Lee Hyun Jung
Department of Obstetrics and Gynecology, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea.
Yeungnam Univ J Med. 2020 Apr;37(2):90-97. doi: 10.12701/yujm.2019.00353. Epub 2019 Oct 10.
To minimize damage to the ovarian reserve, it is necessary to evaluate the follicular density in the ovarian tissue surrounding endometrioma on preoperative imaging. The purpose of the present study was to evaluate the usefulness of subtraction pelvic magnetic resonance imaging (MRI) to detect ovarian reserve.
A subtracted T1-weighted image (subT1WI) was obtained by subtracting unenhanced T1WI from contrast-enhanced T1WI (ceT1WI) with similar parameters in 22 patients with ovarian endometrioma. The signal-to-noise ratio (SNR) in ovarian endometrioma, which was classified into the high signal intensity and iso-to-low signal intensity groups on the T2-weighted image, was compared to that in normal ovarian tissue. To evaluate the effect of contrast enhancement, a standardization map was obtained by dividing subT1WI by ceT1WI.
On visual assessment of 22 patients with ovarian endometrioma, 16 patients showed a high signal intensity, and 6 patients showed an iso-to-low signal intensity on T1WI. Although SNR in endometrioma with a high signal intensity was higher than that with an iso-to-low signal intensity, there was no difference in SNR after the subtraction (13.72±77.55 vs. 63.03±43.90, p=0.126). The area of the affected ovary was smaller than that of the normal ovary (121.10±22.48 vs. 380.51±75.87 mm2, p=0.002), but the mean number of pixels in the viable remaining tissue of the affected ovary was similar to that of the normal ovary (0.53±0.09 vs. 0.47±0.09, p=0.682).
The subtraction technique used with pelvic MRI could reveal the extent of endometrial invasion of the normal ovarian tissue and viable remnant ovarian tissue.
为尽量减少对卵巢储备功能的损害，有必要在术前影像学检查中评估子宫内膜异位囊肿周围卵巢组织中的卵泡密度。本研究的目的是评估减影盆腔磁共振成像（MRI）检测卵巢储备功能的实用性。
对22例卵巢子宫内膜异位囊肿患者，采用具有相似参数的对比增强T1加权成像（ceT1WI）减去未增强T1加权成像（unenhanced T1WI）来获得减影T1加权图像（subT1WI）。将在T2加权图像上分为高信号强度组和等信号至低信号强度组的卵巢子宫内膜异位囊肿中的信噪比（SNR）与正常卵巢组织中的信噪比进行比较。为评估对比增强的效果，通过将subT1WI除以ceT1WI获得标准化图。
在对22例卵巢子宫内膜异位囊肿患者进行视觉评估时，16例患者在T1加权成像上表现为高信号强度，6例患者表现为等信号至低信号强度。虽然高信号强度的子宫内膜异位囊肿中的SNR高于等信号至低信号强度的囊肿，但减影后的SNR无差异（13.72±77.55 vs. 63.03±43.90，p = 0.126）。患侧卵巢的面积小于正常卵巢（121.10±22.48 vs. 380.51±75.87 mm²，p = 0.002），但患侧卵巢存活剩余组织中的平均像素数与正常卵巢相似（0.53±0.09 vs. 0.47±0.09，p = 0.682）。
盆腔MRI使用的减影技术可揭示正常卵巢组织和存活的残余卵巢组织的子宫内膜侵袭范围。
