1,329 calculators and references across 60 specialties, with formula confidence shown up front.
Abdominal Aortic Aneurysm (AAA) Rupture Risk Index: Explanation and Clinical Context AAA Rupture Risk Index is a tool designed to estimate the probability of rupture in patients with abdominal aortic aneurysm. It combines key risk factors including maximum aneurysm diameter, annual growth rate, and aneurysm morphology (fusiform or saccular). Diameter remains the strongest predictor, with risk increasing significantly
Ankle Brachial Index For PAD Risk. Clinical Explanation and Context The Ankle Brachial Index is a simple and validated noninvasive test used to detect the presence and severity of peripheral artery disease. It is calculated by dividing the systolic blood pressure at the ankle by the highest systolic blood pressure measured in both arms. ABI provides an objective assessment of lower extremity perfusion and correlates
Aortic Aneurysm Expansion Index (AAEI): Explanation and Clinical Context The Aortic Aneurysm Expansion Index (AAEI) quantifies the annual relative increase in aortic diameter, expressed as a percentage per year. It is calculated using the formula: (Follow-up Diameter - Baseline Diameter) / (Baseline Diameter × Time Interval) × 100%. AAEI helps clinicians identify patients at risk of rapid aneurysm growth and potentia
BASIL Trial Risk Model: Explanation and Clinical Context The BASIL Trial Risk Model is derived from the multicenter BASIL trial comparing surgical bypass and angioplasty in patients with severe limb ischemia. This model estimates 1-year mortality risk based on key clinical factors including age >75, male sex, renal dysfunction, severe cardiac disease, tissue loss (ulcer or gangrene), and urgency of the procedure. Eac
Fontaine Classification (PAD Severity): Explanation and Clinical Context The Fontaine Classification is a widely used system to assess the severity of peripheral artery disease (PAD) based on clinical presentation of the lower extremities. It stratifies patients into four stages: Stage I (Asymptomatic): Patients have arterial narrowing without symptoms; often detected via ABI or imaging. Stage II (Intermittent Claudi
IRAD Risk Score (Aortic Dissection): Explanation and Clinical Context IRAD Risk Score is a validated clinical tool to assess the probability of acute aortic dissection (AAD) in patients presenting to emergency departments. It is based on three domains: predisposing conditions (such as Marfan syndrome, aortic aneurysm, or chronic hypertension), pain characteristics (abrupt onset, severe intensity, and migrating nature
MR Angiography Index (MRAI): Explanation and Clinical Context MR Angiography Index (MRAI) is a semi-quantitative scoring system used to assess the severity and burden of arterial stenosis based on magnetic resonance angiography (MRA). Each arterial segment is scored from 0 (no stenosis) to 4 (total occlusion), and the total MRAI reflects the overall extent of vascular disease. Higher MRAI values indicate more extensi
Penn Classification (Aortic Dissection Outcome): Explanation and Clinical Context The Penn Classification is a prognostic tool for patients with Type A aortic dissection, focusing on the presence of organ malperfusion and circulatory collapse. It stratifies patients into four categories: - Penn Aa: No evidence of ischemia; patient hemodynamically stable. - Penn Ab: Localized organ ischemia; hemodynamically stable. -
PVI Mortality Score: Explanation and Clinical Context The PVI Mortality Score is a clinical tool used to estimate the risk of mortality in patients undergoing Peripheral Vascular Intervention (PVI). It incorporates factors such as age, creatinine levels, hemoglobin levels, diabetes, and smoking status to stratify patients into low, moderate, or high-risk categories. This score aids clinicians in decision-making, prio
Rutherford Classification: Explanation and Clinical Context Rutherford Classification is a widely accepted system for grading the severity of peripheral arterial disease (PAD). It stratifies patients from stage 0 (asymptomatic) to stage 6 (major tissue loss), incorporating claudication severity, presence of rest pain, and degree of tissue loss. Stage 0 represents no symptoms, stages 1-3 correspond to increasing sever
STABLE Score (TEVAR Risk): Explanation and Clinical Context STABLE Score is a validated tool to predict 30-day mortality in patients undergoing thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection. It incorporates four key clinical factors: Shock at presentation, presence of Malperfusion, Age >70 years, and Previous Aortic Surgery. Each factor scores 1 point if present, and the t
SVS/ISCVS Grading System for Peripheral Artery Disease: Explanation and Clinical Context The SVS/ISCVS grading system provides a standardized framework for assessing the severity of lower extremity peripheral artery disease (PAD), particularly in patients with critical limb ischemia (CLI). It incorporates key clinical parameters including rest pain, presence of ulceration, gangrene, and ankle-brachial index (ABI) val
WIfI Classification (Wound, Ischemia, Foot Infection): Explanation and Clinical Context WIfI Classification is a standardized tool to stratify the risk of major amputation in patients with critical limb ischemia or diabetic foot ulcers. It evaluates three components: wound extent, limb ischemia, and foot infection, each scored 0–3. The combination of these scores determines the WIfI Stage (1–4) and predicts the 1-yea