The use of MRI for the imaging of metastatic bone lesions.

Skeletal metastatic disease accounts for significant overall morbidity in cancer patients. Accurate and accessible imaging forms an integral part of the investigation for patients with suspected or known skeletal metastatic disease; it is considered indispensable in making appropriate oncological treatment decisions. Magnetic resonance imaging (MRI) is a contemporary imaging modality that provides excellent spatial and contrast resolution for bone and soft tissues. Therefore, it is particularly useful for imaging patients suffering from metastatic skeletal disease. This review provides a fundamental overview of the physics and image generation of MRI. The most commonly used MRI sequences in the investigation of metastatic skeletal disease are also discussed. Additionally, a review of the pathophysiological basis of metastatic bone disease is presented, along with an introduction to the interpretation of MRI sequences obtained for metastatic bone disease. Finally, the strengths and drawbacks of MRI are considered in comparison to alternative imaging modalities for the investigation of this common and important oncological complication.

Cost-Effectiveness of Immediate Magnetic Resonance Imaging In the Management of Patients With Suspected Scaphoid Fracture: Results From a Randomized Clinical Trial.

OBJECTIVES: Given the limited diagnostic accuracy of radiographs on presentation to the emergency department (ED), the management of suspected scaphoid fractures remains clinically challenging and poses an unknown economic burden to healthcare systems. We aimed to evaluate the cost-effectiveness of immediate magnetic resonance imaging (MRI) in the management of patients presenting with suspected scaphoid fracture to an ED in England. METHODS: A pragmatic, randomized, single-center trial compared the use of immediate MRI in the ED against standard care with radiographs only. Participants' use of healthcare services and costs were estimated from primary care and secondary care databases and questionnaires at baseline, 1, 3, and 6 months postrecruitment. Costs were compared using generalized linear models and combined with quality-adjusted life years (QALYs, based on the EQ-5D-5L) to estimate cost-effectiveness at 6 months postrecruitment. Cost-effectiveness acceptability curves and bootstrapping techniques were used to estimate the probability of cost-effectiveness at different willingness-to-pay (WTP) thresholds. Four deterministic sensitivity scenarios were considered around key parameters. RESULTS: The MRI intervention dominated standard care in the base case and all 4 deterministic sensitivity scenarios, costing less and achieving more QALY gains, with a probability of 100% of being cost-effective at 6 months using the conventional United Kingdom WTP thresholds of £20 000 to £30 000 per QALY. CONCLUSION: The use of immediate MRI is a cost-effective intervention in the management of suspected scaphoid fractures in a Central Hospital in London. Routine clinical practice at our institution has been changed to include the intervention.

DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS IN CAPTIVE GORILLAS (GORILLA SPP.): APPEARANCES AND DIAGNOSIS.

Diffuse idiopathic skeletal hyperostosis (DISH) is a disorder of unknown cause, in which new bone forms in soft tissues attached to the skeleton. Originally described in humans, in whom it is quite common, it is usually asymptomatic. New bone may completely bridge across joints, especially in the spine. However, it can be difficult to distinguish from diseases such as spondyloarthritis and spondylosis. With safer and increased use of radiography in diagnosis, the unfamiliar skeletal changes of asymptomatic DISH may now be coincidentally revealed during investigation of other disorders and result in misdiagnosis and unnecessary treatment. There have been case reports of its occurrence in great apes, but this is the first study to illustrate its appearances in a series of 11 skeletons of western and eastern lowland gorillas (Gorilla gorilla gorilla and Gorilla beringei graueri) from zoos in Europe and the United States. The study combines a review of available clinical and postmortem records with examination of the skeletons and radiologic investigation, such as computed tomography (CT). The results indicate that the disorder is probably common in older (>30 yr) captive gorillas, but that it is asymptomatic. It was not symptomatic during life in any of these animals. Several cases had unexpected features, such as extensive involvement of the thorax and extra-articular sacroiliac and tibiofibular joint fusions that are not typical in humans. By illustrating these skeletons, the study should aid differentiation of DISH from spondylosis (syn spondylosis deformans) and spondyloarhritis. It illustrates those features that are atypical of human DISH. CT scanning is valuable in such cases for examining diagnostically important areas such as sacroiliac joints. Increased awareness of DISH should help with understanding its cause, both in gorillas and humans.

Rationale and design of the SMaRT trial: A randomised, prospective, parallel, non-blinded, one-centre trial to evaluate the use of magnetic resonance imaging in acute setting in patients presenting with suspected scaphoid fracture.

Background Wrist injury is a common presentation to the Emergency Department in the United Kingdom. Among these injuries, the scaphoid is the most common fractured carpal bone. However, given the limited ability of conventional radiography to accurately diagnose a suspected scaphoid fracture on presentation, its diagnosis and management remain challenging. Despite the vast clinical evidence supporting the superior accuracy of magnetic resonance imaging, there is little to no evidence around the real-world clinical and economic impact of immediate magnetic resonance imaging in the management of suspected scaphoid fractures. Methods Review of design and implementation challenges associated with the identification and subsequent recruitment of eligible patients, implementation of a novel clinical pathway in an acute setting, rationale behind the primary and secondary outcomes selected and measurement of the primary outcome. Results The Scaphoid Magnetic Resonance Imaging in Trauma trial is a single-site prospective, randomised, non-blinded, parallel design trial that aims to evaluate the use of immediate magnetic resonance imaging in the management of patients presenting to the acute setting with suspected scaphoid fractures. The primary outcome is the total 3-month cost per patient associated with the diagnosis and treatment of suspected scaphoid fractures. It is hypothesised that the immediate use of magnetic resonance imaging, a more accurate but expensive imaging modality, in patients with negative findings in the initial four-view radiography, will reduce the overall National Health Service costs by promoting definitive care and avoiding unnecessary diagnostic and treatment procedures. Other rationale design considerations in the recruitment, randomisation, data acquisition and intervention implementation are also discussed. Several of these challenges derive from real-world operational issues associated with the provision of magnetic resonance imaging in an intrinsically complex acute setting. Staff engagement during the trial's planning phase, combined with an extensive training programme rolled out prior to the trial's launch, were essential to raise staff awareness and engagement. Given the acute nature of the clinical condition, the latter was deemed essential as the eligibility assessment, recruitment, randomisation and treatment allocation processes all need to happen in a very tight time frame. Limitations Findings from the Scaphoid Magnetic Resonance Imaging in Trauma trial might not be generalisable to other National Health Service hospitals, foreign healthcare systems nor patient presentations outside normal magnetic resonance imaging working hours. Conclusion The Scaphoid Magnetic Resonance Imaging in Trauma trial was designed to evaluate the costs, patient satisfaction and clinical outcomes around the management of suspected scaphoid fractures and ultimately provide solid evidence on which to base the United Kingdom and international clinical practice. This article discusses the steps considered in the design of this novel trial, with particular emphasis on the issues and lessons learned during the planning and implementation stages.

The value of 99mTc-MDP bone SPECT/CT in evaluation of patients with painful knee prosthesis.

OBJECTIVE: The purpose of this study was to assess the incremental value of technetium-99m-methyl diphosphonate (Tc-MDP) single-photon emission computed tomography/computed tomography (SPECT/CT) over Tc-MDP two-phase bone scan (TPBS) in the assessment of the patients with pain following knee arthroplasty. PATIENTS AND METHODS: Tc-MDP TPBS and Tc-MDP SPECT/CT were performed in 49 patients with knee pain after knee arthroplasty. The scans were reviewed by two readers (nuclear medicine physician and musculoskeletal radiologist). Tc-MDP SPECT/CT studies were interpreted in conjunction with TPBS in this retrospective study to identify the pain generator in painful knee prosthesis. The final diagnosis was established based on a combination of histopathological/cytological findings, other imaging findings (e.g. MRI, radiolabelled white scan), clinical decisions, and management outcomes (including subsequent intraoperative findings). RESULTS: In diagnosing infection or aseptic loosening, a definitive outcome regarding the presence/absence of aseptic loosening or periprosthetic infection was obtained in 41 patients. (a) Sensitivity of Tc-MDP SPECT/CT [100%; 95% confidence interval (CI): 66.4-100%] was higher than Tc-MDP TPBS (88.9%; 95% CI: 51.8-99.7%). (b) Specificity of Tc-MDP SPECT/CT (75%; 95% CI: 53.3-90.2%) was considerably higher than Tc-MDP TPBS (30%; 95% CI: 11.9-54.3%). Alternative diagnoses were identified in 21/49 (43%) patients on Tc-MDP SPECT/CT, which could not be ascertained on Tc-MDP TPBS alone. CONCLUSION: Tc-MDP SPECT/CT has better sensitivity and specificity compared with Tc-MDP TPBS in diagnosis of aseptic loosening and periprosthestic infection in patients with painful knee arthroplasty. Tc-MDP SPECT/CT identified alternative causes of pain in 43% of patients, which was not identified by Tc-MDP TPBS.

Radionuclide bone SPECT/CT in the evaluation of knee pain: comparing two-phase bone scintigraphy, SPECT and SPECT/CT.

OBJECTIVE:: To assess the role of single photon emission computed tomography (SPECT/CT) in the evaluation of knee pain as well as comparing bone scintigraphy (BS), SPECT and SPECT/CT, and assessing the incremental value of SPECT/CT. METHODS:: BS, SPECT and SPECT/CT of patients with knee pain (39 patients, 65 knees, 105 lesions) were directly compared for lesion detection, localisation and characterisation using lesion-based, knee-based and patient-based analyses in this retrospective study. RESULTS:: Lesion detection: BS (91.4%), SPECT (100%) and SPECT/CT (100%). SPECT and SPECT/CT detected significantly more lesions than BS (p < 0.05). Lesion localisation: BS (38.5-41.7%), SPECT (74.4-83.3%) and SPECT/CT (100%). SPECT localised significantly more lesions than BS; SPECT/CT localised significantly more lesions than BS and SPECT (p < 0.01). Lesion characterisation: BS (23.0-52.1%), SPECT (30.8-56.2%) and SPECT/CT (92.3-96.9%). SPECT/CT characterised significantly more lesions than BS and SPECT (p < 0.01). Characterisation of non-arthropathy lesions: BS (6.25%), SPECT (12.5%) and SPECT/CT (93.75%). SPECT/CT characterised significantly more non-arthropathy lesions than BS and SPECT (p < 0.01). BS and SPECT detected none, while SPECT/CT detected 100% of the causative/contributing/associated conditions that co-existed with osteoarthritis. Therefore SPECT/CT detected not only just osteoarthritis but also the causative/contributing/associated conditions. CONCLUSION:: SPECT/CT added significant incremental value to BS and SPECT irrespective of whether evaluation was lesion-based, knee-based or patient-based. SPECT/CT represents a viable alternative to MRI, and addition of SPECT/CT to BS and SPECT should be considered in the evaluation of knee pain. ADVANCES IN KNOWLEDGE:: Incremental value of bone SPECT/CT in knee pain.

Atypical Paget's disease with quantitative assessment of tracer kinetics.

INTRODUCTION: Paget's disease of bone is characterized by alterations in skeletal metabolism, affecting a single or multiple bones. Paget's is usually confined to an individual bone and typically does not spread or extend across joints. A patient with an unusual pattern of disease is presented together with quantitative assessment of the tracer kinetics pre- and posttreatment. MATERIAL AND METHODS: A 75-year-old lady patient presented to her general practitioner in May 2002 with a history of lethargy. Clinical examination was unremarkable and further investigations such as blood tests (alkaline phosphatase levels), Tc-99m MDP bone scan, biopsy, and CT scan were carried out. RESULTS: Alkaline phosphatase levels were greater than 2000 IU/L (Normal: 31-116 IU/L). The Tc-99m MDP bone scan showed strikingly increased uptake in the central skeleton involving the thoracic vertebrae and the adjoining ribs. The bone biopsy was inconclusive. CT scan revealed symmetrical expansion of the ribs with bridging osteophytes across the ribs and spine. The patient was treated with risedronate and quantitative analysis of the pre- and posttherapy bone scans showed reduced plasma clearance in the pagetic bones. CONCLUSIONS: This case illustrates an unusual distribution of bone lesions in Paget's disease, which we think could be due to the result of degenerative disease leading to bridging and allowing direct extension of disease from one bone to another.

Extensor Pollicis Brevis tendon damage presenting as de Quervain's disease following kettlebell training.

Kettlebell exercises are more efficient for an athlete to increase his or her muscle strength. However it carries the risk of injury especially in the beginners. A 39 year old gentleman came to our clinic with radial sided wrist pain following kettlebell exercises. Clinically patient had swelling and tenderness over the tendons in the first dorsal wrist compartment, besides Finklesten test was positive. Patient had a decreased excursion of the thumb when compared to the opposite side. Ultrasound/MRI scan revealed asymmetric thickening of the 1st compartment extensors extending from the base of the thumb to the wrist joint. Besides injury to the Extensor Pollicis Brevis (EPB) tendon by repetitive impact from kettlebell, leading to its split was identified. Detailed history showed that the injury might be due to off-centre handle holding during triceps strengthening exercises. Our report stresses the fact that kettlebell users should be taught about problems of off-center handle holding to avoid wrist injuries. Also, in Kettlebell users with De Quervains disease clinical and radiological evaluation should be done before steroid injection as this might lead to complete tendon rupture.

Potential role of multislice SPECT/CT in impingement syndrome and soft-tissue pathology of the ankle and foot.

INTRODUCTION: Impingement syndrome and soft-tissue pathology have been recognized as significant causes of chronic ankle pain. Conventional bone scintigraphy was traditionally used for osseous pathology, but with the advent of single photon emission computed tomography/computed tomography (SPECT/CT) the role of bone scintigraphy in these patients is being reconsidered. AIM: The aim of this study was to assess the potential role of multislice SPECT/CT in diagnosing impingement syndrome and soft-tissue pathology of the ankle and foot. MATERIALS AND METHODS: A total of 209 patients (age range: 19-80 years) underwent a two-phase Tc-99m methylene diphosphonate bone scan followed by SPECT/CT between 2006 and 2009 for various ankle and foot pathologies. These scans were reviewed for impingement syndrome and soft-tissue pathology. The diagnosis made on SPECT/CT was compared with the clinical diagnosis, and two-phase bone scan findings and additional findings obtained from SPECT/CT were noted. RESULTS: Out of the 209 patients, 43 (21%) were diagnosed with impingement syndrome or soft-tissue pathology. Clinical diagnosis versus bone SPECT/CT: in 24/43 (56%) patients, SPECT/CT provided information not suspected on clinical diagnosis. In 19/43 (44%) patients, SPECT/CT confirmed the clinical diagnosis. Two-phase bone scan versus SPECT/CT: in 31/43 (72%) patients, SPECT/CT provided additional information, which was not diagnosed on the conventional two-phase bone scan. The findings of the two-phase bone scan and SPECT/CT were concordant in 12/43 (28%) patients. CONCLUSION: Tc-99m methylene diphosphonate bone SPECT/CT is useful in localizing and characterizing impingement syndrome and soft-tissue pathology in patients with ankle/foot pain. SPECT/CT may complement MRI and ultrasonography in the investigation of impingement syndrome and soft-tissue pathology.

Value of SPECT/CT in the evaluation of knee pain.

Bone scintigraphy (BS) has a good sensitivity but limited specificity. Moreover, planar imaging limits localization of lesion especially of overlapping structures in close proximity. SPECT allows tomographic imaging, resulting in better localization and characterization of the lesion. Addition of CT to SPECT in hybrid SPECT/CT further improves the precision of localization and accuracy of characterization of the lesion. Combining functional and anatomical imaging is complementary with improved sensitivity, specificity, and diagnostic confidence. These advantages of SPECT/CT are illustrated by 3 cases where diagnostic confidence was higher with SPECT/CT compared to BS or CT alone, highlighting the incremental value of SPECT/CT in assessing knee pain.

The role of 99mTc-diphosphonate bone SPECT/CT in the ankle and foot.

The evaluation of the osseous ankle and foot pathology often poses a clinical and diagnostic challenge because of the complex anatomy and structural biomechanics of the region. Further investigation involves a multimodality imaging approach. Although both structural and functional imaging techniques have their strengths, namely, the high specificity of the former and superior sensitivity of the latter, they also have a number of limitations when used in isolation. These include the inability to determine the functional significance of pathological anatomical abnormalities or to further characterize or localize abnormal metabolic activity. The development of integrated single-photon emission computed tomography/computed tomography systems has aimed to overcome the limitations of separate anatomical and functional imaging techniques. This may be of particular value in ankle and foot assessments, in which multiple joints may be affected by different pathologies. This review article aims to highlight the role of both structural and functional imaging techniques, with particular emphasis on the incremental value of single-photon emission computed tomography/computed tomography in evaluation of this complex anatomical region.

Heterotrophic ossification in a patient suspected of having osteomyelitis: additional value of SPECT/CT.

A 46-year-old man, with a history of bilateral amputations, presented with a long-standing chronic nonhealing wound at the left below-knee amputation, which was sustained after a crush injury. The patient was referred for a bone scan to exclude osteomyelitis of the left stump. The bone scan showed increased uptake in the left below-knee amputation stump, raising the possibility of an infection. However, SPECT/CT of this area confirmed the uptake to correspond to the heterotrophic ossification of the left below-knee stump and no evidence of osteomyelitis.

Beware of the focal uptake at the ischium on the bone scan in prostate cancer.

RATIONALE: The isotope bone scan is routinely used in the management of prostate cancer as the skeleton is the second most common area of metastasis after lymph nodes. A classic site of involvement in the pelvis is the ischium, and the aim of this study was to assess the value of single-photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with focal ischial uptake on the planar scan. MATERIALS AND METHODS: This was a retrospective study of consecutive 150 patients with prostate cancer who were referred for a whole-body bone scan between August 2007 and 2008. Two experienced nuclear medicine consultants along with a musculoskeletal radiologist reviewed the scans. RESULTS: Sixty-eight patients were diagnosed with widespread metastases and 46 patients showed typical degenerative disease changes on planar whole-body imaging. SPECT/CT imaging was done in 36 patients to clarify the diagnosis in areas of indeterminate uptake noted on planar whole-body imaging. Ten of these 36 patients who had focal increased ischial uptake were included in the study. Only three of these 10 patients were diagnosed as having a metastatic lesion with the presence of an enthesopathy, a common finding. CONCLUSION: Isolated focal uptake in the ischium is a relatively common finding in patients with prostate cancer and there is concern that this, on occasion, could be misinterpreted as metastasis. SPECT/CT imaging has an important role in differentiating a benign from a malignant lesion.

SPECT/CT in imaging foot and ankle pathology-the demise of other coregistration techniques.

Disorders of the ankle and foot are common and given the complex anatomy and function of the foot, they present a significant clinical challenge. Imaging plays a crucial role in the management of these patients, with multiple imaging options available to the clinician. The American College of radiology has set the appropriateness criteria for the use of the available investigating modalities in the management of foot and ankle pathologies. These are broadly classified into anatomical and functional imaging modalities. Recently, single-photon emission computed tomography and/or computed tomography scanners, which can elegantly combine functional and anatomical images have been introduced, promising an exciting and important development. This review describes our clinical experience with single-photon emission computed tomography and/or computed tomography and discusses potential applications of these techniques.

Advantages and limitations of imaging the musculoskeletal system by conventional radiological, radionuclide, and hybrid modalities.

The endpoint of an efficient and accurate diagnosis of musculoskeletal pathology can take many different routes. Currently, conventional radiological techniques, such as plain radiography, ultrasonography, computed tomography, and magnetic resonance imaging are used in the assessment of patients with benign and malignant bone disease. An understanding of the advantages and limitations of the modalities available will help expedite diagnosis, and hence treatment. In this review, we discuss the advantages and limitations of the modalities available in investigating benign and malignant musculoskeletal pathology.

Tuberculosis of the spine on Tc-99m MDP bone scan: additional role of SPECT-CT.

Dedicated multislice single-photon emission computed tomography-computed tomography (SPECT-CT) is useful for accurate anatomic localization and lesion characterization of abnormal findings on planar scintigraphy. We present a case of a 33-year-old woman with a history of low back pain. Lumbar spine radiographs demonstrated irregularity of the superior end plate of L2 with an associated compression fracture. A Tc-99m MDP bone scan was performed given her young age and the absence of a history of trauma. The whole body planar imaging revealed nonspecific findings of diffuse linear increased tracer uptake involving L2. The SPECT-CT findings were in keeping with spinal tuberculosis. This was confirmed with culture of CT-guided aspiration of a left psoas collection, which revealed heavy growth of Mycobacterium tuberculosis. This case highlights the benefits of multislice SPECT-CT imaging in the anatomic localization of increased metabolic activity and provision of additional diagnostic information. This enabled rapid diagnosis and management.