New technologies in oral radiology as a diagnostic aid for monostotic fibrous dysplasia: a review

Monostotic fibrous dysplasia is a benign asymptomatic lesion that affects only one bone, which is replaced by amorphous connective tissue. Clinically there is an increase in the volume of the affected area, which is observed by imaging as a radiopaque area with diffuse non-corticalized limits capable of expanding to neighboring structures, and it is histologically evidenced as “resembling Chinese characters”. The lesion is seen as a radiopaque image with diffuse borders in conventional or digital radiography, while cone beam computed tomography identifies the exact location and extension of an isodense, mixed or hyperdense image of non-corticalized edges. Magnetic resonance imaging is also used when the lesion involves soft tissues or nerves, and bone scintigraphy is performed in order to systemically observe bone quality. The objective of this article was to describe the new technologies in oral radiology for the diagnosis of monostotic fibrous dysplasia and the importance of the current imaging methods in achieving an adequate diagnosis. These techniques range from conventional radiography to bone scans, which provide images of higher quality, clarity and better precision with less invasive techniques to the patient. This review of the literature helps to expand the knowledge of dental professionals in relation to the clinical and imaging characteristics of monostotic fibrous dysplasia.

Opportunistic diagnosis of osteoporotic vertebral fractures on standard imaging performed for alternative indications

Osteoporotic vertebral fractures (VF) are the most common type of osteoporotic fracture. Patients with VF are at increased risk of hip fractures or additional VFs, both of which contribute to patient morbidity and mortality. Early diagnosis of VFs is essential so patients can be prescribed appropriate medical therapy. Most patients with clinical suspicion for VF have an X-ray of the spine. Many VFs are invisible on X-ray and require further imaging. CT can provide excellent bony detail but uses high doses of ionising radiation. MRI provides excellent soft tissue detail and can distinguish old from new fractures in addition to differentiating osteoporotic VFs from other causes of back pain. Bone scans have a limited role due to poor specificity. The literature suggests that radiologists frequently miss or do not report VFs when imaging is requested for an alternative clinical indication and when there is no clinical suspicion of VF. Common examples include failure to identify VFs on lateral chest x-rays, sagittal reformats of CT thorax and abdomen, lateral localizers on MRI and scout views on CT. Failure to diagnose a VF is a missed opportunity to improve management of osteoporosis and reduce risk of further fractures. This article discusses the role of radiographs, CT, MRI and Bone Scintigraphy in the assessment and recognition of osteoporotic fractures. This article focuses on opportunistic diagnosis of vertebral fractures on imaging studies that are performed for other clinical indications. It does not discuss use of DXA which is a specific imaging modality for osteoporosis.

Brown Tumor of Lower Right Limb in Patients With Primary Hyperparathyroidism: A Case Report

Background.Brown tumor of Hyperparathyroidism is a metabolic disorder that can affect the entire skeleton and reactive process due to bone resorption caused by primary or secondary hyperparathyroidism (HPT). Brown tumors can occur as solitary or multiple lesions in any bone, most often in the pelvis, ribs, clavicle, mandibula, and extremities. Here, we report the Brown tumor in the lower right limb in patients with primary HPT, and the literature is reviewed. Case presentation. Patients was women 30 years old had married and come with main complains of difficulty walking. This condition has been experienced by patients since diagnosis with lunb of tibia last 8 months and caused pain from hip to lower leg. On laboratory results, it showed elevated PTH 1.249 (normal 15-65) pg/dL, elevated phosphatase alkali 1156 (normal 40-150) u/dL, elevated Ca 10,8 (n:8,6 -10,3) mg/dL, phosphor 2,1 (3–4,5) mg/dL. Histology examination of tibia lump was a benign lesion of bone (Brown Tumor). Ultrasonography transabdominal result revealed kidney stones with bilateral renal pelvis dilation, nephrolithiasis non-obstructive was found with size 1 cm & left kidney cyst with size 0.6 cm. On Neck USG showed giant cyst lesion on parathyroid glands. Radiologist pelvic examination results showed bone metastasis disease. Head CT Scan examination concluded as suspect metastatic bone. Body bone scans examination showed pathological bone metastatic process. Conclusion. Brown tumor in right lower limb caused by primary HPT

Detection of Bone Metastases on Bone Scans through Image Classification with Contrastive Learning

Patients with bone metastases have poor prognoses. A bone scan is a commonly applied diagnostic tool for this condition. However, its accuracy is limited by the nonspecific character of radiopharmaceutical accumulation, which indicates all-cause bone remodeling. The current study evaluated deep learning techniques to improve the efficacy of bone metastasis detection on bone scans, retrospectively examining 19,041 patients aged 22 to 92 years who underwent bone scans between May 2011 and December 2019. We developed several functional imaging binary classification deep learning algorithms suitable for bone scans. The presence or absence of bone metastases as a reference standard was determined through a review of image reports by nuclear medicine physicians. Classification was conducted with convolutional neural network-based (CNN-based), residual neural network (ResNet), and densely connected convolutional networks (DenseNet) models, with and without contrastive learning. Each set of bone scans contained anterior and posterior images with resolutions of 1024 × 256 pixels. A total of 37,427 image sets were analyzed. The overall performance of all models improved with contrastive learning. The accuracy, precision, recall, F1 score, area under the receiver operating characteristic curve, and negative predictive value (NPV) for the optimal model were 0.961, 0.878, 0.599, 0.712, 0.92 and 0.965, respectively. In particular, the high NPV may help physicians safely exclude bone metastases, decreasing physician workload, and improving patient care.

An Iterative Algorithm for Semisupervised Classification of Hotspots on Bone Scintigraphies of Patients with Prostate Cancer

Prostate cancer (PCa) is the second most diagnosed cancer in men. Patients with PCa often develop metastases, with more than 80% of this metastases occurring in bone. The most common imaging technique used for screening, diagnosis and follow-up of disease evolution is bone scintigraphy, due to its high sensitivity and widespread availability at nuclear medicine facilities. To date, the assessment of bone scans relies solely on the interpretation of an expert physician who visually assesses the scan. Besides this being a time consuming task, it is also subjective, as there is no absolute criteria neither to identify bone metastases neither to quantify them by a straightforward and universally accepted procedure. In this paper, a new algorithm for the false positives reduction of automatically detected hotspots in bone scintigraphy images is proposed. The motivation relies in the difficulty of building a fully annotated database. In this way, our algorithm is a semisupervised method that works in an iterative way. The ultimate goal is to provide the physician with a fast, precise and reliable tool to quantify bone scans and evaluate disease progression and response to treatment. The algorithm is tested in a set of bone scans manually labeled according to the patient’s medical record. The achieved classification sensitivity, specificity and false negative rate were 63%, 58% and 37%, respectively. Comparison with other state-of-the-art classification algorithms shows superiority of the proposed method.

Evaluation of the Level of Fit of Radial Fracture Fixation Plates Using Virtual and 3D-printed Models

Radial fractures often require surgical stabilization with fracture fixation plates. Incomplete morphological reconstruction was linked to poor outcome such as limited forearm rotation. Pre-contoured plates are often used, but large inter-subject morphological variations may result in poor fit. Therefore, the goal of this study was to develop a reliable virtual measure of plate-to-bone fit. In addition, the study evaluated the accuracy with which 3D printed bones reproduce the morphology of the physical radius. Virtual models and 3D-printed models of six cadaver radii were produced from bone scans. Level of fit of pre-contoured plates were measured in three ways: directly on pre-contoured physical plates fitted to cadaver bone; pre-contoured physical plates fitted to 3D printed bone; and virtual plate models fitted to virtual bone models. In addition, the study evaluated the accuracy with which 3D printed bone reproduces the physical bone morphology. The results indicate excellent agreement between the physical and virtual level of fit measures as well as excellent geometrical accuracy of the 3D-printed bones. These provide the necessary foundation for guiding the development of better fitted pre-contoured fracture fixation plates as well as for developing pre-surgically patient specific pre-contoured plates.

Q-Bot: automatic DICOM metadata monitoring for the next level of quality management in nuclear medicine

Background Regular and precise inspection of the realization of the local nuclear medicine standard operation procedures (SOPs) is very complex and time-consuming, especially when large amount of patient data is obtained from a wide scale of different scan procedures on a daily basis. DICOM metadata comprise a complete set of data related to the patient and the imaging procedure, and consequently all information necessary to evaluate the compliance with the actual SOP. Methods Q-Bot, an automatic DICOM metadata monitoring tool which is capable to verify SOP conformities, was tested for 11 months at two nuclear medicine departments. Relevant parameters, such as patient ID, patient mass and height, injected activity, and uptake time, were investigated in the case of adult 18F-FDG whole-body PET/CT and 99mTc-MDP gamma camera bone scans on a daily basis. Q-Bot automatically inspected the actual SOP compliance of these relevant DICOM parameters. Q-Bot graphical user interface (GUI) provided a summary of the outliers in a table format to be investigated by a dedicated technologist. In addition, information related to the error handling was also collected for retrospective analysis of long-term tendencies. Results In total, 6702 PET/CT and 2502 gamma camera scans were inspected, from which 8581 were confirmed as valid patient study without errors. Discrepancies related to the lack of a parameter, not appropriate format, or improper scan procedures were found in 623 cases, and 156 out of these were corrected before the medical reading and reporting. SOP non-conformities explored with Q-Bot were found to be non-correctable in 467 cases. Systematic errors to our practice turned out to be the manual radiopharmaceutical injection, the allowance to use both SI and non-SI units, and the clear definition of decimal point symbol to use. Conclusion The daily evaluation of Q-Bot results provided early detection of errors and consequently ensured the minimization of error propagation. Integration of a QM software that inspects protocol compliance at a nuclear medicine department provides significant support to detect non-conformities for technologists, and much higher confidence in image quality for physicians.

Deficiency of Interleukin-1 Receptor Antagonist: New Genetic Autoinflammatory Disease as a Diagnostic Challenge for Pediatricians

Deficiency of interleukin-1 receptor antagonist is a rare autoinflammatory disease that affects infants early in life. It often presents with systemic inflammation, skin and bone involvement. We present a 5-month-old boy who was hospitalized due to generalized erythematous pustular eruption with secondary impetigo, cellulitis, bronchiolitis, and elevated inflammatory markers. The patient was unresponsive to multiple courses of intravenous antibiotics, systemic, and topical steroid medications. The patient was evaluated by dermatology and rheumatology services among other subspecialities. Skin biopsy showed changes consistent with psoriasiform dermatitis, while bone scans showed multifocal osteomyelitis. The patient was started empirically on anakinra with improvement at 72 hours upon administration. This is one of the youngest reported case in the literature to be started on anakinra empirically prior to genetic confirmation of the mutation. A comprehensive literature review revealed that approximately 20 genetically confirmed patients, including our patient, have been reported with this genetic disease. It is imperative to recognize this disease early to achieve adequate response and remission. Therefore, clinical symptoms and the associated differential diagnosis for this disease should be constantly reassessed and reviewed by pediatricians and subspecialists to detect the disease as early as possible and reduce the high morbidity and mortality associated with delayed diagnosis and treatment.

18F-fluciclovine positron emission tomography (PET) in metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate.

TPS171 Background: Conventional imaging of prostate cancer has limitations in staging, restaging after biochemical relapse, and response assessment. Functional imaging with positron emission tomography (PET) can target various aspects of tumor biology and has shown to be superior in the detection of prostate cancer compared with conventional computed tomography (CT) and bone scans. 18F-Fluciclovine, a synthetic amino acid transported across mammalian cell membranes by amino acid transporters that is upregulated to a greater extent in prostate cancer cells than in surrounding tissue, is currently approved for PET imaging for patients with biochemical recurrence. The role of 18F-Fluciclovine PET scans in monitoring response to novel hormonal therapies such as abiraterone acetate is unclear. We hypothesize that 1) using 18F-Fluciclovine PET scanning will allow a more sensitive assessment of mCRPC patients at the initiation of systemic therapy with abiraterone acetate and 2) the changes observed in 18F-Fluciclovine PET will correlate better with the serologic changes in PSA, allowing superior disease monitoring, than conventional imaging modalities. Methods: This single-arm, pilot study (NCT04158245) will describe the changes in 18F-Fluciclovine PET scan and compare these results with PSA and conventional computerized tomography (CT) and bone scans, in mCRPC patients treated with abiraterone acetate plus prednisone. Patients must have a detectable baseline PSA of ≥ 2 ng/mL and metastatic disease detected on conventional CT and bone scans. The use of docetaxel in the hormone-sensitive setting is allowed. Twelve patients will be treated with abiraterone 1000 mg daily plus prednisone 5 mg (or dexamethasone 0.5 mg) daily for mCRPC and get 18F-Fluciclovine PET and conventional CT and bone scans at baseline and 12 weeks after starting abiraterone therapy or at disease progression. PSA progression will be defined as a repeated increase in PSA of at least 2 ng/dL and 25% from nadir values, at least 1 week apart, according to PCWG3 criteria and clinical or radiographic progression by RECIST version 1.1. The co-primary objectives of the study include the 18F-Fluciclovine PET changes at baseline and 12 weeks after abiraterone acetate for mCRPC and the comparison between 18F-Fluciclovine PET and conventional scans. Secondary and exploratory endpoints include PSA response, PSA progression and genomic alterations by next-generation sequencing. As of 12 September 2020, this trial is actively enrolling. Clinical trial information: NCT04158245.