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[T2-dependent sequences in the study of hepatic focal lesions: comparison of the conventional spin echo sequence and
R Manfredi1, G Maresca, T Tartaglione
1Istituto di Radiologia, Università Cattolica del Sacro Cuore, Policlinico A. Gemelli, Roma.
Abstract:
T2-weighted spin echo MR images are widely used in the detection and characterization of focal liver lesions. The main pitfall of this technique is its relatively long acquisition time. Fast spin echo sequences can provide the same contrast as conventional T2-weighted SE images in a shorter scanning time. Our study prospectively compared the effectiveness of T2-weighted conventional spin echo (CSE) versus fast spin echo (FSE) sequences in MRI of focal liver lesions. We examined 24 patients with this condition. All lesions were submitted to percutaneous biopsy and to the diagnostic gold standard technique, which was intraoperative US (13 patients), Lipiodol CT (10 patients) or 6-month follow-up (1 patient). MR images were analyzed from both a quantitative (signal-to-noise and contrast-to-noise ratios) and a qualitative viewpoints (overall image quality, lesion detection rate, number of lesions as compared with the gold standard, lesion conspicuity, internal features and the absence of artifacts). There was no statistically significant difference in contrast-to-noise ratio between the two sequences (p = 0.713). In the qualitative analysis, CSE sequences were superior to FSE for overall image quality in 50% of cases, for lesion conspicuity in 41.5% of cases and for internal features and the absence of artifacts in 46% of cases, FSE sequences had a higher detection rate in 17% of cases, even though both types of sequences underestimated the number of lesions in 29% of cases, as compared with the gold standard. To conclude, FSE sequences were inferior to CSE for image quality, lesion conspicuity, internal features and the absence of artifacts. FSE sequences were superior in the detection and characterization of fluid and nearly fluid lesions.
Insights
Fast spin echo (FSE) MRI sequences are quicker but less effective than conventional spin echo (CSE) for liver lesion detection and characterization, except for fluid-based lesions.
Area of Science:
- Radiology
- Medical Imaging
- Hepatology
Background:
- T2-weighted spin echo (SE) MRI is crucial for focal liver lesion detection.
- Conventional SE (CSE) sequences have long acquisition times, limiting clinical utility.
- Fast SE (FSE) sequences offer reduced scan times while aiming for comparable image quality.
Purpose of the Study:
- To prospectively compare the effectiveness of T2-weighted CSE versus FSE sequences in MRI of focal liver lesions.
- To evaluate quantitative and qualitative parameters of both MRI sequences.
Main Methods:
- 24 patients with focal liver lesions underwent MRI using both CSE and FSE sequences.
- Lesions were pathologically confirmed via biopsy and compared against gold standards (intraoperative US, Lipiodol CT, or 6-month follow-up).
- Quantitative analysis included signal-to-noise (SNR) and contrast-to-noise ratios (CNR); qualitative analysis assessed image quality, lesion detection, conspicuity, internal features, and artifacts.
Main Results:
- No statistically significant difference in CNR between CSE and FSE (p = 0.713).
- CSE sequences were qualitatively superior in overall image quality (50%), lesion conspicuity (41.5%), and absence of artifacts (46%).
- FSE sequences showed a higher detection rate for fluid/near-fluid lesions (17%) but both sequences underestimated lesion counts compared to the gold standard.
Conclusions:
- FSE sequences are inferior to CSE for general liver lesion imaging quality, conspicuity, and artifact assessment.
- FSE sequences demonstrate superiority in detecting and characterizing fluid or near-fluid liver lesions.
- Despite speed advantages, FSE's qualitative limitations necessitate careful consideration in focal liver lesion MRI protocols.