ICD-10-PCS Billable Code

B431Y0Z

Magnetic Resonance Imaging (MRI) Celiac Artery to None with Unenhanced and Enhanced, Other Contrast Approach

Procedural Specifications

Clinical Axis Detail Definition
SectionB Imaging
Body System4 Lower Arteries
Operation3 Magnetic Resonance Imaging (MRI)
Body Part1 Celiac Artery
ApproachY Other Contrast
Device0 Unenhanced and Enhanced
QualifierZ None

Operation Definition

Computer reformatted digital display of multiplanar images developed from the capture of radiofrequency signals emitted by nuclei in a body site excited within a magnetic field

Procedure Overview

This family covers magnetic resonance angiography (MRA) of the arteries supplying the legs and pelvis, including vessels such as the aorta below the diaphragm, the iliac arteries, and the femoral, popliteal, and lower-leg arteries. Rather than using X-rays, the scanner uses a strong magnet and radio waves to build detailed cross-sectional and three-dimensional pictures of the vessel walls and the blood flowing through them. Physicians order it to look for narrowing (stenosis), blockages, aneurysms, or blood clots that could be starving the legs of oxygen-rich blood, a condition often called peripheral arterial disease.

Because it does not expose a patient to ionizing radiation, MRA is frequently chosen for people who need repeat imaging over time, such as those being watched after a vascular repair, or for patients with kidney concerns where iodinated CT contrast would be risky. Contrast agents used here are gadolinium-based rather than iodine-based, and some studies can even be performed without any contrast at all using specialized flow-sensitive sequences.

Anatomy & Axis Detail

Celiac Artery

MRI of the celiac artery is used in much the same clinical settings as CT - stenosis from atherosclerosis or median arcuate ligament syndrome, aneurysm, and preoperative mapping before hepatobiliary or pancreatic procedures - but is often chosen when a patient needs repeated follow-up imaging or cannot receive iodinated contrast. Gadolinium-enhanced MR angiography can depict the trunk's short course and its division into the hepatic, splenic, and left gastric arteries, though the vessel's small caliber and proximity to respiratory motion make image quality more sensitive to technique than with CT. Dynamic sequences obtained during inspiration and expiration are sometimes used specifically to demonstrate the positional narrowing characteristic of ligament compression, a finding that static imaging alone can miss.

Contrast: Other Contrast

Other Contrast captures imaging studies using a contrast medium that is neither high- nor low-osmolar iodinated agent, such as barium sulfate for gastrointestinal studies or gadolinium-based agents for certain applications outside standard MRI classification within this axis. It is used when the contrast administered does not fit the osmolarity-based iodinated categories, distinguishing it from those specific classes and from studies performed with no contrast.

Qualifier: Unenhanced and Enhanced

Unenhanced and Enhanced specifies that an imaging study was performed both before and after administration of contrast material, allowing comparison between the two phases. This is common in studies evaluating enhancement patterns of lesions, such as certain CT or MRI protocols. It differs from None, which reflects a purely unenhanced study, and from single-agent contrast qualifiers used elsewhere.

Coding & Documentation

Coders should confirm from the radiology report exactly which named artery or arterial segment was studied, since the lower artery body system in this section is subdivided by specific vessel, and picking the wrong body part value is the most common error. The report should also make clear whether contrast was administered, since that determines the correct qualifier character; ambiguous documentation stating only "MRA of the leg" without contrast detail should prompt a query. Another frequent mistake is coding a combined pelvic-and-leg run-off study as a single vessel when the study actually covers multiple distinct arterial segments requiring separate codes.

Commonly Confused With

This family is easily confused with Lower Arteries Ultrasonography (B|4|4), but ultrasound uses sound waves for real-time flow assessment and is typically the first-line, lower-cost screening tool, while MRI provides static high-resolution anatomic detail better suited for surgical planning. It can also be confused with CT angiography of the lower arteries, which uses ionizing radiation and iodinated contrast rather than a magnetic field; the modality named in the report, not the clinical question being answered, is what separates the two.