MRI Pelvis – Endometrial Cancer Staging — Dictation, Appropriateness, and Dose for Residents

1. The GYN-ONC Case That Can’t Wait

It’s a busy outpatient Tuesday. The next case on your list is an MRI of the pelvis for a patient with post-menopausal bleeding and a thickened endometrial stripe on ultrasound. The GYN-ONC team has already seen her, and they’re waiting for your read to decide between a simple versus a radical hysterectomy, and whether they need to schedule a lymph node dissection. Your attending is going to want three things, stated unequivocally: the depth of myometrial invasion, the status of the cervical stroma, and the resulting FIGO stage. No waffling.

Getting this right means knowing exactly what to look for and how to structure the report so the surgeons have a clear roadmap. When I was a fellow, I remember spending way too much time trying to perfectly measure invasion on three different planes. The key isn’t just the measurement; it’s knowing which sequences give you the most confidence and how to put it all together. Let’s walk through a template that gets you there efficiently. For more guides like this, check out the residents and fellows resource hub.

2. What an MRI of the Pelvis for Endometrial Cancer Staging Covers and What Attendings Look For

This dedicated pelvic MRI is the gold standard for pre-operative local staging of endometrial cancer. Unlike a routine pelvic MRI, this protocol is optimized with high-resolution, multi-planar T2-weighted images and dynamic contrast-enhanced sequences to answer specific surgical questions. Ultrasound may have found the mass, but MRI tells the surgeon how to approach it.

Your attending expects a report that clearly addresses:

• Tumor Characteristics: Location, size, and signal characteristics of the primary endometrial mass.
• Myometrial Invasion: The single most important factor for Stage I disease. Is it less than 50% (Stage IA) or greater than or equal to 50% (Stage IB)? This distinction often determines the need for lymphadenectomy.
• Cervical Stromal Invasion: Does the tumor extend into and disrupt the cervical stroma? A positive finding upstages the disease to Stage II and changes the surgery from a simple to a radical hysterectomy.
• Extrauterine Extension: Is there involvement of the uterine serosa, adnexa, vagina, or adjacent organs like the bladder and rectum (Stage III/IV)?
• Lymphadenopathy: Assessment of pelvic and para-aortic lymph nodes for metastatic disease.
• Ovarian Evaluation: A crucial check for synchronous primary ovarian cancer, which occurs in 5-15% of cases, especially in patients with Lynch syndrome.

3. Radiology Report Template for MRI of the Pelvis for Endometrial Cancer Staging

Here is a structured template you can adapt. The key principles below the template are your reading checklist—internalize these and you’ll hit all the key findings your attending and the clinical team need.

Technique

Multiplanar, multisequence MRI of the pelvis was performed before and after the administration of intravenous gadolinium-based contrast. High-resolution T2-weighted images were obtained in sagittal, coronal, and oblique axial planes perpendicular to the endometrial cavity and endocervical canal. Dynamic T1-weighted fat-suppressed images were obtained following contrast administration.

Findings

Uterus Size and Contour: [e.g., The uterus is normal in size and anteverted. No fibroids are seen.]

Endometrial Mass: [e.g., There is a T2-hypointense, diffusion-restricting mass centered in the endometrial cavity, measuring X x Y x Z cm. The tumor demonstrates avid, early hypoenhancement relative to the adjacent myometrium.]

Myometrial Invasion: [e.g., The tumor invades the underlying myometrium. The depth of invasion is approximately X mm, with a total myometrial thickness of Y mm. This constitutes less than 50% myometrial invasion.] OR [e.g., The tumor deeply invades the myometrium, extending to the outer myometrial half. This constitutes greater than or equal to 50% myometrial invasion.]

Cervical Stromal Invasion: [e.g., On delayed post-contrast images, the normal enhancing endocervical mucosal line is intact. There is no evidence of tumor extension into the cervical stroma.] OR [e.g., The tumor extends inferiorly to disrupt the fibrovascular cervical stroma, consistent with cervical stromal invasion.]

Adnexal/Parametrial Extension: [e.g., The uterine serosa is intact. There is no extension into the parametria or adnexal structures.]

Ovaries: [e.g., The ovaries are normal in appearance. No suspicious adnexal mass.]

Vagina: [e.g., The vaginal fornices are unremarkable.]

Lymph Nodes: [e.g., No pathologically enlarged pelvic or para-aortic lymph nodes are identified.] OR [e.g., A 1.2 cm short-axis, rounded left external iliac lymph node is noted, suspicious for metastatic involvement.]

Bladder and Rectum: [e.g., The bladder and rectum are unremarkable, with intact fat planes.]

Other Findings: [e.g., Incidental note of a simple cyst in the right kidney. The imaged skeleton is unremarkable.]

Impression

1. Endometrial mass measuring X cm, consistent with known endometrial carcinoma.

2. Myometrial invasion measuring approximately [X%], compatible with FIGO Stage [IA (<50%) or IB (≥50%)].

3. [No evidence of / Evidence of] cervical stromal invasion. If present: This finding upstages the tumor to at least FIGO Stage II.

4. [No evidence of / Evidence of] extrauterine extension or suspicious lymphadenopathy.

Overall FIGO Stage: [e.g., Stage IB. Findings are most consistent with endometrial carcinoma confined to the uterus with deep (≥50%) myometrial invasion.]

Key Reading Principles for Endometrial Cancer MRI

• Myometrial invasion assessment drives staging: <50% (IA) is low-risk; ≥50% (IB) is high-risk and may require lymphadenectomy.
• Tumor on T2: Hypointense relative to normal endometrium and myometrium.
• Tumor on dynamic post-contrast: Hypoenhancing relative to surrounding myometrium—best seen on early phases.
• Late delayed phase (4-5 min) is CRITICAL for cervical invasion: Normal cervical mucosa enhances brightly; tumor disrupts this bright line.
• Cervical stromal invasion = Stage II and alters the surgical approach from simple to radical hysterectomy.
• DWI: Tumor restricts diffusion, which adds sensitivity for detection, especially for small lesions or nodes.
• Lymph node assessment: Pelvic + para-aortic. Suspicious if >8 mm short axis, round, and shows restricted diffusion.
• Always evaluate ovaries: Look for a synchronous primary ovarian cancer, seen in 5-15% of cases.
• Watch for mimics: Adenomyosis can mimic invasion with its diffuse junctional zone thickening, but look for the characteristic bright T2 foci within it.

4. Free Radiology Template Sources

Building your own macro library is a rite of passage, but you don’t have to start from scratch. For standardized templates across all modalities, two great free repositories exist. They are excellent starting points for building your personal or departmental template library.

• RadReport.org: Curated by the RSNA, this is a comprehensive library of peer-reviewed templates. (https://radreport.org/)
• Radiology Templates (AU): A well-maintained, practical template library from Australia with a clean interface. (https://www.radiologytemplates.com.au/home-page/)

These are solid resources for finding a baseline template you can then customize for your own workflow and your attendings’ preferences.

5. The Next-Level Move: AI-Assisted Structured Reporting

Pasting a template is step one. The real time-sink is editing the template, deleting negative statements, and plugging in your positive findings. A more modern workflow involves dictating only the positive findings in free form and letting an AI tool handle the structuring.

For instance, you could dictate: “Large T2 dark mass in the endometrium measuring 4 cm. Invades the outer half of the myometrium. No cervical stromal invasion. Normal ovaries.” The AI then generates a fully structured report based on that input, using pre-loaded ACR-standard templates. This approach, used by tools like GigHz Precision AI, streamlines the process by turning your diagnostic thoughts directly into a clean, organized report. It also helps surface relevant Clinical Decision Support (CDS) criteria automatically, ensuring your report contains all the necessary classifications and follow-up recommendations without you having to look them up.

6. When Should You Order an MRI of the Pelvis for Endometrial Cancer Staging? ACR Appropriateness Criteria

The American College of Radiology (ACR) provides evidence-based guidelines to help clinicians choose the right imaging study. For the “Pretreatment Evaluation and Follow-Up of Endometrial Cancer,” the guidance is clear: MRI of the pelvis is the first-line modality for pre-operative staging.

For the initial staging of a newly diagnosed endometrial cancer, an MRI of the pelvis is rated as Usually Appropriate for assessing local tumor extension, regardless of the tumor grade. This is the core use case for this protocol.

When assessing for lymph node and distant metastasis, the approach depends on tumor grade. For low-grade tumors (Type I, grades 1 and 2), an MRI is still Usually Appropriate. For high-grade tumors (Type I, grade 3, and Type II cancers like serous or clear cell), MRI remains Usually Appropriate, though CT or PET/CT may also be used to evaluate for distant disease.

Finally, for post-therapy evaluation of a clinically suspected recurrence, MRI of the pelvis is again rated as Usually Appropriate to characterize the location and extent of the suspected disease. In contrast, for routine surveillance of asymptomatic patients, imaging is generally not recommended.

7. MRI Pelvis for Endometrial Cancer Staging Imaging Protocol — Phases, Contrast, and Key Parameters

A successful endometrial cancer staging MRI depends entirely on a high-quality, dedicated protocol. The key is combining high-resolution T2 imaging, which provides the best anatomical detail of the uterine zonal anatomy, with multiphase dynamic contrast-enhanced imaging to assess tumor vascularity and invasion. The late delayed phase is non-negotiable for evaluating the cervix.

Below are the critical sequences and parameters for this study.

Common protocol pitfalls: The most common error is omitting or acquiring the late delayed phase (4-5 minutes) too early. This phase is absolutely essential for evaluating cervical stromal invasion, as the normal cervical mucosa enhances late, creating the contrast needed to see tumor disruption. Another pitfall is incorrect planning of the oblique axial images; they must be prescribed perpendicular to the long axis of the endometrial cavity and endocervical canal, respectively, not just based on the patient’s body axis.

8. The 3-Months-Free Offer for Radiology Residents and Fellows

3+ months free for radiology residents and fellows

Look like a rockstar on your reports — dictate positive findings in free form, and the AI generates a structured report using ACR + SIR templates with the appropriate clinical decision support firing automatically. This is your chance to try out the workflow of the future, today. All we ask is feedback so we can keep improving the product for trainees.

To get set up, we just need three things:

1. Your PGY year (e.g., PGY-2, PGY-4)
2. Your training type (radiology residency or specific fellowship — IR, body, MSK, neuro, peds, breast, nucs)
3. Your training program / hospital name
4. (Optional) Your institutional email

There’s no credit card required and no long forms to fill out. Just reply to the application with those three items and we’ll get you set up. You can apply for the residents free-access program here.

9. Frequently Asked Questions

Is it HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. No patient-identifying information is required to use the tool for generating structured reports from your findings.

Do I need my hospital’s IT department to set this up?

No. The tool is browser-based and requires no local software installation or special permissions. It works on any modern computer, including the call-room PC or your personal laptop/iPad.

Does it work with PowerScribe or other dictation systems?

Yes. It works alongside your existing dictation system. You can generate the structured report in the tool and then copy/paste it directly into your PACS/RIS, or use it as a guide for your final dictation.

Can I use this on my phone or iPad?

Yes, the platform is fully responsive and works well on mobile devices and tablets, making it a useful reference even when you’re not at a dedicated reading station.

Can I customize the templates?

Yes. While the system comes pre-loaded with ACR and other society-standard templates, you can create, save, and modify your own templates to match your personal preferences or your institution’s specific requirements.

What happens after my residency or fellowship ends?

Trainee accounts are intended for use during training. After you graduate, you can transition to a standard attending plan, but there is no obligation to do so. Your free access will simply expire at the end of your training period.