Comparison of the novel simultaneous biplane versus in-plane imaging technique in ultrasound-guided biopsy: a prospective randomized multi-operator cross-over phantom study.

Abstract

Purpose: To evaluate and compare the in-plane and novel biplane imaging techniques in ultrasound-guided biopsies (USBx). USBx are effective for obtaining tissue samples in suspected malignancy or infection. The in-plane technique is the gold standard, offering continuous needle visualization. The biplane technique enables simultaneous in-plane and out-of-plane visualization, potentially improving biopsy outcomes. A study was conducted using gel phantoms to simulate USBx, with the goal of determining whether one technique offers distinct advantages over the other.

Methods: A total of 30 participants (mean age: 30 ± 7 years; 20 men) were recruited, primarily consisting of physicians in training with varying levels of experience. Each participant performed biopsies on gel phantoms using both the in-plane and biplane techniques in a randomized order after watching a standardized tutorial video. Procedure-related parameters were analyzed, and post-intervention questionnaires, including the NASA task load index (NASA-TLX), were collected to assess cognitive workload and personal preferences.

Results: All participants achieved successful biopsies with both techniques. The first-puncture success rate was significantly higher with the biplane technique (83% vs. 63%; P = 0.01). The biplane technique required significantly fewer biopsy attempts than the in-plane approach (37 vs. 43; P = 0.03). Although the biplane technique had a longer "mean time to first successful biopsy" (120 seconds vs. 72 seconds), this difference was not statistically significant (P = 0.09), likely due to high variability. No significant differences were found in safety-related parameters, including the number of skin punctures, needle retractions, percentage of time the needle tip was visible, and the number of biopsy attempts without needle tip visualization. The NASA-TLX indicated higher mental demand with the biplane technique (P = 0.013), but other dimensions showed no significant differences. Overall, 83% of participants, including 88% of more experienced operators, preferred the biplane technique, citing enhanced visualization and perceived safety.

Conclusion: In this study, the biplane technique in USBx was substantially superior in terms of total biopsy attempts and first-puncture success rate compared with the in-plane approach. It may offer safety and efficiency advantages, particularly for less-experienced operators. Further studies with larger sample sizes and experienced operators, especially in clinical settings, are needed to determine clear superiority.

Clinical significance: These findings suggest that biplane imaging may be especially beneficial for training less-experienced operators and in cases with elevated complication risk.