| Partâ… Image Analysis of 3.0T MR Sequences in the Chest.PURPOSE: To compare the image quality of FSE-T1, FSE-T2, FSE-T2-FS, T2* and LAVA-enhanced sequences with 3.0T MR in the chest. MATERIALS ANDMETHODS: Fifty-three patients with suspected lung cancer underwent chest MRI. Nineteen out of them combined with obstructive atelectasis or pneumonia at the examination time. The FSE-TI, FSE-T2 and FSE-T2-FS sequences were obtained in all patients. T2* and LAVA-enhanced sequences were obtained in 48 patients, respectively. The quality of MR images was evaluated and scored according to overall image quality, the image quality of masses, of bronchi, of vessels, of chest wall and of the artifacts. The borders of masses and obstructive lesions were evaluated, too.RESULTS: The overall MR image quality, the image quality of masses, of bronchi, of vessels, of chest wall and of the artifacts were significantly different in five sequences (P<0.05). The overall MR image quality of FSE-T2, FSE-T2-FS and LAVA-enhanced sequences was significantly better than that of FSE-T1 and 12* sequences (P<0.01) , and the image quality of FSE-T2-FS sequences was no better than that of FSE-T2 and LAVA-enhance sequences on vessel displays (P<0.05). T2* sequence was inferior to other four sequences on airway displays (P<0.01). There were more artifacts in FSE-T1 sequence than in LAVA-enhanced sequence (P<0.05), in which no or little artifacts were encountered. The tumor and adjacent obstructive lesions could be differentiated on FSE-T2. FSE-T2-FS, and LAVA-enhanced sequences in all 19 patients with obstructive atelectasis or pneumonia but only in 2 cases on FSE-T1 and T2* sequences. CONCLUSION: FSE-T2 and LAVA-enhanced sequences with 3.0T MR could render images with good quality in patients with lung cancer. The image quality of FSE-T2-FS and FSE-T1 is inferior to FSE-T2 and LAVA-enhanced sequence, but they can be used as supplement in the tissue identification. The use of T2* sequence is limited in the chest MRI examinations because of dissatisfied image quality. Partâ…¡3.0T Dynamic Contrast-enhanced Magnetic Resonance Imagingof Lung Cancer: Characterization and Monitoring after Chemoradiation.PURPOSE: To prospectively investigate enhancing characteristics of lung cancer, correlate them with pathology and tumor microvessel density, monitor the enhancing parameters and the T-SI% curve types of lung cancer after chemoradiation, and assess early response after chemoradiation with dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging. MATERIALS AND METHODS: Thirty-seven patients with pathologically proven lung cancer underwent DCE-MR with LAVA sequence. DCE-MR images were acquired intermittently for a total of 4 minitues on 3.0T MR scanner. The relative enhancing percentage (Sl%) of each time point was measured. The shapes of T-SI% curves were defined as A (rapidly ascending followed with descending branch), B (rapidly ascending branch followed with plateau) and C (rapidly ascending followed with slowly ascending branch) and D ( persistently low and flat). The early peak enhancement (SIEP>%). early peak time (TEP), maximum enhancement (SIpeak%), and peak time (Tpeak) were recorded and compared according to different dimension, location, histological types, clinical stages and differentiation grades of lung cancer. The SIEP% and SIpeak% were correlated with microvessel density in ten patients who underwent the resection of tumor. Seventeen patients who underwent chemoradiation were examined repeatedly pre-, mid- and post-chemoradiation, the shapes of T-SI% curves, SIEP% and SIpeak% of pre-, mid-and post-treatment were compared. RESULTS: The SIEP% and SIpeak% of tumors with smaller dimension (≤5cm) were significantly higher than those with larger dimension (>5cm). The SIEP% and SIpeak% were positively correlated with microvessel density. In 17 patients who underwent chemoradiation. no significant differences were observed in the enhancing parameters between response group and nonresponse group. The SIEP% and SIpeak% of pre-, mid- and post-chemoradiation were not significantly different, but Tpeak increased after the treatment (P=0.005). The T-SI% curves were type A (4/17) and type B (13/17) before chemoradiation. however they were type B (3/10) and type C (7/10) after chemoradiation. CONCLUSION:The SIep% and SIpeak% of lung cancer with smaller dimension are higher than those with larger dimension. The SIep% and SIpeak% are positively correlated with the tumor MVD. The small sample research demonstrates the Tpeak delayed and T-SI% curve type changed after chemoradiation. Partâ…¢3.0T MR Diffusion-weighted Imaging in Assessment of TumorResponse after Chemoradiation in Patients with Lung Cancer.PURPOSE: To investigate characteristics of diffusion weighted imaging (DWI) of lung cancer, monitor the apparent diffusion coefficient (ADC) after chemoradiation and assess the value of DWI in early response of lung cancer after chemoradiation.MATERIALS AND METHODS: Thirty-six patients with pathologically proven lung cancer underwent DWI. Fifteen patients who underwent chemoradiation were scaned prior to and post chemoradiation. The quality of diffusion weighed images were evaluated on 3-level grades as good, moderate and failed. ADCs of the lung cancers which were graded as good and moderate were measured from ADC mapping. ADCs were compared among the different types of lung cancers and pre- and post-chemoradiation. RESULTS: The quality of diffusion weighed images was graded as moderate or good in 22 patients, and as failure in 14 patients. ADCs were 1.41×10-3 mm2/s±0.26×10-3mm2/s (mean±standard deviation) for squamous cell carcinoma, and 1.42×10-3mm2/s±0.63×l0-3mm2/s for adenocarcinoma. There were no significant differences between squamous cell carcinoma and adenocarcinoma (P=0.970). The quality of diffusion weighted images of 7 patients were graded as good or moderate pre- and post-chemoradiation. ADCs were 1.13×10-3 mm2/s±0.25×10-3mm2/s for pre-therapy, 1.81×10-3mm2/s±0.25×10-3mm2/s for post-therapy. The differences of ADC values before and after chemoradiation were statistically significant (P=0.000). CONCLUSION: The ADCs of lung cancer are markedly increased after chemoradiation. The DWI has potential value for monitoring early response of lung cancer after chemoradiation, but the image quality of DWI is not satisfied for routine clinical application rencently.
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