Imaging and angiography in male factor infertility
2016; Elsevier BV; Volume: 105; Issue: 6 Linguagem: Inglês
10.1016/j.fertnstert.2016.04.009
ISSN1556-5653
AutoresMichael Jurewicz, Bruce R. Gilbert,
Tópico(s)Sexual Differentiation and Disorders
ResumoUltrasound imaging and angiography play a crucial role in the diagnosis and treatment of men with subfertility. The most commonly used imaging modality is ultrasound (US), which can be used for diagnostic purposes or to aid in treatment. Scrotal US can be used to document varicoceles in subfertile men in the context of difficult examination or for confirmation before treatment. Spectral Doppler, sonoelastography, and power Doppler have aided in the evaluation and treatment of azoospermia and oligospermia. They have proven useful in the detection of spermatogenesis and sperm retrieval. In the population with congenital Wolffian duct abnormalities, renal US can evaluate renal anomalies. In subfertile men with low ejaculate volume and oligospermia or azoospermia transrectal US can be used to evaluate and assist in treatment of ejaculatory duct obstruction. Non-US–based modalities are also commonly used in evaluating and treating men with subfertility. Magnetic resonance imaging (MRI) can be used for evaluation of pituitary adenomas in hypogonadism. More invasive imaging modalities used during treatment of subfertile men include vasography for vasal obstruction, venography and angioembolization for varicocele, and US-guided needle placement for testis-sparing surgery. Male subfertility is a complex problem and the use of imaging techniques is often essential in providing accurate diagnosis and appropriate treatment. Ultrasound imaging and angiography play a crucial role in the diagnosis and treatment of men with subfertility. The most commonly used imaging modality is ultrasound (US), which can be used for diagnostic purposes or to aid in treatment. Scrotal US can be used to document varicoceles in subfertile men in the context of difficult examination or for confirmation before treatment. Spectral Doppler, sonoelastography, and power Doppler have aided in the evaluation and treatment of azoospermia and oligospermia. They have proven useful in the detection of spermatogenesis and sperm retrieval. In the population with congenital Wolffian duct abnormalities, renal US can evaluate renal anomalies. In subfertile men with low ejaculate volume and oligospermia or azoospermia transrectal US can be used to evaluate and assist in treatment of ejaculatory duct obstruction. Non-US–based modalities are also commonly used in evaluating and treating men with subfertility. Magnetic resonance imaging (MRI) can be used for evaluation of pituitary adenomas in hypogonadism. More invasive imaging modalities used during treatment of subfertile men include vasography for vasal obstruction, venography and angioembolization for varicocele, and US-guided needle placement for testis-sparing surgery. Male subfertility is a complex problem and the use of imaging techniques is often essential in providing accurate diagnosis and appropriate treatment. Discuss: You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/jurewiczm-imaging-angiography-male-infertility/ Discuss: You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/jurewiczm-imaging-angiography-male-infertility/ Ultrasound (US) was first introduced to the field of Urology by Takashi and Ouchi in 1963 as they attempted to perform a transrectal ultrasound (TRUS) of the prostate (1Takahashi H. Ouchi T. The ultrasonic diagnosis in the field of urology.Proc Jpn Soc Ultrasonic Med. 1963; 3: 7Google Scholar). It was not until Watanabe et al. (2Watanabe H. Igari D. Tanahasi Y. Harada K. Saito M. Development and application of new equipment for transrectal ultrasonography.J Clin Ultrasound. 1974; 2: 91-98Crossref PubMed Scopus (92) Google Scholar), however, that a discernable image of the prostate was available and able to be used medically to roughly evaluate symmetry and echogenicity and help detect prostate cancer. In 1976 Perri et al. (3Perri A.J. Slachta G.A. Feldman A.E. Kendall A.R. Karafin L. The Doppler stethoscope and the diagnosis of the acute scrotum.J Urol. 1976; 116: 598-600PubMed Google Scholar) began using Doppler US, their "Doppler stethoscope," in the scrotum to evaluate testicular blood flow in the acute scrotum. The first case series of ultrasound used in male fertility came in 1977 from Greenberg et al. (4Greenberg S.H. Lipshultz L.I. Morganroth J. Wein A.J. The use of the Doppler stethoscope in the evaluation of varicoceles.J Urol. 1977; 117: 296-298PubMed Google Scholar) in their evaluation of men with subfertility and varicocele. They found in this study that men with varicocele, observed using their Doppler stethoscope, either before or after varicocelectomy, had abnormal semen parameters. Imaging is a useful adjunct to clinical and laboratory examination in the diagnosis and treatment of male factor infertility. One of the most cost effective and minimally invasive imaging techniques used is US. Ultrasound of the scrotum can quantify varicocele size and confirm diagnosis of varicocele, especially when the examination is challenging due to a thickened scrotal wall or contracted scrotum (5Gilbert B.R. Ultrasound of the male genitalia. Springer-Verlag, New York2015Crossref Scopus (3) Google Scholar). Various US techniques can be used in men with azoospermia to evaluate for obstructive azoospermia versus nonobstructive azoospermia (NOA), to evaluate regions of increased testicular blood flow and potential increased spermatogenesis, and renal abnormalities associated with genetic mutations (6Pinggera G.M. Mitterberger M. Bartsch G. Strasser H. Gradl J. Aigner F. et al.Assessment of the intratesticular resistive index by colour Doppler ultrasonography measurements as a predictor of spermatogenesis.BJU Int. 2008; 101: 722-726Crossref PubMed Scopus (97) Google Scholar, 7Unsal A. Turgut A.T. Taşkin F. Koşar U. Karaman C.Z. Resistance and pulsatility index increase in capsular branches of testicular artery: indicator of impaired testicular microcirculation in varicocele?.J Clin Ultrasound. 2007; 35: 191-195Crossref PubMed Scopus (40) Google Scholar, 8McCallum T. Milunsky J. Munarriz R. Carson R. Sadeghi-Nejad H. Oates R. Unilateral renal agenesis associated with congenital bilateral absence of the vas deferens: phenotypic findings and genetic considerations.Hum Reprod. 2001; 6: 282-288Crossref Scopus (107) Google Scholar, 9Hillelsohn J.H. Chuang K.W. Goldenberg E. Gilbert B.R. Spectral Doppler sonography: a noninvasive method for predicting dyspermia.J Ultrasound Med. 2013; 32: 1427-1432Crossref PubMed Scopus (18) Google Scholar). Ultrasound guidance can also be used for intervention, as it may help locate testicular tumors for biopsy or intervention, or seminal vesicle (SV), or utricular cyst aspiration (10Hopps C.V. Goldstein M. Ultrasound guided needle localization and microsurgical exploration for incidental nonpalpable testicular tumors.J Urol. 2002; 168: 1084-1087Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar, 11Purohit R.S. Wu D.S. Shinohara K. Turek P.J. A prospective comparison of 3 diagnostic methods to evaluate ejaculatory duct obstruction.J Urol. 2004; 171 (discussion 235–6): 232-235Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar). Ultrasound, however, is not the only imaging technique used in male factor infertility. Various other imaging technologies can be used, such as magnetic resonance imaging (MRI), which is more expensive, as well as vasography and venography, with or without embolization, which are more invasive (12Wishahi M.M. Anatomy of the spermatic venous plexus (pampiniform plexus) in men with and without varicocele: intraoperative venographic study.J Urol. 1992; 147: 1285-1289PubMed Google Scholar, 13McDougal W.S. Wein A.J. Kavoussi L.R. Novick A.C. Partin A.W. Peters C.A. et al.Campbell-Walsh urology.10th ed. rev. Elsevier, Amsterdam2011Google Scholar). Our intent is to provide an overview of imaging techniques useful in the evaluation and treatment of the subfertile male. The scrotum is divided into two compartments, each of which contains a testicle, an epididymis, and a spermatic cord. The origin of the testicles begins in the 3-week-old embryo where the primordial germ cells begin to migrate onto the urogenital ridge. The kidney precursors, gonads, and reproductive tract share a common embryology, also originating from the urogenital ridge. During the eighth week of gestation the Müllerian ducts regress and T from the Leydig cells stimulate mesonephric (Wolffian) development. The mesonephric ducts develop into epididymides, vas deferens, and ejaculatory ducts. The SVs form as an outpunching of these ducts. Vestigial remnants of the mesonephric duct include the appendix epididymis and paradidymis (5Gilbert B.R. Ultrasound of the male genitalia. Springer-Verlag, New York2015Crossref Scopus (3) Google Scholar). The spermatic cord contains the ductus deferens, testicular artery, and the pampiniform plexus of testicular veins. The arterial blood supply of the scrotum includes the testicular artery, the cremasteric artery, and the deferential artery. The testicular venous drainage exits the testis as the mediastinum and joins the epididymal veins to form the pampiniform plexus. Cremasteric veins form a separate plexus posteriorly. The right testicular vein drains into the inferior vena cava, whereas the left testicular vein is significantly longer and drains into the left renal vein. These veins typically have valves to promote blood flow in the antegrade fashion. Backflow into dilated veins in the pampiniform plexus can be seen as a varicocele. Also, the increased length and right angle insertion of the left testicular vein is thought to contribute to increased varicocele formation on this side (14Wishahi M.M. Anatomy of the venous drainage of the human testis: testicular vein cast, microdissection and radiographic demonstration. A new anatomical concept.Eur Urol. 1991; 20: 154-160PubMed Google Scholar, 15Carlson B.M. Human embryology and developmental biology. Elsevier, Philadelphia2013Google Scholar, 16Moore K.L. Persaud T.V.N. Torchia M.G. The developing human. Saunders, Philadelphia2011Google Scholar, 17Sadler T.W. Langman medical embryology.Int ed. Wolters Kluwer Health, Auckland2011Google Scholar). The testis is 3–5 cm long × 2–4 cm wide × 3 cm in the anteroposterior direction. The size correlates strongly with spermatogenesis as 85% of its volume is involved in reproduction. The testis is smooth and homogeneous, which allows sonographers to identify pathology (5Gilbert B.R. Ultrasound of the male genitalia. Springer-Verlag, New York2015Crossref Scopus (3) Google Scholar, 13McDougal W.S. Wein A.J. Kavoussi L.R. Novick A.C. Partin A.W. Peters C.A. et al.Campbell-Walsh urology.10th ed. rev. Elsevier, Amsterdam2011Google Scholar, 18AIUM practice guideline for the performance of an ultrasound examination in the practice of urology.J Ultrasound Med. 2012; 31: 133-144PubMed Google Scholar, 19Appelbaum L. Gaitini D. Dogra V.S. Scrotal ultrasound in adults.Semin Ultrasound CT MR. 2013; 34: 257-273Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). Using a consistent protocol for examination will provide similar and consistent results. The patient should be in the supine position with the scrotum supported. The choice of frequency used is a balance of depth of penetration and image resolution. A high frequency (7.5–18 MHz) and linear array transducer is most commonly used. Broad bandwidth transducers allow for multiple focal zones. A lower frequency (3.5–5 MHz) curved array probe is helpful in comparing echogenicity of testes when in a markedly thickened scrotal wall, as occurs in scrotal edema. The highest frequency probe as well as color flow and spectral Doppler should be used for improved resolution and for testicular and paratesticular blood flow detection. The scan should begin with a longitudinal view of the testis and scan from medial to lateral to examine the entire testis and paratesticular structures. The transverse view is obtained by rotating the transducer 90 degrees. The superior portion is surveyed first, followed by the inferior portion. At least one image should be obtained with both testes. The spermatic cord can be found superior and posterolateral to the testis (5Gilbert B.R. Ultrasound of the male genitalia. Springer-Verlag, New York2015Crossref Scopus (3) Google Scholar, 18AIUM practice guideline for the performance of an ultrasound examination in the practice of urology.J Ultrasound Med. 2012; 31: 133-144PubMed Google Scholar, 20Dogra V.S. Gottlieb R.H. Oka M. Rubens D.J. Sonography of the scrotum.Radiology. 2003; 227: 18-36Crossref PubMed Scopus (459) Google Scholar). Varicocele is the dilation of the spermatic vein and pampiniform plexus of veins in the spermatic cord. Left-sided varicocele is more common than the right as it is longer and inserts into the left renal vein; however, they have been shown to be bilateral in up to 80% of cases in some series. They are thought to be the result of incompetent or congenitally absent venous valves allowing for retrograde blood flow (19Appelbaum L. Gaitini D. Dogra V.S. Scrotal ultrasound in adults.Semin Ultrasound CT MR. 2013; 34: 257-273Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 20Dogra V.S. Gottlieb R.H. Oka M. Rubens D.J. Sonography of the scrotum.Radiology. 2003; 227: 18-36Crossref PubMed Scopus (459) Google Scholar, 21Gat Y. Zukerman Z. Chakraborty J. Gornish M. Varicocele, hypoxia and male infertility. Fluid mechanics analysis of the impaired testicular venous drainage system.Hum Reprod. 2005; 20: 2614-2619Crossref PubMed Scopus (114) Google Scholar, 22Braedel H.U. Steffens J. Ziegler M. Polsky M.S. Platt M.L. A possible ontogenic etiology for idiopathic left varicocele.J Urol. 1994; 151: 62-66PubMed Google Scholar, 23Shafik A. Moftah A. Olfat S. Mohi-el-Din M. el-Sayed A. Testicular veins: anatomy and role in varicocelogenesis and other pathologic conditions.Urology. 1990; 35: 175-182Abstract Full Text PDF PubMed Scopus (44) Google Scholar, 24Iafrate M. Galfano A. Macchi V. Ejituru E. Sarasin G. Porzionato A. et al.Varicocele is associated with an increase of connective tissue of the pampiniform plexus vein wall.World J Urol. 2009; 27: 363-369Crossref PubMed Scopus (17) Google Scholar). The US findings include multiple anechoic tubular structures >2 mm superior and posterolateral to the testis. Color flow should be used to demonstrate reversing of flow during valsalva. For best visualization of the spermatic cord US should be completed superior and posterolateral to the testis (19Appelbaum L. Gaitini D. Dogra V.S. Scrotal ultrasound in adults.Semin Ultrasound CT MR. 2013; 34: 257-273Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 25Mirochnik B. Bhargava P. Dighe M.K. Kanth N. Ultrasound evaluation of scrotal pathology.Radiol Clin North Am. 2012; 50: 317-332Abstract Full Text Full Text PDF PubMed Scopus (42) Google Scholar, 26Aganovic L. Cassidy F. Imaging of the scrotum.Radiol Clin North Am. 2012; 50: 1145-1165Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar). The American Urological Association (AUA) guidelines state that US should be used in any patient with a difficult or inadequate examination. These situations might include obese patients, a thickened scrotal wall, or a contracted scrotum (27Jarow J. Sigman M. Kolettis P. Lipshultz L. McClure D. Nangia A. et al.AUA Best Practice Statements: the optimal evaluation of the infertile male. American Urological Association, Linthicum, MD2011Google Scholar) (Fig. 1). Varicocele is present in >30% of men with primary subfertility and >80% in secondary subfertility, making it one of the most common causes in both cases (28Gorelick J.I. Goldstein M. Loss of fertility in men with varicocele.Fertil Steril. 1993; 59: 613-616Crossref PubMed Google Scholar). Clinically significant varicoceles are associated with impaired sperm count, sperm motility, and abnormal sperm morphology. The exact mechanism of pathologic change is not known but increased testicular temperature, hypoxia, and reactive oxygen species have all been postulated as causes (29World Health OrganizationThe influence of varicocele on parameters of fertility in a large group of men presenting to infertility clinics.Fertil Steril. 1992; 57: 1289-1293Abstract Full Text PDF PubMed Google Scholar, 30Benoff S. Gilbert B.R. Varicocele and male infertility: part I. Preface.Hum Reprod Update. 2001; 7: 47-54Crossref PubMed Scopus (66) Google Scholar, 31Robinson S.P. Hampton L.J. Koo H.P. Treatment strategy for the adolescent varicocele.Urol Clin North Am. 2010; 37: 269-278Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar). According to the AUA/American Society for Reproductive Medicine (ASRM) guidelines treatment for varicocele should be considered when it is palpable, the couple has known infertility, the woman has normal fertility, or the male partner has abnormalities on semen analysis (32Practice Committee of American Society for Reproductive MedicineReport on varicocele and infertility.Fertil Steril. 2008; 90: S247-S249Abstract Full Text Full Text PDF PubMed Scopus (278) Google Scholar). After their ligation 70% of patients see improved motility, sperm concentration, and morphology (33Zucchi A. Mearini L. Mearini E. Fioretti F. Bini V. Porena M. Varicocele and fertility: relationship between testicular volume and seminal parameters before and after treatment.J Androl. 2006; 27: 548-551Crossref PubMed Scopus (48) Google Scholar). Balci et al. (34Balci A. Karazincir S. Gorur S. Sumbas H. Egilmez E. Inandi T. Long-term effect of varicocele repair on intratesticular arterial resistance index.J Clin Ultrasound. 2008; 36: 148-152Crossref PubMed Scopus (23) Google Scholar) and Tarhan et al. (35Tarhan S. Ucer O. Sahin M.O. Gumus B. Long-term effect of microsurgical inguinal varicocelectomy on testicular blood flow.J Androl. 2011; 32: 33-39Crossref PubMed Scopus (37) Google Scholar) demonstrated a decrease in intratesticular resistive index (RI) after varicocele ligation in patients with improved semen parameters. In addition, Esteves et al. (36Esteves S.C. Oliveira F.V. Bertolla R.P. Clinical outcome of intracytoplasmic sperm injection in infertile men with treated and untreated clinical varicocele.J Urol. 2010; 184: 1442-1446Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar) showed that after varicocele ligation for clinical varicoceles, not only were semen parameters improved, but also clinical pregnancy and live birth rates with intracytoplasmic sperm injection (ICSI) were higher than in untreated patients. A Cochrane database review was completed by Kroese et al. (37Kroese A.C. de Lange N.M. Collins J. Evers J.L. Surgery or embolization for varicoceles in subfertile men.Cochrane Database Syst Rev. 2012; 10: CD000479Crossref PubMed Google Scholar) who also concluded that patients with a varicocele and otherwise unexplained subfertility were more likely to achieve a pregnancy after surgical or radiological correction of their varicocele. They, however, were not able to provide data on live birth rates. Venography is another technique that can be used in the diagnosis of varicocele. It is one of the most sensitive and specific imaging techniques, but also one of the most invasive. It is not commonly used as US and physical examination have superseded it and its use is not often necessary for the diagnosis of varicocele. Venography is, however, very useful in providing confirmation of reflux in the veins as well as to define varicocele anatomy in challenging recurrences. Hart et al. (38Hart R.R. Rushton H.G. Belman A.B. Intraoperative spermatic venography during varicocele surgery in adolescents.J Urol. 1992; 148: 1514-1516PubMed Google Scholar) advocates for intraoperative use of venography to show collateral drainage in up to 16% of patients, which may have resulted in persistent varicocele. Although surgical ligation of varicoceles is the preferred method of treatment, venography and percutaneous embolization may be considered in certain patient populations including recurrent varicocele after the surgical approach has failed, patients with history of inguinal surgery, or patient preference. It can also be used as repeat treatment after failed embolization (39Tomasini J.M. Bodie J.A. The use of transscrotal venography to guide treatment of a persistent grade 3 varicocele after failure of previous microsurgical varicocelectomy and embolization.Urology. 2013; 82: e22-e23Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar). It is typically done with sclerosing agents or endovascular coils under fluoroscopic guidance. Embolization has been shown to have a success rate of 85%–90% in patients with recurrent varicocele (40Punekar S.V. Prem A.R. Ridhorkar V.R. Post surgical recurrent varicocele: efficacy of internal spermatic venography and steel coil embolization.Br J Urol. 1996; 77: 124-128Crossref PubMed Google Scholar, 41Pryor J.L. Howards S.S. Varicocele.Urol Clin North Am. 1987; 14: 499-513PubMed Google Scholar, 42Gat Y. Bachar G.N. Everaert K. Levinger U. Gornish M. Induction of spermatogenesis in azoospermic men after internal spermatic vein embolization for the treatment of varicocele.Hum Reprod. 2005; 20: 1013-1017Crossref PubMed Scopus (67) Google Scholar). Embolization, although minimally invasive, does not come without its risks. It has approximately 11% minor complications and a 5% recurrence rate (43Kwak N. Siegel D. Imaging and interventional therapy for varicoceles.Curr Urol Rep. 2014; 15: 399Crossref PubMed Scopus (19) Google Scholar). Some of the potential major complications include major vascular injury and endovascular coil migration (44Halpern J. Mittal S. Pereira K. Bhatia S. Ramasamy R. Percutaneous embolization of varicocele: technique, indications, relative contraindications, and complications.Asian J Androl. 2016; 18: 234-238Google Scholar) (Fig. 2). Oligoozospermia and azoospermia can be signs of underlying pathology including ductal obstruction, testicular tumors, and varicocele. The US provides a noninvasive and real-time assessment when physical examination is inconclusive or intratesticular pathology is suspected. The US can be used to assess testicular size for atrophy, as it commonly relates to spermatogenesis. It can also be helpful in defining an obstructive versus nonobstructive azoospermia (45Donkol R.H. Imaging in male-factor obstructive infertility.World J Radiol. 2010; 2: 172-179Crossref PubMed Google Scholar, 46Honig S.C. Lipshultz L.I. Jarow J. Significant medical pathology uncovered by a comprehensive male infertility evaluation.Fertil Steril. 1994; 62: 1028-1034Crossref PubMed Google Scholar). According to the American Institute of Ultrasound in Medicine (AIUM) and AUA US is an acceptable tool used in the workup of male infertility (18AIUM practice guideline for the performance of an ultrasound examination in the practice of urology.J Ultrasound Med. 2012; 31: 133-144PubMed Google Scholar). Although physical examination is essential to a diagnosis of congenital bilateral absence of the vas deferens or congenital unilateral absence of the vas deferens as it relates to obstructive azoospermia, US is a helpful additional tool for confirmation of the condition. Also, abnormalities in the vas deferens and mesonephric ducts may be related to other congenital malformations such as renal agenesis (47McCallum T. Milunsky J. Munarriz R. Carson R. Sadeghi-Nejad H. Oates R. Unilateral renal agenesis associated with congenital bilateral absence of the vas deferens: phenotypic findings and genetic considerations.Hum Reprod. 2001; 6: 282-288Crossref Google Scholar, 48Kolettis P.N. Sandlow J.I. Clinical and genetic features of patients with congenital unilateral absence of the vas deferens.Urology. 2002; 60: 1073-1076Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar, 49Unsal A. Turgut A.T. Taşkin F. Koşar U. Karaman C.Z. Resistance and pulsatility index increase in capsular branches of testicular artery: indicator of impaired testicular microcirculation in varicocele?.J Clin Ultrasound. 2007; 35: 191-195Crossref PubMed Scopus (21) Google Scholar). Spectral Doppler is an US technique that provides increased information about intratesticular blood flow and reproductive function. The RI was shown by Pinggera et al. (6Pinggera G.M. Mitterberger M. Bartsch G. Strasser H. Gradl J. Aigner F. et al.Assessment of the intratesticular resistive index by colour Doppler ultrasonography measurements as a predictor of spermatogenesis.BJU Int. 2008; 101: 722-726Crossref PubMed Scopus (97) Google Scholar) to be increased in subfertile men with abnormal semen parameters. Unsal et al. (49Unsal A. Turgut A.T. Taşkin F. Koşar U. Karaman C.Z. Resistance and pulsatility index increase in capsular branches of testicular artery: indicator of impaired testicular microcirculation in varicocele?.J Clin Ultrasound. 2007; 35: 191-195Crossref PubMed Scopus (21) Google Scholar) found that RI of capsular vessels and branches were indicative of impaired testicular microcirculation. In multiple studies, RI and peak systolic velocity of intratesticular vessels were better predictors of dyspermia than small testicles and elevated FSH. Also, several investigators have found that a RI >0.6 was indicative of abnormal semen quality (5Gilbert B.R. Ultrasound of the male genitalia. Springer-Verlag, New York2015Crossref Scopus (3) Google Scholar, 9Hillelsohn J.H. Chuang K.W. Goldenberg E. Gilbert B.R. Spectral Doppler sonography: a noninvasive method for predicting dyspermia.J Ultrasound Med. 2013; 32: 1427-1432Crossref PubMed Scopus (18) Google Scholar, 50Biagiotti G. Cavallini G. Modenini F. Vitali G. Gianaroli L. Spermatogenesis and spectral testicular artery.BJU Int. 2002; 90: 903-908Crossref PubMed Scopus (85) Google Scholar) (Fig. 3). Sonoelastography is an ultrasound modality that allows the user the ability to evaluate the elasticity of biological tissues, thus providing additional information to the physical examination. It is now being used to aid in diagnosis of NOA. After initial studies found that sonoelastography could be used as an adjunct to examine testicular architecture (51Schurich M. Aigner F. Frauscher F. Pallwein L. The role of ultrasound in assessment of male fertility.Eur J Obstet Gynecol Reprod Biol. 2009; 144: S192-S198Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar), Li et al. (52Li M. Du J. Wang Z.Q. Li F.H. The value of sonoelastography scores and the strain ratio in differential diagnosis of azoospermia.J Urol. 2012; 188: 1861-1866Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar) further elucidated a five-point scoring system to describe the findings in azoospermic men. They found that on their scale scores of ≥3 were correlated with a diagnosis of NOA, thus aiding in diagnosis and treatment planning for these patients (Fig. 4). Power Doppler is another modality being studied that can be used in treatment of patients with male factor infertility. Nowroozi et al. (53Nowroozi M.R. Ayati M. Amini E. Radkhah K. Jamshidian H. Delpazir A. et al.Assessment of testicular perfusion prior to sperm extraction predicts success rate and decreases the number of required biopsies in patients with non-obstructive azoospermia.Int Urol Nephrol. 2015; 47: 53-58Crossref PubMed Scopus (13) Google Scholar) conducted a study to assess the ability of power Doppler to improve detection of viable sperm in patients with NOA. They found that areas of increased intratesticular perfusion in patients with NOA represented areas of increased spermatogenesis. As a result, these patients required fewer biopsies as the biopsies obtained were better targeted for sperm retrieval (Fig. 5). Testicular tumors have been found to be the cause of male factor infertility in about 6% of cases (10Hopps C.V. Goldstein M. Ultrasound guided needle localization and microsurgical exploration for incidental nonpalpable testicular tumors.J Urol. 2002; 168: 1084-1087Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar). The most common and sometimes sole imaging study used to pick up these tumors is US. Leydig cell tumors represent <3% of all testicular tumors. They are commonly benign but can occasionally be malignant. They may cause precocious puberty or gynecomastia features in males as a result of androgen production. This may also effect sperm production and maturation causing subfertility. They can be seen on testicular US as a nonspecific mass without any definitive identifying features (19Appelbaum L. Gaitini D. Dogra V.S. Scrotal ultrasound in adults.Semin Ultrasound CT MR. 2013; 34: 257-273Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 20Dogra V.S. Gottlieb R.H. Oka M. Rubens D.J. Sonography of the scrotum.Radiology. 2003; 227: 18-36Crossref PubMed Scopus (459) Google Scholar, 26Aganovic L. Cassidy F. Imaging of the scrotum.Radiol Clin North Am. 2012; 50: 1145-1165Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar). Multiple studies have shown utility in testis-preserving surgery in men with solitary testis, bilateral testis lesions, and small incidentally found masses. The preservation of testicular tissue portends for improved spermatogenesis and androgen production in the future (54De Stefani S. Isgrò G. Varca V. Pecchi A. Bianchi G. Carmignani G. et al.Microsurgical testis-sparing surgery in small testicular masses: seven years retrospective management and results.Urology. 2012; 79: 858-862Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar, 55Schlegel P.N. Su L.M. Physiological consequences of testicular sperm extraction.Hum Reprod. 1997; 12: 1688-1692Cros
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