Auto Planning to Simplify Scan Planning

Yutaka Hoshiyama

There is a great need for highly reproducible MRI examinations with the same scan position and angle, and with smooth scan operation regardless of the operator’s experience. Auto Planning, supported by Auto Scan Assist, allows MR Technologists with different levels of experience to perform complex MR procedures easily, while enhancing workflow and reproducibility from patient to patient.
Auto Scan Assist, slice positioning operation support function, is an AI-based application that automatically assists target plane setting*. Auto Scan Assist aims to support the reduction of operation time and to improve the reproducibility of scan plane without depending on the operators. Currently, Auto Scan Assist supports the examination of the Brain, Cardiac, Liver, Spine, Whole Spine, Prostate, and Knee. Each function is commercialised as NeuroLine+, ^SUREVOI Cardiac/CardioLine+, ^SUREVOI Liver/LiverLine+, SpineLine+, W-SpineLine+, ProstateLine+, and ^SUREVOI Knee/KneeLine+, respectively (Figure 1).

Now, NeuroLine+ implements machine learning techniques instead of direct image analysis, such as symmetrical analysis and multiple-template-matching techniques to improve accuracy and robustness for a variety of head orientations and shapes due to individual difference. In Neuro MRI examinations, a middle Sagittal plane and Axial planes such as Anterior Commissure-Posterior commissure (AC-PC) line and Orbitomeatal (OM) line are basic planes, and NeuroLine+ detects those planes.

A verification study was performed to evaluate the clinical usefulness of NeuroLine+ in Auto Scan Assist. In this study, plane detection error defined by angular error was measured. The measurement of the plane detection error was performed for 13 patient datasets acquired with Canon's Vantage Galan 3T system. This study showed that the accuracy was improved compared to conventional NeuroLine+ (Figure 2). In addition, the operation time, and the operation steps for each head slice positioning with and without the Auto Scan Assist were measured. The measurement of slice positioning for the brain was performed on two volunteers by three different certified Radiological Technologists. The operation time was reduced by 63% and the operation step (the number of clicks) was reduced about 79% compared without using NeuroLine+ in Auto Scan Assist (Figures 3 and 4). In conclusion, Auto Scan Assist can reduce operation time while increasing reproducibility in order to enhance the users’ and patients’ MR experience.