# Lumbar safety triangle: comparative study of coronal and coronal oblique planes in 3.0-T magnetic resonance imaging

## TL;DR

This study compares the lumbar safety triangle measurements in two MRI planes and finds that the coronal oblique plane provides smaller measurements, which is important for preoperative planning.

## Contribution

The study introduces a comparative analysis of the lumbar safety triangle in coronal and coronal oblique planes using 3.0-T MRI.

## Key findings

- The safety triangle area was consistently smaller in the coronal oblique plane compared to the coronal plane.
- Six of seven dimensions of the triangle were significantly smaller in the coronal oblique plane.
- The dorsal root ganglion invaded the triangle in all analyzed images.

## Abstract

To compare the measurements of the lumbar safety triangle (Kambin’s triangle)
and the invasion of the dorsal root ganglion in the triangle in coronal and
coronal oblique planes.

A cross-sectional study, in which 210 3.0-T magnetic resonance images of
L2-L5 were analyzed in coronal and coronal oblique planes. Exams with lumbar
spine anomalies were excluded. Demographic (sex and age) and radiological
variables were recorded by a single evaluator.

Most sample was female (57.1%), mean age 45.5 ± 13.3 (18–98 years).
The measurements average, as well as the areas, gradually increased from L2
to L5. The dorsal root ganglion invaded the triangle in all images. The
safety triangle average area was smaller in the coronal oblique plane than
in the coronal plane. Of the seven dimensions of safety triangle obtained
for each level of the lumbar spine, six were significantly smaller in the
coronal oblique plane than in the coronal plane. The only dimension that
showed no difference was the smallest ganglion dimension.

The dimensions and areas investigated were smaller in coronal oblique plane,
especially the area (difference > 1 mm). The analysis of the triangular
zone in this plane becomes important in the preoperative assessment of
minimally invasive procedures.