Renal scintigraphy

Static renal scintigraphy: functional assessment

In clinical practice, radioisotope renal imaging is used for precise quantitative assessment of the organ's functional state. A prime example is static renal scintigraphy using a specialized radiopharmaceutical—dimercaptosuccinic acid (DMSA).

During this study, the specialist is able to calculate the percentage ratio of function. For example, in one clinical case, quantitative analysis of radiopharmaceutical uptake demonstrates only minimal function of the left kidney. Numerically, this means that the uptake on the left is only about 3–5%. At the same time, the healthy right kidney takes on the main workload, and its uptake level reaches 94–96%. Thus, static renal scintigraphy provides an objective picture of the distribution of functional activity.

Ultrasound examination (US) in megaureter

In addition to radioisotope methods, ultrasound plays a crucial role in diagnostics. Let us consider a classic clinical example of left-sided megaureter in a 3-year-old boy. In this clinical case, the right kidney was within normal limits according to the examination.

However, the sonograms of the left kidney demonstrate a completely different pathological picture. Ultrasound scanning clearly visualizes severe hydronephrosis of the left kidney. The main ultrasound sign in this situation is marked dilation of the pelvicalyceal system. On the screen, this dilation appears as large, confluent anechoic structures. It is anechoic properties that allow the physician to differentiate fluid collections.

Diseases associated with cystic renal lesions

Diseases accompanied by cystic renal lesions represent a broad group. Globally, all cystic diseases are divided into hereditary and acquired. Among the main pathologies accompanied by cyst formation are the following:

• Autosomal dominant polycystic kidney disease (Autosomal dominant polycystic kidney disease).
• Autosomal recessive polycystic kidney disease (Autosomal recessive polycystic kidney disease).
• Multicystic dysplastic kidney disease (Multicystic dysplastic kidney disease).
• von Hippel–Lindau syndrome (von Hippel–Lindau syndrome).
• Tuberous sclerosis (Tuberous sclerosis).
• Lithium-induced renal disease (Lithium-induced renal disease).

A separate category is acquired cystic kidney disease (Acquired cystic disease of the kidney). Typically, this form of pathology is directly associated with chronic kidney disease (CKD) in the patient, as well as with dialysis.

Bosniak classification of renal cysts

To standardize the evaluation of cystic lesions, the Bosniak renal cyst classification system (Bosniak Renal Cyst Classification System) is used. This system was first proposed by the American radiologist Morton A. Bosniak (Morton A. Bosniak) in 1986.

This eponymous classification (including its subsequent modifications) remains the modern global standard today. It is used to evaluate cystic lesions based on imaging data. The main purpose of the Bosniak classification is to accurately determine the risk of malignancy of detected lesions, which helps determine the correct patient management strategy.

Class and exam questions

What else to study on this topic

• Mechanism of dimercaptosuccinic acid (DMSA) uptake in the renal parenchyma
• Differential diagnosis of anechoic structures on renal ultrasound
• Genetic basis of autosomal dominant and autosomal recessive polycystic kidney disease
• Pathogenesis of cyst formation in von Hippel–Lindau syndrome and tuberous sclerosis
• Modifications of the Bosniak classification and their application in modern radiology

Other topics in the section "Diagnostic Radiology of the Abdominal Organs"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.