Imaging Diagnosis and Analysis of Ganglioneuroma

Objective: We intend to improve the imaging diagnosis of ganglioneuroma by discussing its manifestation of CT and MRI. Methods: We collected the MRI and clinical data of 33 cases with ganglioneuroma confirmed by operation and pathology, then performed retrospective analysis on the imaging manifestation obtained. Results: Among the 30 cases of single lesions, 9 cases were found located in the posterior mediastinum (5 ceses on the right and 4 cases on the left), 9 cases in the adrenal gland (4 cases on the right and 5 cases on the left), 8 cases in retroperitoneum, 1case in pelvis and 1case in parapharyngeal space. There were 3 cases found located inside and outside of the spinal canal, including 2 cases with multiple subcutaneous nodules in retroperitoneal, occipital and low back. Plain CT scan indicated even low density in 11 cases with average CT value (26.1±7.2) HU while the density was lower than that of the muscle at the same level. Meanwhile 9 cases showed speckle and patchy calcification, which were located at the edge of the focus, and 2 cases showed fat density. Among the 19 cases of enhanced CT scan, 6 cases showed mild enhancement at the arterial phase, 4 cases showed mild-moderate enhancement at the venous phase, 4 cases showed mild-moderate enhancement at the venous phase and delayed phase, 4 cases rogressive enhancement at the third phase and 1 case didn't show any enhancement at any phase. Through plain MRI scan, T1WI presented low or equal signal intensity, T2WI presented high or mixed high signal intensity, and STIR mostly presented high signal intensity. Among the 10 cases of enhanced MRI scan, 3 cases showed homogeneous enhancement, 6 cases showed flocculent or patchy inhomogeneous enhancement among which 1 case showed obvious inhomogeneous progressive enhancement while 1 case showed no obvious enhancement. Conclusion: The imaging manifestation of gangliocytoma hold certain characteristics, if they are seen in the adrenal gland, posterior mediastinum, inside and outside of the spinal canal and retroperitoneum, the boundary is quite clear, accompanying with pseudopodia or embedded growth, enclosing the great blood vessels with none or mild enhancement. Ganglioma should be considered first when the low signal intensity of "whirlpool sign" is seen on MRI T2 sequence.