MRI of the Wrist: What you should know

The wrist and hand have complex anatomy with many intricate structures. So, to evaluate different traumatic and pathological conditions of the wrist, we need a credible imaging diagnostic modality like MRI (magnetic resonance...

Introduction

MRI, a veritable tool for assessing multiple wrists conditions

MRI of the wrist helps by providing comprehensive observations related to traumatic and pathological conditions of the wrist including hidden fractures, osteonecrosis, injuries to ligaments and tendons, as well as entrapment neuropathies.

Due to the presence of multiple small structures with intricate morphologies and anatomical variability, diagnostic imaging of the wrist and hand is challenging. In such a scenario, an MRI comes with high-resolution spatial and contrast capabilities, enabling detailed assessment of bone and soft tissues without the use of ionizing radiation.

Hence, MRI stands out as an optimal imaging modality for evaluating pathological conditions affecting joints. MRI is a commonly employed modality in clinical practice for its all-round indications, which include the detection of hidden bone injuries not visible on radiographs, evaluation of the triangular fibrocartilage complex and intrinsic ligaments within the wrist, the study of ligament tears affecting the fingers, as well as assessment of flexor and extensor tendon injuries.

Apart from this, MRI plays an important role in characterizing obvious abnormalities such as ganglion cysts, soft tissue masses, and bony outgrowths. It also helps in identifying causes of peripheral neuropathies involving the median and ulnar nerves within the wrist and hand.

The procedure of MRI wrist

When it comes to getting an MRI of the wrist, we will have to consider certain things to get the best results while keeping the patient comfortable. It is important to optimize the imaging parameters, like the field of view, slice thickness, bandwidth, repetition time, and echo time. These parameters are important to capture detailed images of the joint and its internal structures.

Nowadays, most MRI studies are carried out at higher field strength, preferably 3T, which returns higher resolution of the images. The technicians use a combination of different imaging sequences to look for specific things. For instance, chemically-selective fat-suppressed or fluid-sensitive sequences are used to check for swelling in the bone and soft tissues. There is also the use of a non-fat suppressed sequence to detect fractures and other bone issues.

To get the perfect images, patients are usually positioned with their arms extended over their heads. However, this position can be discomforting for some patients, so some adjustments have to be made to it.

Use of contrast dye

In most cases of MRI for the wrist and hand, contrast dye is not always necessary, but it can be beneficial in certain situations. For instance, if there are obvious soft tissue abnormalities or signs of inflammation, the contrast dye can augment differentiating between different types of lesions and detecting areas of active synovitis. It can also boost diagnosing infections or assessing bone conditions like osteonecrosis. However, there is a perennial debate about the utility of dynamic post-contrast imaging compared to routine MRI.

Overall, we can say that MRI is a valuable tool for evaluating the hand and wrist, but it calls for careful consideration of imaging parameters and patient comfort to ensure the best possible results.

Magnetic resonance arthrography (MRA)

Magnetic resonance arthrography (MRA) can help us in the detection of injuries to the triangular fibrocartilage complex (TFCC) and intrinsic ligaments of the wrist with far better accuracy. MRA enhances sensitivity and diagnostic accuracy by enhancing the contrast between normal structures and areas of injury.

There are two methods of performing MRA

The first one is called direct MRA, where a diluted gadolinium contrast is injected directly into the joint that has to be examined.

The second method is called indirect MRA, where the contrast is injected intravenously, and through exercise-induced hyperemia, the contrast gets circulated throughout the body and reaches the specific joint for investigation.

Direct MRA is more commonly used than indirect MRA due to its ability to enhance intra-articular pressure.

Earlier, direct wrist arthrography was performed using a two- or three-compartment approach. This means injecting contrast into multiple compartments of the wrist and then using MRI or radiography to see if there were any abnormal connections between them. But, it was very uncomfortable for the patient and at times returned false negative results.

So, many facilities have relinquished this technique, preferring a single-compartment approach. In this, the contrast is injected directly into the radiocarpal joint.

While in indirect arthrography, the synovium starts excreting gadolinium after about 10-11 minutes. Hence, post-contrast imaging is performed around 25-30 minutes after the injection so that enough gadolinium has entered the joint.

So, MRA is a valuable tool to detect injuries in the wrist ligaments more accurately by enhancing the contrast and improving sensitivity.

It is important to note that apart from the minor risks of infection, bleeding, and local injury, direct MRA also has certain limitations and disadvantages that need to be taken care of.

Firstly, it is an invasive procedure that can lead to reactive synovitis, causing pain for several days after the injection. Moreover, due to the increased intra-articular pressure the diluted gadolinium has a chance to leak either along the needle path or through weaker areas of the joint capsule. Hence, it might potentially obscure or mimic the pathological findings. Also, direct MRA is a bit costly and needs more time for completion.

As we have discussed the MRI of the wrist, it is worth mentioning that a whole-hand MRI is not very common because of the potential drawbacks it has. The larger field of view in whole-hand MRI can compromise the spatial resolution and make it more difficult to identify internal abnormalities accurately.

However, when evaluating both hands, a specific positioning technique can be used. This involves extending both arms overhead and placing the hands together with the palms facing each other. This positioning allows for a direct comparison of corresponding joints on the same images, facilitating a comprehensive assessment.

MRI wrist price

When it comes to the price of wrist MRI scans, several factors govern the price. The cost of an MRI wrist examination can be different in different locations, and it also depends on the imaging facility, the specific protocols requested by the referring physician, etc. Remember, MRI wrist prices may include expenses related to the scan itself, radiologist interpretation fees, and any extra services or contrast agents (if required) for a comprehensive examination.

It's important to note that prices can also differ based on whether the MRI is performed at a hospital, an independent imaging center, or a specialized clinic. Some healthcare providers may offer discounted packages or negotiate prices for patients who pay out-of-pocket. To gather accurate and up-to-date information about MRI wrist prices, you should consult with your respective medical facility or contact the healthcare provider's billing department directly.

Conclusion

So, we now know that MRI offers great contrast and spatial resolution, helping in the precise and noninvasive examination of the wrist along with the musculoskeletal structures of the hand. For more efficient diagnostic images, it is crucial to optimize patient positioning, scanner and coil selection, and MRI parameters. It is also important to tailor the imaging approach to attend to specific clinical inquiries. Recent advancements in MRI techniques, such as 3D volumetric acquisition, not only enhance image quality but also expedite the imaging process, providing a faster assessment of the region.