MR Guidance Speeds Sacroiliac Injections

CHICAGO — Use of real-time magnetic resonance imaging to guide sacroiliac joint puncture is feasible and safe, and allows for interactive interventions in patients who have refractory sacroiliitis, according to a study presented at the annual meeting of the Radiological Society of North America.

Researchers injected steroids into the sacroiliac joints (SIJs) of 73 patients who had inflammatory back pain and acute sacroiliitis unresponsive to conventional drug therapy for longer than 6 months using real-time magnetic resonance (MR) guidance exposure, Dr. Jan Fritz said at a poster session. The other term for the imaging technique, MR fluoroscopy, is a misnomer; unlike traditional fluoroscopy, MR fluoroscopy does not involve radiation. The entire procedure is performed using an interventional C-shaped open ultrafast MR scanner that provides an image every 1.2 seconds as the needle is being advanced.

“This allows you patient access while doing a procedure that formerly was done using x-ray fluoroscopy [and] CT, which have the disadvantage of exposure to ionizing radiation,” said Dr. Fritz, with the department of diagnostic radiology at Eberhard Karls University of Tübingen (Germany). “Spondyloarthropathy patients are typically under age 30 and in their reproductive years, and we don't like to expose them to ionizing radiation,” he said.

Each SIJ was injected with 40 mg triamcinolone acetonide using an MR-compatible 20-G puncture needle, they wrote.

Prior to intervention and 3 months after intervention, inflammatory back pain (IBP) was assessed on a visual analog scale, and volume and signal intensity of the sacroiliac bone marrow edema (BME) were quantified on high-field short-TI inversion-recovery (STIR) MR images with a semi-automatic algorithm using Matlab software.

Technical success was achieved in 72 of the 73 patients, most of whom were injected bilaterally, Dr. Fritz said, adding that there were no complications.

In bilateral intervention (n=64), real-time MR guidance (n=36) required a mean time of 40.5 minutes, compared with 55 minutes for intermittent MR imaging guidance (n=28).

Postintervention, IBP decreased by 63%. Volume and signal intensity of the sacroiliac BME decreased by 69% and 64%, respectively, which was a statistically significant difference. Mean remission time was 10 months. “MR fluoroscopy guidance for percutaneous steroid injections into the SIJ is safe and accurate, allowing for shorter interventions. MR fluoroscopy proved to be effective in sacroiliitis unresponsive to conventional drug therapy,” Dr. Fritz concluded.

The red arrows indicate the tip of the needle as it advances toward the site of sacroiliitis in a patient with back pain. Courtesy Dr. Jan Fritz

Use of real-time MRI in younger patients enables them to avoid radiation exposure. DR. FRITZ

CHICAGO — Use of real-time magnetic resonance imaging to guide sacroiliac joint puncture is feasible and safe, and allows for interactive interventions in patients who have refractory sacroiliitis, according to a study presented at the annual meeting of the Radiological Society of North America.

Researchers injected steroids into the sacroiliac joints (SIJs) of 73 patients who had inflammatory back pain and acute sacroiliitis unresponsive to conventional drug therapy for longer than 6 months using real-time magnetic resonance (MR) guidance exposure, Dr. Jan Fritz said at a poster session. The other term for the imaging technique, MR fluoroscopy, is a misnomer; unlike traditional fluoroscopy, MR fluoroscopy does not involve radiation. The entire procedure is performed using an interventional C-shaped open ultrafast MR scanner that provides an image every 1.2 seconds as the needle is being advanced.

“This allows you patient access while doing a procedure that formerly was done using x-ray fluoroscopy [and] CT, which have the disadvantage of exposure to ionizing radiation,” said Dr. Fritz, with the department of diagnostic radiology at Eberhard Karls University of Tübingen (Germany). “Spondyloarthropathy patients are typically under age 30 and in their reproductive years, and we don't like to expose them to ionizing radiation,” he said.

Each SIJ was injected with 40 mg triamcinolone acetonide using an MR-compatible 20-G puncture needle, they wrote.

Prior to intervention and 3 months after intervention, inflammatory back pain (IBP) was assessed on a visual analog scale, and volume and signal intensity of the sacroiliac bone marrow edema (BME) were quantified on high-field short-TI inversion-recovery (STIR) MR images with a semi-automatic algorithm using Matlab software.

Technical success was achieved in 72 of the 73 patients, most of whom were injected bilaterally, Dr. Fritz said, adding that there were no complications.

In bilateral intervention (n=64), real-time MR guidance (n=36) required a mean time of 40.5 minutes, compared with 55 minutes for intermittent MR imaging guidance (n=28).

Postintervention, IBP decreased by 63%. Volume and signal intensity of the sacroiliac BME decreased by 69% and 64%, respectively, which was a statistically significant difference. Mean remission time was 10 months. “MR fluoroscopy guidance for percutaneous steroid injections into the SIJ is safe and accurate, allowing for shorter interventions. MR fluoroscopy proved to be effective in sacroiliitis unresponsive to conventional drug therapy,” Dr. Fritz concluded.

The red arrows indicate the tip of the needle as it advances toward the site of sacroiliitis in a patient with back pain. Courtesy Dr. Jan Fritz

Use of real-time MRI in younger patients enables them to avoid radiation exposure. DR. FRITZ

CHICAGO — Use of real-time magnetic resonance imaging to guide sacroiliac joint puncture is feasible and safe, and allows for interactive interventions in patients who have refractory sacroiliitis, according to a study presented at the annual meeting of the Radiological Society of North America.

Researchers injected steroids into the sacroiliac joints (SIJs) of 73 patients who had inflammatory back pain and acute sacroiliitis unresponsive to conventional drug therapy for longer than 6 months using real-time magnetic resonance (MR) guidance exposure, Dr. Jan Fritz said at a poster session. The other term for the imaging technique, MR fluoroscopy, is a misnomer; unlike traditional fluoroscopy, MR fluoroscopy does not involve radiation. The entire procedure is performed using an interventional C-shaped open ultrafast MR scanner that provides an image every 1.2 seconds as the needle is being advanced.

“This allows you patient access while doing a procedure that formerly was done using x-ray fluoroscopy [and] CT, which have the disadvantage of exposure to ionizing radiation,” said Dr. Fritz, with the department of diagnostic radiology at Eberhard Karls University of Tübingen (Germany). “Spondyloarthropathy patients are typically under age 30 and in their reproductive years, and we don't like to expose them to ionizing radiation,” he said.

Each SIJ was injected with 40 mg triamcinolone acetonide using an MR-compatible 20-G puncture needle, they wrote.

Prior to intervention and 3 months after intervention, inflammatory back pain (IBP) was assessed on a visual analog scale, and volume and signal intensity of the sacroiliac bone marrow edema (BME) were quantified on high-field short-TI inversion-recovery (STIR) MR images with a semi-automatic algorithm using Matlab software.

Technical success was achieved in 72 of the 73 patients, most of whom were injected bilaterally, Dr. Fritz said, adding that there were no complications.

In bilateral intervention (n=64), real-time MR guidance (n=36) required a mean time of 40.5 minutes, compared with 55 minutes for intermittent MR imaging guidance (n=28).

Postintervention, IBP decreased by 63%. Volume and signal intensity of the sacroiliac BME decreased by 69% and 64%, respectively, which was a statistically significant difference. Mean remission time was 10 months. “MR fluoroscopy guidance for percutaneous steroid injections into the SIJ is safe and accurate, allowing for shorter interventions. MR fluoroscopy proved to be effective in sacroiliitis unresponsive to conventional drug therapy,” Dr. Fritz concluded.

The red arrows indicate the tip of the needle as it advances toward the site of sacroiliitis in a patient with back pain. Courtesy Dr. Jan Fritz

Use of real-time MRI in younger patients enables them to avoid radiation exposure. DR. FRITZ