MRI for Ovarian Cancer Detection

Magnetic resonance imaging (MRI) of the ovaries is a powerful, non-invasive imaging technique that provides detailed pictures of the pelvic organs. It plays a critical role in detecting, characterising, and staging ovarian tumours, especially when cancer is suspected. MRI offers greater soft tissue contrast than ultrasound or computed tomography (CT), making it especially useful when ovarian masses are complex or ambiguous.

Why You Might Need an Ovary MRI

An ovarian MRI might be recommended for several reasons:

• When an ovarian or adnexal mass looks indeterminate or worrisome on ultrasound, MRI helps distinguish benign lesions from malignant tumours with much higher accuracy, especially in complex or large cystic masses. This can guide whether you need surgery and what kind of surgery^1,2.
• If markers like CA-125 or HE4 are raised, MRI provides cross-sectional detail to see whether there is a solid tumour, papillary projections, ascites, or peritoneal deposits that might explain the abnormal blood tests³. Because CA-125 and HE4 can be elevated in many benign conditions, MRI helps avoid overtreatment by better characterising the ovaries when blood results and ultrasound do not align.
• In people with BRCA or other high-risk mutations, any suspicious ultrasound finding usually triggers more thorough imaging, and MRI can be used to characterise small or complex lesions without radiation exposure⁴. This is particularly relevant if risk-reducing surgery is being timed or if there is concern for early-stage disease, where preserving fertility might still be considered.
• For ongoing pelvic pain, bloating, early satiety, or unexplained weight loss where ultrasound is normal or equivocal, MRI can assess the ovaries, uterus, bowel, pelvic sidewalls, and peritoneum in one exam¹. It can also help differentiate ovarian causes from other pelvic or abdominal conditions that might explain symptoms.
• Once ovarian cancer is diagnosed, cross-sectional imaging of the abdomen and pelvis is used to map how far it has spread (staging), which is critical for planning surgery and systemic therapy^5,6. CT is most commonly used, but MRI is valuable in selected cases to better define pelvic organ involvement, small peritoneal deposits, diaphragmatic or liver capsule lesions, and residual disease after treatment.
• Borderline ovarian tumours and endometriomas often require surveillance rather than immediate radical surgery, and MRI helps track size, internal architecture, and any new solid or nodular components over time⁷. This allows clinicians to watch for features suggesting progression or malignant transformation, while supporting conservative or fertility-preserving management where appropriate.

How to Prepare for Your Ovarian MRI

Here are a few tips to help you prepare for your MRI⁸:

• Take your usual medications and eat normally, unless instructed to fast for sedation or contrast. Avoid heavy caffeine intake and stay hydrated.
• Inform staff about any metal implants or devices, and bring safety cards for “MR-Conditional” implants, such as pacemakers or aneurysm clips.
• Remove all metal items, including jewellery, hairpins, dental plates, and transdermal patches with foil, to prevent image distortion.
• Wear comfortable, metal-free clothing; ask about earplugs, music, or mirror goggles if you’re claustrophobic.
• If contrast is planned, fast for 4–6 hours prior to the procedure. Inform staff about any kidney issues or past reactions to contrast agents, as safer alternatives may be available.
• Arrange an escort home if you need sedation for claustrophobia.

You can read more about preparation for Ezra’s MRI Scan with Spine here.

What Happens During the Ovary Scan?

Upon arrival for your MRI, you will need to check in and complete a screening form. This will allow you to confirm the presence of implants, allergies, and whether you might need any anxiety medication.

During the scan, you will lie down on a sliding table. A dedicated surface or phased-array coil is typically placed over the limb or region of interest⁹. Your head will be nestled in a small cushion that will keep you still. The scan typically lasts 30-45 minutes of actual “table time”, during which the technician may acquire multiple sequences (settings). Expect loud knocking noises (up to 110 dB); earplugs or headphones are provided to reduce discomfort. It’s normal to feel mild table vibrations.

You’ll stay in touch with the team via a two-way intercom and a squeeze bulb, allowing you to communicate or pause the scan if needed. If contrast is required, it’s injected halfway through, possibly causing a brief cool sensation. After the final sequence, the coil is removed, and you’re free to go. 

At Ezra, our MRI Scan with Spine scan takes around 60 minutes total, with 45 minutes of table time. Earplugs or headphones are available.

After the scan, you will be contacted by a medical provider working with Ezra within roughly a week. On the day of the appointment, you will receive a copy of your report and access to your scanned images through the online portal.

MRI Safety, Risks & Side Effects

MRI is generally considered very safe when proper screening and protocols are followed, but certain risks and side effects should be understood:

• Metal and implants: The strong 3-Tesla magnet can pull or heat older pacemakers, aneurysm clips, or metal fragments¹⁰. Most modern “MR-Conditional” devices (like cochlear implants or pain pumps) are safe after screening, but all implants must be checked before scanning¹¹.
• Gadolinium contrast: Macrocyclic gadolinium agents (e.g., gadobutrol) have an extremely low risk of allergic reactions or nephrogenic systemic fibrosis (NSF) when kidneys are healthy¹². However, gadolinium can accumulate in tissues, and rare side effects such as headaches or skin changes have been reported. Many centres now offer contrast-free alternatives for routine follow-up¹³. You can read more about gadolinium contrast side effects here.
• Incidental findings: MRI-focused reviews describe incidental adnexal masses as “common”, citing underlying prevalence figures of around one-third of premenopausal women and about one-sixth of postmenopausal women having an adnexal mass if carefully looked for, though the vast majority are benign physiologic or simple cysts¹⁴.
• Claustrophobia: Anxiety inside the scanner is common. Wide-bore scanners, music, mirror goggles, or a single dose of oral sedative can help alleviate symptoms. Open MRI is an option if image detail can be sacrificed.
• Zero Ionising Radiation: MRI uses magnetic fields and radio waves, not X-rays, so there is no ionising radiation exposure, making it safer for repeated scans compared to CT scans¹⁵.
• Minor Sensations: Expect loud knocking, mild table vibration, and a brief cool flush if contrast is injected. Rare side effects include headaches, fatigue, or mild skin heating.

A deeper dive into possible side effects (such as heat, headaches, and gadolinium deposition) is available in our full guide.

At Ezra, we employ a contrast-free approach using wide-bore T3 machines to deliver a comfortable scanning experience.

Terms You Might See in Your MRI Report (And What They Mean)

MRI reports of the ovary include specific terms that help clinicians assess the nature of a lesion or condition. Some common terms (and their meaning) include:

Complex Cyst: A “complex cyst” is a fluid-filled structure that is not completely simple; it may have internal septations (walls), debris, or small solid areas instead of being a thin-walled, clear fluid bubble¹⁶. Complex cysts are still often benign (e.g., haemorrhagic cyst, endometrioma, benign cystadenoma), but because they show more than just clear fluid, they usually need closer follow-up or further characterisation and sometimes surgery, depending on age, size, and other features.

Papillary Projections: These are small, finger-like or frond-like growths sticking out from the cyst wall or internal septations into the cyst cavity¹⁷. These are considered a type of “solid tissue” within a cyst, and the more or larger papillary projections present (especially if they enhance with contrast), the higher the concern for borderline tumour or invasive ovarian cancer rather than a purely benign cyst.

Restricted diffusion: This refers to tissue that looks bright on diffusion-weighted images and dark on the corresponding ADC map, suggesting tightly packed cells and limited water movement¹⁸. This pattern is often seen in malignant tumours, so restricted diffusion within a solid component or papillary area raises suspicion, although some benign lesions can occasionally show similar behaviour¹⁹. 

Enhancement: “Enhancement” means that a structure takes up contrast dye and becomes brighter after injection, indicating blood flow²⁰. When solid areas, nodules, or papillary projections within an adnexal mass enhance (especially more than the outer myometrium or more than expected for benign tissue), this supports the idea that they are living solid tissue rather than simple debris or cloth, and increases concern for neoplasm.

Thick Septations: Septations are internal walls that divide a cyst into compartments; “thick septations” means these walls are appreciably thicker rather than hairline thin²¹. Thin septations can be seen in benign multilocular cysts, but irregular or thick septations, particularly if they enhance after contrast, push the lesion into a higher-risk category and often prompt surgical evaluation.

Solid Component: A “solid component” is any part of the lesion that is made of tissue rather than fluid, such as a mural nodule, papillary formation, irregular thickened wall, or a larger solid mass within or alongside a cyst²². The presence, size, and behaviour of solid components (enhancement, restricted diffusion, irregular margins) are key drivers in risk scores such as O-RADS MRI; more and more suspicious solid tissue generally means a higher probability that the mass could be malignant or borderline. 

After the MRI Scan

After the MRI scan, you will be free to go home and continue with your day without any precautions²³. If you received a sedative, you will need another person to pick you up. You will also not be able to drive, consume alcohol, or operate heavy machinery 24 hours after the sedative. 

A team of experts will review your results and determine whether a follow-up is necessary and recommend the appropriate treatment if needed. If abnormalities are found, you may undergo ongoing monitoring every 2-3 months to track recurrence. You can receive support in the form of counselling and advice on how to handle aspects like claustrophobia. 

If you have a scan with us here at Ezra, you will receive your report within five to seven days and have the option to discuss it with a medical practitioner. You can also access your scan images through the online portal.

What MRI Can Show About Ovarian Cancer

MRI can provide comprehensive information about ovarian cancer, aiding diagnosis, staging, and treatment monitoring. 

Tumour Type and Origin

MRI can often suggest whether a mass most likely arises from the ovary, fallopian tube, or peritoneum based on its attachment, how it displaces nearby organs, and which structures it appears to arise from²⁴. It can also hint at tumour subtype (e.g., mucinous, serous, endometriosis-related) by the pattern of cysts, solid areas, fat, or blood, but final typing still relies on pathology.

Size and Exact Location

MRI measures the maximum tumour diameter and can show precisely which ovary (or tube) is involved and how the mass relates to the uterus, bladder, rectum, and pelvic sidewalls¹. This helps surgeons plan the incision, anticipate the difficulty of removal, and decide whether fertility-sparing surgery could be possible.

Solid vs Cystic Nature

MRI clearly distinguishes fluid from solid tissue, showing whether a mass is mainly cystic, mainly solid, or mixed, and whether there are papillary projections, thick septa, or necrosis that raise concern for malignancy. Dynamic contrast and diffusion-weighted sequences further separate benign-appearing cysts from more suspicious, highly vascular, or diffusion-restricted solid components²⁵.

Spread to Other Organs

MRI can show whether a tumour has invaded nearby organs (uterus, vagina, bladder, rectum) or the pelvic sidewall, and can depict peritoneal or omental deposits and implants on the serosal surfaces²⁶. This information feeds into FIGO staging and helps determine whether optimal cytoreductive surgery is feasible.

Lymph Nodes

MRI can detect enlarged pelvic and para-aortic lymph nodes and describe their size, shape, and internal signal, which may suggest metastatic involvement, though small-volume nodal disease can still be missed²⁷. MRI findings are often interpreted alongside other imaging and clinical data.

Ascites and Peritoneal Fluid

MRI is sensitive to free fluid and can show ascites, loculated collections, and fluid tracking in the abdomen and pelvis, which are common in advanced ovarian cancer²⁸. The presence and volume of ascites, especially with peritoneal nodules, support a diagnosis of malignant spread and influence both staging and symptom management decisions.

Ezra provides a radiologist-reviewed report in a non-technical and easy-to-understand format on your dashboard.

Types of Ovary Tumours and How They Look on MRI

MRI can often suggest what type of ovarian tumour is present by its internal contents (fluid, blood, fat, solid tissue), signal pattern, and enhancement.

Epithelial Carcinoma

These cancers usually look like a bulky “lump and cyst” mixed mass rather than a simple, thin-walled cyst. The walls can be thick and uneven, with little lumps or fronds growing inside, and the solid parts light up strongly after contrast, which tells doctors the tissue is very active²⁹. Cancer of this type often comes with extra fluid in the tummy (ascites) and tiny deposits on the lining of the abdomen, and it may affect both ovaries, all of which increase suspicion for invasive epithelial carcinoma rather than a benign cyst.

Borderline Epithelial Tumour

Borderline tumours often look like bunches of connected cysts with a more tidy, organised structure. They can have papillary projections or small solid areas that still take up contrast, but they usually cause less fluid in the abdomen and less obvious spread than full-blown cancer³⁰. On MRI, they often sit in the “in-between” zone: more worrying than a simple cyst, but not as aggressive-looking as invasive carcinoma.

Endometrioma

Endometriomas are “blood-filled cysts” related to endometriosis, sometimes called “chocolate cysts”. On MRI, the blood inside makes them look very bright in some pictures and darker in others, in a pattern that is quite characteristic³¹. They usually do not have suspicious solid lumps inside; if a new or growing solid nodule appears in the wall and takes up contrast, that can be a warning sign that a cancer is developing inside an endometrioma and needs closer assessment.

Dermoid (Mature Cystic Teratoma)

Dermoids are benign tumours that can contain fat, hair, and sometimes teeth or bone. The fat makes them stand out on MRI, so radiologists can often recognise them easily³¹. They often look like a mix of fluid and fatty material, sometimes with a more solid “plug” (a Rokitansky nodule). Most are harmless, but if a new, irregular solid area grows inside and enhances with contrast, doctors may worry about the rare chance of a cancer forming within a dermoid.

H3: Fibroma (and fibro-thecoma)

Fibromas are solid, firm ovarian tumours made mostly of fibrous tissue (a bit like a rubbery scar). On MRI, they tend to look very dark on the fluid-sensitive images compared with many other ovarian tumours, which helps radiologists recognise them³³. They usually take up contrast slowly and less strongly than cancers. They can sometimes cause fluid in the abdomen and a pleural effusion (Meigs syndrome), but their very dark appearance on MRI often points toward a benign fibrous tumour rather than a malignant one.

Ezra screens for over 500 conditions, including the brain.

Types of MRI Scans Used in Ovary Cancer Detection

MRI for ovarian cancer uses a set of sequences that each answer a different question about the mass.

T1-Weighted MRI

T1‑weighted images are good at showing fat and blood‑containing material as bright, and simple fluid as darker, which helps identify fat‑containing tumours (such as dermoids) and blood‑filled cysts (such as endometriomas)³⁴. 

T2-Weighted MRI

T2-weighted images make fluid appear bright and dense fibrous tissue appear darker, which helps show the overall shape and internal structure of an ovarian mass³⁵. Radiologists use T2 to assess how many cystic spaces there are, how thick the walls and septa are, and whether there are internal solid nodules or papillary projections.

Diffusion-Weighted Imaging (DWI)

DWI assesses how water molecules move within tissues. Tumours tend to restrict water movement, so they stand out as areas of restricted diffusion^36–38. This helps in identifying and confirming suspicious lesions, even when they are small or subtle.

Apparent Diffusion Coefficient (ADC)

This is a map derived from DWI that provides a numerical value to help separate aggressive cancers (which have lower ADC values) from less aggressive tumours. Lower ADC suggests increased tumour cell density^36,37.

Dynamic Contrast-Enhanced MRI (DCE)

DCE captures images over time after a contrast dye is injected. Malignant tumours often soak up the dye earlier than normal bladder wall tissue, a sign of abnormal blood vessels^36,37,39. This helps distinguish cancer from benign tissue and is useful for staging and treatment monitoring.

MRI vs. Other Imaging Tests for Ovarian Cancer Detection 

MRI Scan Cost

Ezra’s MRI Scan with Spine costs £2,395 and is currently available at their partner clinic in Marylebone, London, and in Sidcup, with more locations planned in the future. No referral is required, so you can book your scan directly without consulting a GP or specialist first. Most people pay out-of-pocket, as insurance typically does not cover self-referred scans, but you may be able to seek reimbursement depending on your policy. 

Frequently Asked Questions

Is MRI better than ultrasound for ovarian cancer?

Yes, for complex or suspicious cases.

Is MRI painful?

No, it is painless, but it can be noisy and requires you to be still for a period of time.

Can I have an MRI with an IUD or implants?

Often, yes, but you should disclose all devices to your radiologist.

Key Takeaways

• MRI is a highly effective tool in evaluating ovarian masses and cancer.
• It offers superior soft tissue resolution, especially with contrast and DWI. 
• MRI interpretation relies on features like enhancement, restricted diffusion, solid components, and septations. 
• MRI complements other tests (e.g., ultrasound, CA-125) for a holistic diagnosis and treatment plan.