From the Guidelines
If Claudia is suspected of having cauda equina syndrome and is unable to undergo an MRI, a CT lumbar spine without IV contrast is the most appropriate alternative diagnostic method to determine if cauda equina compression is present. This is based on a recent retrospective review of 151 patients with clinically suspected cauda equina syndrome, which showed that 50% thecal sac effacement on CT predicted significant spinal stenosis, and <50% thecal sac effacement reliably excluded cauda equina impingement, using MRI as the reference standard 1.
The symptoms of cauda equina syndrome include low back pain, weakness in the lower limbs, sensory changes or numbness in the lower limbs, or absent lower limb reflexes, as well as impairment of the bladder, bowel, or sexual function and perianal or saddle numbness 1. The most common cause of cauda equina syndrome is lumbar disc herniation at the L4-L5 and L5-S1 levels, but other etiologies such as neoplasm, infection/inflammation, spinal stenosis, and hemorrhage should also be considered 1.
Some key points to consider when evaluating a patient with suspected cauda equina syndrome include:
- The importance of urgent MRI assessment in patients who present with new-onset urinary symptoms in the context of low back pain or sciatica 1
- The use of a single 3-D heavily T2-weighted fat-saturated sequence protocol as a rapid and highly sensitive tool for evaluating cauda equina syndrome in the emergency department 1
- The potential role of CT myelography in assessing the patency of the spinal canal/thecal sac and of the subarticular recesses and neural foramen, particularly for surgical planning 1.
Overall, while MRI is the preferred diagnostic method for evaluating suspected cauda equina syndrome, CT lumbar spine without IV contrast is a suitable alternative when MRI is not possible, and can provide valuable information to guide further management 1.
From the Research
Claudia Equine Suspected Unable to Do MRI
- The provided studies do not directly address the issue of a horse (equine) being unable to undergo an MRI scan 2, 3, 4, 5, 6.
- However, it can be inferred that MRI scans are typically used for human diagnosis and treatment, and may not be suitable or available for equine patients.
- The studies discuss the use of MRI scans in human medicine, including the principles and techniques of MRI 3, radiological imaging methods such as CT, MRI, and ultrasonography 4, and patient preparation and evaluation for vascular and interventional radiology procedures 5.
- One study focuses on supporting claustrophobic patients during MRI examinations, highlighting the importance of radiographer experience and education in assisting anxious patients 6.
- There is no direct evidence to suggest that equine patients can or cannot undergo MRI scans, and further research would be needed to determine the feasibility and safety of MRI scans for horses.