 affected testes according to duration of ischemia and degree of testicular torsion. Black circles = salvage testes; white circles = ischemic testes that underwent orchiectomy. All three salvage testes are within the boundary lines of 270° of torsion and 6 hours’ duration of ischemia (dashed lines). Patient 6 (black arrow) underwent manual detorsion by the surgeon immediately after sonographic diagnosis of testis torsion. Although Patient 8 (gray arrow) was within the boundary lines, he still underwent orchiectomy due to ischemic change of his torsed left testis.

a long and narrow mesentery or a bell-clapper deformity. The deformity leaves the testis free to swing and rotate within the tunica vaginalis much like a clapper inside a bell. The bell-clapper deformity is bilateral in most cases, suggesting that it is a more common deformity than extravaginal testicular torsion [8]. Patients with acute torsion present after a sudden onset of pain followed by nausea, vomiting, and low-grade fever. Physical examination reveals a swollen, tender, and inflamed hemiscrotum. The cremasteric reflex is usually absent [9], and the pain cannot be relieved by elevating the scrotum [10]. The ability of color and power Doppler US to demonstrate testicular perfusion aids in reaching a specific diagnosis in patients with acute scrotal pain, and color Doppler US plays an important role in the diagnosis of acute testicular torsion by using the absence of identifiable intratesticular flow as the criterion for detecting testicular torsion. Burks et al reported that color Doppler US was 86% sensitive, 100% specific, and 97% accurate in the diagnosis of torsion [5]. In our study, all of the 11 patients with the final diagnosis of testicular torsion

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confirmed at operation showed an absence of intratesticular flow within the affected testis in the initial color Doppler US evaluation. Grayscale US findings vary with the duration and degree of rotation of the spermatic cord, but are nonspecific for testicular torsion and often appear normal if the torsion has just occurred [2]. In our experience, if a torsed testis is present with an absence of intratesticular flow on color Doppler US, but appears to be homogeneously echogenic on grayscale US (Fig. 1A), it will have a higher salvage rate and a potentially better outcome. In the setting of testicular torsion, normal testicular echogenicity is a strong predictor of testicular viability [11]. Testicular swelling and decreased echogenicity are the most commonly encountered findings, usually 4– 6 hours after the onset of torsion. Twenty-four hours after onset, the testis has a heterogeneous echotexture secondary to vascular congestion, hemorrhage, and infarction (Figs. 2A and 3A) [12]. An enlarged hypoechoic epididymal head may be visible (Fig. 2B), because the deferential artery supplying the epididymis is often involved in the torsion [13]. Sometimes, a spiral twisting of the spermatic cord at the external inguinal ring can be detected and appears as a round or oval homogeneous extratesticular mass with or without blood flow (Fig. 3B). Zoller et al reported a patient with acute scrotal pain, in whom initial power Doppler US demonstrated arterial testicular perfusion. No amelioration [14] was achieved by conservative treatment. Due to intermittent scrotal pain, surgical exploration was carried out after 7 days, and partial testicular torsion with 180° rotation was found. This case demonstrated that the detection of intratesticular arterial blood flow cannot exclude testicular torsion [14]. The correct diagnosis of this type of patient with partial testicular torsion or spontaneous detorsion requires considerable experience and evaluation of all the facts, including clinical history, results of palpation, and structural or perfusional changes of the scrotal contents on grayscale and color Doppler US [15]. The extent of testicular ischemia depends on the degree of torsion, which ranges from 180° to 720°

Ultrasonographic Analysis of Testicular Torsion or greater. The testicular salvage rate depends on the degree of torsion and the duration of ischemia. Patriquin et al reported a nearly 100% salvage rate within the first 6 hours after the onset of symptoms, a 70% rate within 6–12 hours, and a 20% rate within 12–24 hours [16]. In our study, we found that all three salvage testes were within the boundary lines of 270° of torsion and 6 hours of duration of ischemia (Fig. 4). Although Patient 8 was within the boundary lines (torsion 180° and duration of 4 hours; Fig. 4, gray arrow), he still underwent orchiectomy due to ischemic change in the torsed left testis. After reviewing his initial US images, the affected left testis appeared to show mild heteroechogenicity on grayscale US. We, therefore, state that the appearance of testicular echogenicity on grayscale US plays an important role that can be reflected in the outcome of the affected testis.

4.

5.

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8. 9.

10.

Conclusion 11.

Color Doppler US accurately assesses testicular torsion. Although the testicular salvage rate depends on the degree of torsion and duration of ischemia, the appearance of testicular echogenicity on grayscale US plays an important role that can reflect the outcome of the affected testis.

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