الفهرس 
Anatomy of male reproductive systemOnly 14 pages are availabe for public view
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Abstract
Obstructive azoospermia is an infrequent cause of male infertility, the term obstructive azoospermia is diagnosed when a patient has normal spermatogenesis with obstructed ductal system.
Understanding causes of obstructive azoospermia requires perfect understanding of male genital system as regard anatomical considerations and the physiology of spermatogenesis and sperm transmission.
Several congenital and acquired pathologies causes obstructive azoospermia at different levels of the ductal system.
Evaluation of obstructive azoospermia requires good history taking, physical examination and laboratory investigations mainly in the form of semen analysis and estimation of hormonal levels followed by testicular biopsy.
Radiologic imaging in the form of transrectal ultrasound and vasography plays an important role in identifying the site of obstruction.
Ultrasonography, a widely used imaging modality for the diagnosis and staging of many diseases, is an important cost-effective technique, however, technical improvements are necessary to realize its full potential. 2D viewing of 3D anatomy using conventional ultrasonography limits our ability to quantify and visualize most diseases causing, in part, the reported variability in diagnosis and ultrasound guided therapy and surgery. This occurs because conventional ultrasound images are 2D, yet the anatomy is 3D; hence, the diagnostician must integrate multiple images in his mind. This practice is inefficient, and may lead to operator variability and incorrect diagnoses. In addition, the 2D ultrasound image represents a single thin plane at some arbitrary angle in the body. It is difficult to localize and reproduce the image plane subsequently, making conventional ultrasonography unsatisfactory for follow-up studies and for monitoring therapy.
Efforts have focused on overcoming these deficiencies by developing 3D ultrasound imaging techniques that can acquire B mode, colour Doppler and power Doppler images. With a 3D ultrasonographic system, transducer motion is mechanically con¬trolled and standardized, and the 3D integra¬tion is achieved by means of a computer system. An inexpensive desktop computer is used to reconstruct the information in 3D and then is also used for interactive viewing of the 3D images.
After acquiring a series of 2D ultrasound images, a 3D image is reconstructed. The 3D image allows the physician to interactively view the organ under investigation in multiple simultaneous planes, or to view the surfaces of structures using volume rendering techniques that allow better visualization of its internal architecture. These approaches allow physicians to
diagnose disease, measure volumes accurately, and plan and guide minimally invasive procedures.
This study was conducted on ten patients, diagnosed as having obstructive azoospermia, and five normal controls. For all patients and controls a conventional 2-D scrotal ultrasound followed by 3-D scrotal ultrasound was performed at the same setting using the same ultrasound equipment. The greatest diameters of the caput, corpus and cauda of the epididymis were recorded. Structural analysis of the epididymis and the testis including search for inhomogeneity, hypo or hyper-echoic areas, calcifications, cysts or any other abnormalities were also recorded. For all patients scrotal exploration was performed to examine the epididymis and the patency of the vasa deferentia.
Findings of scrotal exploration were compared to clinical and ultrasonographic findings. 2-D and 3-D ultrasonographic images were compared.
Comparing mean epididymal size in patients and controls using the 3-D mode of ultrasound, the mean sizes of the head and the body were statistically significantly larger on both sides in patients compared to controls, however on using the 2-D mode, this difference was not always statistically significant.
Comparing mean epididymal size using both modes of ultrasound, mean epididymal sizes of the caput and the corpus were statistically significantly larger in patients when using the 3-D mode compared to their measurements using the 2-D mode.
Exploration was performed for six out of the ten examined patients. Exploration showed that five patients had epididymal obstruction while vasal obstruction was detected in one patient.
In the present study, the site of obstruction was epididymal in 80% of azoospermic patients (eight out of ten patients), and post-epididymal in 20% of azoospermic patients (two out of ten patients). These values differ from those demonstrated in other studies. Differences in the etiology of the obstruction may account for these results, as in the majority of our studied patients, obstruction was attributed to epididymal inflammation.
It is vital to pin point the site of obstruction with some accuracy and determine the possible etiological factors of obstruction in order to be able to restore patency, establish the plan of treatment and offer the infertile male the prognosis of expected fertility. Ultrasonographic evaluation of the genital tract is performed to confirm the presence of and identify the site of genital duct obstruction. In addition, introduction of scrotal ultrasonography has offered a safe, objective and accurate method for epididymal measurement which was found to be larger than normal in either epididymal or post-epididymal obstruction.
In the present study, epididymal enlargement detected by scrotal ultrasonography was maximum at the head (caput epididymis). The caput revealed mixed echogenicity which is probably indicative of healed inflammation, as most patients gave a history of epididymitis or epididymo-orchitis.
Reports about application of 3D ultrasonogra¬phy in scrotal imaging are rare, and to our knowledge, there has been no report of 3D ultrasonography applied to depict the anatomy of the male reproductive system. No 3-D ultrasound standards for epididymal head size have been reported thus far neither in normal nor in obstructive azoospermic patients.
In the present work, using the 3-D scrotal ultrasonography, epididymal head measurement in normal controls did not differ significantly from that obtained using conventional 2-D scrotal ultrasonography (p>0.05). However measurement of epididymal dimensions in the studied azoospermic patients differed significantly when using 2-D ultrasound compared to 3-D ultrasound (p<0.05). Epididymal size was found to be significantly larger when estimated using the 3-D scrotal ultrasonography than when using the conventional 2-D scrotal ultrasonography.
This significant difference in size when using each ultrasound modality may be attributed to the ability of the 3-D scrotal ultrasound to provide a complete view of the epididymes and hence provide a basis for more accurate and precise estimate of volume. Three dimensional scrotal ultrasound demonstrates the whole epididymis at the maximum dimensions in a single plane, through translation and rotational adjustment of the sectional (orthogonal) planes, getting the best modified coronal plane of the epididymis. The immediate real-time reconstruction with unlimited off-site review of images may speed localization and could be useful in obstructive azoospermia.
The potential usefulness of 3-D over 2-D ultrasound imaging is based on its multiplanar capabilities. Therefore in cases of obstructive azoospermia where most cases are of epididymal origin, the use of 3-D ultrasound may be more beneficial than 2-D as the epididymal anatomy is more objectively visualized and measured. This objectivity of data is helpful in reassessment and counseling of patients.
In summary, our preliminary data suggest that 3D ultrasonography has the potential to become a practical imaging technique for evaluation of obstructive azoospermic patients. Future developments in ultrasonographic equipment and clinical experience may allow 3D ultra¬sonography a more reliable and practical imaging modality in obstructive azoospermia.