MRI Kidneys (Renal Mass) — Dictation, Appropriateness, and Dose for Residents

Outpatient renal mass MRI on the list. It’s an indeterminate cystic lesion from an outside CT. Your attending is going to want a definitive Bosniak classification, and you’re trying to remember if those whisper-thin enhancing septa push it from a IIF to a III. We’ve all been there, staring at the subtraction images, knowing that call has major surgical implications.

Getting these reports right isn’t just about avoiding a correction; it’s about delivering clarity for the urologist. This guide breaks down the MRI renal mass protocol into a dictation template you can use on call today. It’s built from the ground up for residents and fellows, focusing on what attendings care about most. For more guides like this, check out the residents and fellows resource hub.

What an MRI of the Kidneys for a Renal Mass Covers and What Attendings Look For

An MRI of the kidneys for a renal mass is the problem-solving study for lesions that are indeterminate on CT or ultrasound. It excels at characterizing tissue—differentiating hemorrhagic cysts from solid tumors, identifying macroscopic fat in an angiomyolipoma (AML), and evaluating the extent of vascular invasion in renal cell carcinoma (RCC).

Your attending expects a report that systematically answers these key clinical questions:

• Characterization: Is the mass cystic, solid, or mixed? If cystic, what is its Bosniak classification?
• Malignancy Features: If solid, are there features to suggest a specific histology? (e.g., macroscopic fat for AML, avid early enhancement for clear cell RCC, hypoenhancement for papillary RCC).
• Staging (if suspicious for RCC): What is the size? Is there capsular invasion? Is there involvement of the renal vein or inferior vena cava (IVC)? Are there suspicious locoregional lymph nodes or adrenal metastases?
• Background Kidneys: Are there other lesions? Is there evidence of chronic kidney disease?

The core of the read is applying a systematic approach to the multiphase post-contrast and subtraction sequences to confidently classify the lesion and guide the next step, whether it’s surveillance, biopsy, or resection.

Radiology Report Template for MRI of the Kidneys (Renal Mass)

This template provides a solid framework. You can adapt it for your institution’s specific macros in PowerScribe or other dictation software. The key is to be systematic, addressing every critical component.

Technique

Multiplanar, multisequence MRI of the kidneys was performed without and with intravenous administration of [volume] mL of [contrast agent name]. Sequences include T2-weighted imaging, T1-weighted in-and-out-of-phase imaging, diffusion-weighted imaging, and 3D T1-weighted fat-saturated imaging pre- and post-contrast in the corticomedullary, nephrographic, and excretory phases. Subtraction images were also generated.

Findings

Right Kidney: Measures [size] cm. Normal contour and parenchymal thickness. No hydronephrosis.

A [size] cm mass is identified in the [upper pole / midpole / lower pole].

[If cystic:] The lesion is a [simple/complex] cyst. It demonstrates [describe wall thickness, septations, calcifications, enhancement]. Per the Bosniak classification, this is a Category [I, II, IIF, III, or IV] lesion.

[If solid:] The lesion is solid. It demonstrates [T1 signal], [T2 signal], and [restricted/no restricted] diffusion. It contains [macroscopic fat, hemorrhage, necrosis]. Following contrast, it demonstrates [avid, moderate, minimal] enhancement, with a [corticomedullary, nephrographic] peak.

No evidence of renal vein invasion.

Left Kidney: Measures [size] cm. Normal contour and parenchymal thickness. No hydronephrosis. No suspicious renal mass.

Vasculature: The main renal arteries and veins are patent. The inferior vena cava is patent with no evidence of tumor thrombus.

Adrenal Glands: The adrenal glands are unremarkable.

Lymph Nodes: No retroperitoneal lymphadenopathy.

Other Findings: The visualized portions of the liver, spleen, and pancreas are unremarkable. No free fluid.

Impression

1. [Size] cm [right/left] renal mass in the [location], as described above.

[If cystic:] Findings are consistent with a Bosniak Category [class] cystic renal lesion.

[If solid, suspicious for RCC:] Findings are suspicious for renal cell carcinoma. The enhancement pattern is most suggestive of a [clear cell / papillary] subtype. There is no evidence of local invasion or definite renal vein/IVC tumor thrombus.

[If solid, suspicious for AML:] Findings are characteristic of an angiomyolipoma, given the presence of macroscopic fat.

[If indeterminate solid:] Indeterminate solid enhancing renal mass. Features overlap between oncocytoma and chromophobe renal cell carcinoma. Biopsy may be considered for definitive characterization.

2. No evidence of retroperitoneal lymphadenopathy or adrenal metastasis.

Where to Find Other Free Radiology Report Templates

Building a personal library of high-quality templates is a game-changer during residency. While you’ll develop your own over time, two great free repositories exist to get you started. They are excellent, peer-reviewed sources maintained by major radiology organizations.

• RadReport.org: Curated by the Radiological Society of North America (RSNA), this is the definitive source for standardized templates across nearly every modality and subspecialty.
• Radiology Templates (AU): A fantastic, user-friendly library maintained by Australian radiologists, offering a slightly different flavor and format that many trainees find helpful.

The Next-Level Move: From Free-Form Dictation to Flawless Structured Reports

The templates above are a great start, but the real friction on call isn’t finding a template—it’s populating it accurately under pressure. You see the positive finding, you dictate it, and then you spend time slotting it into the right place, adding classifications, and making sure the impression matches the findings perfectly.

This is where AI-powered tools can streamline your workflow. With GigHz Precision AI, you can dictate your positive findings in free form—”avidly enhancing 4 cm mass in the right upper pole with a central scar”—and the software structures it into a complete, attending-ready report. It uses pre-loaded templates from the American College of Radiology (ACR) and Society of Interventional Radiology (SIR) and is designed to fire the appropriate Clinical Decision Support (CDS) automatically for frameworks like LI-RADS or Bosniak, ensuring you never miss a required element.

When Should You Order an MRI of the Kidneys for a Renal Mass? ACR Appropriateness Criteria

The American College of Radiology (ACR) provides evidence-based guidelines to help clinicians choose the right study. For evaluating a renal mass, MRI is a key player, especially when CT is inconclusive or contraindicated.

For an Indeterminate Renal Mass on initial imaging, an MRI of the abdomen and pelvis with and without contrast is rated as “Usually Appropriate.” This holds true whether the patient has no contrast contraindications, a contraindication only to iodinated CT contrast, or even contraindications to both (in which case a non-contrast MRI is still considered appropriate). It is a first-line alternative to a multiphase CT scan, which is also “Usually Appropriate.”

Similarly, for Staging of Renal Cell Carcinoma, an MRI with and without contrast is “Usually Appropriate.” It is particularly valuable for assessing the extent of tumor, especially for evaluating potential inferior vena cava (IVC) tumor thrombus, a critical factor in surgical planning. Again, this high rating applies across various scenarios, including for patients with contraindications to iodinated CT contrast.

MRI of the Kidneys (Renal Mass) Imaging Protocol — Phases, Contrast, and Key Parameters

A dedicated renal mass MRI protocol is designed to maximize tissue characterization. It hinges on identifying fat and meticulously evaluating enhancement patterns with multiphase imaging and subtractions. The sequences are chosen to answer specific questions about the lesion’s composition.

The table below outlines a typical protocol. Note the inclusion of in/out-of-phase imaging to detect intracellular and macroscopic fat (the signature of an angiomyolipoma) and the critical multiphase post-contrast acquisition, which helps differentiate RCC subtypes and characterize complex cysts.

A common pitfall is misinterpreting a hemorrhagic or proteinaceous cyst as enhancing. These can be intrinsically T1-bright on pre-contrast images. Subtraction imaging is absolutely essential here; true enhancement will be bright on the subtracted images, while intrinsic T1 signal will subtract out. Overlooking this step can lead to incorrectly upgrading a Bosniak IIF cyst to a surgical Bosniak III lesion.

3+ months free for radiology residents and fellows

Look like a rockstar on your reports. With the GigHz Radiology Report Assistant, you can dictate positive findings in free form, and our AI generates a structured report using ACR + SIR templates, with the appropriate clinical decision support firing automatically. It’s designed to help you produce high-quality, consistent reports that make your attendings happy, even at the end of a long call shift.

All we ask in return is your feedback so we can keep improving the product for trainees. The signup is simple—no credit card, no long forms. To get started, just provide the following:

1. Your PGY year (e.g., PGY-2, PGY-4)
2. Your training type (radiology residency or specific fellowship)
3. Your training program / hospital name

Ready to give it a try? You can apply for the residents free-access program here.

Free GigHz Tools That Pair With This Article

Three free tools that complement the material above:

• ACR Appropriateness Criteria Lookup — Type an indication or clinical scenario in plain language and get the imaging studies the ACR rates for it, with adult and pediatric radiation levels. Built directly from 297 ACR topics, 1,336 clinical variants, and 15,823 procedure ratings.
• GigHz Imaging Protocol Library — A searchable library of 131 imaging protocols with the physics specs surfaced and the matching ACR Appropriateness Criteria alongside. Plain-English narratives readable in 60 seconds, organized by modality.
• GigHz Radiation Dose Calculator — Pick the imaging studies a patient has had and see total dose in millisieverts (mSv) with comparisons to natural background radiation, transatlantic flights, and chest X-rays. Useful for shared decision-making.

Frequently Asked Questions

Is it HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. No patient-identifying information is required or stored, ensuring compliance with HIPAA privacy standards.

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

No. GigHz Precision AI is browser-based and requires no local software installation. It works on any hospital workstation, personal laptop, or even the call-room iPad without needing IT involvement.

Does it work with PowerScribe or other dictation systems?

Yes. It functions as a co-pilot. You can generate the structured report in the browser and then copy-paste the clean text directly into your existing dictation system. It complements your current workflow, it doesn’t replace it.

Can I customize the templates?

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

What happens after my residency or fellowship ends?

The free access program is specifically for trainees. After you graduate, you can transition to a standard attending subscription if you find the tool valuable in your practice. There are no automatic charges or obligations.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 7, 2026