[Using 3.0 T MR to dynamically observe ablated lung tumors after percutaneous cryotherapy therapy].
Objective:To initially explore MRI features and its changing trends including of lung tumors after Argon-Helium cryoablation therapy, and enhance the recognition of MR findings of lung tumors postcryoablation.Methods:Twenty-three cases of patients with twenty six nodules of pulmonary malignance who received Argon-Helium cryoablation therapy in Henan Cancer Hospital from July 2014 to January 2016 were enrolled.All patients underwent unenhanced and dynamic contrast-enhanced MRI scans at pre-and 1-day, 1-week, 1-, 3-, 6-, 12-month postcryoablation. Two radiologists independently reviewed MRI images, signal intensity in the ablated zone on T1WI and T2WI were assessed by a 5-point scale.The changing trends of size and signal intensity with time were showed by time-maximum diameter and time-score curve.Time-signal intensity curves based on dynamic enhanced sequence were also performed.Results:Typical MRI findings includes: heterogeneous signal intensity on both T1WI and T2WI at 1-day postcryoablation(26/26, 100%). Hyper-intense on T1WI(22/26, 84.6%) and T2WI(17/26, 65.4%) with a hypo-intense rim at 1-week postcryoablation.Decreasing signal intensity on T1WI(17/26, 65.4%) and increasing signal intensity on T2WI(22/26, 84.6%) at 1-month.Signal intensity declined to the level of muscle on both T1WI(18/26, 69.2%) and T2WI(19/26, 73.1%) at 3-month, nineteen ablated zone turned into patchy shape(19/26, 73.1%). The maximum diameter was largest at 1-day and gradually shrunk with time. The mean score value toped at 1-week and gradually decreased. A straight line type without definite enhancement was found from 1-day to 1-month postcryoablation, an inflow curve with a mild delayed enhancement was seen from 3- to 12- month. Totally 4 recurrence (4/26, 15.4%) all occurred at 3-month and were lack of a complete hypo-intense rim at 1-week postcryoablation.Conclusion:MRI findings of lung tumors postcryoablation are characteristic, a complete hypo-intense rim at 1-week is helpful to determine further recurrence, 1-week to 3-month is an important period to observe significant change of the ablation zone, MRI is valuable in identifying the ablation zone and can reflect its evolution with time.
Department of Radiology, Henan Cancer Hospital, Zhengzhou 450008, China.
J
J
Li
J R
JR
Qu
H K
HK
Zhang
J C
JC
Xiao
L N
LN
Jiang
Y
Y
Zhao
H L
HL
Li
D003452:Cryosurgery; D006801:Humans; D008175:Lung Neoplasms; D008279:Magnetic Resonance Imaging; D012008:Recurrence