MRI reliability in pediatric abdominal lymph node metastases?

Background: Although positron emission tomography-computed tomography (PET-CT) is an effective imaging method used in the detection of lymph node metastases, repeated imaging increases X-ray exposure, especially in pediatric patients. Magnetic resonance imaging (MRI) may detect abdominal lymph nodes and provide subtle anatomic detail, and functional information without radiation.

Purpose: To evaluate the reliability of MRI in detecting lymph node metastases in pediatric abdominal malignancies and to determine whether X-ray dose can be reduced by comparing its effectiveness with PET-CT.

Material And Methods: Patients aged <18 years, diagnosed with abdominal malignant solid lesions between January 2015 and 2022 were included in this retrospective single-center study. A total of 14 A total of 14 different anatomic locations were defined for lymph nodes in MRI and PET-CT examinations. Cohen's kappa test was used to evaluate the consistency between PET-CT and MRI.  < 0.05 was considered statistically significant.

Results: In total, 25 patients (18 [72%] girls, 7 [28%] boys; mean age = 9.32 ± 16.9 years; age range = 1-18 years) with abdominal solid malignant tumors were included. The reliability of MRI and inter-observer reliability differed depending on the location of the lymph nodes. The reliability was almost perfect for the internal iliac (k = 0.915), porta hepatis, and aortocaval lymph node stations, while fair reliability was observed for the mesenteric lymph nodes (k = 0.525).

Conclusion: The results showed that MRI was as reliable as PET-CT in detecting some intra-abdominal metastatic lymph nodes, while its reliability was lower in some lymph node stations.