First MRI application of an active breathing coordinator

Abstract

A commercial active breathing coordinator (ABC) device, employed to hold respiration at a specific level for a predefined duration, was successfully adapted for magnetic resonance imaging (MRI) use for the first time. Potential effects of the necessary modifications were assessed and taken into account. Automatic MR acquisition during ABC breath holding was achieved. The feasibility of MR-ABC thoracic and abdominal examinations together with the advantages of imaging in repeated ABC-controlled breath holds were demonstrated on healthy volunteers. Five lung cancer patients were imaged under MR-ABC, visually confirming the very good intra-session reproducibility of organ position in images acquired with the same patient positioning as used for computed tomography (CT). Using identical ABC settings, good MR-CT inter-modality registration was achieved. This demonstrates the value of ABC, since application of T1, T2 and diffusion weighted MR sequences provides a wider range of contrast mechanisms and additional diagnostic information compared to CT, thus improving radiotherapy treatment planning and assessment.

Lung volume reproducibility under ABC control and self‐sustained breath‐holding

“…We used the modified MR‐compatible ABC system described by Kaza et al, consisting of the ABC respiratory system (breathing tube with filter, digital volume transducer & pickup assembly, balloon valve, and couplers), modified MR alert bulb and adapter as well as custom connectors and balloon valve tube extension. The digital volume transducer & pickup assembly, balloon valve, and 2.25 m pneumatic tubing dedicated for MR application were denoted as “MR‐ABC kit.” The corresponding components of the ABC apparatus used in our institution during CT lung treatment planning scans and of the ABC device used for treating breast cancer patients participating in a trial were borrowed for comparison and named “CT‐ABC kit” and “trial‐ABC kit,” respectively.…”

“…The module was connected via a serial cable to a computer executing the ABC 2.00 control software in the scanner control room. The set up was similar to, except that no external triggering circuits were used in the present work.…”

“…The present work serves as a quality assurance of clinically used ABC devices during clinically applicable imaging of human subjects without radiation exposure. We evaluated intra‐session and inter‐session lung volume reproducibility achieved with ABC control, by repeating breath‐holds with the modified MR‐compatible ABC system applied to lung cancer imaging . The study was performed on healthy volunteers, assuming no significant physiological changes in the course of one to 4 weeks between two imaging sessions.…”

Mechanism and non-mechanism based imaging biomarkers for assessing biological response to treatment in non-small cell lung cancer

“…As for other modalities, debate remains relating to standardisation of image acquisition sequences and post processing, with different techniques available for the purpose of mitigating respiratory motion [62,63]. Few reports address the optimal timing of DW-MRI following treatment, but it is informative to note that signal change in cerebral infarction is measurable within 30 minutes of symptom onset, demonstrating a high sensitivity to biological change in this context [64].…”

Audiovisual biofeedback guided breath-hold improves lung tumor position reproducibility and volume consistency

“…Breath-hold techniques are frequently used to immobilize respiratory-induced tumor motion, leading to the reduction of respiratory-related motion artifacts in medical imaging and clinically meaningful tumor positions and shapes in respiratory-gated radiation treatment. 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 In addition, the immobilization of lung tumors 1 can reduce phase or time shift between surrogates (ie, abdomen, chest, and diaphragm) and tumors 9 and system latency between tumor positioning and gating. 10 Immobilizing the tumor position is advantageous in reducing treatment margins and treatment delivery time.…”