Role of SPECT/CT Compared With MRI in the Diagnosis and Management of Patients With Wrist Trauma Occult Fractures

Outcome of follow-up computed tomography of suspected occult scaphoid fracture after normal radiography

PURPOSE

To evaluate the rate of missed scaphoid fractures on follow-up computed tomography (CT) for suspected occult scaphoid fracture after normal radiography with residual radial-sided wrist pain.

METHODS

In a retrospective analysis, wrist CT during a five-year period was analyzed. The CT examinations and radiological reports were re-evaluated. Available clinical findings and radiologic follow-up performed during a period of a minimum of three years served as outcome reference.

RESULTS

In total, 178 examinations had been performed on 174 patients for suspect scaphoid fracture, 67 men and 107 women, showing 15 and 6 scaphoid fractures, respectively; a statistically significant sex difference (p = 0.0024). In 157 examinations, no scaphoid fracture was detected on CT, instead 29 other wrist or carpal bone fractures were found. On follow-up, no missed scaphoid fractures were found. Before CT, 124 of the 157 patients had been treated with a cast. After CT, 35 patients continued with cast treatment for a median of 14 days.

CONCLUSIONS

CT appears to be a reliable method for evaluating suspect scaphoid fracture as part of a diagnosis-treatment regimen including pain immobilization with a plaster cast.

Epidemiology of carpal fractures: is it only about the scaphoid?

Because of their low incidence, studies about carpal fractures are rare. The aim of the present study was to analyze epidemiology and treatment of fractured carpal bones. We retrospectively analyzed data of 178 patients admitted to our emergency room with carpal fractures over 6 years. More males than woman were injured. In 91%, a CT scan was performed. The most commonly affected bone was the triquetrum followed by the scaphoid. Almost all triquetral fractures were treated conservatively as opposed to perilunate dislocations that were all operated on. Half of all patients with scaphoid fractures were operated. Young men had the highest risk to sustain a carpal fracture. The triquetrum and the scaphoid are most frequently affected. Usually a CT scan is needed. Treatment of scaphoid and perilunate luxation fractures is rather operative whereas the other fractures mostly allow conservative casting. Nevertheless, correct indication for treatment is important to avoid sequelae.

Vertebral fracture: epidemiology, impact and use of DXA vertebral fracture assessment in fracture liaison services

Vertebral fractures are independent risk factors for vertebral and nonvertebral fractures. Since vertebral fractures are often missed, the relatively new introduction of vertebral fracture assessment (VFA) for imaging of the lateral spine during DXA-measurement of the spine and hips may contribute to detect vertebral fractures. We advocate performing a VFA in all patients with a recent fracture visiting a fracture liaison service (FLS). Fracture liaison services (FLS) are important service models for delivering secondary fracture prevention for older adults presenting with a fragility fracture. While commonly age, clinical risk factors (including fracture site and number of prior fracture) and BMD play a crucial role in determining fracture risk and indications for treatment with antiosteoporosis medications, prevalent vertebral fractures usually remain undetected. However, vertebral fractures are important independent risk factors for future vertebral and nonvertebral fractures. A development of the DXA technology, vertebral fracture assessment (VFA), allows for assessment of the lateral spine during the regular DXA bone mineral density measurement of the lumbar spine and hips. Recent approaches to the stratification of antiosteoporosis medication type according to baseline fracture risk, and differences by age in the indication for treatment by prior fracture mean that additional information from VFA may influence initiation and type of treatment. Furthermore, knowledge of baseline vertebral fractures allows reliable definition of incident vertebral fracture events during treatment, which may modify the approach to therapy. In this manuscript, we will discuss the epidemiology and clinical significance of vertebral fractures, the different methods of detecting vertebral fractures, and the rationale for, and implications of, use of VFA routinely in FLS. • Vertebral fracture assessment is a tool available on modern DXA instruments and has proven ability to detect vertebral fractures, the majority of which occur without a fall and without the signs and symptoms of an acute fracture. • Most osteoporosis guidelines internationally suggest that treatment with antiosteoporosis medications should be considered for older individuals (e.g., 65 years +) with a recent low trauma fracture without the need for DXA. • Younger individuals postfracture may be risk-assessed on the basis of FRAX® probability including DXA and associated treatment thresholds. • Future fracture risk is markedly influenced by both site, number, severity, and recency of prior fracture; awareness of baseline vertebral fractures facilitates definition of true incident vertebral fracture events occurring during antiosteoporosis treatment. • Detection of previously clinically silent vertebral fractures, defining site of prior fracture, might alter treatment decisions in younger or older FLS patients, consistent with recent IOF-ESCEO guidance on baseline-risk-stratified therapy, and provides a reliable baseline from which to define new, potentially therapy-altering, vertebral fracture events.

Prevalence and Clinical Significance of Occult Fractures in the Extremities in Children

Objective: Diagnosis of occult fractures by initial plain radiographs remains challenging in children in the emergency room. This study was to assess the prevalence and distribution of occult fracture in children with acute extremities injuries (AEI) and clinical suspicion of fracture. Methods: We conducted a retrospective study to review the medical records of all pediatric patients with AEI in the orthopedic emergency room from January 1, 2017, to December 31, 2019. For patients with concerning history and physical examination but negative initial radiographs, we conducted the following three diagnostic strategies according to the choic of children's parents: immediate MRI scanning, [2] immediate CT scanning, or [3] empiric cast immobilization with orthopedic follow-up radiographs at 2 weeks post-injury (late radiographs). Prevalence and distribution of occult fracture were recorded. Results: A total of 43,560 pediatric patients meet the inclusion criteria. A total of 4,916 fractures of the extremities were confirmed by initial plain radiographs, and 550 occult fractures were confirmed by immediate MRI, immediate CT, or late radiographs. The prevalence of occult fracture in the extremities was 10.1% (550/5,466). Supracondylar fractures were the most prevalent (2,325/5,466, 42.5%) but had the lowest rate of occult fractures (117/2,325, 5.0%). The highest rate of occult fracture was distal epiphyseal fracture of the tibia and fibula (49/145, 33.8%), but these had a relatively lower prevalence of fractures (145/5,466, 2.65%). Conclusions: We should be aware of the relative high prevalence of occult fractures in the extremities in children, especially when the injured site is in the high incidence area of occult fracture such as ankle.

Two decades of SPECT/CT - the coming of age of a technology: An updated review of literature evidence

PURPOSE

Single-photon emission computed tomography (SPECT) combined with computed tomography (CT) was introduced as a hybrid SPECT/CT imaging modality two decades ago. The main advantage of SPECT/CT is the increased specificity achieved through a more precise localization and characterization of functional findings. The improved diagnostic accuracy is also associated with greater diagnostic confidence and better inter-specialty communication.

METHODS

This review presents a critical assessment of the relevant literature published so far on the role of SPECT/CT in a variety of clinical conditions. It also includes an update on the established evidence demonstrating both the advantages and limitations of this modality.

CONCLUSIONS

For the majority of applications, SPECT/CT should be a routine imaging technique, fully integrated into the clinical decision-making process, including oncology, endocrinology, orthopaedics, paediatrics, and cardiology. Large-scale prospective studies are lacking, however, on the use of SPECT/CT in certain clinical domains such as neurology and lung disorders. The review also presents data on the complementary role of SPECT/CT with other imaging modalities and a comparative analysis, where available.

Imaging for Acute and Chronic Scaphoid Fractures

The scaphoid is the most commonly fractured bone in the wrist but 20% to 40% of scaphoid fractures are radiographically occult. Delayed or misdiagnosis can have significant consequences with late complications such as nonunion, malunion, or the development of avascular necrosis in the proximal pole. After initial negative radiographs, advanced cross-sectional imaging, including CT and MRI, ultimately may provide more accurate and rapid diagnosis than conventional radiography. With chronic fractures, the preferred modality depends on the clinical question. New techniques are evolving that will further advance imaging for diagnosis and treatment of scaphoid fractures.

ACR Appropriateness Criteria® Shoulder Pain-Traumatic

Traumatic shoulder pain is pain directly attributed to a traumatic event, either acute or chronic. This pain may be the result of either fracture (the clavicle, scapula, or proximal humerus) or soft-tissue injury (most commonly of the rotator cuff, acromioclavicular ligaments, or labroligamentous complex). Imaging assessment of traumatic shoulder pain begins with conventional radiography and, depending on physical examination findings, will require MRI or MR arthrography for assessment of soft-tissue injuries and CT for delineation of fracture planes. Ultrasound excels in assessment of rotator cuff injuries but has limited usefulness for assessment of the deep soft-tissues. CT angiography and conventional arteriography are helpful for assessment of vascular injury, and bone scintigraphy can be used in assessment of complex regional pain syndrome after traumatic shoulder injury. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Development of a Protocol for SPECT/CT in the Assessment of Wrist Disorders

Background Single-photon emission computed tomography and computed tomography (SPECT/CT) is a hybrid diagnostic imaging modality that allows clinicians to integrate their diagnostic evaluations and deliver a definitive diagnosis in musculoskeletal disorders. Specifically, in identification of osseous pathology, the conventional bone scan delivers greater specificity compared with magnetic resonance imaging (MRI). However, use of SPECT/CT enhances the sensitivity and specificity. Use of this modality denotes the possibility to specify the lesion more accurately and precisely while grading the activity according to osseous structural changes. Purpose This study aimed to evaluate the clinical utility of SPECT/CT in the diagnoses and management of osseous wrist disorders. The objectives were to examine the value of SPECT/CT in the diagnosis of osseous-related wrist pain and whether the findings altered management. Patients and Methods A retrospective cohort study of 20 patients with such wrist pain was conducted. SPECT/CT was used in the diagnostic process for these patients. Results Following SPECT/CT imaging, the common final diagnoses were osteoarthritis (10; 50%) and avascular necrosis (5; 25%). Less common diagnoses included ulnar carpal impact syndrome, infection, malunion, complex regional pain syndrome, and carpal boss. Some presented with multiple pathologies. SPECT/CT changed the final diagnosis in 11 cases, resulting in nonoperative treatment (7; 63%) or surgery (4; 37%). Conclusion Findings from this study and the literature demonstrate the clinical utility of SPECT/CT in the assessment of osseous-related wrist disorders. We present an algorithm for the assessment of wrist pain with osseous pathology. This commences with clinical assessment and plane radiographs (first-line investigation). Some cases will require a second-line investigation (ultrasound, CT, and/or MRI). If the diagnosis remains unclear, SPECT/CT is recommended as a third-line investigation.

Pitfalls and Limitations of Radionuclide Planar and Hybrid Bone Imaging

The radionuclide (99m)Tc-MDP bone scan is one of the most commonly performed nuclear medicine studies and helps in the diagnosis of different pathologies relating to the musculoskeletal system. With its increasing utility in clinical practice, it becomes more important to be aware of various limitations of this imaging modality to avoid false interpretation. It is necessary to be able to recognize various technical, radiopharmaceutical, and patient-related artifacts that can occur while carrying out a bone scan. Furthermore, several normal variations of tracer uptake may mimic pathology and should be interpreted cautiously. There is an important limitation of a bone scan in metastatic disease evaluation as the inherent mechanism of tracer uptake is not specific for tumor but primarily relies on an osteoblastic response. Thus, it is crucial to keep in mind uptake in benign lesions, which can resemble malignant pathologies. The utility of a planar bone scan in benign orthopedic diseases, especially at sites with complex anatomy, is limited owing to lack of precise anatomical information. SPECT/CT has been significantly helpful in these cases. With wider use of PET/CT and reintroduction of the (18)F-fluoride bone scan, increasing knowledge of potential pitfalls on an (18)F-fluoride bone scan and (18)F-FDG-PET/CT will help in improving the accuracy of clinical reports.

Diagnosis of Occult Scaphoid Fractures: A Cost-Effectiveness Analysis

BACKGROUND

Scaphoid fractures are common but may be missed on initial radiographs. Advanced imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) have improved diagnostic accuracy, but at an increased initial cost. The purpose of this study was to evaluate the cost-effectiveness of immediate advanced imaging for suspected occult scaphoid fractures.

METHODS

A decision analysis model was created to evaluate three diagnostic strategies for patients with concerning history and examination but negative radiographs: (1) empiric cast immobilization with orthopaedic follow-up and repeat radiography at two weeks post-injury, (2) immediate CT scanning, or (3) immediate MRI. Prevalence of occult scaphoid fracture, sensitivity and specificity of CT and MRI, and risks and outcomes of a missed fracture were derived from published clinical trials. Costs of imaging, lost worker productivity, and surgical costs of nonunion surgery were estimated on the basis of the literature.

RESULTS

Advanced imaging was dominant over empiric cast immobilization; advanced imaging had lower costs and its health outcomes were projected to be better than those of empiric cast immobilization. MRI was slightly more cost-effective than CT on the basis of the mean published diagnostic performance, but was highly sensitive to test performance characteristics. Advanced imaging would have to increase in cost to more than $2000 or decrease in sensitivity to <25% for CT or <32% for MRI for empiric cast immobilization to be cost-effective.

CONCLUSIONS

Given its relatively low cost and high diagnostic accuracy, advanced imaging for suspected scaphoid fractures in the setting of negative radiographs represents a cost-effective strategy for reducing both costs and morbidity. The decision to use CT compared with MRI is a function of individual institutional costs and local test performance characteristics.

Initial experience of SPECT/CT in the diagnosis of occult scaphoid fracture

BACKGROUND

*Equal contributors.Planar bone scintigraphy (PBS) is often advocated for diagnosing occult scaphoid fractures. PBS is a sensitive diagnostic modality, but lacks specificity, which may result in over-diagnosis.

PURPOSE

To examine, in a pilot study, the potential additional value of single photon emission computed tomography (SPECT) combined with low dose computed tomography (CT) for the diagnosis of an occult scaphoid fracture.

MATERIAL AND METHODS

Ten patients that underwent combined PBS and SPECT/CT for a clinically suspected scaphoid fracture, where radiographs could not detect a fracture, were included in this pilot study. The PBS and SPECT/CT results were independently and separately evaluated by a nuclear physician for scaphoid fractures and other injuries.

RESULTS

PBS was positive for a scaphoid fracture in four patients and diagnosed three other fractures. SPECT/CT showed five scaphoid fractures and one other fracture. SPECT/CT - PBS had discrepant results in three patients. In two patients PBS diagnosed a trapezoid fracture where SPECT/CT showed a scaphoid fracture. The other patient was diagnosed with a scaphoid fracture on PBS, whereas SPECT/CT showed bone bruise of other carpal bones.

CONCLUSION

SPECT/CT has the potential to be more accurate than PBS as it uses anatomical information of the CT to discriminate between the scaphoid, other carpal bones, and bone bruises. Larger studies with an independent reference standard are needed for confirmation of these preliminary data.

[Occult fractures of extremities in adults and children. Exemplified by foot and ankle injuries]

BACKGROUND

Occult fractures in children and adults cannot by definition be diagnosed by conventional radiographs. These injuries are usually recognized as bone marrow edema by magnetic resonance imaging (MRI). There are no randomized controlled trials or prospective cohort studies concerning the correct management of occult fractures and, therefore, no evidence-based treatment guidelines can be drafted.

OBJECTIVES

This article summarizes the current diagnostic and treatment concepts for occult fractures under special consideration of foot and ankle injuries.

METHODS

A selective search of the current literature was performed and also taking own experience into consideration.

RESULTS AND CONCLUSION

The clinical prognosis of occult fractures is generally good and there is no evidence that these lesions need specific treatment. Besides forensic applications and problems pursuant to insurance law, MRI examination is only indicated when conventional radiographs are unremarkable, pain persists for an unusually long period of time and when a relevant therapeutic consequence can be expected from the MRI results. Classical pitfalls are combinations of occult fractures with potentially unstable ligamentous injuries and patients with disordered pain perception as in cases of diabetic polyneuropathy, as the common therapeutic concept of weight bearing according to pain is not suitable for these patients and can lead to severe complications.