無論是歐洲、美國或國際尿控協會的文章，均表示使用恥骨上超音波測量膀胱壁厚度(BWT)及膀胱逼尿肌厚度(DWT)來預測男性膀胱出口阻塞 (BOO)是可靠的。無論群族特性、掃描技巧或研究設計方法如何，總結這些研究報告，利用膀胱壁厚度及膀胱逼尿肌厚度來預測男性膀胱出口阻塞的正確率可以將近90%，並且是跟病人的症狀分數及臨床表現是成正相關的。如果作為藥物或是手術治療後的排尿功能改善情況的預測工具也是很理想的工具。因為膀胱出口阻塞，膀胱必須要增加收縮壓力來抵抗膀胱出口阻塞因而多出一些負擔，因而造成膀胱逼尿肌厚度增加及膀胱壁小樑化，因此可以說膀胱逼尿肌厚度增加及膀胱壁小樑化代表這些病人有膀胱出口阻塞。也因為陸陸續續有動物實驗證實，有膀胱出口阻塞的膀胱壁肥厚是因於膀胱平滑肌肥大、纖維細胞增生及膠原纖維沈澱在逼尿肌裏，超音波估計的膀胱壁總重量（UEBW）也用來評估男性良性膀胱出口阻塞造成的下泌尿道症狀。

超音波估計的膀胱壁總重量≥35克會增加兩倍的風險(OR: 2.29)，未來很有可能會需要手術。相對的，如果病人接受藥物治療，例如乙型阻斷劑，或是接受手術，例如攝護腺刮除手術，膀胱壁總重量均會降低。這在我們觀察到經過TURP，並且症狀改善後的病人在幾年後，再接受膀胱鏡檢查後會發現膀胱壁小樑化會有很明顯改善是吻合的。膀胱壁厚度的閾質定在≥2.9 mm，會有100%正向預測值來診斷男性的BOO，並且可能可以代替壓力尿流檢查。 膀胱逼尿肌厚度的測量如果是2.4 mm是確定是膀胱出口阻塞，如果是3mm以上則是嚴重膀胱出口阻塞。

使用膀胱壁厚度或膀胱逼尿肌厚度來評估男性良性膀胱出口阻塞造成的下泌尿道症狀是簡單、高度正確、並且是不具侵入性的檢查。但是要標準化它的臨床實施技巧，如果標準化之後，可能可以減少男性良性膀胱出口阻塞造成的下泌尿道症狀的病人，不必要再接受較具侵入性的壓力尿流尿路動力學檢查。=

BACKGROUND:
To evaluate the role of the ultrasound assessments of the bladder/detrusor wall thickness (BWT/DWT) and the ultrasound estimated bladder weight (UEBW) in lower urinary tract symptoms diagnosis and treatment.

EVIDENCE ACQUISITION:
A systematic literature search from January 1995 until February 2016 was performed on PubMed using the following terms: “bladder weight”, “bladder wall thickness”, “detrusor wall thickness”, “LUTS”, “bladder outlet obstruction” (BOO), “benign prostatic obstruction”. Additional references were obtained from the refer¬ence list of full-text manuscripts. Abstracts presented at the annual congresses of the European Association of Urology, American Urology Association and the International Continence Society were also included.

EVIDENCE SYNTHESIS:
BWT and DWT are accurate predictors of BOO. Despite several differences in the technique assessment, population characteristics and study design, the BWT/DWT accuracy for BOOwas close to 90%. Further¬more, the ultrasound evaluation of bladder/detrusor thickness correlates positively with symptoms score and the main clinical parameters in BPH patients. Lastly, BWT and DWT have proved to be optimal predictor of response to medical/surgical treatment of lower urinary tract symptoms/benign prostatic obstruction (LUTS/BPO). However, the lack of standardization among the available studies marks these methods promising but still experimental and further studies are needed to clarify the standard methodology.

CONCLUSIONS:
The ultrasound evaluation of bladder/detrusor thickness appears to be simple, highly accurate and non-invasive technique to predict BOO and to evaluate the clinical outcomes after medical/surgical treatments for LUTS/BPH. The implementation of these techniques and their standardization will probably better define their role in the diag¬nostic algorithms of patients with LUTS and possibly reduce the number of unnecessary pressure flow-studies.