Normal US anatomy of the prostate

Recent concepts on prostate anatomy are first emphasized. The sonographic approaches to the prostate and the seminal vesicles are then described. They are the external suprapubic and transperineal and the transrectal and transurethral approaches. The most detailed images were obtained with transrectal sonography by using a radial then a linear-array probe. The various views of the prostate and seminal vesicles are shown according to the approach and scan orientation. Their advantages and drawbacks are discussed. Our routine protocol includes suprapubic, transperineal and transrectal scanning with a radial and a linear-array probe. Linear-array probes also allow the voiding study of the bladder neck and prostatic urethra.     

经直肠超声诊断精囊疾病的应用

作者采用７．５ＭＨｚ凸弧阵阴道探头，经直肠超声检查，获得精囊的高清晰图像。文中报告１８例共２４个精囊病变的声像图表现，包括急、慢性炎症、结石、畸形、囊肿等。直肠法高频超声检查，是一种简便、安全、准确早期诊断精囊病变的重要检测手段     

A 5-MHz cylindrical dual-layer transducer array for 3-D transrectal ultrasound imaging

Two-dimensional transrectal ultrasound (TRUS) is being used in guiding prostate biopsies and treatments. In many cases, the TRUS probes are moved manually or mechanically to acquire volumetric information, making the imaging slow, user dependent, and unreliable. A real-time three-dimensional (3-D) TRUS system could improve reliability and volume rates of imaging during these procedures. In this article, the authors present a 5-MHz cylindrical dual-layer transducer array capable of real-time 3-D transrectal ultrasound without any mechanically moving parts. Compared with fully sampled 2-D arrays, this design substantially reduces the channel count and fabrication complexity. This dual-layer transducer uses PZT elements for transmit and P[VDF-TrFE] copolymer elements for receive, respectively. The mechanical flexibility of both diced PZT and copolymer makes it practical for transrectal applications. Full synthetic aperture 3-D data sets were acquired by interfacing the transducer with a Verasonics Data Acquisition System. Offline 3-D beamforming was then performed to obtain volumes of two wire phantoms and a cyst phantom. Generalized coherence factor was applied to improve the contrast of images. The measured -6-dB fractional bandwidth of the transducer was 62% with a center frequency of 5.66 MHz. The measured lateral beamwidths were 1.28 mm and 0.91 mm in transverse and longitudinal directions, respectively, compared with a simulated beamwidth of 0.92 mm and 0.74 mm.     

Histological analysis of ultrasonic images of the prostate: an accurate technique.

Ultrasonography of the prostate furnishes images which still cannot be fully interpreted morphologically. In a cadaver study, the ultrasound images of two groups (21 and 19) prostates, obtained in a water bath, were compared with histology slides taken at corresponding levels. In the first part of the study, using a 4 MHz probe, there was a correlation between hyperechoic lesions and stone formations in 9 out of 15 cases. A relation between hypoechoic lesions and the existence of a carcinoma could also be established in 4 out of 12 cases. In the second part of the study, using a 7 MHz probe, there was a correlation between hyperechoic lesions and stone formations in all cases. Hypoechoic lesions correlated with the presence of a carcinoma in 1 out of 8 cases. The technique used appears to be well suited for the comparative study of ultrasound images and histology. Application of the 7 MHz probe is preferable as, because of a better resolution, smaller lesions can be detected. The results of this study are not very encouraging for the use of transrectal ultrasound for the detection of small prostatic carcinomas.     

前列腺癌经直肠超声和CT征象的敏感性分析

目的比较经直肠超声及CT显示前列腺癌征象的敏感性。方法 分析24例经病理证实的前列腺癌患者的声像图及CT图像，并与病理结果进行对照。结果24例前列腺癌共检测到32个痛结节，经直肠超声显示低回声14例，17个结节，等回声4例，6个结节，强回声6例，9个结节；21例前列腺增大，20例检测到异常血流信号，9例侵犯精囊，3例侵犯膀胱，5例包膜未受侵犯。CT显示密度不均21例（含小钙化3例），5例侵犯精囊，4例侵犯膀胱，3例侵犯直肠前壁，盆腔区域淋巴结转移3例，髂骨转移1例，6例包膜未受侵犯。结论经A肠超声对病灶的回声改变敏感，且对侵犯及精囊腺的敏感度较CT更高，但对微小的包膜侵犯及盆腔淋巴结转移的敏感度较低，CT对小钙化及骨转移较高，CT及经直肠超声对于前列腺中央区的小癌灶均不敏感。     

经直肠彩色多普勒血流显像对前列腺病变鉴别诊断的价值

目的　本文探讨经直肠彩色多普勒血流显像对前列腺病变鉴别诊断的价值。方法　在本研究中我们使用ＡＴＬ公司超九彩色多普勒超声诊断仪和经直肠探头（ 探头频率为７５ ＭＨｚ） 检测了２０ 例前列腺疾病患者。结果　前列腺增生、脓肿和癌症三者均可显示前列腺内有结节回声,但结节的回声特点、血流供应情况有所不同。结论　经直肠彩色多普勒是鉴别诊断前列腺增生、脓肿和癌症简便有效的方法     

经直肠三维高频超声诊断前列腺癌

目的：探讨经直肠三维高频超声城像对前列腺癌的诊断价值。方法：应用Combison^R530三维超声成像仪（7.5MHz经直肠探头）检测46例前列腺癌,对其声像图表现进行回顾性分析。结果：前列腺癌在超声声像图上可表现为单纯结节型,结节浸润型及弥漫浸润型三种改变。三维超声新技术通过多平面观察,可获得比二维超声更多的诊断信息,提高了前列腺癌的超声诊断率（尤其对后二型病变）,本组诊断符合率为82.6％,且更容易观察前列腺病灶与包膜及邻近结构之间的空间位置关系,有助于对肿瘤进行分期。结论：经直肠三维超声为操作者提供了更丰富的诊断信息,明显提高了前列腺癌的超声诊断率。     

超声引导下经直肠精囊穿刺术

作者使用７．５ＭＨｚ凸弧阵阴道探头，经直肠进行精囊穿刺。本文报告１２例共２１个病变精囊经直肠穿刺均获成功，无并发症发生。文中介绍了穿刺的具体操作方法，讨论了其优点。该方法简便易行，准确安全，用于治疗急、慢性精囊炎效果显著，具有临床实用价值。     

超声引导联合药物注射治疗难治性前列腺炎

目的探讨超声引导联合药物注射治疗难治性前列腺炎的可行性.方法采用经直肠超声引导对34例难治性前列腺炎患者行前列腺两侧外腺(或回声减低区)及精囊腺联合药物注射治疗,每周2次,4～5周为一疗程,观察疗效及副作用.结果28例治愈,6例有效.术后小腹胀痛15例,大小便带血或血性精液10例,均自行消失,无感染或大出血发生.结论经直肠超声引导前列腺两侧外腺和精囊腺内联合药物注射是治疗难治性前列腺炎的一种安全有效的方法.     

实时谐波灰阶超声造影评价犬前列腺射频消融灶

目的应用实时谐波灰阶超声造影技术观察实验犬前列腺射频消融灶,并与常规二维超声检查、彩色能量多普勒超声检查及病理学结果进行比较,以评估实时谐波灰阶超声造影评价前列腺射频消融灶的有效性。方法对5条犬前列腺两侧叶行射频消融,术后即刻行经直肠二维超声检查、能量多普勒超声检查和超声造影。超声造影下测量消融灶体积,并与病理学标本大体测量的结果相比较。结果常规二维超声在射频消融后即刻无法准确地观测消融灶的范围。彩色能量多普勒超声虽然不能准确评价消融灶的体积,但对消融灶的血流变化比较敏感,能及时反映消融灶血流状态的改变。超声造影则能准确评价消融灶的范围,其测量结果与病理学结果比较没有统计学差异,且超声造影能够实时观察消融灶内部及周边血流灌注的情况。结论常规二维超声和彩色能量多普勒超声能实时反映消融灶回声的变化和血流情况的改变。实时谐波灰阶超声造影技术能准确地评价前列腺射频消融灶的范围。     

青年男性前列腺炎与射精管梗阻性无精子症：MR辨析及术前评估

目的探讨青年男性前列腺炎症与射精管梗阻的关系,协助临床对男性不育患者进行个性化治疗及评估。方法2011年4月-2013年5月在我院男科诊断为射精管梗阻性无精子症的46例患者接受了前列腺、射精管、精囊MR检查和经直肠超声检查,总结其MR和超声表现。结果MR所见：46例均存在前列腺炎症（弥漫性37例,局灶性9例）,4例患者同时存在前列腺苗勒氏囊肿。44条射精管表现为单点粘连,8例可见射精管囊肿（2个粘连点）,13条射精管表现为多点粘连,增强扫描22条射精管壁明显强化（提示炎性充血）。12例同时存在双侧精囊发育不良或不发育,40例存在精囊炎。超声所见：对前列腺苗勒氏囊肿、射精管扩张及囊肿的诊断与MR一致,但未对前列腺炎进行报告,缺乏射精管粘连点的判断,将7例精囊不发育患者的血管神经丛误诊为精囊。结论青年男性前列腺炎容易导致射精管粘连梗阻,MR在协助选择手术适应证和术前评估方面较超声有明显优势。     

Effect of split-focus approach on producing larger coagulation in swine liver

The split-focus approach has the potential to substantially improve the throughput of coagulation high-intensity focused ultrasound (HIFU) treatment. A prototype split-focus transducer with four elements at 4.25 MHz, combined with a small imaging probe at 6.5 MHz, was constructed for transrectal treatment of a prostate. Computer simulation predicted that 1.57 times larger acoustic power than a single-spot focus was required for a split focus to heat the tissue up to the same peak temperature at 4 s from the start of insonation. When the peak temperature was 100 degrees C, the tissue volume above 70 degrees C was predicted to be 2.3 times larger for a split focus. Swine liver lobes were intraoperatively insonated with the split-focus transducer for 4 s. A lesion of coagulation necrosis 3 to 4 times larger in volume than with a single-spot focus was formed with a split focus at the same acoustic power ratio as described above. Furthermore, a lesion about 2 times larger in volume was formed when compared at the same acoustic power. These results show the great advantage of a split-focus approach over a conventional single-spot focus in coagulation treatment.     

Transrectal ultrasonography in prostatic carcinoma

Transrectal ultrasonography of the prostate is a diagnostic technique allowing visualization of the internal anatomy of the prostate gland, the seminal vesicles, and the prostatic urethra. Although there is still considerable controversy about its reliability, indications for transrectal prostatic ultrasonography include the following: diagnosis of prostate cancer, guidance of transrectal needle biopsies, guidance of staging biopsies, staging previously diagnosed prostate cancers, monitoring treatment response, and assessing glandular size and volume.     

端扫超声探头经直肠探测子宫附件的方法与临床价值

目的 探讨端扫式超声探头经直肠探查子宫附件的方法与临床价值。方法 女性患者51例，采用端扫式经直肠阴道两用探头检查子宫附件。结果 51例患者中49例(96．08％)经直肠超声均清晰显示子宫与附件病变，全部患者经直肠超声彩色多普勒血流信号均比经腹部超声丰富。结论 使用端扫式超声探头经直肠检查子宫附件拓宽了经直肠超声的临床应用范围。     

经直肠高频彩色多普勒超声诊断直肠肛管周围脓肿的研究

目的探讨经直肠高频彩色多普勒超声诊断直肠肛管周围脓肿的声像图特点及术前定位的临床应用价值。方法应用7-10 MHz的高频双平面探头,对88例直肠肛周脓肿患者进行经直肠彩色多普勒超声(简称腔内超声)检查,并应用常规腹部3.5 MHz探头在体表肛门周围超声(简称肛周超声),观察声像图特征,分析对比这两种超声方法对肛周脓肿的诊断、内口判断的准确性。结果本组病人腔内超声与肛周超声对脓肿是否形成及脓肿内口的判定均有显著性差异(P0.05),腔内超声对脓肿形成诊断率达98.8%,对脓肿内口的判断准确率达95%,均高于肛周超声;此两种超声方法观察到的肛周脓肿声像学特点无明显差异。结论经直肠高频彩色多普勒超声是对肛周脓肿更为有效的影像学诊断方法,对脓肿的观察、定位具有良好的直观性,有助于临床上更好地确定治疗方案。     

A 120-MHz Ultrasound Probe for Tissue Imaging

Ultrasound transducers with center frequency above 100 MHz are expected to be used for future diagnostic tissue characterization because of their high lateral resolution. We have fabricated a 120-MHz transducer that consists of a ZnO piezoelectric film on a sapphire substrate that has a concave acoustic lens. The lateral resolution was calculated as 13 μm. The insertion loss of the transducer, defined as the difference between the received voltage and the transmitted one, was −45 dB. The 6-dB bandwidth of the received signal was approximately 40 MHz. The transducer was mounted in a rod-shaped probe to ensure contact within vivotissue, because of the low penetration of ultrasound in the high frequency region. While the probe is rotated and moved along its axis mechanically, the transducer receives backscattered ultrasound from the surrounding tissue on a cylindrical plane that is kept a constant distance from the probe surface. The feasibility of this high-frequency tissue imaging probe has been demonstrated by obtaining preliminary images of anin vitrobovine kidney.     

High frequency ultrasonic imaging of skin: experimental results

Experimental results are presented demonstrating the application of pulse echo ultrasound to imaging the skin. A laboratory prototype B-mode mechanical scanner was employed to obtain images of human skin, both in vitro and in vivo, using broadband pulsed ultrasound at 25 MHz. Images were formed by processing digitized A-mode waveforms and displaying the resulting two-dimensional cross sections using a digital imaging system. Images obtained by rectifying the A-modes are compared to those derived using a software-based cross-correlation technique. Scans of test targets demonstrate that an axial resolution of 100 m can be achieved at 25 MHz when the digital correlation method is employed. Lateral resolution is limited by the 0.25 mm half-power focal beamwidth of the transducer. Seventeen in vitro ultrasonic scans of human skin were compared to frozen section histology. Average skin depth was well correlated between the two techniques ( = 0.99, p less than 0.001). Application of cross-correlated processing to 25 MHz in vivo images produced good delineation of epidermis, papillary, and reticular dermis. Conversion to a 50 MHz transducer did not delineate skin layers as well as the 25 MHz transducer due to inherent difficulties with transducer reverberations.     

A 3D computer simulation to study the efficacy of transperineal versus transrectal biopsy of the prostate

Objectives This paper aims to provide an explanation for the positive findings of the improved prostate cancer detection rate by the transperineal approach when compared to the transrectal approach. The peripheral zone (PZ) is a region of the prostate with the most cancer occurrence. Hence, the ability to reach it consistently can improve the cancer detection rate significantly. Methods In a prospective study, ultrasound images taken from five patients were used to reconstruct the prostate, rectum and pubic bone with the perineal wall data obtained from the same patient. Each anatomical model virtually underwent prostate biopsy transperineally and transrectally with 10 cores biopsy each. We assessed the efficacy by calculating the volume of PZ tissue obtained from each approach. Results The overall volume of virtual core tissue taken from the PZ was 81.7% from a total volume of 100 prostate biopsy cores. Of the volume of tissue extracted transperineally, 98.5% was from the PZ compared to only 64.9% of the transrectally extracted tissue. Conclusions This is the first paper that acquires and reconstructs the virtual anatomy of the prostate, rectum and pubic bone with the perineal wall. Transperineal biopsy is superior to the transrectal method in obtaining the peripheral zone tissue. This explains the findings that the prostate cancer detection rate is higher via the transperineal approach.     

经直肠超声检查在血精病因分析中的价值

目的探求经直肠超声检查在血精病因诊断中的价值。方法对53例血精患者经直肠超声检查前列腺、精囊及射精管。结果53例血精患者中47例(88.7%)伴有射精管囊肿、苗勒氏管囊肿、精囊炎、前列腺病变;9例患者在前列腺、精囊及射精管囊肿内发现结石或钙化。炎症是本组血精最常见的病因(26例,39.6%)。结论经直肠超声检查对确定血精的局部性病因具有较高的价值,是血精首选的影像学诊断方法。     

Development and application of new equipment for transrectal ultrasonography

We have successfully developed a new type of equipment for transrectal ultrasonography. The equipment consists of three parts: a transducer assembly, a radial scanner, and a chair. The specially designed transrectal transducer assembly consists of a double tube system; a concave oscillating disc is attached to the rotative inner tube. The top of the transducer tube is covered with a water-filled rubber balloon which is kept in contact with the rectal wall. The chair has a hole over which the anus is positioned and the tube with the radial scanner is introduced into the rectum from below. The angle of the. projecting transducer tube can be shifted freely with a lever. The depth of insertion of the transducer is controlled by the scanner handle. This “sitting posture” procedure has several advantages over the lithotomy position. The diagnostic application of this method is described for examination of different intrapelvic organs such as the prostate, the urinary bladder and the uterus.