CT Protocoling & Dosimetry: Sandbox Approach

⚠️ EDUCATIONAL SANDBOX ONLY: Demonstrates AI Governance & Guidelines. Not for clinical use.

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CLINICAL HARD STOP

Guideline Violation:

MULTIPHASE CT NOT INDICATED

ACR Appropriateness Enforcement:

Redirect message goes here.

Override Accountability Log

Per departmental governance, bypassing an ACR Hard Stop requires a documented clinical justification. This event is logged for peer review.

Clinical Justification -- Select Reason -- Prior imaging (US/MRI) was non-diagnostic Known complex vascular anatomy / variant Specific off-guideline trial/oncology protocol Direct Attending / Subspecialist Override

Ordering Provider NPI / ID

Precision CT Protocoling
& Dosimetry

Adult Abdomen & Pelvis | ACR Appropriateness & Pharmacokinetics

Developed by Dr. Sharad Maheshwari MD
Radiologist & Founder, BeResponsibleAI.com

Clinical Protocol Engine ⚙️

Simulates ACR criteria to enforce stewardship. Unnecessary unenhanced or multiphase exams trigger deterministic Hard Stops. Tracked by the RATSe framework.

Select Clinical Indication: -- Choose Adult Indication -- 🩺 Acute Abdominal Pain (Appendicitis/Diverticulitis) 🦠 Suspected Abscess / Infection 🧱 Routine Hernia (No bowel compromise) 🎗️ Cirrhosis / HCC Screening 🎯 Pre-TACE / Pre-TARE Liver Mapping 🎗️ Suspected Pancreatic Mass / Jaundice 🩸 Living Renal Donor Evaluation 🫀 Living Liver Donor Evaluation 🛑 CTA Aorta / Aortogram 🚨 Active GI Bleed (CTA) ⚠️ General Pain - "Order With and Without Contrast" ⚠️ Incidental Ovarian Cyst Follow-up

AI Governance Evaluation

Optimal

⚠️

Clinician Override Active Reason: Pending | NPI: Pending

QA Logged

Approved Imaging Pathway

Phase Rule & Delays

Contrast Strategy

Adult Dosimetry Simulator 📊

Simulate the impact of patient habitus (BMI), study type, and contrast concentration (Iodine Delivery Rate) on tube potential (kVp) and radiation dose (CTDIvol / SSDE).

Study Type (Modifies phases) Routine Abdomen/Pelvis (Single Venous Phase) CTA Aorta / Runoff (High Volume Arterial) Pre-TACE / TARE Mapping (Quadraphasic Liver) Living Liver Donor / HCC (Tri/Quadraphasic) Living Renal Donor (Triphasic)

Contrast Conc. 300 mg I/mL (Standard) 350 mg I/mL (High) 370 mg I/mL (Ultra-High)

Scan Length 45 cm (Standard Abd/Pel) 25 cm (Abdomen Only) 20 cm (Pelvis Only)

Patient Weight 80 kg

40 kg180 kg

Patient Height 175 cm

140 cm210 cm

Patient BMI 26.1 Overweight

Contrast Protocol 100mL @ 3.0 mL/sec IDR: 0.9 g I/s

Target kVp 120 Modulated for BMI

Est. Total DLP 540 mGy*cm (All Phases)

Radiation Physics Analytics

Values account for 1 discrete scan phase(s).

High Dose

Est. CTDIvol (per phase) 12.5 mGy

AAPM SSDE (Size Corrected) 14.2 mGy

Phase Breakdown

• Portal Venous65-70 sec delay

Guidelines & Stewardship 📚

Adults face lower lifetime stochastic risk than children, but the sheer volume of CTs and systemic overuse of multiphase protocols creates substantial cumulative population risk.

Choosing Wisely in Adults 🎯

• ✦
  Eliminate Unenhanced Phases: "With and without" contrast is rarely needed for routine pain. A single venous phase suffices for >85% of acute indications.
• ✦
  Contrast Kidney Risk: Risk of CA-AKI is historically overstated. Do not withhold life-saving CTA for slightly elevated creatinine (unless eGFR <30 or dialysis).
• ✦
  Obesity & Image Quality: Use lower kVp (100) for thin adults to increase iodine contrast resolution. Obese patients require 120-140 kVp to penetrate tissue.

Dose Escalation of Multiphase CT 📊

Each phase multiplies the radiation (DLP)

Common Clinical Pitfalls 🎴

Tap cards to reveal evidence-based corrections to outdated clinical habits.

Workflow Error

"Routine Appendicitis Protocol: With and Without Oral & IV Contrast"

Tap to reveal 🔄

ACR Correction

Oral contrast delays ED throughput and is unnecessary for appendicitis in adults. Unenhanced phase doubles radiation.

Correct: Single Phase IV Contrast Only.

Pharmacokinetics

"Just give 100 mL of contrast for every adult."

Tap to reveal 🔄

Physics Correction

Standardizing 100mL overdoses thin adults and underdoses obese adults. Contrast should be weight-based (approx 1.5 - 2.0 mL/kg) or based on total Iodine Load.

Positioning Error

Scanning the abdomen with the patient's arms down by their sides.

Tap to reveal 🔄

Artifact Correction

Arms down creates severe beam-hardening artifacts. It also forces the Tube Current Modulation to spike the radiation dose unnecessarily. Arms MUST be raised.

Diagnostic Fallacy

"Adding a delayed phase (5 mins) to a routine CT just in case we see a liver lesion."

Tap to reveal 🔄

Stewardship Rule

Unjustified 'fishing'. Most incidental liver lesions on routine venous CT are benign. Characterize indeterminate lesions later with MRI, avoiding irradiating the entire pelvis again.

Competency Assessment (OSCE)

Test your knowledge of adult CT protocols, contrast dynamics, and physics.

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QUESTION 1 / 5 SCORE: 0

© 2026 Adult Abdomen Precision CT

Strictly an educational interface. Protocols rely on ACR and AAPM frameworks.