Role of MRI in Monitoring ADPKD in Young Individuals
Ultrasonography, not MRI, is the recommended primary imaging modality for monitoring Autosomal Dominant Polycystic Kidney Disease (ADPKD) in young individuals under 15 years of age. 1
Primary Imaging Recommendations
- Ultrasonography is the current radiological method of choice for screening and monitoring ADPKD in children, with moderate evidence supporting this recommendation 1
- There are no established MRI-based diagnostic criteria for ADPKD in children younger than 15 years of age 1
- MRI usually requires sedation in children younger than 6 years and is more expensive than ultrasonography, making it not the diagnostic method of choice for pediatric ADPKD 1
Limited Role of MRI in Young ADPKD Patients
MRI has specific limited applications in young ADPKD patients:
- In teenage children (but not younger children), MRI is more sensitive than ultrasonography for detection of kidney cysts in ADPKD 1
- MRI can be valuable specifically for clinical trials in patients with ADPKD to evaluate kidney cysts 2
- MRI may be considered in older children with tuberous sclerosis complex to evaluate both kidney cysts and angiomyolipomas 2
Diagnostic Criteria and Follow-up
- In a child under 15 years with a positive family history of ADPKD, sonographic detection of one or more kidney cysts is highly suggestive of ADPKD 1
- If kidney ultrasonography is normal in an at-risk child, this finding does not exclude ADPKD, and rescreening should occur at intervals no shorter than 3 years 1
- Multiple kidney cysts in childhood are highly suggestive of ADPKD or another cystic nephropathy and require clinical work-up 1
- Detection of a solitary cyst in childhood requires follow-up imaging 1
Special Considerations for MRI Use
- In adults and older adolescents (>15 years), MRI provides both high sensitivity and specificity (100%) for ADPKD diagnosis using the criterion of >10 cysts 3
- MRI has been successfully used in research settings to monitor total kidney volume, cyst volume, and cyst number in children with ADPKD, particularly in those with hypertension who show more rapid disease progression 4
- For children participating in interventional trials, MRI may be the preferred renal imaging approach due to its precision in measuring kidney and cyst volumes 4
Pitfalls and Caveats
- Parents should be counseled that the negative predictive value of a normal ultrasonography scan in childhood is limited, and later appearance of cysts may be due to a milder underlying genetic alteration 1
- The diagnostic sensitivity of imaging is better in older than in younger children and with high-resolution versus lower-resolution ultrasonography 1
- Genetic testing, rather than advanced imaging, may be more appropriate for children with very-early-onset symptomatic disease or those with progressive disease and a negative family history 1