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CMR Calculators

BSA Calculator


Body Surface Area (BSA): 0 m²
LA Calculator



Left atrial volume: 0 mL


LA area – 2 chamber
MALE: MEAN±SD: 21±5cm2, Lower limit – Upper limit: 12-30
FEMALE: MEAN±SD: 19±5cm2, Lower limit – Upper limit: 10-28

LA area – 4 chamber
MALE: MEAN±SD: 23±5cm2, Lower limit – Upper limit: 13-32
FEMALE: MEAN±SD: 21±4cm2, Lower limit – Upper limit: 13-29

LA volume
MALE: MEAN±SD: 72±20ml, Lower limit – Upper limit: 31-112
FEMALE: MEAN±SD: 64±18ml, Lower limit – Upper limit: 28-100

The Biplane Area-Length method, also known as the B-Planer method, is a technique used to measure left atrial volume using cardiovascular magnetic resonance (CMR) imaging. This method involves acquiring images in the horizontal and vertical long-axis cines to measure left atrial end-systolic areas and longitudinal dimensions.[1]

  • The above areas are segmented at the end of ventricular systole – when the left atrium is the biggest and just before the opening of the mitral valve.
  • The atrial endocardial border should be traced to determine LA area with the exclusion of the pulmonary veins and mitral valve recess. The normal values can vary depending on the inclusion or exclusion of atrial appendage.
  • The normal values mentioned exclude LA appendage in segmentation.


The Biplane Area-Length method is based on the assumption that the left atrium is shaped like an ellipsoid. The left atrial volume is then calculated using the formula: 8/3π * (Area1 * Area2 / Length), where Area1 and Area2 are the maximum areas of the left atrium in the four-chamber and two-chamber views, respectively, and Length is the shortest left atrial dimension measured in either view.[1]

This method has been shown to be effective for evaluating left atrial volumes and ejection fraction in both normal subjects and patients with atrial fibrillation.[1] It has also been found to be highly reproducible and accurate, with good interobserver agreement.[1]


  1. SCMR Position Paper (2020) on Clinical Indications for Cardiovascular Magnetic Resonance. Leiner T, Bogaert J, Friedrich MG, et al. Journal of Cardiovascular Magnetic Resonance : Official Journal of the Society for Cardiovascular Magnetic Resonance. 2020;22(1):76. doi:10.1186/s12968-020-00682-4.
ECV Calculator


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CMRPCWP Calculator


CMR derived PCWP: 0 mmHg

Cardiac Magnetic Resonance (CMR) derived Left Ventricular Filling Pressure (LVFP) is a significant tool in the assessment and prognosis of heart failure (HF). Studies have shown that elevated CMR-derived LVFP is strongly associated with symptoms and signs of HF, such as pleural effusions, orthopnoea, lower limb oedema, and breathlessness.[1] Furthermore, raised CMR-derived LVFP is independently associated with subsequent HF hospitalization and major adverse cardiovascular events (MACE).[1]

CMR can estimate LVFP in patients with suspected HF, and this CMR-modelled LVFP has been shown to have prognostic power.[2] It was found to be superior to transthoracic echocardiography in classifying patients as having normal or raised filling pressures and was associated with an increased risk of death.[2]

In addition to its role in HF, CMR-derived LVFP can also be used to measure acute and dynamic changes in preloading conditions on the left ventricle during adenosine administered first-pass perfusion CMR, where it has been observed to rise significantly.[3]

In conclusion, CMR-derived LVFP is a valuable tool in the diagnosis, management, and prognosis of HF and other cardiovascular conditions. It provides critical insights into the patient’s condition and can guide therapeutic decisions.


  1. Cardiac Magnetic Resonance Left Ventricular Filling Pressure Is Linked to Symptoms, Signs and Prognosis in Heart Failure. Grafton-Clarke C, Garg P, Swift AJ, et al. ESC Heart Failure. 2023;. doi:10.1002/ehf2.14499.
  1. Cardiac Magnetic Resonance Identifies Raised Left Ventricular Filling Pressure: Prognostic Implications. Garg P, Gosling R, Swoboda P, et al. European Heart Journal. 2022;43(26):2511-2522. doi:10.1093/eurheartj/ehac207.
  2. An Acute Increase in Left Atrial Volume and Left Ventricular Filling Pressure During Adenosine Administered Myocardial Hyperaemia: CMR First-Pass Perfusion Study.Garg P, Javed W, Assadi H, et al. BMC Cardiovascular Disorders. 2023;23(1):246. doi:10.1186/s12872-023-03230-x.

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  • These calculators are for educational and informative purposes ONLY.
  • The calculators provided are not meant to be a substitute for professional advice.
  • The information provided is not to be used for medical diagnosis.
  • The authors make no claims of the accuracy of the information contained herein.
  • The authors make no claims whatsoever, expressed or implied, about the authenticity, accuracy, reliability, completeness, or timeliness of the material, software, text, graphics, and links given.
  • In no event shall the authors, its suppliers, affiliates, or any third parties be liable in any manner whatsoever for any damage arising upon use of any information provided.

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