Introduction

Obesity presents unique challenges in daily life and, perhaps unexpectedly, in radiology. Performing MRI scans on obese patients often requires bespoke solutions to ensure both quality imaging and patient comfort. From specialised tables to custom-fit coils, innovative approaches and creative adaptations are essential to achieve the best possible results. This article examines the specific hurdles obese patients face when undergoing MRI and provides practical solutions to make their MRI experience smoother, safer and more effective.

(Image: GUSTOIMAGES/Photo Researchers, Inc., as published in IRP NIH)

Challenges

Conducting MRI scans for obese patients brings a unique set of challenges to radiology departments. A primary issue is that MRI tables typically have lower weight limits compared to conventional X-ray tables, meaning that heavier patients often require specialised MRI tables with higher load capacities. An especially critical aspect here is the hydraulic system that raises and lowers the table, as it’s often less durable than the main gantry itself.

Another significant challenge lies in patient positioning, which is vital for both image quality and patient comfort in MRI. Achieving optimal positioning for obese patients can be particularly difficult. Additionally, direct skin contact—whether between skin folds or with the gantry —can lead to increased heat buildup, putting obese patients at a higher risk of burns.

MR Safety Pads help prevent thermal burns (Source: Pearl Technology AG)

The confined space of the MRI gantry can also trigger claustrophobia, a common issue for obese patients. They may need specialised coils suited to their body size and weight, as using inappropriate coils can lead to poor image quality. MRI protocols also require specific adjustments to ensure optimal image quality and patient comfort during the scan.

Finally, safety plays an especially important role in MRI examinations for obese patients. Measures must be taken to prevent falls, burns, and other injuries. Comprehensive documentation of all aspects of the MRI process is essential to ensure both patient safety and quality of care.

Solutions

To address these challenges, one of the first steps is to use MRI tables with high load capacities—ideally supporting at least 250 kg across all components. Developing more patient-friendly positioning aids can also enhance both comfort and image quality, particularly for obese patients who may have trouble maintaining optimal positions.

Monitoring the specific absorption rate (SAR) and B1+ rms is crucial to minimize the risk of overheating. Increasing ventilation and using safety pads can help prevent burns caused by direct skin contact or prolonged exposure to the magnetic field.

“Wide-bore” MRI machines, with gantry openings of at least 70 cm, are also recommended. While open MRI systems might seem beneficial for patients with claustrophobia, they generally offer lower image quality, which can be a trade-off.

The development of special coils designed for the needs of obese patients is another key solution. MRI protocols should be carefully adjusted, with particular attention to the signal-to-noise ratio and SAR. However, such adjustments may lead to longer scan times, which are often necessary to ensure optimal image quality.

For more efficient MRI scans, creating separate protocols tailored specifically for obese patients and using alternative coil combinations are advised. Additionally, deep-learning algorithms can further improve image quality. Training staff on handling obese patients is also vital, with a focus not only on patient care but also on self-protection. Ergonomic techniques and workplace health management play an important role in preventing back injuries and promoting overall well-being among the radiology team. Finally, thorough documentation of all aspects of the MRI process is essential to safeguard against potential legal issues. 

For cases where the image quality is affected by excess fat tissue in “fat-sat” sequences, techniques like STIR (Short Tau Inversion Recovery) or DIXON sequences can be used. Adjusting contrast levels through tailored MRI protocols can also work wonders in enhancing image quality.

Conclusion

Obesity presents unique and complex challenges in the field of radiology, requiring thoughtful adjustments to both equipment and procedures to provide safe and effective care. By addressing the specific needs of obese patients and implementing the proposed solutions, radiology departments can significantly improve the quality of imaging, reduce risks, and enhance patient comfort and safety. With advancements like specialized tables, custom coils, and tailored protocols, MRI exams for obese patients can be optimized, ultimately ensuring a higher standard of care and better diagnostic outcomes.

Copyright: Martin Methlow

15.04.2023