The psoas sign, hepatic angle, normal patients, and everyday practice

Area of Science:

• Radiology
• Anatomy
• Diagnostic Imaging

Background:

• Disease in the posterior pararenal space can obscure the psoas margin.
• Limited data exists on the frequency of psoas margin visualization in healthy individuals.

Purpose of the Study:

• To determine the frequency of psoas margin non-visualization in normal individuals.
• To evaluate the diagnostic utility of psoas margin visualization in identifying retroperitoneal abnormalities.

Main Methods:

• Radiographic analysis of normal individuals.
• Assessment of psoas margin visibility.
• Evaluation of ancillary radiographic signs.

Main Results:

• The right psoas margin is absent in 16-43% of normal patients.
• Absence of the left psoas margin can indicate posterior pararenal space abnormalities.
• Ancillary signs like mass displacement or gas are crucial.
• Hepatic and splenic angles have questionable diagnostic value due to frequent absence in normal subjects.

Conclusions:

• The right psoas margin is not a consistently reliable indicator of retroperitoneal disease.
• Left psoas margin visualization, alongside other signs, aids in diagnosing posterior pararenal space abnormalities.
• Radiographic assessment requires careful consideration of multiple signs.