[Determination of the amount of functioning renal parenchyma based on multipositional scintigraphy data]

Area of Science:

• Nuclear medicine
• Medical imaging
• Renal physiology

Background:

• Accurate quantification of functioning renal parenchyma is crucial for diagnosing and managing kidney diseases.
• Polyposition scintigraphy is a common technique, but its accuracy can be affected by patient positioning and anatomical variations.
• Determining the depth of kidney location is essential for precise functional assessments.

Observation:

• Analysis of 122 patients revealed significant variations in kidney depth (over 1-3 cm in 41.7% to 5.7% of cases).
• A 3 cm anterior shift can attenuate gamma irradiation by over 1.5x (99mTc) or 1.75x (197Hg).
• Standard anterior and posterior projections may lead to underestimation of renal function in cases of significant depth variation.

Findings:

• Mathematical calculations for two methods to determine functioning renal parenchyma using polyposition scintigraphy data were performed.
• Significant differences in kidney depth location were observed in a substantial portion of the patient cohort.
• Gamma irradiation intensity is significantly affected by the depth of the kidney from the body surface.

Implications:

• The findings highlight the potential for significant errors in renal parenchyma quantification using standard scintigraphy techniques.
• A revised method incorporating lateral projections is recommended for estimated renal parenchyma depth (RPD) accumulation, particularly in renal insufficiency and obese patients.
• This study underscores the need for improved scintigraphy protocols to account for anatomical variations and ensure accurate patient assessment.