Received: 22 July 2022 Revised: 29 July 2022 Accepted: 29 July 2022 DOI: 10.1111/andr.13260 SUPPLEMENT ARTICLE The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: An overview on male genital tract ultrasound reference ranges Francesco Lotti1 Francesca Frizza1 Giancarlo Balercia2 Arcangelo Barbonetti3 Hermann M. Behre4 Aldo E. Calogero5 Jann-Frederik Cremers6 Felice Francavilla3 Andrea M. Isidori7 Sabine Kliesch6 Sandro La Vignera5 Andrea Lenzi7 Marios Marcou4 Adrian Pilatz8 Olev Poolamets9 Margus Punab9 Maria Fernanda Peraza Godoy10 Claudia Quintian10 Osvaldo Rajmil10 Gianmaria Salvio2 Osama Shaeer11 Wolfgang Weidner8 Elisa Maseroli1 Sarah Cipriani1 Elisabetta Baldi1 Selene Degl’Innocenti1 Giovanna Danza12 Anna Lucia Caldini13 Alessandro Terreni13 Luca Boni14 Csilla Krausz1 Mario Maggi12 1 Andrology, Female Endocrinology and Gender Incongruence Unit, Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy 2 Endocrinology Unit, Ospedali Riuniti Ancona, Polytechnic University of Marche, Ancona, Italy 3 Andrology Unit, Department of Life, Health and Environmental Sciences, University of L’Aquila, L’Aquila, Italy 4 Center for Reproductive Medicine and Andrology, Martin Luther University Halle-Wittenberg, Halle, Germany 5 Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy 6 Department of Clinical and Surgical Andrology, Centre of Reproductive Medicine and Andrology, Münster University Hospital, Münster, Germany 7 Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy 8 Department of Urology, Pediatric Urology and Andrology, Justus Liebig University, Giessen, Germany 9 Andrology Unit, Tartu University Hospital, Tartu, Estonia 10 Andrology Department, Fundació Puigvert, Universitat Autònoma de Barcelona, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Barcelona, Spain 11 Department of Andrology, Kasr El Aini Faculty of Medicine, Cairo University, Cairo, Egypt 12 Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy 13 Department of Laboratory, Careggi Hospital, Florence, Italy 14 Clinical Trials Coordinating Center, Toscano Cancer Institute, University Hospital Careggi, Florence, Italy Correspondence Francesco Lotti, Andrology, Female Abstract Endocrinology and Gender Incongruence Unit, Department of Experimental and Clinical Background: So far, male genital tract color-Doppler ultrasound (MGT-CDUS) was Biomedical Sciences, University of Florence, not standardized. Recently, the European Academy of Andrology (EAA) published the Viale Pieraccini 6, 50139, Florence, Italy. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2022 The Authors. Andrology published by Wiley Periodicals LLC on behalf of American Society of Andrology and European Academy of Andrology. 118 wileyonlinelibrary.com/journal/andr Andrology. 2022;10(Suppl. 2):118–132. LOTTI ET AL . 119 Email: flottimd@yahoo.it; francesco.lotti@unifi.it results of a multicenter study assessing the CDUS characteristics of healthy-fertile men (HFM) to obtain normative parameters. [Correction added on 25 November 2022, after first online publication: CRUI-CARE Objectives: To report the EAA US study (i) standard operating procedures (SOPs) for funding statement has been added.] assessing MGT-CDUS, (ii) main MGT-CDUS normative parameters, and (iii) compare Funding information the EAA and previously published “normal” CDUS values. European Academy of Andrology; Ministry of Methods: A cohort of 248 HFM (35.3 ± 5.9 years) was studied, evaluating MGT-CDUS University and Scientific Research (Scientific Independence of young Researchers [SIR] before and after ejaculation following SOPs. project to Francesco Lotti), Grant/Award Results: SOPs for MGT-CDUS assessment are summarized here. All subjects under- Number: RBSI14LFMQ went scrotal CDUS and 188 men underwent transrectal ultrasound before and after ejaculation. The main CDUS reference ranges and characteristics of the HFM-MGT are reported here. The mean testicular volume was ∼17 mL. The lower limit for right and left testis was 12 and 11 mL, defining testicular hypotrophy. The upper limit for epididymal head, body, tail, and vas deferens was 11.5, 5, 6, and 4.5 mm, respectively. Testicular and epididymal arterial reference ranges are reported. The EAA varicocoele classification is reported. CDUS-varicocoele was detected in ∼37% of men. Prostate mean volume was ∼25 mL, while lower and upper limits were 15 and 35 mL, defin- ing hypotrophy and enlargement, respectively. Prostate arterial reference ranges are reported. Prostate calcifications and inhomogeneity were frequent; midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. The upper limit for periprostatic venous plexus was 4.5 mm. Lower and upper limits of seminal vesicles (SV) anterior–posterior diameter were 6 and 16 mm, defining hypotrophy or dila- tion, respectively. Seminal vesicle volume and ejection fraction reference ranges are reported. SV-US abnormalities were rare. Deferential ampullas upper limit was 6 mm. A discussion on the EAA and previously published “normal” CDUS values is reported here. Conclusions: The EAA findings will help in reproductive and general male health management. KEYWORDS healthy, fertile men, scrotal and transrectal ultrasound, male genital tract ultrasound, scrotal organs reference ranges and normative parameters, prostate and seminal vesicles reference ranges and normative parameters 1 INTRODUCTION of the scrotal and prostate-vesicular organs, and to detect their abnormalities.1,2 So far, scrotal US has shown a relevant impact both To date, imaging of the male genital tract (MGT) represents an essential on reproductive and general male health, assessing scrotal features diagnostic tool in andrology, allowing physicians to complete the diag- related to reproductive health, scrotal pain, masses, and trauma.1–7 In nostic work-up of the andrologic patient, especially when anamnesis, addition, transrectal US (TRUS) application has assumed a growing rel- physical, and biochemical examinations do not provide sufficient infor- evance especially in infertility and chronic pelvic pain assessment.1,8–14 mation for adequate patient management.1 In particular, ultrasound Although US has been widely used to explore the MGT organs, (US) represents the gold standard method for scrotal investigation,1,2 until very recently the method used to assess several qualitative and and a useful tool to evaluate the prostate-vesicular region.1 Using high- quantitative US parameters had not been standardized, and norma- frequency sound waves, US is a simple, rapid, and harmless diagnostic tive parameters and thresholds to distinguish normal and pathologic tool able to provide live images of the MGT organs and, among imaging features were often not evidence-based.1 In the last few years, techniques, is the least expensive.1,2 The high-resolution grey-scale thanks to the efforts of different radiological, urological, and andro- mode associated with color- and power-Doppler examination allow logical societies,3,5–10,15–21 some standards in MGT US have been sonographers to investigate size, echotexture, and vascular features achieved. However, only very recently the European Academy of 120 LOTTI ET AL . Andrology (EAA) published the results22–24 of an international mul- 2.2 SOPs to assess MGT-CDUS parameters ticenter study entitled “Standardization of the MGT color-Doppler ultrasound (CDUS) parameters in healthy, fertile men” (shortened The MGT-CDUS parameters to be analyzed and the meth- to “EAA US study”; see http://www.andrologyacademy.net/studies),22 ods used to evaluate them were standardized and reported at aimed at establishing the reference ranges and characteristics of the http://www.andrologyacademy.net/studies.22 In addition, exem- organs of the scrotal and prostate-vesicular regions in healthy, fertile plary figures reporting (a) how to measure quantitative parameters men. The EAA US study provided the standard operating procedures and (b) classifications of qualitative characteristics—using Likert (SOPs) for the assessment of MGT-CDUS qualitative and quantita- scales—of the organs of the scrotal and prostate-vesicular regions tive parameters and defined MGT-CDUS normative parameters.23–25 were reported on the EAA website,22 and the most relevant figures In addition, the EAA US study evaluated and reported the associations have been reported in previous studies.24,25 Finally, standardized between MGT-CDUS parameters and clinical, seminal, and biochemical schedules to report parameters detected before and after ejacu- characteristics of healthy, fertile men.23–25 lation in each EAA center were uploaded and made available at We report here an overview on the EAA US study-derived (i) SOPs http://www.andrologyacademy.net/studies.22 for the assessment of MGT-CDUS qualitative and quantitative param- eters, (ii) main MGT-CDUS normative parameters, and (iii) discuss the comparison between the EAA US study and previously published 2.3 Scrotal CDUS and TRUS “normal values,” focusing on clinical implications. Scrotal CDUS and TRUS have been performed systematically on the subjects studied, scanning the organs at various longitudinal, 2 METHODS transverse, and oblique scans using a high-frequency linear probe (7– 15 MHz)24 and a transrectal probe (3–13 MHz),25 respectively. To The EAA US study was designed as a multicenter, international, obser- make the study results applicable to the clinical reality of any sonogra- vational study.23 Eleven EAA centers (Ancona, Italy; Barcelona, Spain; pher, the EAA US consortium approved the use of any US equipment Cairo, Egypt; Catania, Italy; Florence, Italy; Giessen, Germany; Halle, present in the different centers instead of using a standard US con- Germany; L’Aquila, Italy; Muenster, Germany; Rome, Italy; Tartu, Esto- sole. The US equipment used by the different EAA centers have been nia) joined the project and enrolled 248 healthy, fertile men from reported in previous studies.24,25 February 2016 to February 2019.23 The definition of “healthy, fertile men” established by the EAA US consortium has been reported and discussed in a previous study.23 In particular, the inclusion criteria of 2.4 Intra- and inter-operator comparability of the EAA US study were: 1. healthy, fertile men (see below); 2. age ≥ MGT-CDUS parameters 18 years; 3. capacity to give consent for study participation. “Fertile men” were defined as (i) partners of a pregnant woman in the second Intra- and inter-operator comparability of the MGT-CDUS parameters or third trimester of pregnancy or (ii) men with a child less than one were assessed on seven males of infertile couples.23–25 Intra-operator year old, achieved through natural conception.23 “Healthy men” were comparability was assessed for the main quantitative and qualitative defined as subjects with no personal history of previous or current MGT-CDUS parameters considering the results of three evaluations systemic diseases or treatments with a recognized negative effect on for each parameter. Inter-operator comparability was derived from semen parameters.23 All subjects were asked to undergo a standard- the measures and observations obtained by six different sonographists ized protocol performed entirely on the same day, including scrotal (Francesco Lotti; Francesca Frizza; Olev Poolamets; Gianmaria Salvio; and transrectal CDUS before and after ejaculation.23 The SOPs for Elisa Maseroli; Sarah Cipriani) for the main quantitative and qual- the assessment of MGT-CDUS qualitative and quantitative parame- itative parameters, respectively. The comparability of quantitative ters and the intra- and inter-operator comparability of the MGT-CDUS and qualitative parameters was expressed using the coefficient of parameters among different operators have been defined during inves- variation (CV) ([standard deviation (σ) / mean (μ)] × 100) and the tigator meetings organized before starting the enrollment of healthy, concordance rate (CR) ([number of concordant observations/number fertile men, as previously reported,23 and have been described in pre- of operators] × 100), respectively.24–26 A CV < 10 is considered vious studies.24,25 Below we summarize the EAA US study SOPs for the acceptable.24,25,27 assessment of the main MGT-CDUS parameters (see “Results” section). 2.5 Statistical analysis 2.1 Clinical, biochemical, and seminal parameters Statistical analysis used in the EAA US study has been extensively The methods related to the clinical, seminal, and biochemical param- discussed in previous studies.23–25 Of note, the reference range eters of the cohort studied have been reported and discussed in a for MGT-CDUS organs was estimated according to the Clinical and previous study.23 Laboratory Standard Institute (CLSI) guidelines,28 as the 5th and LOTTI ET AL . 121 TA B L E 1 EAA standard operating procedures (SOPs) to assess scrotal CDUS Testis Testicular volume Evaluate the three maximum diameters of each testis (anterior–posterior [height] and transverse [width] diameters in transverse scan; longitudinal diameter [length] in longitudinal scan) Calculate TV using the ellipsoid formula (length × height × width × 0.52) Testicular homogeneity Use a four point-Likert scale: 0. Homogeneity 1. Mild (grade 1) inhomogeneity [presence of small hypoechoic foci/thin hypoechoic striae] 2. Moderate (grade 2) inhomogeneity [presence of thick hypoechoic striae] 3. Severe (grade 3) inhomogeneity [diffuse inhomogeneity with “netting”/“geographical map” appearance]) Testicular echogenicity Use a three point-Likert scale: 0. Normoechoic 1. Mainly hypoechoic 2. Mainly hyperechoic Calcifications and microlithiasis Macrocalcifications: calcifications with a size >3 mm Microcalcifications: small (1–3 mm) bright echogenic foci with no acoustic shadowing Microlithiasis: presence of ≥5 microcalcifications in a single US scan, classified as: 1, limited; 2, "clusters"; or 3, diffuse ("starry sky" appearance). Report localization in the upper, middle, and lower third of the testis Testicular nodules Evaluate the three diameters and characteristics (0, cystic; 1, mixed; 2, solid), shape (0, regular; 1, irregular), homogeneity (0, homogeneous; 1, inhomogeneous), echogenicity (0, normal echogenicity; 1, mainly hypoechoic; 2, mainly hyperechoic), calcifications and/or cysts (0, absent; 1, present) and vascularization (0, absent; 1, peripheral; 2, intranodular) Testicular vascularization Qualitative assessment: normal, reduced, enhanced (in the entire testis and/or focal areas); compare the two testes Quantitative assessment: evaluate arterial PSV, acceleration, RI, and PI in the testicular artery—in the spermatic cord, 2 cm before the gonadal hilum—and the intratesticular arteries (recurrent rami of the centripetal arteries). Other findings Evaluate and measure dilated rete testis (three diameters). Evaluate and measure parenchymal cysts (major diameter). Evaluate and measure testis appendices (longitudinal diameter). Evaluate and measure (major diameter) extratesticular calcifications (including scrotoliths). Evaluate and measure hydrocele (three diameters and volume); use convex probe when bulky. Epididymis and vas deferens Evaluate the CDUS features of the three epididymal segments (head, body, and tail) and vas deferens Size (diameters) Head: measure the longitudinal diameter from the top to the base of the triangle Body and tail: measure the anterior-posterior diameters in a single longitudinal scan (if possible, including the proximal vas deferens) Vas deferens: evaluate presence or absence. Measure the anterior-posterior diameter (if possible, in the same longitudinal scan with epididymal body and tail) Homogeneity/inhomogeneity Report it as a dummy variable (0, homogeneous; 1, inhomogeneous), Echogenicity Use a three-point Likert scale (0, normal echogenicity; 1, mainly hypoechoic; 2, mainly hyperechoic) Vascularization Qualitative assessment: normal, reduced, enhanced; compare the two epididymis (Continues) 122 LOTTI ET AL . TA B L E 1 (Continued) Epididymis and vas deferens Quantitative assessment: evaluate arterial PSV, acceleration, RI, and PI at the level of the head (branch of the testicular artery) and of the tail (branch of the deferential artery) Other findings Evaluate the presence of nodules (in the same way of “testicular nodules”) Evaluate the presence and number of cysts and the three diameters of the major cyst for each segment Evaluate and measure epididymal calcifications (major diameter). Evaluate and measure epididymal appendices (longitudinal diameter). Pampiniform plexus/varicocoele Measure the largest vein, irrespective of location, with the patient standing, at rest, bilaterally. Evaluate the extension of the largest vein to the funicular region, upper or lower pole of the testis. Evaluate the presence of a retrograde venous flow the patient standing, at rest, using CDUS, and classify it as a dummy variable (0: absent or intermittent/fluctuating during spontaneous breath; 1: continuous). Then evaluate the presence of a retrograde venous flow during Valsalva maneuver. CDUS varicocoele is defined in presence of venous vessels >3 mm at rest, with retrograde venous flow detected at least during Valsalva maneuver. Use Sarteschi et al./Liguori et al. classifications for grading varicocoele. “Severe” varicocoele: venous vessels dilation (>3 mm) characterized by a continuous venous reflux at rest, increasing or not during a Valsalva maneuver (consistent with grade 4 and 5 of Sarteschi et al./Liguori et al. classifications) Subclinical varicocoele: venous reflux detected by CDUS but not clinically evident EAA classification of varicocoele ∙ Grade 1: venous vessels dilation (>3 mm) at rest at the funicular region with retrograde venous flow absent/intermittent at rest and enhanced during Valsalva maneuver. ∙ Grade 2: venous vessels dilation (>3 mm) at rest at the upper pole of the testis with retrograde venous flow absent/intermittent at rest and enhanced during Valsalva maneuver. ∙ Grade 3: venous vessels dilation (>3 mm) at rest at the lower pole of the testis with retrograde venous flow absent/intermittent at rest and enhanced during Valsalva maneuver. ∙ Grade 4: venous vessels dilation (>3 mm) at rest (irrespective of location, but usually extending to the peritesticular region) with retrograde venous flow continuous at rest and enhanced during Valsalva maneuver. Possible testicular hypotrophy ∙ Grade 5: venous vessels dilation (>3 mm) at rest (irrespective of location, but usually extending to the peritesticular region) with retrograde venous flow continuous at rest and not increasing during Valsalva maneuver. Possible intratesticular varices and/or testicular hypotrophy The EAA SOPs are derived from the EAA scrotal US study.24 See also https://www.andrologyacademy.net/eaa-studies.22 Abbreviations: PSV, peak systolic velocity; RI, resistive index; PI, pulsatility index. Source: Adapted from reference [2] . the 95th percentiles of its distribution.24,25,28 All statistical analysis (WHO, 2010),29 representing a valid reference point for assessing was performed on SPSS (Statistical Package for the Social Sciences, MGT-CDUS normative parameters.23 Chicago, IL, USA) for Windows 26.0. 3.1 SOPs to assess MGT-CDUS parameters 3 RESULTS Tables 1 and 2 summarize the SOPs used to assess scrotal (Table 1) and Overall, 248 healthy, fertile men (35.3 ± 5.9 years; range 23–53) transrectal (Table 2) CDUS qualitative and quantitative parameters. were enrolled in the EAA US study from February 2016 to Febru- ary 2019.23 All subjects underwent scrotal CDUS24 and 188 men underwent TRUS25 before and after ejaculation. 3.2 Intra- and inter-operator comparability of The socio-demographic, clinical, seminal, and biochemical charac- MGT-CDUS parameters teristics of the sample have been extensively reported in previous studies.23,25 In particular, the cohort studied showed semen parame- The intra- and inter-operator comparability of the main MGT- ters consistent with those reported by the World Health Organization CDUS parameters have been reported in previous studies.24,25 The LOTTI ET AL . 123 TA B L E 2 EAA standard operating procedures (SOPs) to assess prostate-vesicular CDUS Prostate Prostate volume Evaluate the three maximum diameters (anterior–posterior and transverse diameters in transverse scan; longitudinal diameter in longitudinal scan) of the prostate and, if present, of enlarged transitional zone or adenoma Calculate prostate (and adenoma) volume using the ellipsoid formula (length × height × width × 0.52) Report whether adenoma lifts the bladder floor (median lobe) and by how much Prostate symmetry Prostate symmetry should be evaluated, and classified as 0. symmetric, 1. asymmetric (report the biggest lobe) Prostate homogeneity It should be classified as: 0. homogeneity; 1: mild (grade 1) inhomogeneity [presence of small hypo- or hyper-echoic foci]; 2: moderate (grade 2) inhomogeneity [presence of large hypo- or hyper-echoic areas]; 3: severe (grade 3) inhomogeneity [diffuse inhomogeneity with “geographical map” appearance] Prostate echogenicity It should be classified as: 0: normal echogenicity; 1: mainly hypoechoic/presence of large hypoechoic areas; 2: mainly hyperechoic/presence of large hyperechoic areas; 3: mixed [diffuse hypo- and hyper-echoic areas] Calcifications Macrocalcifications: calcifications with a size >3 mm; microcalcifications: small (<3 mm) Report a. the type of calcification (micro- or macro-), b. their localization (transitional zone/peri-urethral; peri-transitional/surgical capsule; right lobe; left lobe; peripheral) and if they are a cluster or isolated. The major calcification should be measured (three diameters: lateral–lateral, anterior–posterior, and longitudinal) Midline prostatic cyst Evaluate the three diameters and volume (ellipsoid formula) Prostate arterial vascularization It should be evaluated before ejaculation, to avoid the bias because of its increase after ejaculation Qualitative assessment: normal, reduced, enhanced (hyperemia) Quantitative assessment: evaluate arterial PSV, acceleration, RI, and PI in the transitional zone (or adenoma) Prostatic venous plexus Measure the maximum anterior–posterior diameter in longitudinal scan, and eventually blood flow velocity Prostate peripheral nodules/equivocal areas Evaluate, measure, and report the presence of peripheral nodules / equivocal areas Other findings Evaluate and measure parenchymal cysts (major diameter). Ejaculatory ducts (EDs) EDs characteristics should be evaluated after ejaculation, to better emphasize indirect US signs of obstruction EDs abnormalities (dilation, calcifications, cysts) should be reported and classified as: 0, absent; 1, uni-; or 2, bilateral When dilated, ED anterior–posterior diameter should be measured Seminal vesicles (SV) Absence and/or abnormalities of one or both SV must be reported. In subjects with oligo/azoospermia and/or low seminal volume (and pH), evaluation of SV before and after ejaculation (with a standard sexual abstinence of 4 days) can be useful to evaluate indirect US signs of obstruction (see below “SVEF”). SV should be studied after ejaculation to better emphasize indirect US signs of obstruction. Diameters and volume The maximum longitudinal diameter (from the “SV pole” to the insertion in the prostate) and the maximum anterior–posterior diameter of the fundus should be measured, SV volume, before and after ejaculation, should be calculated using the “ellipsoid/prolate (d1 > d2 = d3) spheroid” mathematical formula (d1 × d2 × d3 × 0.52, considering d1 = 1/2 the maximum SV-longitudinal diameter, d2 = 1/2 the maximum anterior–posterior diameter and d3 = d2). Report SV dilation or hypoplasia, according to reference ranges. SV ejection fraction (SVEF) SVEF can be calculated as “[(total SV volume before ejaculation−total SV volume after ejaculation)/total SV volume before ejaculation] × 100″. A SVEF < 21.6% suggests distal partial or complete obstruction (Continues) 124 LOTTI ET AL . TA B L E 2 (Continued) Seminal vesicles (SV) SV homogeneity/inhomogeneity SV homogeneity should be classified as a dichotomous variable (0. homogeneous; 1. inhomogeneous) SV echogenicity SV echogenicity should be classified as: 0, normal echogenicity; 1, mainly hypoechoic/with hypoechoic areas; 2, mainly hyperechoic/with hyperechoic areas; 3, mixed: areas of hypo- and hyper-echogenicity SV vascularization Qualitative (report hyperemia) and quantitative (arterial PSV, acceleration, RI, PI in peripheral Doppler spots) study SV abnormal findings SV US abnormalities should be reported and classified as: 0, absent; 1, uni-; or 2, bilateral: areas of endocapsulation/roundish anechoic areas; wall thickening and septa; calcifications; giant cyst. Deferential ampullas/ distal vas deferens Their 0, presence or 1, absence must be reported. Their anterior–posterior diameter must be measured. Report dilation. The EAA SOPs are derived from the EAA TRUS study.25 See also https://www.andrologyacademy.net/eaa-studies.22 Abbreviations: PSV, peak systolic velocity; RI, resistive index; PI, pulsatility index. coefficient of variation for quantitative parameters was < 10 for and qualitative MGT-CDUS parameters, respectively, according to the all parameters and the concordance rate between operators for National Association of Testing Authorities.26 Following the EAA SOPs qualitative parameters was 83%–100%.24,25 in clinical practice will help in reducing the operator-dependent dif- ferences among sonographers. In addition, the use of different US equipment in different EAA centers makes the study results applicable 3.3 Reference ranges of MGT-CDUS parameters to the clinical reality of any sonographer. The EAA US study reported the reference range of US-derived tes- Tables 3 and 4 show the reference ranges of the main scrotal (Table 3) ticular volume (TV) according to different mathematical formulas.24 and transrectal (Table 4) CDUS quantitative parameters as well as the Using the ellipsoid formula, a mean TV of ∼17 mL was found in healthy, prevalence of the main MGT-CDUS echotexture abnormalities. fertile men. Previous studies using the ellipsoid formula reported a median TV of ∼14 mL in healthy men30–32 and a mean TV of ∼15 mL and ∼19 mL in young33 and fertile12,34,35 men, respectively. Con- 3.4 Comparison of previously published versely, infertile patients have a lower US-TV, ranging from ∼10 mL to and EAA US study-derived normal values, cut-off, ∼15 mL.12,21,34,36 In the EAA US study, the lower limit for right and and classifications of the main MGT-CDUS left testis was 12 and 11 mL, respectively, allowing to define “testicular parameters hypotrophy” in an evidence-based way. Previous studies defined testic- ular hypotrophy for a TV < 12 mL37,38 or < 10 mL,39,40 however, with Table 5 summarizes the previously published and EAA US study- no evidence. TV reflects the sperm production and hormonal status of derived normal values, cut-off, and classifications of the main MGT- the subject as well as the presence of previous or current testicular CDUS parameters / characteristics. or systemic disorders.1,41,42 Hence, the availability of evidence-based US-TV thresholds represents an essential tool in andrological clinical practice. 4 DISCUSSION In the EAA US study, most of the subjects evaluated showed testic- ular echotexture homogeneity, and when inhomogeneity was found it The EAA US study is the first study which standardized the SOPs to was of mild degree.24 On the other hand, infertile men frequently show evaluate by CDUS the entire human MGT and assessed the refer- testicular inhomogeneity (TI).1,2 TI has been associated with testicular ence range, the echotexture, and vascular characteristics of the organs function impairment31,43–46 and several pathological conditions.1 The of the scrotal and prostate-vesicular regions in a reference cohort of fact that TI is virtually absent in healthy, fertile men points out that it is healthy, fertile men.23–25 an US characteristic associated with testicular dysfunction, and enno- The EAA SOPs for the assessment of MGT-CDUS parameters23–25 bles US as a diagnostic tool useful to find out infertility-related findings are summarized here. The careful methodological workout and the not detectable with physical examination. TI was previously classified agreement reached by the different EAA centers led to high inter- on a five-point scale by Lenz et al.31 and Westlander et al.47 The EAA and intra-operator comparability,24,25 expressed by a low coefficient US consortium proposed a new, four-point scale classification, easy to of variation (<10)27 and a high concordance rate for quantitative use in clinical practice.2,24 LOTTI ET AL . 125 TA B L E 3 Reference range and mean/median values and TA B L E 3 (Continued) percentages of the scrotal organs color-Doppler ultrasound (CDUS) parameters in healthy, fertile men Mean/median Testis main CDUS parameters values and Reference Mean/median (n = 248) percentages range Testis main CDUS parameters values and Reference Epididymal tail echotexture 19.6 (n = 248) percentages range inhomogeneity (%) Testicular volume (mL) Epididymal body or tail, or vas 0.0 (“ellipsoid” mathematical deferens cysts (%) formula) Epididymal head mean PSV 4.2 ± 0.6 3.1–4.6 Mean 17.2 ± 4.1 11.8–24.4 (cm/s) Right 17.9 ± 4.4 12.0–25.7 Epididymal tail mean PSV (cm/s) 5.5 ± 1.6 1.8–8.0 Left 16.5 ± 4.1 11.0–24.1 Epididymal hyperaemia (%) 0.8 Testicular homogeneity (%) Varicocoele / pampiniform Homogeneous (grade 0) 97.2 plexus main CDUS parameters Mild inhomogeneity (grade 1) 2.8 Left side varicocoele (%) 37.2 Moderate inhomogeneity 0.0 Grade I 0.0 (grade 2) Grade II 12.8 Severe inhomogeneity (grade 0.0 Grade III 6.0 3) Grade IV 16.0 Testis echogenicity (%) Grade V 2.4 Normoechoic 97.2 Right side varicocoele (%) 3.2 Hypoechoic 2.8 Bilateral varicocoele (%) 3.2 Hyperechoic 0.0 “Severe” varicocoele * (grade IV 18.4 Testicular 1.2 and V **) (%) macro-calcifications (> 3 mm) (%) Continuous venous reflux 4.7 ± 2.2 2.0–10.0 velocity (cm/s) in “severe” Testicular micro-calcifications 16.8 varicocoele at rest (1-3 mm) (%) ˆ Data are expressed as mean ± SD when normally distributed, as medians Testicular microlithiasis (%) 0.0 (quartiles) for parameters with non-normal distribution, and as percent- Dilated rete testis (%) 2.0 ages when categorical. The reference range of each testicular parameter has Parenchymal cysts (%) 1.2 been estimated according to the CLSI Guidelines28 as the 5th and the 95th percentiles of its distribution. Hypoechoic micronodular lesion 0.4 Abbreviations: US, ultrasound; PSV, peak systolic velocity. (spermatocele) (%) ˆ Hyperemia was defined as a “diffuse enhanced vascularization.” Testicular artery mean PSV 9.0 ± 3.0 3.0–11.0 *“Severe” varicocoele was defined as venous vessel dilation (> 3 mm) char- (cm/s) acterized by a continuous venous reflux at rest, increasing or not during a Valsalva maneuver.2,24. Intratesticular arteries mean 5.7 ± 1.1 3.7–7.0 **Grade IV and V CDUS varicocoele according to Sarteschi et al./Liguori PSV (cm/s) et al. classifications.2,24 Epididymal and vas deferens Source: Adapted from reference 24 . main CDUS parameters Epididymal head diameter 9.5 ± 1.5 6.9–12.0 (including men with cysts) The EAA US study did not reveal testicular microlithiasis or nodular (mm) lesions in healthy, fertile men. Currently, the association between Epididymal head diameter 9.0 ± 1.5 7.0–11.5 infertility and testicular microlithiasis is debated,19,48–50 while that (excluding men with cysts) with testicular malignancy is consolidating over time.2 In this scenery, (mm) the EAA US study suggests a possible relationship between male Epididymal body diameter (mm) 3.8 ± 0.8 2.5–5.0 infertility and testicular microlithiasis (the latter to be considered, Epididymal tail diameter (mm) 4.8 ± 0.7 4.0–6.0 at least, an epiphenomenon of spermatogenesis derangement), and Vas deferens diameter (mm) 3.5 ± 0.7 2.3–4.5 supports an increased risk of testicular tumor in infertile men.51,52 Epididymal head echotexture 25.0 The EAA US study reported, for the first time, the reference inhomogeneity (%) range of several blood flow parameters related to testicular arteries. Epididymal head cysts (%) 30.0 Increased testicular vascularization represents a qualitative sign (Continues) suggestive of orchitis53–55 or some hematological tumors.55 On the other hand, the research in the US field is trying to find out testicular 126 LOTTI ET AL . TA B L E 4 Reference range and mean or median values and TA B L E 4 (Continued) percentages of the TRUS-related color-Doppler ultrasound (CDUS) parameters in healthy, fertile men Mean or median values Mean or and Reference median values Prostate CDUS parameters percentages range and Reference Periprostatic venous plexus size 2.9 ± 0.9 1.5–4.5 Prostate CDUS parameters percentages range (mm) before ejaculation Volume (mL) 25.0 ± 6.3 15.0–35.0 Periprostatic venous plexus flux 3.8 ± 1.4 2.0–7.0 Diameters (mm) velocity (cm/s) before ejaculation Transversal (td) 45.0 ± 4.4 38.0–52.5 Transitional arteries mean PSV 9.8 ± 1.9 6.5–13.0 Anterior–posterior (apd) 25.5 ± 3.7 18.0–31.0 (cm/s) after ejaculation Longitudinal (ld) 42.0 ± 4.3 34.0–49.0 Hyperaemia (%) after ejaculation 0.5 Asymmetry (%) 0.0 Periprostatic venous plexus size 3.0 ± 0.9 1.7–4.6 Homogeneity (%) (mm) after ejaculation Homogeneous (grade 0) 65.4 Periprostatic venous plexus flux 5.0 ± 1.4 3.0–8.0 Mild inhomogeneity (grade 1) 29.8 velocity (cm/s) after ejaculation Moderate inhomogeneity 4.8 (grade 2) Seminal vesicles (SV) CDUS parameters Severe inhomogeneity (grade 0.0 3) Before ejaculation Echogenicity (%) Mean SV ld (mm) 48.1 ± 5.4 40.0–56.0 Normoechoic 87.8 Mean SV apd (mm) 12.5 ± 3.5 8.0–18.0 Mainly hypoechoic 6.4 Median SV volume (mL) 3.4 [2.1–5.8] 1.4–9.0 Mainly hyperechoic 0.5 Total SV volume (mL) 6.7 [4.3–11.6] 3.0–18.0 Mixed 5.3 SV arteries mean PSV (cm/s) 6.4 ± 1.3 4.0–9.0 Calcifications (%) 42.5 After ejaculation Micro-calcifications (1–3 mm) 9.0 Mean SV ld (mm) 44.9 ± 5.4 37.0–53.0 (%) Mean SV apd (mm) 9.8 ± 3.3 6.0–16.0 Macro- 33.5 Median SV volume (mL) 1.9 [1.1–3.5] 0.6–6.0 calcifications (>3 mm)** Total SV volume (mL) 3.8 [2.3–7.0] 1.2–12.0 (%) SV arteries mean PSV (cm/s) 6.6 ± 1.3 4.4–9.5 Major calcification diameter 7.5 [4.2–12.0] 3.0–18.0 (mm) Delta SV and SVEF Midline prostatic cyst (%) 5.0 Delta SV ld (mm) 3.3 ± 1.4 2.0–6.3 Transversal diameter (mm) 4.0 3.0–5.0 Delta SV apd (mm) 2.7 ± 1.0 2.0–4.8 [3.25–4.75] Delta SV total volume (DSTV) 3.1 [2.0–4.4] 1.3–6.4 Anterior-posterior diameter 3.0 2.0–6.0 (mL) (mm) [2.25–4.75] SV total ejection fraction (SVEF) 43.2 20.0–58.0 Longitudinal diameter (mm) 6.0 [4.0–7.5] 4.0–9.0 (%) [35.0–52.0] Volume (mL) 0.038 [0.026– 0.012–0.117 Echotexture abnormalities 0.069] Inhomogeneity (%) Parenchymal cysts (%) 3.2 Before ejaculation 34.2 Ejaculatory ducts After ejaculation 16.7 Dilation (>2 mm) 0.5 Roundish anechoic areas/areas Cysts 0.0 of endocapsulation Micro-calcifications 0.0 Before ejaculation 16.4 Peripheral nodules 0.0 After ejaculation 8.3 Transitional arteries mean PSV 8.3 ± 1.8 5.0–11.0 Wall/thickened septa 3.6 (cm/s) before ejaculation (%) Hyperaemia (%) before 0.5 Calcifications (%) 0.0 ejaculation (Continues) (Continues) LOTTI ET AL . 127 TA B L E 4 (Continued) severe prostate enlargement, respectively. In addition, the EAA US study derived a mathematical formula (1/3 age + 15) to calculate, in Mean or median values young-adult men, the age-adjusted normative mean PV,25 useful in and Reference clinical practice to derive the expected average PV by age. Prostate CDUS parameters percentages range Regarding prostate arterial vascular parameters, the EAA study Giant cysts (%) 0.0 found in healthy, fertile men an upper limit of prostatic arterial peak Deferential ampullas mean size 4.4 ± 0.6 3.5–6.0 systolic velocity (PSV) of 11 cm/s.25 Previous studies found that a (mm) PSV > 11 cm/s identifies men with prostatitis-like symptoms, indicating Data are expressed as mean ± SD when normally distributed, as medians current prostate inflammation.13,61 Hence, in young-adult men, a pro- (quartiles) for parameters with non-normal distribution, and as percent- static arterial PSV < 11 cm/s can be considered “normal,” while higher ages when categorical. The reference range of each parameter has been values indicate current prostate inflammation. Of note, to standard- estimated according to the CLSI guidelines28 as the 5th and the 95th ize the use of prostatic arterial PSV to assess inflammation, it must percentiles of its distribution. Abbreviations: PSV, peak systolic velocity; SV, seminal vesicles; ld, longitu- be measured before ejaculation. In fact, the EAA US study found that dinal diameter; apd, anterior–posterior diameter. PSV increases significantly after ejaculation,25 in line with a previous Source: Adapted from reference 25 . report.62 Evaluating prostate US abnormalities, calcifications and inhomo- vascular predictors of positive surgical sperm retrieval in men with geneity were found in ∼43% and ∼33% of subjects, respectively.25 non-obstructive azoospermia.1,2 In this scenery, the availability of Previous studies attributed these findings to chronic prostate normative quantitative testicular vascular parameters could help to inflammation or inflammatory outcomes.1 Some authors sug- better define differential diagnosis between normal and pathological gested that prostate inflammation could be associated with poor conditions and, maybe, in surgical sperm retrieval prognosis. seminal parameters63 and male infertility,64 however this issue is The EAA US study investigated the reference range of epididymal controversial.13,63,65 So far, the detection of the aforementioned segments and vas deferens, reporting an upper limit for epididymal prostate US abnormalities plays a modest role in the clinical man- head, body, and tail of 11.5, 5, and 6 mm, respectively, and for proximal agement of male infertility.1 The EAA US study, reporting a high vas deferens of 4.5 mm. Previously, some authors proposed as abnor- frequency of prostate calcifications and inhomogeneity in healthy, mal an epididymal head > ∼11–12 mm56–58 and a tail > 6 mm,57,58 fertile men, supports the latter vision, suggesting that these findings considered suggestive of inflammation and/or obstruction, while vas have a marginal impact on male fertility. deferens thresholds have never been reported. Epididymis and vas In the EAA US study, no ejaculatory duct abnormalities were found deferens US reference ranges can increase the diagnostic accuracy in fertile men, supporting their negative role on male fertility.66–68 of proximal or distal obstruction (along with other prostate-vesicular Furthermore, midline prostatic cysts (MPC) were rare (5%) and small US signs) and of epididymal inflammation.1,2 In addition, the EAA (volume < 0.117 mL and transversal diameter < 5 mm).25 A previous US study reports the reference range for epididymal arterial-related study12 reported in men with a severe infertility factor a higher preva- parameters. Previously, some authors53,55 reported that epididymal lence of MPC (up to 15%) and a larger size than those observed in hyperemia, a qualitative parameter, could indicate inflammation. Now, fertile men. In particular, a MPC volume > 0.117 mL identified men the availability of EAA quantitative vascular normative values can help with severe oligo- or azoospermia with good accuracy, and almost in ameliorating the diagnosis of epididymal inflammation. Finally, the half of these patients had a volume > 0.250 mL (transversal diame- EAA US study found epididymal cysts or inhomogeneity in one out of ter > 1 cm).12 Hence, small MPC (< 0.117 mL) seem to exert no negative four fertile men, suggesting their scanty role in male infertility.1,2 impact on male fertility,25 while larger MPC, frequent in infertile men, The EAA US study reported the reference range of pampiniform can lead to oligo- or azoospermia.12 MPC must be investigated during plexus and the prevalence and characteristics of varicocoele in fertile infertility work-up as they represent a treatable cause of obstructive men.24 The study found a high frequency of varicocoele (∼37%) in fer- infertility. In fact, in males of infertile couples with oligo-/azoospermia tile men, similar to that of men with primary infertility,3,4 suggesting and low semen volume, the transrectal aspiration of MPC, especially its scanty effect on male fertility and prompting to limit varicocoele when large and when FSH is in the normal range (< 8 U/L), can restore surgical correction to highly selected populations. Accordingly, the a good semen quality and eventually lead to natural pregnancy.12 European Association of Urology8 supports specific indications for The EAA US study reported, for the first time, the reference range of varicocoele treatment. Of note, recently the EAA published its own the periprostatic venous plexus, identifying an evidence-based upper varicocoele classification,2 resembling that of the European Society of limit of 4.5 mm. Some authors previously suggested to define peripro- Urogenital Radiology.3 static venous plexus dilation as > 3 mm69 or >4 mm,70 however with Regarding TRUS, the EAA US study reported a mean prostate no evidence. volume (PV) of ∼25 mL, with a lower and upper limit of 15 Evaluating the seminal vesicles (SV), the EAA US study reported, for and 35 mL, respectively,25 defining, in men of reproductive age, a the first time, evidence-based upper and lower limits of their diame- small (< 15 mL) or enlarged (> 35 mL) prostate. Previous studies sug- ters and volume before and after ejaculation, and criteria to define SV gested a PV > 30 mL59 and >60 mL60 as indicative of an initial and asymmetry.25 Regarding SV diameters, the upper and lower limits of 128 LOTTI ET AL . TA B L E 5 EAA US study derived and previously published normal values, cut-off and classifications of the main MGT-CDUS parameters/characteristics Previously proposed normal values, cut-off and EAA US study normal values, cut-off and classifications at classifications at CDUS CDUS Testis Mean TV (ellipsoid) From 14 to 19 mL in different studies 17 mL Right TV ≥12 mL ≥12 mL (when < 12 mL: hypotrophy) Left TV ≥12 mL ≥11 mL (when < 11 mL: hypotrophy) 31 TI classification Lenz et al. (1993) EAA US study 1. Very uniform pattern 0. Homogeneity 2. Slightly irregular pattern 1. Mild inhomogeneity (presence of small hypoechoic foci/thin hypoechoic striae) 3. Moderately irregular pattern or small echogenic points 2. Moderate inhomogeneity (presence of thick hypoechoic striae) 4. Very irregular pattern or bright echogenic spots 3. Severe inhomogeneity (diffuse TI with “netting”/“geographical map” appearance) 5. Tumor suspected (demarcated area) Westander et al. (2001)47 1. Homogeneous 2. Homogeneous with some hyperechogenic foci 3. Heterogeneous with spread hyperechogenicity 4. Heterogeneous with both hyperechogenic and cystic (hypoechogenic) parenchyma 5. Post-operative intratesticular lesion TML (most used ≥5 Microcalcifications per field of view ≥5 Microcalcifications per field of view definitions) ≥5 Microcalcifications in the whole testis Vascularization Normal, reduced or enhanced Testicular artery PSVˆ: 3–11 cm/s Intratesticular arteries PSVˆ: 3.7–7 cm/s Epididymis and vas deferens Head diameter ≤12 mm ≤12 mm and ≤11.5 mm in men with and w/o cysts Body diameter ≤4 mm ≤5 mm Tail diameter ≤6 mm ≤6 mm Vas deferens Not reported ≤4.5 mm diameter Higher values suggestive of inflammation/obstruction Higher values suggestive of inflammation/obstruction Inhomogeneity Homogeneous or inhomogeneous EAA US study 0. Homogeneity 1. Inhomogeneity Echogenicity Normoechoic, hypoechoic, hyperechoic EAA US study 0. Normal echogenicity 1. Mainly hypoechoic 2. Mainly hyperechoic Vascularization Normal or enhanced Head artery PSVˆ: 3.1–4.6 cm/s Tail artery PSVˆ: 1.8–8.0 cm/s Varicocoele Several classifications* Venous vessels >3 mm at rest, irrespective of location, with retrograde venous flow detected at least during Valsalva maneuver, with grading according to Sarteschi et al. /Liguori et al. (Continues) LOTTI ET AL . 129 TA B L E 5 (Continued) Previously proposed normal values, cut-off and EAA US study normal values, cut-off and classifications at classifications at CDUS CDUS Prostate Volume Normal: 20–25 mL. Enlarged: > 30 mL Severe Normal: reference range 15–35 mL (when <15 mL enlargement: > 60 mL or >35 mL suggestive of hyportrophy or hyperplasia, respectively) Inflammation Hyperemia: qualitative Hyperemia: semiquantitative1 Normal arterial prostatic PSVˆ < 11 cm/s (young adults) (when higher suggestive of inflammation) Midline prostatic cyst No cut-off for EDs obstruction Normal volume < 0.117 (when higher, especially when >0.250 mL with normal FSH, suggestive of partial and complete obstruction) Ejaculatory ducts Dilated: >2 mm Normal: <2 mm (when >2 mm suggestive of obstruction) (EDs) Periprostatic venous Dilated: >3 or 4 mm (not evidence based) Normal: reference range 1.5–4.5 mm plexus Seminal vesicles (SV) Diameters Dilation: SV apd > 15 mm Before ejaculation ∙ apd: reference range 8–18 mm ∙ ld: reference range 40–56 mm Hypoplasia: SV apd < 5 or < 7 mm and/or SV longitudinal After ejaculation d < 25 mm ∙ apd: reference range 6–16 mm (< 6 mm suggestive of hypoplasia; > 16 mm suggestive of dilation) ∙ ld: reference range 37–53 mm Volume No cut-off for dilation or hypoplasia Before ejaculation: reference range 1.4–9 mL After ejaculation: reference range 0.6–6 mL SVEF SVEF < 21.6% suggestive of distal obstruction Normal SVEF > 20.0% (when < 20.0% suggestive of partial and complete obstruction) Deferential ampullas Diameter Normal apd < 6 mm apd: reference range 3.5–6.0 mm (when > 6 mm suggestive of partial and complete obstruction) Of note, we report here the main findings of the EAA US study. In the original articles24,25 normative values/reference ranges of all the scrotal organs CDUS parameters have been reported extensively. ˆAlong with peak systolic velocity (PSV) reference range, the EAA US study reports normative values for acceleration, pulsatility and resistive index in different MGT organs. For a detailed description of “previously published normal values,” see the main text. Abbreviations: TV, testicular volume; TI, testicular inhomogeneity; SVEF, seminal vesicles ejection fraction; ld, longitudinal diameter; apd, anterior–posterior diameter. the mean SV anterior-posterior diameter, often used in literature to SV emptying with ejaculation can be defined by a reduction in the SV define the cut-off for SV dilation57,67,68 or hypotrophy,57,71,72 respec- diameters of at least 2 mm, introducing an evidence-based, easy to use, tively, were 16 and 6 mm after ejaculation. Previous studies proposed parameter in US clinical practice. In addition, the EAA US study evalu- an SV anterior–posterior diameter > 14 mm57 or >15 mm67,68 to indi- ated another parameter, the “SV ejection fraction” (SVEF).25 Previous cate SV dilation, suggestive of partial or complete ejaculatory duct studies1,14 reported, in infertile men, that a SVEF < 21.6% identifies obstruction. On the other hand, some authors proposed a SV anterior- subjects with reduced seminal volume (< 1.5 mL) and pH (< 7.2), rep- posterior diameter < 7 mm57 or <5 mm71 to indicate SV hypotrophy, resenting a useful indicator of ejaculatory ducts sub-obstruction. The or a longitudinal diameter < 25 mm.72 Conversely, the EAA US study lower SVEF limit observed in the EAA US study was 20%,25 similar to identified a longitudinal diameter threshold of 36 mm.25 Regarding that reported above in infertile men with distal sub-obstruction.1,14 SV volume, the upper and lower limits of a single SV “after ejacula- The EAA US study reported also a deferential ampulla upper limit of tion” were 0.6 and 6 mL, thresholds that could be used to define SV 6 mm, in line with previous reports,1,14 suggesting that a larger size can hypotrophy or dilation, respectively.25 represent another indicator of distal sub-obstruction. Evaluating the SV before and after ejaculation, the normative “delta The EAA US study evaluated also SV-US abnormalities. The study SV total volume” (SV total volume before ejaculation − SV total volume found25 that the detection of “roundish anechoic areas,”1 observed after ejaculation) was reported, and the lower limit of “delta” SV longi- before ejaculation in one out of six men, was halved after ejaculation. tudinal and anterior–posterior diameters was 2 mm. Hence, the normal Similar figures were previously observed in infertile men,14 which, 130 LOTTI ET AL . however, showed a frequency of these areas double14 than that of 2. Lotti F, Bertolotto M, Maggi M. Historical trends for the standards in fertile men.25 The EAA and previous studies suggest that these find- scrotal ultrasonography: what was, what is and what will be normal. Andrology. 2021;9(5):1331-1355. ings represent liquid areas expelled from the SV with ejaculation, and 3. Freeman S, Bertolotto M, Richenberg J, et al. Ultrasound evaluation that when present in the SV after ejaculation may indicate incomplete of varicoceles: guidelines and recommendations of the European Soci- SV emptying.25 Previous studies reported that anechoic areas can ety of Urogenital Radiology Scrotal and Penile Imaging Working Group indicate SV stasis14,66 and/or chronic inflammation.14,57,58 The EAA (ESUR-SPIWG) for detection, classification, and grading. Eur Radiol. 2020;30(1):11-25. US study agrees with this vision, however suggesting to asses these 4. Bertolotto M, Cantisani V, Drudi FM, Varicocoele LF. Classification areas after ejaculation, to avoid their overestimation and an excessive and pitfalls. Andrology. 2021;9(5):1322-1330. diagnosis of pathology. The EAA US study25 also observed, in healthy, 5. Sidhu PS, Cantisani V, Dietrich CF, et al. The EFSUMB guidelines and fertile men, rare SV thickened septa, usually associated with chronic recommendations for the clinical practice of contrast-enhanced ultra- sound (CEUS) in non-hepatic applications: update 2017 (long version). SV inflammation14,57,58 and no SV giant cysts, which conversely are Ultraschall Med. 2018;39(2):e2-e44. frequent in men with genitourinary abnormalities.1,14 6. Săftoiu A, Gilja OH, Sidhu PS, et al. The EFSUMB guidelines and rec- ommendations for the clinical practice of elastography in non-hepatic applications: update 2018. Ultraschall Med. 2019;40(4):425-453. 5 CONCLUSIONS 7. Ramanathan S, Bertolotto M, Freeman S, et al. Imaging in scrotal trauma: a European Society of Urogenital Radiology Scrotal and Penile The EAA US study, for the first time, standardized the SOPs to eval- Imaging Working Group (ESUR-SPIWG) position statement. Eur Radiol. 2021;31(7):4918-4928. uate with US the organs of the entire human MGT and assessed, in a 8. Salonia A, Bettocchi C, Carvalho J, et al. Sexual and Reproduc- multinational cohort of healthy, fertile men, the reference ranges and tive Health. European Association of Urology Guidelines. https:// characteristics of scrotal and transrectal CDUS parameters.24,25 The uroweb.org/guideline/sexual-and-reproductive-health/. Accessed on findings of the EAA US study represent a new milestone in the uro- July 2022. 9. Gravas S, Cornu JN, Gacci M, et al. Management of Non- andrological and radiological fields, and can help in clinical practice neurogenic Male LUTS. European Association of Urology Guidelines. to reduce the operator-dependent differences among sonographers, https://uroweb.org/guideline/treatment-of-non-neurogenic-male- define normal and pathologic CDUS characteristics, better under- luts/#4. Accessed on July 2022 standing the significance attributed to specific MGT-CDUS findings, 10. Engeler D, Baranowski AP, Berghmans B, et al. Chronic pelvic pain. European Association of Urology Guidelines. https://uroweb.org/ and the relationship between abnormal CDUS parameters and male guideline/chronic-pelvic-pain/#4. Accessed on July 2022 reproductive and general health. 11. Schaeffer AJ. Clinical practice. Chronic prostatitis and the chronic pelvic pain syndrome. N Engl J Med. 2006;355(16):1690-1698. ACKNOWLEDGMENTS 12. Lotti F, Corona G, Cocci A, et al. The prevalence of midline prostatic Open Access Funding provided by Universita degli Studi di Firenze cysts and the relationship between cyst size and semen parameters within the CRUI-CARE Agreement. among infertile and fertile men. Hum Reprod. 2018;33(11):2023-2034. 13. Lotti F, Corona G, Mondaini N, et al. Seminal, clinical and colour- Doppler ultrasound correlations of prostatitis-like symptoms in males CONFLICT OF INTEREST of infertile couples. Andrology. 2014;2(1):30-41. The authors declare no conflict of interest. 14. Lotti F, Corona G, Colpi GM, et al. 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