J Korean Soc Magn Reson Med.  2005 Dec;9(2):101-108.

Evaluation between 3.0 T vs 1.5 T MRI in Detection of Brain Metastasis using Double Dose Gd-DTPA

• Chung WS
• Chung TS
• Kim HJ
• Ahn CM
• Lee JH
• Hur J
• Cho AE

Abstract

PURPOSE
Early detection of small brain metastases is important. The purpose of this study was to compare the detectability of brain metastases according to the size between 1.5 T and 3.0 T MRI. MATERIALS AND METHODS: We reviewed 162 patients with primary lung cancer who were examined for TNM staging. After administration of double dose of Gd-DTPA, MR imaging was performed with SPGR by 3.0 T MRI and then with T1 SE sequence by 1.5 T MRI. In each patient, three readers performed qualitative assessment. Sensitivity, positive predictive value, and diagnostic accuracy were calculated in 3.0 T and 1.5 T MRI according to size. Using the signal intensity (SI) measurements between the metastatic nodules and adjacent tissue, nodule-to-adjacent tissue SI ratio was calculated. RESULTS: Thirty-one of 162 patients had apparent metastatic nodules in the brain at either 1.5 T or 3.0 T MR imaging. 143 nodules were detected in 3.0 T MRI, whereas 137 nodules were detected at 1.5 T MRI. Six nodules, only detected in 3.0 T MRI, were smaller than 3.0 mm in dimension. Sensitivity, positive predictive value, and diagnostic accuracy in 3.0 T MRI were 100 %, 100 %, and 100 % respectively, and in 1.5 T MRI were 95.8 %, 88.3 %, and 85.1 % respectively. SI ratio was significantly higher in the 3.0 T MRI than 1.5 T MRI (p=0.025). CONCLUSION: True positive rate of 3.0 T MRI with Gd-DTPA was superior to 1.5 T MRI with Gd-DTPA in detection of metastatic nodules smaller than 3.0 mm.

Keyword

Magnetic resonance (MR), high-field-strength imaging; Brain neoplasm, metastases; Contrast medium

MeSH Terms

Brain*
Gadolinium DTPA*
Humans
Lung Neoplasms
Magnetic Resonance Imaging*
Neoplasm Metastasis*
Neoplasm Staging
Gadolinium DTPA