SPECT/CT in Postoperative Hand and Wrist Pain

Influence of Metal Implants on Quantitative Evaluation of Bone Single-Photon Emission Computed Tomography/Computed Tomography

When visualizing biological activity at nonunion sites by the radioisotopes, gamma rays are more attenuated if metal implants are placed in the bone. However, the effects of various implant types and their placement on gamma ray attenuation in quantitative evaluation remain unknown. To elucidate these effects, we created a phantom that simulated the nonunion of the femur in this study. The count of gamma rays was measured by single-photon emission computed tomography/computed tomography (SPECT/CT) while considering CT-based attenuation correction (CTAC), metal implant placement, type (intramedullary nail or plate), and position. The count differed significantly with and without CTAC and with and without implants (both types) under CTAC. Significantly different counts were observed between the intramedullary nail and plate placed contralaterally to the lesion (i.e., non-lesion side). No significant difference was observed between the intramedullary nail and plate on the lesion side or between plates on the non-lesion and lesion sides. The measured standardized uptake value (SUV) was closer to the true SUV with CTAC than without. Moreover, the count was higher with implants than without. However, even with implants, it was lower than the actual count, indicating the absence of overcorrection. Implant type and position do not seem to influence the count.

Posttreatment Imaging of the Wrist and Hand: Update 2022

Common indications for surgical procedures of the wrist and hand include acute fractures or fracture-dislocations; nonunited fractures; posttraumatic, degenerative, and inflammatory arthritides and tendinopathies; injuries to tendons, ligaments, and the triangular fibrocartilage complex; and entrapment neuropathies. Soft tissue or osseous infections or masses may also need surgical treatment. Several of these procedures require surgical hardware placement, and most entail clinical follow-up with periodic imaging. Radiography should be the first imaging modality in the evaluation of the postoperative wrist and hand. Computed tomography, magnetic resonance imaging, diagnostic ultrasonography, and occasionally nuclear medicine studies may be performed to diagnose or better characterize suspected postoperative complications. To provide adequate evaluation of postoperative imaging of the wrist and hand, the interpreting radiologist must be familiar with the basic principles of these surgical procedures and both the imaging appearance of normal postoperative findings as well as the potential complications.

[What does the hand surgeon expect from the radiologist in diagnostic imaging of the hand?]

BACKGROUND

For hand surgeons, in addition to anamnesis and clinical examination, imaging is the essential component in diagnostics and the basis for therapy planning. The focus on the special field of the "hand" and the adjacent joints is limited with regard to the anatomical extent, but with regard to the possible clinical pictures it encompasses the entire range of pathological changes.

CLINICAL ISSUE

Which imaging techniques support the goal of maintaining the functionality of the hand?

PERFORMANCE

The carpal bones can be represented by computer tomography without superimposition. The navicular (scaphoid) should be evaluated sagittally in its longitudinal axis. MRI imaging is useful, for example, when assessing possible ligament injuries or ulnar-carpal complaints on the triangular disc. Stress images prove additional information in the case of of dynamic ligament or joint instabilities.

ACHIEVEMENTS

Imaging with conventional X‑rays is the basis of radiological diagnostics of the hand. In addition, the small structures of the hand and fingers to be assessed must be specifically visualized.

PRACTICAL RECOMMENDATION

In order to enable precise assessment of the fine and complex structures on the hand in relation to the clinical complaints, close communication of the anamnesis and questions with the radiologist is desirable.

Computed Tomography (CT) Protocols Associated with Cardiac and Bone Single-Photon Emission Computed Tomography/CT (SPECT/CT) in Korea

PURPOSE

Single-photon emission computed tomography/computed tomography (SPECT/CT) is an advanced hybrid nuclear medicine technology that generates both functional and anatomical images in a single study. As utilization of SPECT/CT in Korea has been increasing, the purpose of this study was to survey its application of cardiac and skeletal SPECT/CT imaging for protocol optimization.

METHODS

We surveyed CT protocols established for cardiac and skeletal SPECT/CT. We searched the guidelines for the CT protocols for SPECT/CT and reviewed the literature recently published.

RESULTS

Among 36 hybrid SPECT scanners equipped with four or more multi-channel detector CTs (MDCTs), 18 scanners were used to perform cardiac studies at both very low current CT (30-80 mA; 11.1%) and ultra-low current CT (13-30 mA; 88.9%). Among the 33 canners, very low current (≤ 80 mA) CT or low current CT (80-130 mA) was used in 23.5%, and 41.8% for spine disorders, and in 36.4% or 30.3% for foot/ankle disorders, respectively. In the CT reconstructions, slice thickness of 5 mm for cardiac studies was most commonly used (94.4%); thinner slices (0.6-1.0 mm) for spine and foot/ankle studies were used in 24.2% and 45.5%, respectively. We also reviewed the international guidelines.

CONCLUSIONS

The results and current recommendations will be helpful for optimizing CT protocols for SPECT/CT. Optimization of SPECT/CT protocols will be required for generating the proper strategy for the specific lesions and clinical purpose.

Clinical applications of nuclear medicine in the diagnosis and assessment of musculoskeletal sports injuries

Increased participation in sports and physical exercise are widely promoted as an approach to a physically active lifestyle which has a positive effect on healthy aging, in patients and athletes of all ages, beginners and experts, including amateur athletes and professional athletes. Unfortunately, this has caused a higher incidence of sports-related injuries. In the sports context, the early and accurate diagnosis of injuries is of the utmost importance in order to enable early treatment to achieve a full recovery. Imaging techniques are increasingly important for the successful diagnosis and management of the patient. The nuclear medicine techniques with bone tracers provide physiological and metabolic information in the early phases of musculoskeletal injuries, which often precede anatomical changes and they reflect changes in bone turnover. This allows early diagnosis, along with evaluation of the activity and phase of the injury. In this article, the applications of nuclear medicine techniques, focusing on bone scintigraphy, alongside the important contribution of hybrid studies (SPECT/CT), in the diagnosis of bone and soft tissue sports injuries, will be described. In addition, we explain their usefulness in the expression of the pathophysiology of these lesions and their scintigraphic patterns. The article will also describe biomechanical and physiopathological aspects, injury mechanisms and clinical presentations of bone and joint sports injuries, knowledge of this is essential for the correct diagnostic assessment of imaging studies.