What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 79954-4: Aorta root Diameter at end systole (by US 2D)/Body surface area

Name: LOINC Code 79954-4: Aorta root Diameter at end systole (by US 2D)/Body surface area
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:01.838Z

79954-4 is a LOINC code used to identify Aorta root Diameter at end systole (by US 2D)/Body surface area in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Diameter.end systole/Body surface area. It is commonly used with the system or sample type Aorta.root.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Diameter.end systole/Body surface area. It is commonly used with the system or sample type Aorta.root.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation
Method: US.2D

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Aorta root Diameter at end systole (by US 2D)/Body surface area
Diameter.end systole/Body surface area
2D US; AO; AO root; Aortic; Bdy surface; bod; Bodies; BSA; CARD.US; CARD.US.DICOM; Cardio; Cardiology; DIA; Diam; Echography; ES; ES diameter; Heart Disease; Point in time; QNT; Quan; Quant; Quantitative; Random; Sonogram; Sonograph; Sonography; Surf; Sys; Syst; ULS; Ultrasound; Ultrasound - 2-dimensional

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Aorta root Diameter at end systole (by US 2D)/Body surface areaAO root ES diameter (2D US)/BSADiameter.end systole/Body surface areaCARD.US.DICOMArLenPtAorta.root

Frequently asked questions

Code details

Code79954-4

SystemLOINC

Display nameAorta root Diameter at end systole (by US 2D)/Body surface area

DescriptionDiameter.end systole/Body surface area

Short nameAO root ES diameter (2D US)/BSA

ComponentDiameter.end systole/Body surface area

PropertyArLen

TimingPt

System (specimen)Aorta.root

ScaleQn

MethodUS.2D

ClassCARD.US.DICOM

Example unitscm/m2

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.54

Last changed2.54

Part names

Diameter.end systole/Body surface areaArLenPtAorta.rootQnUS.2DLength/AreaPoint in time (spot)Aorta rootUltrasound 2D

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.