MR-guided biopsy using a T2-weighted single-shot zoom imaging sequence (Local Look technique)

Area of Science:

• Radiology
• Medical Imaging
• Interventional Radiology

Background:

• Magnetic Resonance (MR)-guided percutaneous interventions require precise visualization of instruments and target lesions.
• Traditional imaging techniques may present limitations in terms of speed, contrast, or artifact generation during these procedures.

Purpose of the Study:

• To evaluate the clinical utility of the T2-weighted single shot turbo spin-echo technique, "Local Look" (LoLo), now "Zoom Imaging," for MR-guided percutaneous interventions.
• To compare the performance of the LoLo technique against a fast gradient-echo sequence for needle guidance.

Main Methods:

• Twenty-eight MR-guided percutaneous procedures were performed on 22 patients using a 1.5-T MR system.
• The LoLo technique, acquiring T2-weighted images in 600 ms with a small field of view and single-shot method, was used for all procedures.
• Orthogonal pulse orientation prevented backfolding artifacts; half of the procedures also used a fast gradient-echo sequence for comparison.

Main Results:

• All 28 procedures were technically successful with no complications.
• The LoLo technique demonstrated superior or equal delineation of the needle tip compared to the gradient-echo sequence in 100% of cases.
• Images acquired with LoLo exhibited good lesion contrast and smaller needle artifacts than the gradient-echo technique.

Conclusions:

• The LoLo (Zoom Imaging) technique is an accurate and effective method for MR guidance of percutaneous procedures.
• It provides excellent lesion contrast and minimal needle artifacts, crucial for precise needle tip monitoring.
• Gradient-echo sequences may be beneficial for planning complex cases, but LoLo is superior for real-time needle tip visualization.