膀胱癌盆腔正常大小的淋巴结转移：CT、MRI评价的比较

Detecting metastases in normal-sized pelvic lymph nodes in patients with bladder cancer： comparison of computed tomography and magnetic resonance imaging

目的探讨CT和MRI对正常大小的膀胱癌转移淋巴结的诊断效能。 方法回顾性分析2012年1月至2016年12月我院118例行根治性膀胱切除术患者的临床资料。男107例，女11例，年龄34～83岁，平均63岁。93例行泌尿系多排螺旋CT扫描，27例行MRI扫描，其中2例同时行两种检查。分析患者的CT和MRI资料，与病理结果对照，分别以淋巴结短径≥0.3 cm和≥1.0 cm作为阳性诊断阈值，计算CT和MRI诊断的敏感性、特异性及阳性预测值。结果118例患者术后病理检查示27例（22.7%, 27/118）发生淋巴结转移，共检测淋巴结1 705枚，转移119枚，其中分布在膀胱周围41枚（34.5%），髂内15枚（12.6%），髂外36枚（30.3%），闭孔25枚（21.0%）及骶前2枚（1.7%）。以淋巴结短径≥0.3 cm为阳性，CT和MRI的敏感性、特异性和阳性预测值分别为16.0%（13/81）、99.2%（1 342/1 353）、54.2%（13/24）和56.5%（13/23）、99.2%（246/248）、86.7%（13/15），两者的敏感性和阳性预测值比较差异均有统计学意义（P〈0.001、P＝0.036）。以淋巴结短径≥1.0 cm为阳性，CT和MRI的敏感性、特异性、阳性预测值分别为6.2%（5/81）、99.9%（1 342/1 353）、83.3%（5/6）和13.0%（3/23）、100.0%（248/248）、100.0%（3/3），两者的敏感性和阳性预测值比较差异均无统计学意义（P＝0.275、P＝1.000）。结论正常大小的淋巴结转移发生率较高，MRI对其的诊断效能明显优于CT；当淋巴结短径≥1.0 cm时，两者的诊断效能无明显差异。

To estimate the diagnostic performance of computer tomography （CT） and magnetic resonance imaging （MRI） for detecting metastasis in pelvic lymph nodes with normal size in patients with bladder cancer.Methods Imaging of CT and MRI and clinical data of 118 patients who underwent radical cystectomy and pelvic lymphadenectomy were reviewed. The diagnostic efficacy of CT and MRI were analyzed when taking lymph nodes short axis diameter ≥0.3 cm and ≥1.0 cm respectively as diagnostic criterion of metastasis with correlation of pathological results.Results 22.7% （27/118） of patients were confirmed lymph nodes malignancies among 118 patients based on pathology. Totally 1 705 lymph nodes were detected in surgery and 119 of them were observed malignancy according to pathological presentation. The malignant nodes were mainly distributed in the perivesical （35.4%, 41/119）, internal iliac （12.6%, 15/119）, external iliac （30.3%, 36/119）, obturator region （21.0%, 25/119） and presarcal region （1.7%, 2/119）. Imaging of CT and MRI showed that when taking nodes with ≥0.3 cm in maximum short-axis diameter （MSAD） as positive, the sensitivity （Se）, specificity （Sp）, and positive predictive values （PPV） were 16.0%, 99.2%, 54.2% and 56.5%, 99.2%, 86.7% respectively. While taking MSAD≥1.0 cm as malignant, the Se, Sp and PPV of CT and MRI were 6.2%, 99.9%, 83.3% and 13%, 100%, 100% respectively. When taking MSAD ≥0.3 cm as positive, the Se and PPV between CT and MR were statistically different（P〈0.001 and P=0.036, respectively）. When taking MSAD ≥1.0 cm as positive, there was no statistically difference （P=0.275 and 1.000, respectively）.Conclusions The incidence of normal-sized lymph node metastasis was higher in patients with bladder cancer. At this phase the MRI evaluation was superior to that of CT. When the MSAD ≥1.0 cm, there was no significant difference between CT and MRI.