Novel use of gamma correction for precise 99mTc-HDP pinhole bone scan diagnosis and classification of knee occult fractures

Objective  

The aim of this study was to introduce gamma correction pinhole bone scan (GCPBS) to depict specific signs of knee occult fractures (OF) on ^99mTc-hydroxydiphosphonate (HDP) scan.     

Paget's disease of the bone in a Chinese woman

Paget's disease, otherwise known as osteitis deformans, is an unusual condition in the Oriental population. We report a case of Paget's disease in a Chinese woman, incidentally diagnosed on a bone scan. This was confirmed by clinical history, biochemistry and imaging findings using other modalities. Although bone scans are commonly performed to diagnose traumatic occult fractures and bone metastases, they can also be used to diagnose metabolic bone diseases, such as osteoporotic fractures, and to evaluate Paget's disease. It can also diagnose acute fractures secondary to renal osteodystrophy and osteomalacia.     

Basic principles of nuclear medicine techniques for detection and evaluation of trauma and sports medicine injuries

Nuclear medicine skeletal imaging is a very sensitive technique for evaluating bone and muscle abnormalities because it can detect minor changes in metabolism and blood flow. The specificity of bone imaging, however, depends on the ability of the nuclear medicine physician to make a differential diagnosis. To aid in making a specific diagnosis, this article describes the various patterns of abnormality in stress fractures, tibial stress syndrome (shin splints), compartment syndrome, enthesopathy, and traumatic fractures. The characteristic scintigraphic appearance of joint injuries, muscle injuries (rhabdomyolysis), and radionuclide arthrography is discussed and the way the scan patterns change with time in these various disorders is described. A brief summary of the basic anatomy and physiology of bone and muscle in normal and injured tissue is presented and the basic mechanisms which cause the various abnormal scan patterns is postulated. In addition, a staging system for stress fractures is presented to help direct the referring physician toward the proper management of the injured patient. In most cases, nuclear medicine skeletal imaging can be used to differentiate between acute muscle injury, tibial stress syndrome, skeletal injury (periosteal reaction, stress fracture, and traumatic fracture) or an abnormality that is entirely associated with the joint or connective tissue. This differential diagnosis is easier if the nuclear medicine procedure is performed within a few days after the onset of injury.     

Nuclear medicine studies in metabolic bone disease

The principal application of nuclear medicine in metabolic bone disease is the isotope bone scan. Often, it is not a diagnostic tool but can be useful in clarifying the nature of a clinical problem. The best-established role for the bone scan in metabolic bone disease is in Paget's disease, in which it is diagnostic, provides definition of the extent of disease, and probably reflects disease activity. The isotope bone scan is also important in osteoporosis, for which it is not diagnostic but may often provide useful information to confirm that fracture has occurred, determine the age of the fracture, identify unsuspected fractures, and identify other causes for pain, for example, facet joint disease. The bone scan is less useful in other metabolic bone diseases, for example, renal osteodystrophy and osteomalacia, but will often have a characteristic appearance, with several metabolic features. The degree of positivity of the scan generally relates to the severity of the hyperparathyroidism. In patients with metabolic bone disease, other specific clinical problems may arise, such as osteomyelitis or avascular necrosis, and the bone scan may be diagnostic in these conditions. Nuclear medicine techniques are also of value in hyperparathyroidism and to localize the site of the adenoma where surgical treatment is being considered; the use of technetium Tc 99m sestamibi is now routine. More recently, positron emission tomography (PET) scanning has been found to be helpful in the more difficult cases.     

Clinical spectrum and diagnostic pitfalls of multiple abnormal uptakes on bone scintigraphy

Bone scintigraphy with technetium-99m (^99mTc)-labeled diphosphonates is one of the most frequently performed radionuclide procedures. Accumulation of ^99mTc-labeled diphosphonate is well recognized to reflect conditions of accelerated bone turnover and metabolism. Therefore, it is a functional imaging modality for detecting metastatic bone tumors, metabolic bone disease, traumatic injury, and inflammation. This pictorial essay describes the possible patterns of distribution of abnormal uptake for differential diagnosis of metastatic bone tumor, as well as the diagnostic pitfalls of bone scintigraphy.     

Does the Addition of a “Black Bone” Sequence to a Fast Multisequence Trauma MR Protocol Allow MRI to Replace CT after Traumatic Brain Injury in Children?

BACKGROUND AND PURPOSE:Head CT is the current neuroimaging tool of choice in acute evaluation of pediatric head trauma. The potential cancer risks of CT-related ionizing radiation should limit its use in children. We evaluated the role of MR imaging, including a “black bone” sequence, compared with CT in detecting skull fractures and intracranial hemorrhages in children with acute head trauma.MATERIALS AND METHODS:We performed a retrospective evaluation of 2D head CT and brain MR imaging studies including the black bone sequence of children with head trauma. Two experienced pediatric neuroradiologists in consensus created the standard of reference. Another pediatric neuroradiologist blinded to the diagnosis evaluated brain MR images and head CT images in 2 separate sessions. The presence of skull fractures and intracranial posttraumatic hemorrhages was evaluated. We calculated the sensitivity and specificity of CT and MR imaging with the black bone sequence in the diagnosis of skull fractures and intracranial hemorrhages.RESULTS:Twenty-eight children (24 boys; mean age, 4.89 years; range, 0–15.5 years) with head trauma were included. MR imaging with the black bone sequence revealed lower sensitivity (66.7% versus 100%) and specificity (87.5% versus 100%) in identifying skull fractures. Four of 6 incorrectly interpreted black bone MR imaging studies showed cranial sutures being misinterpreted as skull fractures and vice versa.CONCLUSIONS:Our preliminary results show that brain MR imaging complemented by a black bone sequence is a promising nonionizing alternative to head CT for the assessment of skull fractures in children. However, accuracy in the detection of linear fractures in young children and fractures of aerated bone remains limited.

CT is the initial neuroimaging technique of choice for the acute evaluation of pediatric head trauma due to its wider availability, lower cost, and short acquisition time. In addition, CT identifyies most traumatic injuries that require urgent treatment and correlates well with clinical scales and outcome.¹ However, CT-related ionizing radiation involves the potential risk of patients developing cancer and strongly argues in favor of alternative neuroimaging techniques such as MR imaging.² The lifetime cancer mortality risk attributable to the radiation from a single CT scan of the head in a 1-year-old child has been estimated as 0.07%. This small risk translates into a large population-level risk, especially because head trauma in children from 0 to 14 years of age accounts for nearly half a million emergency department visits in the United States annually.^3,4MR imaging is a nonionizing technique that provides superior contrast resolution and has a higher sensitivity and specificity for parenchymal lesions compared with CT.^3,4 Especially, advanced MR imaging techniques (DWI, SWI) provide additional information that correlates well with outcome.^5,6 Nonhemorrhagic shear injuries and subtle microhemorrhages are typically seen with higher sensitivity by MR imaging compared with CT. Nevertheless, the role of MR imaging in the acute diagnostic work-up of head trauma in children is still limited.^2,7,8 This limitation may be partially explained by longer acquisition times and the subsequent need for sedation as well as the low sensitivity of MR imaging for skull fractures.^2,8 Recently, black bone MR images have been introduced as a new sequence for the evaluation of structural bony abnormalities such as craniosynostosis.⁹On the basis of the inherent diagnostic quality of the black bone sequence, we aimed to determine whether a trauma brain MR imaging protocol with an included black bone MR image could be an alternative to head CT in the acute work-up of children with head trauma. To address our goal, we compared the diagnostic accuracy of brain MR imaging including the black bone sequence with CT for the detection of skull fractures after traumatic brain injury in children. Images were also studied for coexisting intracranial lesions.     

Bildgebung des Schläfenbeins

This article presents a review of diseases of the temporal bone which are relevant for radiologists in routine clinical practice. First the most prominent imaging methods will be briefly summarized with respect to the current state of the art and the most important aspects of cross-sectional anatomy of the temporal bone will be presented. This is followed by the presentation of various inflammatory diseases. Fractures (longitudinal, transverse and mixed fractures), auditory ossicle lesions and contusions of the labyrinth will be discussed in connection with injuries of the temporal bone. Tumors and tumor-like lesions and the clinical symptoms of otosclerosis and malformations will also be discussed. Finally the postoperative use of imaging methods will be presented. Special importance is given to the position of imaging techniques in the diagnostic chain and their evidential value. This is supplemented by special morphological imaging characteristics and aspects of differential diagnostics.     

Bone scintigraphy and metabolic disorders.

The most important features of bone scintigraphy in metabolic bone disease are its high sensitivity and its capacity to easily image the whole body. Although in the early stages of evolution bone scintigraphy may present difficulties in disease detection because of its usual discrete generalized increased uptake, as the disease progresses, bone scintigraphy has well-recognized appearances, and with the knowledge of the different patterns of abnormality its highest diagnostic value can be obtained. Currently, the main clinical value of bone scan in metabolic bone disease is the detection of focal conditions or focal complications of such generalized disease, its most common use being the detection of fractures in osteoporosis, pseudofractures in osteomalacia and the evaluation of Paget's disease.     

Penile implant on bone scan imaging: a case study

We present an unusual case of the incidental finding of a penile implant on a whole-body bone scan obtained for back pain in a patient with osteoporosis and vertebral body fractures. On 2 separate occasions, this patient underwent 3-h delayed whole-body bone scanning with (99m)Tc-methylene diphosphonate. The images showed acute and then subacute vertebral body fractures. On both imaging occasions, the bone scan that included the region of the implant clearly showed the penis, but visualization was better on the second scan. Penile implants have not been described in the nuclear medicine literature, and it is important to recognize the diagnostic possibilities when penile photopenia is identified.     

Radionuclide imaging in metabolic and systemic skeletal diseases

Radionuclide imaging with Tc-99m diphosphonates is not an effective method for detecting or ruling out most osteoporotic diseases including senile osteoporosis or accelerated postmenopausal osteoporosis, and the slow loss of bone tissue generally remains undetected by this modality. Nonetheless, it frequently surpasses or supplements radiographic findings in evaluating the focal complications of metabolic bone disease, including fractures, microfractures, stress fractures, vertebral compressions, Milkman-Looser zones, aseptic necrosis, and acute infarction. In contrast to its secondary role in osteoporosis, bone imaging is of prime importance in investigating hypercalcemia, because the major cause of this abnormality is skeletal metastatic malignancy. In defective bone mineralization due to hyperparathyroidism or osteomalacia, a general increase in diphosphonate skeletal uptake is detected more frequently than radiographic abnormalities. However, normal skeletal images do not rule out metabolic bone disease. Biochemical testing is more reliable in detecting primary hyperparathyroidism. On the other hand, in renal osteodystrophy, biochemical abnormalities are variable and bone imaging is helpful in assessing the severity of skeletal involvement, but not its etiology. Many methods of quantitating the kinetics of Tc-99m diphosphonates have been explored, such as plasma clearance, bone-to-soft-tissue ratios, 24-hour total body retention and 24-hour urinary excretion. None of these have been widely accepted. The value of bone imaging is established in other systemic diseases, most notably in Paget's disease, hypertrophic pulmonary osteoarthropathy, sickle cell disease, fibrous dysplasia, and sympathetic dystrophy.     

Post-traumatic knee pain leading to the diagnosis of spondyloarthropathy

The authors report a patient with persistent left knee pain after traumatic injury. The initial bone scan seemed to confirm a valgus stress knee injury. The final diagnosis, however, was focal inflammation of the knee ligaments (enthesopathy) related to ankylosing spondylitis. The diagnostic procedure and the results of other imaging modalities are presented. The bone scan findings are discussed.     

Radiología del oído externo: indicaciones,anatomía normal y procesos patológicos

The external ear is accessible to direct examination; the clinical history and otoscopy are sufficient to diagnose and treat most diseases of the external ear. We aim to describe the normal anatomy of the external ear, specify the indications for imaging tests, and review the clinical and radiological manifestations of the most common diseases affecting the external ear. We classify these diseases according to their origin into congenital, inflammatory, infectious, or traumatic disease or benign bone tumors or malignant tumors.Imaging does not play an important role in diseases of the external ear, but in certain clinical scenarios it can be crucial for reaching a concrete diagnosis and establishing the best treatment. Computed tomography is the first-choice technique for most diseases. Magnetic resonance imaging complements computed tomography and makes it possible to differentiate among different tissue types and to evaluate the extension of disease accurately.     

Subchondral bone infractions in acute ligamentous knee injuries demonstrated on bone scintigraphy and magnetic resonance imaging.

Bone scintigraphy is used to detect radiographically silent fractures. Magnetic resonance imaging (MRI) is currently used to screen knee injuries for cartilage and ligament damage. MRI also delineates bone marrow and fractures. We investigated the bone scintigraphic findings in patients who had subchondral bone injuries demonstrated on MRI. Thirteen patients underwent MRI, three-phase bone scintigraphy with SPECT, and arthroscopic surgery after sustaining acute traumatic hemarthrosis of a knee. They all had clinically unsuspected subchondral bone injuries demonstrated on MRI with normal radiographs and normal overlying articular cartilage at arthroscopy, consistent with occult fractures. All showed focal bone repair on scintigraphy. Two of the 13 patients showed additional bone injuries only on bone scan. Two other patients scintigraphically showed focal bone repair at the medial femoral condyle due to avulsion of the medial collateral ligament. SPECT was easier to interpret than multi-view planar imaging. Bone scintigraphy confirms subchondral fractures demonstrated on MRI but also demonstrates ligament avulsion injuries and additional more subtle bone injuries.     

Methotrexate osteopathy demonstrated by Technetium-99m HDP bone scintigraphy

The authors report a case of methotrexate osteopathy as revealed by Tc-99m HDP bone scintigraphy in a patient with rheumatoid arthritis. Methotrexate is used widely in high doses as a chemotherapeutic agent. Lower doses are given in rheumatoid and psoriatric arthritis. Methotrexate affects bone metabolism, resulting in methotrexate osteopathy, characterized by osteoporosis, osseus pain, and even spontaneous (micro)fractures. Radiographic visualization of microfractures is difficult. Tc-99m HDP bone scans have been shown to be very sensitive in the visualization of changes in bone metabolism as a result of methotrexate osteopathy.     

颈动脉海绵窦瘘的临床及MSCT表现特征

目的:分析颈动脉海绵窦瘘(CCF)的临床及MSCT表现特征,提高对CCF的诊断准确率。材料和方法:采用16层螺旋CT对13例CCF病人进行扫描,图像后处理分别行MPR、MIP及VR成像,其中10例外伤性CCF还采用骨窗重建。结果:CCF的主要临床表现为眼球突出、视力减退、结膜充血、血管杂音等,MSCT的直接征象为海绵窦扩大13例(100%),眼上静脉扩张13例(100%),瘘口显示6例(46.2%),大脑中、浅静脉早显8例(61.5%)。间接征象为眼突、眼肌肥厚、眶内软组织肿胀、颅面部骨折等。MSCT检查结合临床病史可以对外伤性CCF作出准确的诊断,自发性CCF临床表现不典型,需与炎性假瘤、眼眶肿瘤、Craves眼病、血管畸形等眼部疾病进行鉴别诊断,本组采用MSCT对CCF的诊断准确率为100%。结论:MSCT具有安全、快速、准确的检查优势,多种成像技术结合使用,能清楚显示CCF的直接征象和间接征象,为临床及介入治疗提供可靠的诊断依据。     

全身骨显像联合局部SPECT/CT对功能不全性骨折的诊断价值

目的 探讨99Tcm-MDP SPECT全身骨显像联合局部SPECT/CT融合显像对骨质疏松患者功能不全性骨折（IF）的诊断价值。 方法 回顾性分析2012年12月至2017年6月于河南省骨科医院收治的90例符合骨质疏松症诊断标准的患者的99Tcm-MDP SPECT全身骨显像和阳性部位的局部SPECT/CT融合显像结果,分析联合显像对IF的临床诊断效能。90例患者中,男性32例、女性58例,年龄（67.56±7.68）岁,其中22例可疑IF、68例已确诊局部IF。所有患者的最终诊断结果均经过6个月以上临床及影像学随访证实。 结果 99Tcm-MDP SPECT全身骨显像共检出IF病灶234个,均表现为显像剂摄取增高,病变部位及个数为骨盆78个、腰椎49个、胸椎46个、肋骨45个、股骨8个、胫骨4个、跟骨3个及胸骨1个。全身骨显像联合局部SPECT/CT融合显像对IF的诊断灵敏度为100%（234/234）。68.89%（62/90）的患者联合显像检出的IF数目多于显像之前已知的骨折数目。在局部SPECT/CT融合显像检查范围内,CT显示骨折病灶293个,其中SPECT/CT诊断新鲜IF病灶234个、陈旧性IF病灶59个,SPECT/CT对新鲜IF的诊断灵敏度为100%（234/234）。 结论 99Tcm-MDP SPECT全身骨显像联合局部SPECT/CT融合显像对骨质疏松患者IF病灶数目的全身显示及诊断具有较高的临床应用价值。     

Orbital apex injury: trauma at the junction between the face and the cranium

Orbital apex injury is usually seen in multiply and severely injured patients who are subject to high-energy trauma. Orbital apex injury rarely occurs in isolation. By proximity, the face, the skull base, or their combination are the most likely regions to be injured in association with orbital apex trauma. The vast majority of these injuries occur as an extension of orbital, LeFort, naso-orbito-ethmoid, panfacial, sphenoid, or temporal bone fractures of the skull. Complex osseous anatomic structures with intimately related multiple neurovascular organs make injuries to the orbital apex diagnostically and therapeutically challenging. Often other facial fractures extend into the orbital apex, or the orbital apex is damaged in conjunction with fractures of the skull base. Therefore abnormal imaging findings within the orbital apex may be indicators of traumatic injury to the entire junctional zone of face and cranium. In this article, we will give an overview of normal CT anatomy, review clinical syndromes, which may indicate traumatic injury of the orbital apex and present an imaging strategy for evaluation of the orbital apex.     

Bacterial osteomyelitis: findings on plain radiography, CT, MR, and scintigraphy

Early detection of osteomyelitis is essential if appropriate therapy is to be started before bone devitalization. Although the 99mTc-methylene diphosphonate (MDP) bone scan may signify the possibility of osteomyelitis days or weeks before osseous changes are apparent on standard radiographs, the radiographic changes may provide important diagnostic clues. The 67Ga-citrate scan augments the diagnostic value of the 99mTc-MDP scan, and the 111In-labeled WBC scan is useful for detecting abscesses. CT aids in the detection of sequestra, and MR imaging is useful in defining the extent of the inflammatory process and in distinguishing osteomyelitis from cellulitis. In this article, we review and correlate the changes of bacterial osteomyelitis shown by these imaging methods.     

Iatrogenic Cushing's syndrome on 18F-FDG-PET/CT: A pitfall in metabolic assessment of oncologic response

Iatrogenic Cushing's syndrome has very well-known stigmata on physical examination but can pose a diagnostic challenge when it rarely presents radiologically. We present a classic albeit rarely encountered imaging appearance of Iatrogenic Cushing's on ¹⁸F-FDG-PET/CT, with diffuse subcutaneous white adipose proliferation and metabolic activation in a 7-year old patient one-month after starting a high dose steroid regimen for lymphoma. There was an extreme shift in the expected FDG biodistribution with dominant localization to the subcutaneous adipose tissue. This metabolic shift led to sub-threshold visceral biodistribution, rendering the scan non-diagnostic with regards to assessment of oncologic response. Aside from detailing the characteristic imaging findings of Iatrogenic Cushing's and its clinical importance, we discuss the physiologic basis of this imaging pattern and the rarer differential diagnosis to consider when this pattern of uptake is encountered on ¹⁸F-FDG-PET/CT.     

Imaging and treatment of scaphoid fractures and their complications

The scaphoid is the most commonly fractured carpal bone, with frequent complications that are predisposed by its anatomical location, anatomical configuration (shape and length), and vascular supply. The most common mechanism of injury is a fall onto an outstretched hand. Imaging plays a significant role in the initial evaluation and treatment of scaphoid fractures and their complications. Radiography should be the first imaging modality in the initial evaluation and follow-up of scaphoid fractures. Computed tomography with its superb spatial resolution enables better visualization and characterization of the fracture line, and the amount of displacement and angulation of the fracture fragments. Using the metal reduction artifact with computed tomography allows good follow-up of scaphoid fractures despite surgical hardware. Magnetic resonance imaging without contrast is the imaging modality of choice for depiction of radiographically occult scaphoid fracture, bone contusion, and associated soft tissue injury; contrast-enhanced imaging aids assessment of scaphoid fracture nonunion, osteonecrosis, fracture healing after bone grafting, and revitalization of the necrotic bone after bone grafting. Proper identification and classification of scaphoid fracture and its complications is necessary for appropriate treatment. This article describes the normal anatomy, mechanism of injury, and classification of stable and unstable fractures, together with the imaging and treatment algorithm of scaphoid fractures and their complications with an emphasis on magnetic resonance imaging.