救急患者用ベッドサイド・ポータブル低磁場核磁気共鳴画像検査実用へ

 low-field, portable MRI

 脳損傷の臨床評価において、神経画像診断は重要なステップである。従来の磁気共鳴イメージング（MRI）装置は高磁場（1.5～3T）で動作するため、アクセス制御された厳しい環境が必要とされていた。集中治療室で神経損傷の発生と進行を効果的にモニターするためには、タイムリーな神経画像診断へのアクセスが限られていることが、依然として重要な構造的障壁となっている。最近の低磁場MRI技術の進歩により、放射線室の外でも、ベッドサイドで強磁性体の存在下でも、臨床的に意味のある画像を取得することが可能になった。

Assessment of Brain Injury Using Portable, Low-Field Magnetic Resonance Imaging at the Bedside of Critically Ill Patients

Kevin N. Sheth, et al.

JAMA Neurol. Published online September 8, 2020. doi:10.1001/jamaneurol.2020.3263

https://jamanetwork.com/journals/jamaneurology/article-abstract/2769858

We investigated patients with neurological injury or alteration using a low-field (0.064-T) portable MRI device at the bed- side in neuroscience intensive care units (ICUs) and COVID-19 ICUs. This point-of-care (POC) MRI used no cryogens and plugged into a single, 110-V, 15-A standard power outlet. 

The device dimensions rendered it maneuverable within the confines of an ICU patient room (Figure 1). 

A self-contained motor and driving capability facilitated the deployment of a single device across the institution. The 5-Gauss (0.0005-T) safety perimeter had a radius of 79 cm from the center of the magnet. This work aimed to demonstrate the potential role of low-field, portable MRI to obtain bedside neuroimaging in an ICU setting.

The POC MRI examinations were performed at the bedside using a prototype 0.064-T MRI system (with Mk 1.2 RC6.3-7.2 software and Mk 1.6 POC MRI RC8.0.2 software [Hyperfine Re- search Inc]). Examinations were acquired using an 8-channel head coil. The POC MRI used a biplanar, 3-axis gradient system with a peak amplitude of 26 mT/m (on the z-axis) and 25 mT/m (on the x-axis and y-axis). Scan parameters were controlled using a computer interface (iPad Pro, third generation; Apple). 

Available pulse sequences included T1- weighted (T1W), T2-weighted (T2W), fluid-attenuated inver- sion recovery (FLAIR), and diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping. 

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本来は日本のメーカーが率先して開発すべき分野だと思うのだけど・・・

全ての分野で遅れてしまった日本