Department of Radiology, University of Michigan, Ann Arbor, MI 48109-0322, USA.
Ultrasound Obstet Gynecol. 2012 Apr;39(4):444-51. doi: 10.1002/uog.9082.
To evaluate the utility of magnetic resonance imaging (MRI) in diagnosing structural injury in primiparous women at risk for pelvic floor injury.
This was an observational study of 77 women who underwent 3T MRI after delivery. Women were operationally defined as high risk (n = 45) for levator ani muscle tears (risk factors: second-stage labor > 150 min or < 30 min, anal sphincter tear, forceps, maternal age > 35 years and birth weight > 4000 g) or low risk (n = 32): vaginally delivered without these risk factors (n = 12); delivered by Cesarean section after second-stage labor > 150 min (n = 14) or delivered by Cesarean section without labor (n = 6). All women were imaged using fluid-sensitive MRI sequences. Two musculoskeletal radiologists reviewed images for bone marrow edema, fracture, pubic symphysis measurements and levator ani tear.
MRI showed pubic bone fractures in 38% of women at high risk for pelvic floor injury and in 13% of women at low risk for pelvic floor injury (χ(2) (3) = 9.27, P = 0.03). Levator ani muscle tears were present in 44% of the high-risk women and in 9% of the low-risk women (χ(2) (3) = 11.57, P = 0.010). Bone marrow edema in the pubic bones was present in 61% of women studied across delivery categories. Complex patterns of injury included combinations of bone marrow edema, fractures, levator ani tears and pubic symphysis injuries. No MRI-documented injuries were present in 18% of women at high risk and 44% at low risk for pelvic floor injury (χ(2) (1) = 6.2, P = 0.013).
Criteria identifying primiparous women at risk for pelvic floor injury can predict increased risk of bone and soft tissue changes at the pubic symphysis. Fluid-sensitive MRI has utility for differential diagnosis of structural injury in postpartum women.
评估磁共振成像（MRI）在诊断初次分娩且有盆底损伤风险的女性结构性损伤中的作用。
这是一项对 77 名产后行 3T MRI 检查的女性进行的观察性研究。女性根据是否存在肛提肌撕裂的风险因素被分为高风险（n=45）和低风险（n=32）：高风险（风险因素：第二产程>150 分钟或<30 分钟、肛门括约肌撕裂、产钳、产妇年龄>35 岁且出生体重>4000 克）；低风险（无上述风险因素的经阴道分娩，n=12；第二产程>150 分钟行剖宫产分娩，n=14；无产程行剖宫产分娩，n=6）。所有女性均使用液体敏感 MRI 序列进行成像。两名肌肉骨骼放射科医生对骨髓水肿、骨折、耻骨联合测量和肛提肌撕裂进行阅片。
MRI 显示，高风险组中有 38%的女性存在耻骨骨折，低风险组中有 13%的女性存在耻骨骨折（χ²(3)=9.27，P=0.03）。高风险组中有 44%的女性存在肛提肌撕裂，低风险组中有 9%的女性存在肛提肌撕裂（χ²(3)=11.57，P=0.010）。各分娩组中，61%的女性存在耻骨骨骨髓水肿。复杂的损伤模式包括骨髓水肿、骨折、肛提肌撕裂和耻骨联合损伤的组合。高风险组中有 18%的女性和低风险组中有 44%的女性无 MRI 记录的损伤（χ²(1)=6.2，P=0.013）。
识别初次分娩且有盆底损伤风险的女性的标准可以预测耻骨联合处骨和软组织变化的风险增加。液体敏感 MRI 对产后女性结构性损伤的鉴别诊断具有一定作用。
