Table 3.
Summary of MRI-based classification systems of adenomyosis.
| Author, Year | Classification | Criteria | |
|---|---|---|---|
| Gordts et al., 2008 [6] | JZ hyperplasia | JZ thickness measuring ≥8 mm but <12 mm on T2-weighted images in women aged 35 years or less. Partial or diffuse type | |
| Adenomyosis | JZ thickness ≥12 mm; high-signal intensity myometrial foci; involvement of the outer myometrium: <1/3, <2/3, >2/3 | ||
| Adenomyoma | Myometrial mass with indistinct margins of primarily low-signal intensity on all MR sequences. Retrocervical, retrovaginal, fallopian tube, and bladder types | ||
| Kishi et al., 2012 [7] | Subtype I (intrinsic) | Adenomyosis has an intimate relationship with inner structural components of the uterus such as the endometrium and JZ | |
| Subtype II (extrinsic) | Adenomyosis arising from the outer shell of the uterus, disrupting the serosa but not affecting the inner components | ||
| Subtype III (intramural) | Adenomyosis residing solely in the myometrium | ||
| Subtype IV (others) | Indeterminate, does not fit into other subtypes | ||
| Grimbizis et al., 2014 [25] | Diffuse | Foci of endometrial mucosa scattered throughout the uterine musculature | |
| Focal | Adenomyoma | Infiltration of a restricted area of the myometrium with clear borders and mainly solid characteristics | |
| Cystic adenomyosis | Single adenomyotic cyst within the myometrium | ||
| Polypoid | Typical | Circumscribed endometrial masses composed of endometrioid glands and smooth muscle without architectural or cellular atypia | |
| Atypical | A variant of polypoid with atypical endometrial glands and cellular smooth muscle stroma | ||
| Other | Endocervical | Adenomyomatous polyps in the cervix that contain epithelial component of endocervical type | |
| Retroperitoneal | Nodules thought to arise from metaplasia of Müllerian remnants beneath the peritoneum and in the upper rectovaginal septum | ||
| Dashottar et al., 2015 [26] | Focal | Focal widening of the JZ ≥14 mm | |
| Diffuse | Even | Consistent JZ thickening ≥14 mm throughout the uterus | |
| Uneven | Variable JZ thickening ≥14 mm throughout the uterus | ||
| Bazot et al., 2018 [24] | Internal adenomyosis | Focal | Localized intramyometrial tiny cystic component with or without JZ bulging |
| Superficial | Disseminated subendometrial tiny cystic component without JZ hypertrophy | ||
| Diffuse | Disseminated intramyometrial tiny cystic component with JZ hypertrophy | ||
| Adenomyomas | Intramural solid | Ill-defined myometrial lesion with tiny cystic component | |
| Intramural cystic | Ill-defined myometrial lesion with hemorrhagic cystic cavity | ||
| Submucosal | Ill-defined myometrial lesion with tiny cystic component and intracavitary protrusion | ||
| Subserosal | Ill-defined subserous myometrial lesion with tiny cystic component | ||
| External adenomyosis | Posterior | Ill-defined posterior myometrial mass associated with posterior deep endometriosis | |
| Anterior | Ill-defined subserosal anterior myometrial mass associated with anterior deep endometriosis | ||
| Kobayashi et al., 2020 [24] | Affected area | A | Internal adenomyosis, thickness of JZ >12 mm |
| B | External adenomyosis, thickness of JZ <8 mm | ||
| Size & pattern | A1 or B1 | <1/3 of uterine wall, mostly focal | |
| A2 or B2 | <2/3 of uterine wall, can be focal or diffuse | ||
| A3 or B3 | >2/3 of uterine wall, mostly diffuse | ||
| Concomitant pathologies | C0–5 | None C0, peritoneal endometriosis C1, ovarian endometrioma C2, deep infiltrating endometriosis C3, uterine fibroids C4, others C5 | |
| Location | D1–5 | Anterior D1, posterior D2, left lateral D3, right lateral D4, fundus D5 | |