CT Appendicitis (CT Abd/Pel) — Dictation, Appropriateness, and Dose for Residents

Stat CT abdomen/pelvis from the ED on a 25-year-old with right lower quadrant pain, fever, and leukocytosis. The surgeon is on the phone. Your attending wants a definitive call on appendicitis, but more than that, they expect you to rule out the mimics—ovarian torsion, cecal diverticulitis, a ureteral stone. They want a clean, structured report that covers all the bases, and they want it now. This is a classic call scenario, and having a solid framework is key to looking sharp and being right. When I was a resident, nailing these common-but-critical reads was the fastest way to build confidence and earn trust. This guide is built to give you that framework. We’ll cover the template, the key findings, and the common pitfalls. For more guides like this, check out the residents and fellows resource hub.

What a CT Abdomen and Pelvis for Suspected Appendicitis Covers and What Attendings Look For

A CT Abdomen/Pelvis for suspected appendicitis is the workhorse for acute, non-traumatic abdominal pain, especially in the right lower quadrant (RLQ). While the primary goal is to evaluate the appendix, its true value lies in its comprehensive assessment of the entire abdomen and pelvis, allowing you to confidently rule in or rule out a wide differential. The surgeon isn’t just asking “Is it appendicitis?”; they’re asking “If it’s not appendicitis, what is it?”

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

• Is the appendix visualized? If so, is it normal (<6 mm, no stranding) or abnormal? If not, state it explicitly.
• Are there primary signs of appendicitis? Dilated >6 mm, wall thickening, periappendiceal fat stranding.
• Are there secondary or complicating signs? Appendicolith, phlegmon, abscess, free fluid, or extraluminal air suggesting perforation.
• What about the mimics? Your report must address alternative diagnoses like cecal diverticulitis, terminal ileitis (Crohn’s), mesenteric adenitis, omental infarct, epiploic appendagitis, ureteral stones, and, in female patients, ovarian or adnexal pathology.
• Are there significant incidental findings? A quick but thorough survey of the solid organs, vasculature, and bony structures is non-negotiable.

Radiology Report Template for CT Abdomen and Pelvis for Suspected Appendicitis

This template provides a solid starting point for your macros. It’s structured to ensure you hit all the key points your attending and the clinical team need to see. Remember to always correlate with the provided clinical history.

Technique

CT of the abdomen and pelvis was performed with [100 mL] of intravenous contrast material. Axial images were obtained with coronal and sagittal reformations. [Comparison is made to prior study/studies from DATE].

Findings

Appendix: The appendix is [visualized/not definitively visualized]. It arises from the cecal base. The maximal diameter is [___] mm (normal <6 mm). There is [no] appendiceal wall thickening or enhancement. There is [no] surrounding periappendiceal fat stranding. [No] appendicolith is identified.

Bowel and Mesentery: The terminal ileum and cecum are unremarkable. No evidence of bowel obstruction, wall thickening, or inflammatory changes to suggest Crohn’s disease or diverticulitis. The mesenteric fat is unremarkable. No mesenteric adenopathy.

Right Lower Quadrant Structures: No evidence of omental infarct or epiploic appendagitis. No free fluid or focal fluid collection in the right lower quadrant.

Genitourinary:

(Male) The seminal vesicles and prostate are unremarkable.

(Female) The uterus is unremarkable. The ovaries are symmetric in appearance with normal enhancement. No adnexal mass or evidence of ovarian torsion.

The kidneys and ureters are unremarkable. No hydronephrosis or radiopaque calculus.

Solid Organs: The liver, spleen, pancreas, and adrenal glands are unremarkable.

Vasculature: The aorta and inferior vena cava are of normal caliber. No evidence of thrombosis.

Bones and Soft Tissues: No acute osseous abnormality. The visualized portions of the lungs are clear.

Impression

EXAMPLE 1 (Negative for Appendicitis):

1. Normal appendix, measuring up to [X] mm in diameter without wall thickening or surrounding inflammatory changes.

2. No CT evidence of acute appendicitis.

3. No alternative acute inflammatory process in the abdomen or pelvis to explain the patient’s symptoms.

EXAMPLE 2 (Positive for Acute Appendicitis):

1. Dilated, fluid-filled appendix measuring up to [X] mm in diameter with wall thickening, enhancement, and significant periappendiceal fat stranding, consistent with acute appendicitis.

2. [No evidence of perforation, abscess, or phlegmon.] OR [Findings concerning for perforation, including a 2.1 cm rim-enhancing fluid collection adjacent to the appendiceal tip, consistent with an abscess.]

Free Template Sources for Radiology Residents

Building your own macro library is a rite of passage, but you don’t have to start from scratch. Two great free repositories exist that are curated by radiologists and cover a huge range of modalities and subspecialties. They are excellent resources for finding high-quality, peer-reviewed templates.

• RadReport.org: Maintained by the Radiological Society of North America (RSNA), this is a comprehensive library of standardized templates.
• Radiology Templates (AU): An excellent, user-friendly site maintained by Australian radiologists with a wide variety of practical templates.

The Next-Level Move: AI-Powered Structured Reporting

A solid template is your foundation. The next step is making the reporting process faster and more consistent, especially when you have positive findings. Instead of manually slotting measurements and descriptors into a rigid template, you can dictate your findings in free form—”dilated appendix up to 1.2 cm with an adjacent 3 cm abscess and a calcified appendicolith”—and let an AI tool handle the rest. This is what GigHz Precision AI is designed to do. It takes your free-form dictation of positive findings and generates a clean, structured report using pre-loaded templates from the American College of Radiology (ACR) and Society of Interventional Radiology (SIR). It helps ensure your reports are consistently formatted and contain the key elements attendings and referring physicians expect, without slowing down your natural dictation flow.

When Should You Order a CT Abdomen and Pelvis for Suspected Appendicitis? ACR Appropriateness Criteria

The American College of Radiology (ACR) provides evidence-based guidelines to help clinicians choose the right imaging study. For RLQ pain, the recommendations vary based on the patient’s age and clinical presentation.

For an adult with right lower quadrant pain, fever, and leukocytosis where appendicitis is suspected, a CT of the abdomen and pelvis with IV contrast is “Usually Appropriate” as the initial imaging study. This is the classic indication where CT provides a rapid and definitive diagnosis.

The situation is different for pediatric and pregnant patients. For a child with suspected acute appendicitis, ultrasound is the first-line imaging modality. The ACR rates ultrasound as “Usually Appropriate” for children with low, intermediate, or high clinical risk. A CT is reserved for cases where the ultrasound is equivocal or nondiagnostic; in that specific scenario, a CT then becomes “Usually Appropriate” as the next imaging study.

For a pregnant woman with suspected appendicitis, ultrasound is also the first-line choice. If the ultrasound is non-diagnostic, an MRI of the abdomen and pelvis without contrast is the preferred next step and is rated “Usually Appropriate.” CT is considered an alternative but is used judiciously due to radiation dose to the fetus.

How Much Radiation Does a CT Abdomen and Pelvis for Appendicitis Deliver?

A standard portal-venous-phase CT of the abdomen and pelvis for suspected appendicitis delivers an effective radiation dose of approximately 6-10 mSv. To put this in perspective, this is comparable to the amount of natural background radiation a person receives over several months to a few years. While this is a moderate dose, the diagnostic benefit in an acutely ill patient typically far outweighs the risk.

Dose reduction is a key principle, especially in younger patients. Modern scanners and techniques can significantly lower the dose.

Both dedicated adult low-dose “appy protocols” and weight-based pediatric protocols utilize techniques like reduced kVp and iterative reconstruction algorithms to lower the effective dose into the 3-5 mSv range without a significant loss in diagnostic quality for this specific indication.

CT Abdomen and Pelvis for Appendicitis Imaging Protocol — Phases, Contrast, and Reconstructions

A well-executed protocol is the foundation of an accurate diagnosis. For suspected appendicitis, a single portal-venous phase acquisition with IV contrast is the standard of care at most institutions. This phase provides optimal enhancement of the appendiceal wall, solid organs, and vasculature, making it easier to identify inflammation and potential complications.

Below is a typical protocol for an adult patient on a 64-slice or wider detector CT scanner.

Common protocol pitfalls:

• Oral Contrast: The use of oral contrast is highly variable and institution-dependent. Many academic centers no longer use it for this indication, as IV contrast alone provides sufficient bowel wall visualization to diagnose appendicitis and its common mimics.
• Slice Thickness: Always ensure you have thin reconstructions (1-1.5 mm) available. They are critical for creating high-quality multiplanar reformats (MPRs) and for scrolling through the appendix in its true plane, which is often tortuous.
• Low-Dose Protocols: Be aware of your institution’s low-dose protocols for appendicitis, particularly for younger adults and pediatric patients. These protocols often use lower kVp and mAs settings combined with iterative reconstruction to reduce dose while maintaining diagnostic image quality.

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. All we ask in return is feedback so we can keep improving the product for trainees.

Signup is simple. There is no credit card required and no long forms. To apply, just provide these three items:

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 GigHz Precision AI HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. It processes the clinical content of your dictation without requiring or storing Protected Health Information (PHI). All data is encrypted in transit and at rest.

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 or special permissions from your IT department. It works on any modern computer, including the workstations in your reading room or a personal laptop or iPad.

Does it work with PowerScribe or other dictation systems?

Yes. It works alongside your existing dictation system, not as a replacement for it. You dictate as you normally would, and the tool can be used to structure your findings before you finalize the report in your PACS/RIS. Many residents use it on a second monitor or an iPad.

Can I use this on my phone or iPad on call?

Yes, the platform is fully responsive and works well on tablets like the iPad, which is perfect for on-call use when you might be away from your primary workstation.

Can I customize the templates?

The core templates are based on ACR and other society guidelines to promote standardization. However, the output is fully editable, so you can always tweak the final report to match your personal style or an attending’s specific preference before signing.

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 plan for practicing radiologists. We offer discounts for recent graduates to help you get started in your new role.

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