MRI Female Pelvis – Generic Standard Protocol

1. Executive Summary

Female pelvic MRI is one of the most clinically impactful examinations in gynaecological imaging. Across the complete spectrum of gynaecological indications — from uterine leiomyoma mapping to endometriosis staging, from cervical cancer local staging to adnexal mass characterisation — MRI provides soft tissue contrast, multiplanar capability, and functional information (DWI, DCE) that ultrasound and CT cannot replicate. The European Society of Urogenital Radiology (ESUR) has produced a series of indication-specific guidelines [1, 2, 3, 4, 5] that, taken together, define the current evidence base for female pelvic MRI protocols.

The generic adult female pelvic MRI described on this page is designed for non-specific indications — the initial assessment examination when the primary clinical question has not yet been fully defined, or when multiple gynaecological conditions are being surveyed simultaneously. It covers the uterus, cervix, vagina, adnexa (ovaries and fallopian tubes), pelvic floor, bladder base, and regional lymph nodes. It is built around the ESUR minimum protocol core endorsed across multiple gynaecological indication-specific guidelines, providing the foundational multiplanar T2 and T1 sequences that are common to all female pelvic indications.

The technical foundation of female pelvic MRI is T2-weighted imaging, which provides the uterine zonal anatomy (endometrium, junctional zone, myometrium) that underpins nearly all diagnostic reasoning. No other imaging modality depicts the junctional zone, the cervical stroma, or the internal architecture of adnexal lesions with the resolution and tissue contrast that T2 provides. This places T2 — in multiple planes, with specific oblique angulations relative to the uterus — at the absolute centre of every female pelvic MRI protocol.

1.1 Core Strengths

Uterine zonal anatomy: the endometrium, junctional zone (JZ), and outer myometrium are uniquely depicted on T2. The JZ thickness — normally ≤ 12 mm — is the primary imaging marker for adenomyosis. Myometrial invasion depth in endometrial cancer is staged directly from T2 multiplanar images. No other modality provides this information reliably.

Cervical cancer local staging: MRI is the standard modality for cervical cancer local staging (FIGO stage IB and above). The intact low-signal cervical stroma on T2 — the "cervical ring" — is the key finding indicating absence of parametrial invasion (Stage IIB). Vaginal vault involvement, parametrial extension, and bladder/rectal wall invasion are all assessed on multiplanar T2 [4].

Endometriosis assessment: deep pelvic endometriosis (DPE) is demonstrated by multiplanar T2 TSE (thickening and "kissing" obliteration of structures) and T1-FS (haemorrhagic implants and endometriomas appear bright). MRI is the only non-invasive method for pre-surgical mapping of DPE compartments [3, 6].

Leiomyoma mapping: MRI provides the three-dimensional map of leiomyoma number, size, location (submucosal/intramural/subserosal), and degeneration type that guides fertility-sparing surgery, embolisation planning, and HIFU candidacy assessment [2].

Adnexal mass characterisation: for sonographically indeterminate adnexal lesions, MRI achieves substantially higher specificity for benign characterisation than ultrasound alone. T2 characterises cyst morphology; T1-FS identifies haemorrhagic content; DWI and DCE improve solid lesion discrimination [5, 7].

No ionising radiation: critical for reproductive-age women who may require serial imaging for endometriosis surveillance, fibroid follow-up, or cancer staging.

1.2 Intrinsic Limitations of the Generic Protocol

The generic female pelvic protocol is a broad-coverage examination designed for initial assessment. It is not optimised for any single indication, which means:

Oblique planes are indication-specific: the uterine long-axis oblique planes that are mandatory for endometrial cancer staging and leiomyoma mapping require knowledge of the uterine position and orientation before prescribing. In a truly generic protocol, the technologist must prescribe these oblique planes from the sagittal T2 at the beginning of the examination — this requires training and cannot be delegated to a non-adapted body axial prescription.

DPE requires bowel preparation: the ESUR guidelines for endometriosis specifically recommend bowel preparation (enema) and vaginal opacification for optimal DPE assessment [3, 6]. The generic protocol without these preparations is diagnostically suboptimal for suspected DPE.

DCE is not universal: dynamic contrast-enhanced (DCE) MRI for adnexal mass characterisation and tumour perfusion assessment is increasingly recommended by ESUR [5, 7] but is not universally available and adds time and patient burden. The generic protocol includes DCE as conditional.

Endometrial cancer myometrial invasion staging requires < 3 mm slices on specific planes: the generic protocol at standard 3–4 mm slices is suboptimal for staging early-stage endometrial cancer. Dedicated high-resolution oblique sequences are required.

The generic protocol does not reliably exclude superficial endometriosis: peritoneal implants < 5 mm may be invisible even on optimised MRI. MRI has limited sensitivity for superficial endometriosis regardless of protocol quality.

When dedicated child protocols are required: endometrial carcinoma staging; cervical carcinoma staging; deep pelvic endometriosis surgical planning; leiomyoma mapping for embolisation or HIFU; IOTA/ESUR adnexal mass characterisation; ovarian cancer staging; pelvic floor assessment; congenital Müllerian anomaly assessment; fetal MRI (dedicated paediatric/obstetric protocols not covered here).

2. Main Clinical Indications

2.1 Standard Indications

Uterine assessment covers the spectrum from leiomyoma mapping through adenomyosis to endometrial polyps and congenital anomalies. For leiomyoma mapping before myomectomy, hysterectomy, uterine artery embolisation (UAE), or MR-guided focused ultrasound surgery (MRgFUS), MRI provides the complete three-dimensional inventory — number, size, location, relationship to the endometrial cavity, and degeneration type — that ultrasound underestimates in multi-fibroid uteri [2]. The ESUR leiomyoma guidelines recommend MRI as the standard imaging method for pre-procedural mapping [2]. Adenomyosis is characterised on MRI by junctional zone thickening, small foci of high T1/low T2 signal within the myometrium, and characteristic T2 morphology — findings that are not reliably depicted by ultrasound in many cases.

Endometrial cancer staging is the primary oncological indication for female pelvic MRI. MRI accurately assesses myometrial invasion depth (the key FIGO staging determinant distinguishing IA from IB), cervical stromal invasion (FIGO stage II), and parametrial extension. DWI improves lesion detection and characterisation. Post-contrast T1 sequences add specificity for myometrial invasion. The generic protocol provides the baseline sequences; the dedicated staging child protocol adds high-resolution oblique planes and quantitative DCE [1].

Cervical cancer local staging is a specific and well-validated indication. MRI is recommended by multiple international guidelines (FIGO, ESMO, NCCN, ESUR) as the standard for local staging of FIGO Stage IB1 and above [4]. The intact low-signal cervical stroma on T2 is the key stage IIB exclusion sign. The generic protocol provides the necessary multiplanar T2 coverage; the staging protocol adds specific thin-section oblique planes centred on the cervix.

Endometriosis and pelvic pain assessment: when ultrasound is inconclusive or incomplete for suspected deep pelvic endometriosis, MRI is the next-line investigation. ESUR guidelines recommend MRI for pre-surgical DPE mapping [3, 6]. The generic protocol with full T2 and T1-FS is adequate for initial assessment; the dedicated endometriosis protocol adds bowel preparation, vaginal opacification, and potentially rectal opacification for complete compartmental mapping.

Adnexal mass characterisation: for sonographically indeterminate adnexal lesions after appropriate ultrasound (including IOTA assessment), MRI with T2, T1-FS, DWI, and post-contrast sequences provides characterisation that substantially improves specificity for benign lesions. The ESUR adnexal mass guidelines [5] and the O-RADS MRI scoring system [7] provide structured characterisation frameworks. The generic protocol is adequate for most adnexal characterisation questions; DCE-MRI adds specificity and is recommended by ESUR [5, 7].

Post-treatment surveillance for gynaecological malignancies — cervical cancer, endometrial cancer, ovarian cancer — requires standardised serial MRI. The generic protocol provides the baseline sequences; modifications for specific treatment types are addressed in dedicated child protocols.

2.2 Urgent Red Flags Requiring Expedited or Emergency Imaging

Female pelvic pathology uncommonly presents as a true imaging emergency; however, the following scenarios require expedited or urgent MRI:

3. Preparation Reference

Universal MRI safety screening is covered in the general MRI preparation page and is not repeated here.

3.1 Anatomy-Specific Preparation Items

Bladder filling — the most important pelvic preparation step: the female pelvic MRI requires a moderately filled bladder (not overdistended, not empty). A partially filled bladder: (1) provides an anatomical landmark delineating the uterovesical pouch and the anterior lower uterine segment; (2) lifts the uterus off the pelvic floor, improving access for oblique plane planning; (3) provides natural T2 contrast for assessing bladder wall invasion in advanced cervical or endometrial cancer. Overdistention is counterproductive — it pushes the uterus posteriorly and produces patient discomfort and motion. Standard instruction: void 1 hour before examination; drink 500 mL water 30–45 minutes before the appointment.

Antiperistaltic agents: bowel peristalsis produces motion artefacts in the female pelvis — particularly on T2 sequences — because the sigmoid colon and small bowel loops are adjacent to the uterus and adnexa. Hyoscine butylbromide (20 mg IV) or glucagon (0.1 mg IV) substantially improves T2 image quality by reducing bowel motion [3, 6]. ESUR guidelines for endometriosis specifically recommend antiperistaltic agents; their use is strongly encouraged for all female pelvic MRI regardless of indication.

Bowel preparation (indication-specific): ESUR endometriosis guidelines recommend a low-residue diet 1–2 days before the examination and a cleansing enema the morning of the examination for DPE assessment [3, 6]. For the generic protocol in non-endometriosis indications, formal bowel preparation is not universally required but a mild laxative the evening before improves image quality.

Vaginal opacification (conditional — endometriosis, vaginal/vault assessment): sonographic gel (ultrasound gel) inserted into the vagina immediately before the examination improves delineation of the vaginal walls, vaginal fornices, and the rectovaginal septum — all relevant for DPE mapping and vaginal vault assessment in cancer staging. For the generic protocol this is optional; for the dedicated endometriosis child protocol it is mandatory per ESUR guidelines [3, 6].

Removal of vaginal pessaries and intrauterine devices (IUDs): metallic IUDs (copper-bearing) produce susceptibility artefacts centred on the endometrial cavity on T2 and DWI sequences, which may obscure endometrial lesions. When an IUD is present and endometrial assessment is the primary question, the referring clinician should be contacted regarding IUD removal before MRI. Levonorgestrel-releasing IUDs (plastic frame with metallic marker) produce less artefact. Document IUD presence in the report and note artefact limitations.

Menstrual cycle timing: the signal of the endometrium, junctional zone, and myometrium varies with the menstrual cycle. For leiomyoma mapping and endometriosis, no cycle timing is required in routine practice. For adnexal mass characterisation, functional cysts are largest in the first half of the cycle; scanning in the follicular phase (days 5–14) reduces the likelihood of a dominant follicle being misinterpreted as an adnexal cyst. For endometrial cancer staging, cycle timing is not relevant.

Prior surgery documentation: prior hysterectomy, myomectomy, oophorectomy, or caesarean section changes the expected anatomy and must be communicated before scanning. Post-caesarean section niche (isthmocele) assessment requires specific T2 sagittal planes; post-hysterectomy vault assessment requires adjusted coverage.

3.2 Patient Positioning on the MRI System

Standard position: supine, feet-first entry. The female pelvis is positioned near isocentre for optimal signal homogeneity with the phased-array coil. Arms should be on the chest or at the sides — not elevated, as in abdominal imaging — because arm elevation shifts the coil away from the pelvic structures.

Coil selection: a multi-channel phased-array pelvic coil (minimum 16 channels recommended) in combination with the integrated posterior spine coil provides optimal SNR for the deep pelvic structures. A dedicated pelvic coil placed on the lower abdomen and upper thighs (anterior elements) combined with the posterior coil provides the best coil coupling for the uterus, cervix, and adnexa. Endoluminal coils (endorectal, endovaginal) are not standard practice for generic female pelvic MRI; they are used in specific research or focused examinations (cervical cancer microanatomical staging) and are not described here.

Centring: isocentre at the level of the uterine fundus — approximately at the level of the anterior superior iliac spine, or 2–3 cm above the pubic symphysis. Verify on the three-plane localiser that: the uterine fundus is included in the superior coverage; the posterior vaginal wall and pouch of Douglas are in the inferior coverage; both ovaries are within the lateral FOV. For retroflexed or retroverted uteri, the fundus is lower and more posterior — adjust the centring accordingly.

Common positioning errors:

• Centring too cranially: the cervix and vaginal vault are excluded inferiorly
• Centring too caudally: the uterine fundus is excluded superiorly — a frequent error in nulliparous women with a high uterine fundus
• FOV too narrow laterally: ovaries excluded — the adnexa may lie lateral to the lateral uterine walls by 3–5 cm

4. Standard Protocol Design

The female pelvic protocol is centred on multiplanar T2 imaging relative to the uterine long axis, supplemented by T1-FS for haemorrhagic content, DWI for lesion detection and characterisation, and post-contrast T1 for enhancement assessment.

4.1 Mandatory Core Sequences

4.2 Conditional Sequences

4.3 Rationale Summary Per Sequence

Sagittal T2 is the planning sequence and the orientation providing the most anatomical information about the uterus as a whole — uterine position (anteversion/retroversion/flexion), length, endometrial thickness, junctional zone, myometrial signal, and the relationship to the cervix, bladder, and rectum. Every female pelvic MRI must begin with a sagittal T2 because the uterus-specific oblique planes for subsequent sequences can only be correctly prescribed from this orientation. The sagittal T2 is also the primary sequence for assessing the cervix, the posterior vaginal fornix, the uterovesical space, and the anterior rectal wall.

The tissue contrast logic: the uterine junctional zone (compact myometrium) is T2-hypointense; the outer myometrium is T2-intermediate; the endometrium is T2-hyperintense; the cervical stroma is T2-hypointense. This zonal anatomy is the diagnostic substrate for virtually all uterine pathology interpretation.

Axial oblique T2 (perpendicular to the uterine long axis) provides true cross-sections of the uterine body. This is the plane for assessing the myometrial invasion depth in endometrial cancer (the T2 depth measurement is a surrogate for the histopathological staging criterion), the leiomyoma relationship to the endometrial cavity (submucosal classification), the JZ thickness for adenomyosis grading, and the transverse extent of any uterine lesion. This plane is only achievable by angulating from the sagittal T2 — it is uterus-specific and cannot be produced by standard body axial slices for anything but a perfectly anteverted uterus.

Coronal oblique T2 (parallel to the uterine long axis) displays the full endometrial cavity length, the uterine fundal contour (important for congenital anomalies — arcuate, septate, bicornuate), and both uterine cornua simultaneously. The ovaries and parametrial tissues are seen in relation to the uterus on this plane.

Axial T1 (large FOV, no fat suppression) is the fundamental haemorrhage and fat detection sequence. For the female pelvis, T1 hyperintensity without fat suppression indicates: haemorrhagic content (endometriomas, haemorrhagic cysts, adenomyotic cysts, haemorrhagic infarction of a fibroid); proteinaceous content; fat-containing lesions (dermoid cysts — teratomas — are T1-bright from their fatty content). The large FOV (36–40 cm) on this sequence is intentional: it includes the para-aortic region and retroperitoneal structures that are relevant for staging and incidental finding documentation.

T1 with fat suppression (T1-FS) distinguishes fat-containing lesions from haemorrhagic lesions: dermoids lose signal on T1-FS (fat suppressed); endometriomas retain T1-bright signal on T1-FS (haemorrhagic, not fat). This is the single most important sequence for endometrioma detection and for distinguishing dermoid (teratoma) from other T1-bright adnexal lesions. The T1-FS also depicts haemorrhagic peritoneal implants — the typical finding in superficial haemorrhagic endometriosis — as focal T1-bright foci against the dark suppressed fat background.

DWI with multi-b-value provides diffusion restriction assessment for lesion detection and malignancy characterisation. In the female pelvis, DWI serves three main functions: (1) lesion detection — restricted diffusion makes endometrial and cervical tumours conspicuous even when their T2 signal is not dramatically different from background myometrium; (2) lymph node characterisation — restricted diffusion in lymph nodes supports metastatic involvement; (3) adnexal mass solid component detection — restricted diffusion in solid ovarian tumour components supports malignancy. The ADC map must always be reviewed alongside the high-b images to exclude T2 shine-through. DWI is now recommended as a standard component of all gynaecological malignancy protocols by ESUR and multiple oncological guidelines [1, 4].

Post-contrast T1 3D FS provides enhancement characterisation for: myometrial invasion enhancement pattern (endometrial cancer child protocol); enhancement of solid components in adnexal masses; DCE kinetics for adnexal lesion characterisation (conditional); parametrial enhancement in cervical cancer; lymph node enhancement in staging.

4.4 Sequence Matching and Cross-Sequence Consistency

The three T2 planes (sagittal, axial oblique, coronal oblique) are all angulated relative to the uterus — not relative to the body. They must all be prescribed from the sagittal T2 using the uterine long axis as the reference. For the sequences to be diagnostically consistent — enabling cross-referencing of a lesion across all three planes — their slice positions must be aligned so that a lesion visible in one plane is identifiable in the corresponding location in the other planes. This requires that the centre of the FOV for all three planes coincides with the uterine body/isthmus junction (the reference point for the uterus-specific planes).

For post-contrast T1, the pre-contrast T1 3D must use identical geometry. In gynaecological malignancy, subtraction of post minus pre allows detection of subtle enhancing lesions against T2-dark background myometrium.

For serial studies (tumour response assessment, endometriosis follow-up, fibroid surveillance), the uterine long axis angle must be reproduced. Document the angulation in degrees from the coronal plane and the sagittal plane in the first examination.

4.5 Fat Suppression — Region-Specific Technical Considerations

Fat suppression in the female pelvis is used exclusively on T1 sequences — not on T2 sequences. This is the critical difference from many other anatomical regions:

T2 sequences: never fat suppress in routine female pelvic MRI. The perivascular fat, parametrial fat, and periovarian fat provide essential T2 anatomical landmarks. The junctional zone-to-myometrium interface and the cervical stroma-to-parametrial fat interface are defined by this fat signal. Fat suppression on T2 eliminates these reference points and degrades the assessment of parametrial invasion, peritoneal implants (which appear against the fat background), and ovarian-uterine relationships.

T1-FS: the standard fat suppression technique for pelvic T1 sequences is SPAIR or Dixon. At 1.5T, SPAIR provides acceptable fat suppression; at 3T, Dixon is preferred for its B0-independence because the pelvic B0 field at 3T can be significantly inhomogeneous near the iliac vessels, bladder base, and the lumbosacral region. Uniform fat suppression throughout the pelvis — including the parametria, the pouch of Douglas, and the presacral space — is essential for reliable T1-FS endometrioma detection.

STIR as alternative T1-FS: STIR is not the primary T1-FS choice for female pelvic MRI because it substantially reduces SNR relative to SPAIR/Dixon. However, STIR is a valid backup when fat suppression fails near metallic implants (hip prostheses, sacral hardware) and can be used as the sole fat suppression method in patients with substantial metallic artefact. As with all MRIninja protocols, STIR must never be used after gadolinium injection.

Dixon for pre- and post-contrast T1: the Dixon acquisition providing simultaneous water-only and fat-only images is the preferred approach for the dynamic post-contrast T1 3D sequence in the female pelvis. The fat-only image confirms fat suppression quality throughout the pelvis. The water-only image is the primary diagnostic post-contrast image.

5. Optimisation Strategy

5.1 Artifact Reduction by Source

Bowel peristalsis — the primary motion artefact source: the sigmoid colon, rectum, and small bowel loops are intimately adjacent to the uterus, adnexa, and pouch of Douglas. Peristaltic motion produces ghosting in the phase direction on all T2 sequences. This is the dominant image quality degradation factor in female pelvic MRI. Mitigation: antiperistaltic agents (Buscopan 20 mg IV or glucagon 0.1 mg IV) administered 5 minutes before scanning; bowel preparation the morning of the examination; positioning the phase encoding direction R-L for axial sequences (displaces bowel artefacts away from the uterus); saturation bands over the anterior bowel loops.

Pulsation artefacts from pelvic vessels: the iliac arteries and veins are adjacent to the ovaries and parametria. Arterial pulsation in the A-P direction on axial sequences can produce ghost images at the uterine level. Mitigation: phase encoding direction R-L for axial sequences displaces vascular pulsation from the uterus; pre-saturation bands over the iliac vessels superior and inferior to the acquisition slab.

IUD susceptibility artefact: copper IUDs produce T2 signal loss centred on the endometrial cavity, which degrades DWI and T2 sequences at the uterine fundus. On T2 TSE sequences, the IUD produces a small linear susceptibility void at the endometrial cavity that must be distinguished from an endometrial polyp or myoma. Mitigation: document IUD presence in the report; widen bandwidth on DWI to reduce distortion; inform the referring clinician that endometrial assessment is limited; recommend IUD removal for definitive endometrial assessment if clinically appropriate.

Chemical shift at the ovary-fat interface: at narrow bandwidth on T1 sequences, a chemical shift displacement artefact produces bright and dark bands at the ovary-fat interface in the frequency direction, simulating a perilesional rim or thin endometrioma wall. Mitigation: adequate bandwidth (≥ 200 Hz/pixel at 3T); the displacement is systematic and reproducible — its direction changes with swap of frequency and phase encoding.

B1 inhomogeneity at 3T in the pelvis: at 3T, the B1 field in the pelvis produces a characteristic signal inhomogeneity pattern — often a central brightening and peripheral darkening — that can simulate abnormal signal variation within the uterine myometrium. This is a B1-related RF field variation, not a tissue signal change. Mitigation: Dixon fat suppression (B0-independent, partially mitigates B1 effects on fat suppression); dielectric cushions placed on the lower abdomen can improve B1 homogeneity at 3T specifically; awareness of the pattern to avoid over-interpretation.

Motion from patient discomfort (full bladder, pain): a patient in pain or with a markedly overdistended bladder will move during long T2 TSE acquisitions, producing blurred or ghosted images. Mitigation: reduce bladder filling to comfortable level before scanning (not completely empty); administer analgesics if the patient reports significant pain before starting; keep individual sequence acquisitions ≤ 4–5 minutes; explain the examination duration and breathing requirements before starting.

5.2 Protocol Efficiency and Throughput

A complete female pelvic MRI with T2 in three planes, T1, T1-FS, DWI, and post-contrast T1 typically requires 35–45 minutes. Without contrast, 25–30 minutes.

For the majority of non-oncological indications (leiomyoma mapping, adnexal characterisation, endometriosis screening), the non-contrast protocol covering T2 in three uterus-specific planes + T1 + T1-FS + DWI is diagnostically adequate.

For gynaecological oncology staging — where both the enhancement pattern and DCE-MRI are diagnostically required — a full contrast-enhanced protocol is mandatory and the additional time is clinically justified.

For adnexal mass characterisation specifically, the ESUR guidelines and O-RADS MRI recommend post-contrast T1 (including DCE) as standard [5, 7]. A non-contrast examination is not sufficient for a complete O-RADS MRI assessment.

5.3 Field Strength Considerations

3T is the preferred field strength for female pelvic MRI, and is now the standard at most expert centres. The higher SNR at 3T enables: higher spatial resolution (3 mm or thinner slices) with equivalent acquisition time; improved DWI quality with less motion blur per acquisition; better lesion-to-background contrast for small endometrial and cervical lesions.

3T-specific challenges in the pelvis: B1 inhomogeneity (addressed by dielectric cushions); higher SAR restricts long-ETL TSE sequences; fat suppression inhomogeneity (Dixon preferred at 3T).

1.5T produces excellent female pelvic MRI with an optimised protocol and remains fully acceptable. The ESUR endometriosis guidelines [3] explicitly state that 1.5T and 3T provide similar diagnostic quality for female pelvic assessment when both are optimised. 1.5T is preferred for patients with metallic pelvic implants (fewer susceptibility artefacts), and may be more practical in obese patients where coil coupling efficiency differences are smaller.

Practical choice: use 3T as the default; use 1.5T when metallic implants are present, when the patient is very obese with poor B1 homogeneity at 3T, or when scanner access requires it.

6. Contrast Use Principles Specific to Female Pelvic MRI

6.1 Non-Contrast Standard Protocol — Sufficient For

Non-contrast female pelvic MRI (T2 multiplanar + T1 + T1-FS + DWI) is diagnostically adequate for:

• Leiomyoma mapping and characterisation (size, location, submucosal classification)
• Adenomyosis diagnosis and grading
• Endometrioma detection and surveillance
• Simple adnexal cyst characterisation (T2-bright, no solid component, no wall thickening)
• Congenital uterine anomaly assessment (Müllerian anomalies)
• Endometrial thickness measurement and initial assessment
• Pelvic floor assessment for prolapse
• Initial assessment of chronic pelvic pain

For most of these indications, non-contrast MRI is sufficient and gadolinium adds no diagnostic value that changes management.

6.2 Gadolinium Indicated — Region-Specific Contexts

Gadolinium-enhanced sequences are required or strongly useful for:

• Adnexal mass characterisation: enhancement of solid components, time-intensity curves for O-RADS MRI, solid papillary projection enhancement — all require contrast [5, 7]
• Endometrial cancer staging: myometrial invasion enhancement pattern; enhancement of lymph nodes; distinction of tumour from retained secretions in the endometrial cavity
• Cervical cancer staging: parametrial enhancement; cervical stroma integrity after contrast; lymph node characterisation [4]
• DPE malignant transformation: mural nodule enhancement in an endometrioma is a high-risk finding requiring gadolinium [3]
• Inflammatory pelvic disease / tubo-ovarian abscess: abscess wall enhancement and extent
• Post-treatment surveillance: scar enhancement vs recurrence; fistula tract enhancement
• Pelvic mass of uncertain origin: organ of origin and enhancement pattern
• Leiomyoma UAE candidacy assessment: uterine artery anatomy (MRA) and fibroid vascularity [2]

Non-ionic extracellular GBCAs (gadoteridol, gadobutrol, gadoterate meglumine) are standard for female pelvic MRI. Hepatobiliary agents provide no specific benefit for pelvic structures and should not be used for female pelvic indications.

Pregnancy: gadolinium is Category C and should be avoided unless the expected benefit clearly outweighs the risk. Non-contrast MRI is the standard for most obstetric indications.

6.3 Post-Contrast Acquisition Timing

Standard late phase: a single post-contrast T1 3D FS acquisition at 3–5 minutes after injection provides the equilibrium phase enhancement that characterises most pelvic pathology — myometrial enhancement, lymph node enhancement, adnexal lesion solid component enhancement.

DCE-MRI (for adnexal mass characterisation and endometrial cancer): a rapid time-series T1 3D FS acquisition beginning immediately after injection and continuing for 2–5 minutes, with temporal resolution of 15–30 seconds per volume. This provides the time-intensity curve data for O-RADS MRI [7] type II and type III adnexal lesion characterisation, and the enhancement kinetics distinguishing malignant from benign ovarian lesions. DCE requires specific vendor implementation (VIBE DCE on Siemens, THRIVE DCE on Philips, LAVA DCE on GE) and is not universally available in its validated form.

Subtraction imaging: post-minus-pre subtraction is standard for post-contrast T1 in all gynaecological oncology staging examinations and whenever pre-contrast T1 signal is elevated (haemorrhagic lesion, fat-containing lesion). In endometrial cancer, subtraction helps distinguish enhancing tumour from T2-bright retained secretions and from intrinsic T1 signal within the lesion.

7. Reporting Essentials

7.1 Interpretation Framework

Female pelvic MRI reporting requires systematic evaluation of four anatomical compartments — the uterine corpus, the cervix, the adnexa, and the pelvic supporting structures — before synthesising a diagnostic impression. The report must explicitly address the clinical question on the request form.

Uterine corpus assessment: size (three dimensions); position (anteverted/retroverted, anteflexed/retroflexed); endometrial thickness and signal on T2; junctional zone thickness and continuity; myometrial signal and presence of lesions; fibroids (number, size, location, type); adenomyosis features.

Cervix assessment: morphology; T2 stroma integrity; endocervical canal; any mass or signal change.

Adnexal assessment: each ovary individually — size; follicles; any cystic or solid lesion (characterise per O-RADS or descriptive criteria); Fallopian tubes (any hydrosalpinx, thickening).

Pelvic floor and peritoneum: pouch of Douglas contents; uterosacral ligaments; peritoneal implants; ascites; lymph nodes.

Broad diagnostic axes (applicable to all pelvic examinations): acute vs chronic; benign vs malignant; focal vs diffuse; single vs multifocal; confined vs spread beyond the organ; enhancing vs non-enhancing.

7.2 Mandatory Reporting Checklist

Technical quality:

• [ ] Field strength and contrast (if used) documented
• [ ] Uterus-specific oblique planes correctly prescribed and documented
• [ ] Antiperistaltic agent use noted
• [ ] Artefacts limiting interpretation (IUD, motion, fat suppression failure) noted

Uterus:

• [ ] Size (AP × transverse × longitudinal in cm)
• [ ] Position (anteverted/retroverted)
• [ ] Endometrial thickness (mm on midline sagittal T2) and signal
• [ ] JZ: maximum thickness (mm); regularity
• [ ] Myometrium: homogeneous / fibroid(s) present (number, size, location, FIGO subtype if known)
• [ ] Any focal lesion: size, signal characteristics, enhancement

Cervix:

• [ ] Stroma: intact / disrupted
• [ ] Endocervical canal: normal / mass
• [ ] External os: normal appearance

Adnexa (each side):

• [ ] Ovary visible: yes / no (postmenopausal atrophy)
• [ ] Ovary size (if visible)
• [ ] Any lesion: size, T2, T1, T1-FS, DWI, enhancement (O-RADS category if applicable)
• [ ] Fallopian tube: normal / dilated

Pelvis:

• [ ] Pouch of Douglas: free / fluid / adhesion / mass
• [ ] Uterosacral ligaments: normal / thickened / nodular
• [ ] Lymph nodes (iliac, obturator, para-aortic if in FOV): normal / suspicious
• [ ] Bladder wall: normal / thickened / invaded
• [ ] Rectal wall: normal / adjacent mass / invaded
• [ ] Peritoneum: normal / implants

7.3 Structured Reporting

Reports must include: Indication (specific clinical question — fibroid mapping, staging, pelvic pain, adnexal characterisation); Technique (field strength, sequences, contrast type and dose if used, preparation); Comparison (prior imaging); Findings (organised by anatomical compartment); Impression (direct answer to clinical question; O-RADS category if adnexal characterisation; FIGO stage if oncological; relevant negative findings); Recommendations; Limitations (artefacts, incomplete coverage, preparation suboptimal).

7.4 Incidental Findings — Clinical Decision Framework

Usually benign, document only: small nabothian cysts in the cervix; small Bartholin gland cysts; minor perifollicular free fluid (normal midcycle); small amounts of free fluid in the POD; simple endometrial cyst or Müllerian remnant cysts.

Follow-up required: adnexal cysts ≥ 1 cm in postmenopausal women (per O-RADS/IOTA criteria); T2-dark myometrial foci in a premenopausal patient with no uterine symptoms — may represent adenomyosis or small intramural fibroids; uterine cavity irregularity.

Requires explicit communication or action: unexpected adnexal lesion with O-RADS 4 or 5 features (high suspicion of malignancy); unexpected pelvic lymphadenopathy in a patient referred without known malignancy; free peritoneal fluid with peritoneal thickening suggesting peritoneal disease; unexpected ascites; suspected obstructive uropathy with hydronephrosis; sigmoid or rectal mass incidentally identified.

8. MRI Technologist Pearls

8.1 Sequence Order Logic

The recommended sequence order for female pelvic MRI reflects diagnostic priority and contrast timing:

1. Three-plane localiser
2. Sagittal T2 ← first and essential; this is the planning image for all subsequent oblique prescriptions
3. Axial oblique T2 (prescribed from sagittal T2) ← primary uterine assessment sequence
4. Coronal oblique T2 (prescribed from axial oblique)
5. T1 axial large FOV (no fat suppression) ← haemorrhage and fat detection; pre-contrast mandatory
6. T1-FS axial ← endometrioma and haemorrhage confirmation
7. DWI ← pre-contrast; EPI-sensitive; before patient fatigue
8. T2 large FOV coronal (if staging or lymph node assessment required)
9. Pre-contrast T1 3D FS ← immediately before injection
10. Contrast injection
11. DCE (if adnexal characterisation or staging) → standard post-contrast T1 3D at 3–5 min

The sagittal T2 must always be first because it determines the prescription of all subsequent T2 oblique planes. This is a non-negotiable order constraint.

8.2 Positioning Tricks

For patients with a retroflexed uterus: the fundus extends posteriorly; the axial oblique prescription must be steep in the opposite direction from an anteverted uterus. Check the prescribed angulation carefully on the sagittal T2.

For patients with a large fibroid uterus: the uterus may fill the entire pelvis. Extend the FOV laterally (40 cm) and superiorly to include the fundus of large subserosal fibroids. The standard "uterine" oblique planes may be difficult to define when the uterus is grossly distorted.

For postmenopausal patients with a small atrophic uterus: the uterus may be difficult to identify on the three-plane localiser. Use the T2 sagittal to identify the vaginal vault and work superiorly to locate the small uterus.

For patients with hip prostheses: the susceptibility artefact from hip prostheses does not typically reach the midline female pelvic structures at 1.5T, but at 3T it may extend into the lateral adnexa on that side. Use 1.5T if the prosthesis is bilateral or if the adnexal region is the primary clinical question.

8.3 Fast Salvage Protocol

This 14–17 minute non-contrast protocol provides sufficient information for most non-emergency female pelvic questions. Post-contrast sequences can be added if the patient recovers compliance.

8.4 Common Avoidable Errors

9. Quality Control Checklist

• [ ] Sagittal T2: uterine fundus to vaginal vault fully included; cervix visible in full length
• [ ] Axial oblique T2: prescription perpendicular to uterine long axis (verify angulation on sagittal); both adnexa included
• [ ] Coronal oblique T2: both cornua visible; full endometrial cavity length
• [ ] T1 large FOV: both adnexa and para-aortic region included
• [ ] T1-FS: fat uniformly suppressed throughout pelvis including adnexal regions and pouch of Douglas
• [ ] DWI: all b-values acquired; ADC map generated; acceptable distortion
• [ ] Pre-contrast T1 3D acquired before injection (if contrast protocol)
• [ ] Post-contrast T1 3D geometrically matched to pre-contrast
• [ ] Motion artefacts on T2 sequences assessed — bowel ghosting not crossing uterus or adnexa
• [ ] Antiperistaltic agent administration documented
• [ ] IUD presence noted and report documents limitations if present
• [ ] Bladder filling adequate (not empty, not overdistended)
• [ ] Both ovaries identified or absence documented
• [ ] Phase encoding direction verified: R-L for axial sequences; A-P for sagittal
• [ ] DCE post-processing completed if acquired (time-intensity curves available)

11. Evidence Gaps and Ongoing Debate

DCE-MRI standardisation for adnexal characterisation: the O-RADS MRI scoring system [7] requires DCE acquisition, but the temporal resolution, acquisition protocol, and post-processing for time-intensity curve analysis are not universally standardised. Different vendor implementations produce different curve shapes for identical enhancement patterns. The clinical validation of O-RADS MRI at centres without dedicated DCE protocols is not established.

3T vs 1.5T clinical equivalence: ESUR guidelines state that both field strengths are adequate for female pelvic MRI when properly optimised [3]. No randomised comparative study has demonstrated systematic clinical superiority of 3T for any specific gynaecological indication. The assumption of 3T superiority is based primarily on SNR and resolution arguments rather than diagnostic outcome data.

Role of DWI in endometrial cancer staging: DWI significantly improves detection of endometrial carcinoma compared with T2 alone, but its specific contribution to myometrial invasion staging accuracy relative to T2 alone remains debated. Published meta-analyses show variable additional benefit. The optimised combination of T2 + DWI + DCE achieves the highest staging accuracy, but the marginal contribution of each sequence component is not standardised.

Endovaginal coil for cervical cancer staging: endorectal and endovaginal coils improve resolution for parametrial assessment but their routine use is not universally recommended, and patient acceptance is low. Their diagnostic benefit over optimised external coil studies at 3T is not established.

Non-contrast equivalent protocols for serial surveillance: non-contrast female pelvic MRI is increasingly used for leiomyoma and endometriosis serial surveillance to reduce gadolinium cumulative exposure. Formal comparative validation studies for specific surveillance decision endpoints are lacking.

AI-assisted adnexal characterisation: deep learning models for O-RADS MRI scoring and adnexal lesion classification are under development. Early validation data are promising but no model has been prospectively validated for routine clinical deployment.

12. Evidence-Based References

A. Guidelines / Consensus / Society Recommendations

B. Systematic Reviews / Meta-analyses

C. Important Prospective / Original Studies

D. Technical MRI Papers

E. Landmark Historical References

End of document — MRI Female Pelvis Generic Standard Protocol — MRIninja v1.0 — May 2026 This master page is the reference for all future female pelvic MRI child pages including: endometrial carcinoma staging; cervical carcinoma staging; deep pelvic endometriosis (DPE) surgical planning; leiomyoma mapping for UAE/MRgFUS; adnexal mass characterisation (O-RADS MRI); ovarian cancer staging; pelvic floor assessment; Müllerian anomaly assessment; post-treatment surveillance.