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Objective To determine the diagnostic accuracy of Necrotizing Otitis Externa (NOE) based on radiologic studies. Methods The PubMed, Cochrane, Embase, Web of Science, SCOPUS, and Google Scholar databases were searched. True-positive and false-negative results were extracted for each study. Methodological quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Results The included studies contained data on 37 studies diagnosed with NOE. The sensitivity of gallium-67, technetium-99m, and Magnetic Resonance Imaging (MRI) was 0.9378 (0.7688–0.9856), 0.9699 (0.8839–0.9927), and 0.9417 (0.6968–0.9913), respectively. For Computed Tomography (CT), the positive criteria consisted of bony erosion alone and bony erosion plus any soft tissue abnormality. The sensitivity of CT based only on bony erosion was 0.7062 (0.5954–0.7971); it was higher 0.9572 (0.9000–0.9823) when based on bony erosion plus any soft tissue abnormality. Conclusion The diagnostic sensitivity of technetium-99m, gallium-67, and MRI was favorable. On CT, the presence of bony erosion may be a useful diagnostic marker of NOE, but the diagnostic sensitivity will be even higher if the criterion of any soft tissue abnormality is also included; however, care should be taken when interpreting the results. Our study demonstrates the potential utility of radiology studies for diagnosing NOE, but their lack of specificity must be considered, and standardized anatomic criteria are still needed. Level of evidence 2A.

A 69-year-old man with dementia presented to our hospital with fever and left back pain. He was diagnosed with acute pyelonephritis based on microscopy and CT findings indicating bacteriuria and elevated fat density around the right kidney, respectively. Three days post admission, the diagnosis of a urinary tract infection was queried and the patient was re-examined. Marked tenderness was observed in the left buttock; contrast CT scan was subsequently performed and a left piriformis abscess was diagnosed. This diagnostic delay occurred due to a communication error—the referral letter to the radiologist stated ‘fever and back pain’—and the physician’s hyposkillia; hence, differential diagnoses were not considered. Physicians can reduce the frequency of related errors by conducting proper physical examinations and not relying on imaging findings alone. Furthermore, to ensure accurate diagnoses, the comments to the radiologist should be clear and detailed when requesting diagnostic imaging.

BACKGROUND: Low frequency vibrations from motorized vehicles and heavy equipment have been associated with musculoskeletal disorders. Spine degeneration on diagnostic imaging provides direct and objective measures of the possible effects of such exposures on the spine. OBJECTIVE: The objective of this systematic review was to evaluate the association of exposure to whole-body vibration (WBV) with spine degeneration on imaging. METHODS: We conducted electronic searches in MEDLINE, CINAHL, EMBASE, and Web of Science to July 2021. Two reviewers independently screened search results, assessed quality, and extracted data. Studies evaluating the exposure to WBV and lumbar spine degeneration on imaging were included. RESULTS: Fifteen studies (16 manuscripts) were included. Seven studies including a meta-demonstrated moderate quality evidence of no association between WBV and disc degeneration. There was also moderate quality evidence of no association between WBV and disc height narrowing and osteophytes. Overall, there was low level evidence of no association between WBV and other degenerations findings. CONCLUSIONS: There was moderate to low quality evidence suggesting no association between WBV exposures with spine degeneration on imaging. The results of this study currently do not support assertion that motorized vehicle and WBV exposure accelerates degeneration and causes structural damage to the spine.

Hundreds of imaging-based artificial intelligence (AI) models have been developed in response to the COVID-19 pandemic. AI systems that incorporate imaging have shown promise in primary detection, severity grading, and prognostication of outcomes in COVID-19, and have enabled integration of imaging with a broad range of additional clinical and epidemiologic data. However, systematic reviews of AI models applied to COVID-19 medical imaging have highlighted problems in the field, including methodologic issues and problems in real-world deployment. Clinical use of such models should be informed by both the promise and potential pitfalls of implementation. How does a practicing radiologist make sense of this complex topic, and what factors should be considered in the implementation of AI tools for imaging of COVID-19? This critical review aims to help the radiologist understand the nuances that impact the clinical deployment of AI for imaging of COVID-19. We review imaging use cases for AI models in COVID-19 (e.g., diagnosis, severity assessment, and prognostication) and explore considerations for AI model development and testing, deployment infrastructure, clinical user interfaces, quality control, and institutional review board and regulatory approvals, with a practical focus on what a radiologist should consider when implementing an AI tool for COVID-19.

Background Evaluation of acute appendicitis (AA) in pregnancy is supported with diagnostic imaging. Typically, ultrasound (US) is performed first, and then often followed by magnetic resonance imaging (MRI) due to continued diagnostic uncertainty. The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of US as compared to MRI and to evaluate the inter-radiologist agreement amongst body Radiologists with varying levels of expertise. Methods We performed a retrospective study of 364 consecutive pregnant patients with clinical suspicion of AA at a single center over a 6-year period. Sensitivity, Specificity, accuracy, positive and negative predictive values were calculated for US and MRI. Inter Radiologist agreement was determined using Cohen's Kappa analysis between original interpreting Radiologist and retrospective review by expert Radiologist. Results 31 of 364 patients (8.5%) underwent appendectomy based on preoperative diagnosis, with confirmation of acute appendicitis (AA) by pathology in 19. US was able to visualize the appendix in only 6 (1.65%), 5 of whom had appendicitis. 141 patients underwent MRI, and correctly diagnosed appendicitis in 9. No patient with a negative MRI diagnosis had AA. The sensitivity, and negative predictive value for diagnosing AA with MRI was 100%. The MRI inter-reader agreement for appendix visualization and overall accuracy were 87.9 and 98% with Cohen Kappa of 0.7 and 0.56 respectively. Conclusion Our data suggests that MRI should be considered the first line imaging modality in pregnant patients suspected of having AA. Body Radiologists with varied levels of experience in MRI readouts had substantial agreement.

Background and Overview Trigeminal neuralgia due to a metastatic lesion is a relatively rare occurrence. These cases pose a diagnostic challenge for the clinician due to a complex clinical presentation. Case Description The authors describe the case of a 65-year-old woman with left-sided facial pain and occasional numbness. The patient also reported autonomic features associated with facial pain, facial muscular weakness, and hearing and visual impairment. The patient's history of breast cancer, for which she was receiving treatment for bone metastasis, warranted diagnostic imaging. Magnetic resonance imaging with and without contrast was performed and revealed a possible metastatic lesion. Conclusions and Practical Implications Unusual clinical features must be identified, and prompt appropriate imaging is instrumental in making at an accurate diagnosis and management plan.

The most common burn wound assessment continues to be the clinical inspection and the tactile examination, which are subjective and remain challenging even for experienced burn surgeons. Recently, hyperspectral imaging camera systems have been increasingly used to support the evaluation of burn wounds. The aim of our study was to determine if hyperspectral imaging analysis differentiates and objectifies the assessment of burn wounds in burns of the upper extremities. We included 97 superficial partial, deep partial dermal burns, and full thickness burns. Hyperspectral imaging analysis was performed for all burns using proprietary software. The software recorded parameters for tissue oxygenation (StO2), tissue hemoglobin index, and near-infrared perfusion. These values were compared with the recordings for healthy, non-burned skin. We found that hyperspectral imaging analysis effectively differentiates burn wounds and shows the ability to distinguish even superficial partial burns from deep partial burns in the near-infrared perfusion analysis feature. Although, it was not possible to differentiate burn wounds in all features. Currently, it is important to optimize the respective reference values of the individual burn degrees for an objectified assessment.

This study evaluated the accuracy of synthetic computed tomography (sCT), as compared to CT, for the 3D assessment of the hip morphology. Thirty male patients with asymptomatic hips, referred for magnetic resonance (MR) imaging and CT, were included in this retrospective study. sCT images were generated from three-dimensional radiofrequency-spoiled T1-weighted multi-echo gradient-echo MR images using a commercially available deep learning-enabled software and were compared with CT images through mean error and surface distance computation and by means of eight clinical morphometric parameters relevant for hip care. Parameters included center-edge angle (CEA), sharp angle, acetabular index, extrusion index, femoral head center-to-midline distance, acetabular version (AV), and anterior and posterior acetabular sector angles. They were measured by two senior orthopedic surgeons and a radiologist in-training on CT and sCT images. The reliability and agreement of CT- and sCT-based measurements were assessed using intraclass correlation coefficients (ICCs) for absolute agreement, Bland-Altman plots, and two one-sided tests for equivalence. The surface distance between CT- and sCT-based bone models were on average submillimeter. CT- and sCT-based measurements showed moderate to excellent interobserver and intraobserver correlation (0.56 0.75). For CEA, the intraobserver agreement was good (ICC > 0.75) and the interobserver agreement was moderate (ICC > 0.69). Limits of agreements were similar between intraobserver CT and intermodal measurements. All measurements were found statistically equivalent, with average intermodal differences within the intraobserver limits of agreement. In conclusion, sCT and CT were equivalent for the assessment of the hip joint bone morphology.

From the first report of the respiratory disease caused by SARS-Cov-2 towards the end of 2019, in Wuhan, China, to June 8, 2020, 6,931,000 people had been affected in the world, and 113,619 in Mexico, where there is a lack of literature describing the tomographic behavior of this disease throughout its evolution and its correlation with patient clinical data.To identify, describe and classify the manifestations detected on chest computed tomography images of patients with pneumonia caused by SARS-CoV-2.Hospitalized patients with RT-PCR-confirmed SARS-CoV-2 infection and who underwent a plain chest tomography were included.The most common tomographic patterns were ground glass opacity, consolidation, cobblestone pattern and mixed pattern, with peripheral and subpleural distribution and bilateral involvement in up to 95 %. Subpleural bands that distorted the architecture were identified in up to 62 % of patients, with an average of seven days of evolution. The most common extrapulmonary finding was an increase in pulmonary artery transverse axis.Knowing the behavior of this type of pneumonia allows becoming familiarized with the characteristic tomographic patterns, in order to aid timely detection and treatment.Desde el primer reporte de la enfermedad respiratoria causada por SARS-Cov-2 a finales de 2019, en Wuhan, China, hasta el 8 de junio de 2020, habían sido afectadas 6 931 000 personas en el mundo y 113 619 en México, donde se carece de informes que describan el comportamiento tomográfico de esta enfermedad a lo largo de su evolución y su correlación con los datos clínicos del paciente.Identificar, describir y clasificar las manifestaciones en las imágenes de tomografía de tórax de pacientes con neumonía causada por SARS-CoV-2.Se incluyeron pacientes hospitalizados con infección por SARS-CoV-2 confirmada mediante PCR-TR y en quienes se realizó tomografía simple de tórax.Los patrones tomográficos más comunes fueron opacidad de vidrio despulido, consolidación, empedrado y patrón mixto, con distribución periférica, subpleural y afectación bilateral hasta en 95 %. Se identificaron bandas subpleurales que distorsionaban la arquitectura hasta en 62 % de los pacientes, con un promedio de siete días de evolución. El aumento del eje transverso de la arteria pulmonar constituyó el hallazgo extrapulmonar más frecuente.Conocer el comportamiento de este tipo de neumonía permite la familiarización con los patrones tomográficos característicos, con el fin de coadyuvar a la detección y tratamiento oportunos.

Background Omission errors in medical imaging can lead to missed diagnosis and harm to patients. The subject has been studied in conventional imaging, but no data is available for functional imaging in general and for PET/CT in particular. In this work, we evaluated the frequency and characteristics of perceptual omission errors in the PET component of oncologic PET/CT imaging and we analyze the hazardous scenarios prone to such modality-specific errors. Materials and methods Perceptual omission errors were collected in one tertiary center PET/CT clinic during routine PET/CT reporting over a 26-month period. The omissions were detected either in reporting follow-up PET/CT studies of the same patient or during multidisciplinary meetings. Results Significant omission errors were found in 1.2 % of the 2100 reports included in the study. The most common omissions were bone metastases and focal colon uptake. We identified six PET-specific causative factors contributing to the occurrence of omissions, and we propose solutions to minimize their influence. Conclusions The data presented here can help to promote the awareness of interpreting physicians to body areas that require higher attention and to implement reading strategies for improving the accuracy of PET/CT interpretation.

By promising more accurate diagnostics and individual treatment recommendations, deep neural networks and in particular convolutional neural networks have advanced to a powerful tool in medical imaging. Here, we first give an introduction into methodological key concepts and resulting methodological promises including representation and transfer learning, as well as modelling domain-specific priors. After reviewing recent applications within neuroimaging-based psychiatric research, such as the diagnosis of psychiatric diseases, delineation of disease subtypes, normative modeling, and the development of neuroimaging biomarkers, we discuss current challenges. This includes for example the difficulty of training models on small, heterogeneous and biased data sets, the lack of validity of clinical labels, algorithmic bias, and the influence of confounding variables.

Synovitis, inflammation of the synovial membrane, is a common manifestation in osteoarthritis (OA) and is recognized to play a role in the complex pathophysiology of OA. Increased recognition of the importance of synovitis in the OA disease process and potential as a target for treatment has increased the need for non-invasive detection and characterization of synovitis using medical imaging. Numerous imaging methods can assess synovitis involvement in OA with varying sensitivity and specificity as well as complexity. This article reviews the role of contrast-enhanced MRI, conventional MRI, novel unenhanced MRI, gray-scale ultrasound (US), and power Doppler US in the assessment of synovitis in patients with OA. The role of imaging in disease evaluation as well as challenges in conventional imaging methods are discussed. We also provide an overview into the potential utility of emerging techniques for imaging of early inflammation and molecular inflammatory markers of synovitis, including quantitative MRI, superb microvascular imaging, and PET. The potential development of therapeutic treatments targeting inflammatory features, particularly in early OA, would greatly increase the importance of these imaging methods for clinical decision making and evaluation of therapeutic efficacy.

Interstitial fibrosis, common to most chronic kidney diseases, can potentially affect the speckle patterns of kidney ultrasound (US). Here we use Radiomics features derived from US images to identify kidneys with chronic kidney disease.B-mode US without speckle reduction was performed on a cohort of CKD patients (n = 75) and healthy subjects (n = 27). Images of the patients with renal cysts, agenesis and calculi were excluded. After background subtraction, regions of interest were selected from each kidney. Four hundred and sixty-five Radiomics features including first and second-order gray level statistics were calculated on the selected regions. Second-order features were also calculated on wavelet transformed images. A random forest model was used to identify the most important features that can differentiate healthy and diseased kidneys. The ten most important features, based on the Gini index, were used to train a support vector machine. Synthetic minority oversampling technique was used to remove over fitting.Wavelet transformed, Gray Level Run Length Matrix based Normalized Run Length Non-uniformity, WT (LH) (GRLN) was identified as the most significant feature in differentiating CKD and healthy kidneys (accuracy - 0.85, sensitivity - 1.0). The mean WT (LH) GRLN of healthy kidneys (0.40 ± 0.01) was significantly higher (p0.01) than that of the CKD kidneys (0.24 ± 0.01). According to the Gini Index, the differentiability of WT (LH) GRLN was highest when the long axis of the kidney was oriented perpendicular to the columns of the image matrix.Radiomics features based on wavelet transformation are sensitive to directionality of US speckle patters and can be successfully used to differentiate CKD and healthy US kidney images.

Purpose Most patients with ankle arthrosis have a history of ankle fracture. Evaluation of malleolar fractures solely on X-ray may be insufficient to identify many pathologies that potentially contribute to ankle arthrosis, with a consequent poor prognosis. We investigated the pathologies that may be overlooked in malleolar fractures evaluated solely on plain X-ray. Methods During 2012–2019, 65,479 patients attended our Emergency Department, of which 6508 complained of an ankle joint problem. X-rays indicated a fracture in 454 of these patients. Patients with isolated, simple fracture of the lateral or medial malleolus, or talus, or a history of surgery to this area were excluded; finally, 67 patients were enrolled (31 males, 36 females; mean age: 51,2 years (range: 9–83 years). Patients underwent X-ray imaging of both ankles in anterio-posterior, lateral, and Mortise views, as well as CT scans. Three independent observers with varied experience in diagnostic imaging (orthopaedic resident, experienced orthopaedic surgeon, and musculoskeletal radiologist) evaluated X-ray images blinded to CT scans. Their diagnoses were subsequently compared with CT findings. Results Modeling results indicated that about 40% [95% CI: 32%, 50%] of pathologies may be overlooked based on X-ray evaluation, regardless of evaluator experience. The most frequently overlooked injuries were: Tillaux fracture, Pillon fracture, loose bodies and syndesmosis injury. All of that missed pathologies required dedicated treatment and could be easily missed with standard surgical approach. Conclusion Evaluation of malleolar fractures by X-ray only inevitably results in overlooking of many pathologies, despite the clinician’s experience. Routine CT scan can help to improve the accuracy of diagnosis, and thereby reduce the risk of ankle osteoarthrosis.

Hearing loss is one of the most common indications for temporal bone imaging in children. Hearing loss may be congenital or acquired, and it may be conductive, sensorineural, or mixed audiologically. Temporal bone imaging plays an important role in the assessment and management of this condition. An understanding of the embryology of ear structures better enables the radiologist to interpret abnormalities on imaging of the temporal bone. Here, we provide a general review of ear development and a description of known genetic defects that contribute to congenital ear anomalies associated with hearing loss. We provide appropriate imaging techniques for the temporal bone depending on the clinical presentation and a systematic approach to imaging for children with hearing loss. Diagnostic imaging for developmental anomalies of the ear and cholesteatoma will be discussed.

Background Adenomyosis is a common gynecologic pathology that relies on diagnostic imaging to guide treatment. Accuracy of both pelvic ultrasound and magnetic resonance imaging (MRI) when specifically evaluating for the presence of adenomyosis is high. However, the accuracy of reported rates in clinical practice is less well understood. Purpose To demonstrate the accuracy in reporting of adenomyosis on pelvic ultrasound and MRI compared to histopathology in common clinical practice. Basic procedures An institutional database was searched for women with a pelvic ultrasound and a pelvic MRI with a subsequent hysterectomy. Findings were extracted from radiology and pathology reports, and the documented presence or absence of adenomyosis was recorded for each modality. Blinded radiologists viewed each imaging pair to directly evaluate for adenomyosis. Main findings Compared to prior published data, imaging had lower accuracy in clinical practice when adenomyosis was not specifically evaluated for. For the finding of adenomyosis, pelvic ultrasound had a sensitivity of 10.9%, a specificity of 98.3%, positive predictive value (PPV) of 77.8%, negative predictive value (NPV) of 66.7%, an accuracy of 67.2%, and a diagnostic odds ratio (DOR) of 7. Pelvic MRI had a sensitivity of 29.7%, specificity of 85.3%, PPV of 52.8%, NPV of 68.8%, an accuracy of 65.6%, and DOR of 2.5. Overall accuracy of MRI improved when adenomyosis was directly evaluated for (82.4% vs 65.6%). Principle conclusions Without direct communication to evaluate for adenomyosis, pelvic ultrasound and MRI may underestimate or misreport adenomyosis. Providers should be aware of these discrepancies when relying on radiology reports to guide treatment and potential interventions when diagnosing and managing adenomyosis.

There is a plethora of surgical procedures that are performed in the eye and orbit. The consequences of these procedures can often be observed on diagnostic imaging through the presence of various implants and altered anatomy. The expected postoperative changes in the eye and orbit, the impact of implants on image quality and safety, and potential associated complications are reviewed in this article. Conventional computed tomography and MR imaging scans are useful for the postoperative assessment of the eye and orbit. The computed tomography and MR imaging findings related to the postoperative eye and orbit are reviewed in this article.

Congenital lung malformations are a spectrum of developmental anomalies comprised of malformations of the lung parenchyma, airways, and vasculature. Imaging assessment plays a pivotal role in the initial diagnosis, management, and follow-up evaluation of congenital lung malformations in the pediatric population. However, there is currently a lack of practical imaging guidelines and recommendations for the diagnostic imaging assessment of congenital lung malformations in infants and children. This article reviews the current evidence regarding the imaging evaluation of congenital lung malformations and provides up-to-date imaging recommendations for pediatric congenital lung malformations.

Pediatric bowel obstructions are one of the most common surgical emergencies in children, and imaging plays a vital role in the evaluation and diagnosis. An evidence-based and practical imaging approach to diagnosing and localizing pediatric bowel obstructions is essential for optimal pediatric patient care. This article discusses an up-to-date practical diagnostic imaging algorithm for pediatric bowel obstructions and presents the imaging spectrum of pediatric bowel obstructions and their underlying causes.

This article describes the technical principles and indications for the most often encountered diagnostic imaging modalities in veterinary dentistry and oral surgery; with extensive coverage of intraoral (and extraoral) dental radiographic imaging and interpretation through detailed example figures of common dental and maxillofacial diseases in the dog and cat. Multidetector/multislice computed tomography (MDCT/MSCT) and emergent technologies such as cone-beam computed tomography (CBCT) are presented here in detail. Magnetic resonance imaging (MRI) and diagnostic ultrasound, which are used less frequently, are briefly discussed.

Lower respiratory tract infection (LRTI) remains a major cause of morbidity and mortality in children. Various organisms cause LRTI, including viruses, bacteria, fungi, and parasites, among others. Infections caused by 2 or more organisms also occur, sometimes enhancing the severity of the infection. Medical imaging helps confirm a diagnosis but also plays a role in the evaluation of acute and chronic sequelae. Medical imaging tests help evaluate underlying pathology in pediatric patients with recurrent or long-standing symptoms as well as the immunocompromised.

Neck masses commonly present in children and several potential diagnostic and management pathways exist, though with a paucity of evidence-based recommendations. The purpose of this article is to evaluate the current literature and utilization of various diagnostic imaging modalities , with a review of imaging features and management pearls for pediatric neck masses. A comprehensive understanding and practical imaging workflow will guide optimal patient workup and management.

Computed tomography (CT) is a main contributor to artificial low-dose exposure. Understanding the biological effects induced by CT exposure and their dependency on the characteristics of photon spectra is essential for knowledge-driven risk assessment. In a previous gene expression study, we have identified upregulation of AEN, BAX, DDB2, EDA2R and FDXR after ex vivo exposure with single-energy CT and dual-energy CT (DECT). In this study, we focused on CT-induced changes of DNA methylation. This epigenetic modification of DNA is a central regulator of gene expression and instrumental in preserving genome integrity. Previous studies reported focal hypermethylation and global hypomethylation after exposure with doses above 100 mSv, however, the effect of low dose exposure on DNA methylation is hardly explored. DNA was isolated from peripheral blood of three healthy individuals 6 h after ex vivo exposition to single-energy (80 kV and 150 kV) and DECT (80 kV/Sn150 kV) with a calculated effective dose of 7.0 ± 0.08 mSv. The experimental setting was identical to the one used in our previous gene expression study enabling a direct comparison of gene expression results with changes of DNA methylation identified in this study. DNA methylation was analyzed by high-throughput sequencing of bisulfite-treated DNA targeted methylation sequencing. Unsupervised hierarchical clustering based on DNA methylation profiles of all samples created three distinct clusters. Formation of these three clusters was solely determined by the origin of samples, indicating the absence of prominent irradiation-associated changes of DNA methylation. In line with this observation, inter-individual comparison of non-irradiated samples revealed 1163, 1224 and 4550 significant differentially methylated regions (DMRs), respectively, whereas the pairwise comparison of irradiated and non-irradiated samples failed to identify irradiation-induced DMRs in any of the three probands. This even applied to the genomic regions harboring AEN, BAX, DDB2, EDA2R and FDXR, the five genes known to be upregulated by CT exposure. CT exposure with various photon spectra did not result in detectable changes of DNA methylation. However, minor effects in a subpopulation of irradiated cells cannot be ruled out. Thus, future studies with extended observation intervals are needed to investigate DNA methylation changes that are induced by indirect effects at later points of time or become detectable by clonal expansion of affected cells. Moreover, our data suggest that DNA methylation analysis is less sensitive in detecting immediate effects of low-dose irradiation when compared to gene expression analysis.

The field of nuclear medicine and molecular imaging has grown tremendously over the past several years with the approval of new imaging agents, diagnostic radiopharmaceuticals, and radiopharmaceutical therapies. Clinical research continues to expand within nuclear medicine and molecular imaging departments. Working as a nuclear medicine technologist on a clinical trial or with investigational radiopharmaceuticals can be quite different from working in an approved-drug setting in the clinic. Nuclear medicine technologists involved in clinical trials can be at the front line of following rigorous trial requirements and ensuring good-quality data. The details of working in clinical research are often not taught in nuclear medicine technologist programs. As such, there is an emerging need for education about clinical research for both experienced and new nuclear medicine technologists, particularly for those working with investigational radiopharmaceuticals. This article is an introduction to the SNMMI Clinical Trials Network Research Series for Technologists. This series of articles aims to provide education on working in the context of a clinical trial within the nuclear medicine department. The following 7 topics will be addressed in the series: ethical issues in clinical research, application of good clinical practice to clinical research in medical imaging, contract research organizations with application in clinical imaging, a clinical research primer on the regulatory process for how and when radiopharmaceuticals can be used and the role of the institutional review board, use of imaging agents in therapeutic drug development and approval, imaging agent trials, and imaging agents with radiopharmaceutical therapies in clinical trials. Other topics may be added over the course of the development of the series.

The American Association of Physicists in Medicine (AAPM) published a position statement regarding the limitation of fetal and gonadal shielding in radiographic imaging procedures. For the imaging community, this statement was alarming, as shielding patients was one of the longest-held principles of imaging technologists. In an effort to alleviate the concerns of technologists and other professionals working in medical imaging, the AAPM created a committee of professionals in the field to disseminate education about the change called the Communicating Advances in Radiation Education Committee. This committee published a frequently asked questions document addressing the concerns of technologists and educators in the field of medical imaging and providing guidance on educating patients and other health professionals. This article seeks to provide an overview of the change in shielding practice, the science that fueled the change, and the implications for healthcare professionals and patients in the medical imaging department. Although technologists, nurses, and any other participating personnel proximal to radiation production must protect themselves, in most instances, patients do not need to be shielded and in fact, may be harmed by the use of shields. Future research should focus on the attitudes of technologists and patients toward shielding and whether or not all medical professionals and the public are informed about shielding recommendations.

With this summarized document we share the standard for positron emission tomography (PET)/(diagnostic)computed tomography (CT) imaging procedures in cardiovascular diseases that are inflammatory, infective, infiltrative, or associated with dysfunctional innervation (4Is) as recently published in the European Journal of Nuclear Medicine and Molecular Imaging. This standard should be applied in clinical practice and integrated in clinical (multicentre) trials for optimal standardization of the procedurals and interpretations. A major focus is put on procedures using [18F]-2-fluoro-2-deoxyglucose ([18F]FDG), but 4Is PET radiopharmaceuticals beyond [18F]FDG are also described in this summarized document. Whilst these novel tracers are currently mainly applied in early clinical trials, some multicentre trials are underway and we foresee in the near future their use in clinical care and inclusion in the clinical guidelines. Diagnosis and management of 4Is related cardiovascular diseases are generally complex and often require a multidisciplinary approach by a team of experts. The new standards described herein should be applied when using PET/CT and PET/magnetic resonance, within a multimodality imaging framework both in clinical practice and in clinical trials for 4Is cardiovascular indications.

As the global population ages, the issue of abdominal aortic aneurysm continues to grow. With the evolution of new devices and refined operative technique, aneurysm treatment via endovascular aortic repair is becoming increasingly favourable. This, however, is not without drawbacks, where regular surveillance is paramount to long‐term success and detection of post‐procedure complications. Of these complications, endoleak is the most notable and poses the greatest risk of potential future aortic rupture. The purpose of this review paper is to discuss the armada of imaging modalities used in the detection and evaluation of endoleak and their varying usefulness. Plain abdominal X‐ray is a cost‐effective tool in detecting gross graft abnormalities such as stent migration or deformity (kinking or fracture). Though it may raise suspicion for endoleak, X‐ray does not allow accurate classification of endoleak type when used alone. Duplex ultrasonography quantifies both aortic anatomy and real time flow dynamics. Most screening programmes are conducted using two‐dimensional ultrasound. Unfortunately, observer and equipment variability may lead to surveillance discrepancies—but reduced when utilising a dedicated vascular sonography laboratory. Contrast enhanced ultrasonography is a promising alternative to computed tomography, though still is emerging. Computed tomography angiography certainly has disadvantages (ionising radiation, contrast‐nephropathy, limited differentiation of endoleak type)—however, it provides near‐real surgical dimensions and highlights graft complications and concomitant disease (such as neighbouring infection). With widespread availability and short scan time, it certainly remains valuable in surveillance. Magnetic resonance angiography has a similar sensitivity to computed tomography (minus the radiation), however is plagued by movement and metal artefact. Other novel modalities in endoleak surveillance include four‐dimensional ultrasound, multiplanar intra‐operative probes, nuclear medicine and wall stress analysis., As the global population ages, the issue of abdominal aortic aneurysm continues to grow. Endovascular aortic repair has helped stem this issue, but from it arises the challenge of managing endoleak. We review the armada of imaging modalities available for the detection and evaluation of endoleak.

CSF-venous fistulas (CVFs), first described in 2014, are an important cause of spontaneous intracranial hypotension. CVFs can be challenging to detect on conventional anatomic imaging because, unlike other types of spinal CSF leak, they do not typically result in pooling of fluid in the epidural space, and imaging signs of CVF may be subtle. Specialized myelographic techniques have been developed to help with CVF identification, but these techniques are not yet widely disseminated. This article reviews the current understanding of CVFs, emphasizing correlations between venous anatomy and imaging findings as well as potential mechanisms for pathogenesis, and describes current imaging techniques used for CVF diagnosis and localization. These techniques are broadly classified into fluoroscopy-based methods, including digital subtraction myelography and dynamic myelography, and cross-sectional methods, including decubitus CT myelography and MR myelography with intrathecal injection of gadolinium. Knowledge of these various options, including their relative advantages and disadvantages, is critical in the care of patients with spontaneous intracranial hypotension. Investigation is ongoing, and continued advances in knowledge about CVFs as well as in optimal imaging detection are anticipated.

Background Cerebrospinal fluid (CSF) rhinorrhea results from abnormal communications between the subarachnoid and sinonasal spaces. Accurate preoperative diagnosis and localization are vital for positive clinical outcomes. However, the diagnosis and localization of CSF rhinorrhea remain suboptimal due to a lack of accurate understanding of test characteristics. Objective This systematic review aims to assess the diagnostic accuracy of various tests and imaging modalities for diagnosing and localizing CSF rhinorrhea. Methods A systematic review of the MEDLINE and EMBASE databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results Our search identified 4039 articles—53 cohort studies and 24 case series describing 1622 patients were included. The studies were heterogeneous and had a wide range of sensitivities and specificities. Many specificities were incalculable due to a lack of true negative and false positive results, thus precluding a meta-analysis. Median sensitivities and specificities were calculated for cohort studies of the following investigations: high-resolution computed tomography (HRCT) 0.93/0.50 (sensitivity/specificity), magnetic resonance cisternography (MRC) 0.94/0.77, computed tomography cisternography (CTC) 0.95/1.00, radionuclide cisternography (RNC) 0.90/0.50, and contrast-enhanced magnetic resonance cisternography (CEMRC) 0.99/1.00, endoscopy 0.58/1.00, topical intranasal fluorescein (TIF) 1.00/incalculable, intrathecal fluorescein (ITF) 0.96/1.00. Case series were reviewed separately. Etiology and site-specific data were also analyzed. Conclusion MR cisternography is more accurate than high-resolution CT at diagnosing and localizing CSF rhinorrhea. CT cisternography, contrast-enhanced MR cisternography, and radionuclide cisternography have good diagnostic characteristics but are invasive. Intrathecal fluorescein shows promising data but has not been widely adopted for purely diagnostic use. Office endoscopy has limited data but does not sufficiently diagnose CSF rhinorrhea independently. These findings confirm with current guidelines and evidence.

INTRODUCTION This study aimed to assess understanding of the potential risks associated with medical imaging among caregivers and adolescent patients in a paediatric emergency department (PED) in Singapore. METHODS A prospective convenience sample survey was performed involving adolescents and caregivers presenting to our PED from December 2015 to May 2016. The questionnaire examined demographic data, knowledge of imaging procedures and radiation risks, and expectations regarding information provided about medical radiation. RESULTS A total of 349 questionnaires were returned (caregivers 82.5%, adolescents 17.5%). A mean of 6.2 ± 2.4 (out of 11) questions were correctly answered. Those who had tertiary education fared better than those who did not (36.4% vs. 17.2% scoring above the mean, p = 0.001). Age, gender, history of previous imaging and imaging performed during the visit did not affect the score. Two-thirds of the participants did not associate medical radiation with any negative lifetime risk of cancers or know that different scans entailed differing amounts of radiation. Most were unaware that the radiation dose in medical imaging is adjusted to a child’s size. Among patients who underwent imaging, 90.1% received explanations on the need for scans, and 26.5% were informed of the risks involved. Almost all participants wished to be informed of imaging indications and risks. More preferred to learn this from physicians (75.6%) or technicians (51.6%) rather than through educational pamphlets (34.4%) or Internet resources (22.9%). CONCLUSION Awareness regarding medical radiation needs to be improved in our patient population. A mismatch exists between caregiver expectations and the actual procedure of disclosure of the risk associated with radiation.

BACKGROUND Local treatment of the primary or metastatic sites in urologic malignancies is promising when compared to systemic therapy alone, leading to the definition of a potentially curative oligometastatic state. OBJECTIVES Comparison of imaging modalities regarding local and metastatic tumor sites in urologic cancers. METHODS Review of comparative trials addressing quality criteria of imaging modalities. RESULTS Depending on primary tumor and metastatic site, conventional imaging modalities such as computer tomography (CT) and bone scintigraphy still represent the standard of care in Germany. Due to superior quality criteria, hybrid-imaging techniques were widely adopted for oncological staging and particular due to the new PSMA-ligand (PSMA-PET/CT) in prostate cancer imaging. The development of new radioisotopes as well as their clinical application remains a focus of current research. CONCLUSIONS High-quality diagnostic imaging modalities lay the groundwork for a precise definition of an oligometastatic state. By enabling treatment of the entire tumor burden, a delay of systemic therapy, longer progression-free survival, or even curative treatment may become achievable.

Backed by more powerful computational resources and optimized training routines, deep learning models have proven unprecedented performance and several benefits to extract information from chest X-ray data. This is one of the most common imaging exams, whose increasing demand is reflected in the aggravated radiologists’ workload. Consequently, healthcare would benefit from computer-aided diagnosis systems to prioritize certain exams and further identify possible pathologies. Pioneering work in chest X-ray analysis has focused on the identification of specific diseases, but to the best of the authors' knowledge no paper has specifically reviewed relevant work on abnormality detection and multi-label thoracic pathology classification. This paper focuses on those issues, selecting the leading chest X-ray based deep learning strategies for comparison. In addition, the paper discloses the current annotated public chest X-ray databases, covering the common thorax diseases.

Radiomics, a method used to extract large amount of data, may be useful for discriminating malignant characteristics for lung cancer staging. We aimed to critically appraise the current use of radiomics in medical imaging for determining nodal involvement in lung cancer. The literature was searched using Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and Web of Science for observational studies between the databases’ inception and January 2020. All observational studies compared diagnostic tests for lung cancer in comparison to diagnostic tests with a radiomic adjunct. For each study, data were extracted for study characteristics, methodological quality, and accuracy. Discrepancies in screening and extraction were resolved by a third reviewer. Data were synthesized narratively. 15 studies were included, 13 of which were full reports, while two were conference abstracts. Overall, 3164 patients were enrolled with a total of 3379 LNs recorded (69% malignancy). Point estimate sensitivities for algorithms ranged from 52 to 99%, while specificity for the algorithms ranged from 60 to 92%. Area under the curve c-statistics were only reported for algorithms and not the clinician. Point estimate c-statistics ranged from 0.64 to 0.94, suggesting that the algorithms possessed good discrimination potentials. The current level of evidence of radiomic analysis methods for staging lung cancer is inconclusive and possesses heterogeneity in study design. Prospective external validation of these algorithms and direct comparisons using cut-off thresholds is required to determine their true predictive capability prior to implementation in clinical practice. PROSPERO ID: CRD42020162952.

Single ventricle patients typically undergo some form of advanced diagnostic imaging prior to superior cavopulmonary connection (SCPC). We sought to evaluate variability of diagnostic practice and associated comprehensive risk. A retrospective evaluation across 4 institutions was performed (1/1/2010–9/30/2016) comparing the primary modalities of cardiac catheterization (CC), cardiac magnetic resonance (CMR), and cardiac computed tomography (CT). Associated risks included anesthesia/sedation, vascular access, total room time, contrast agent usage, radiation exposure, and adverse events (AEs). Of 617 patients undergoing SCPC, 409 (66%) underwent at least one advanced diagnostic imaging study in the 60 days prior to surgery. Seventy-eight of these patients (13%) were analyzed separately because of a concomitant cardiac intervention during CC. Of 331 (54%) with advanced imaging and without catheterization intervention, diagnostic CC was most common (59%), followed by CT (27%) and CMR (14%). Primary modality varied significantly by institution (p

Objectives Canine insulinomas are uncommon malignant functional pancreatic neuroendocrine tumours with a high metastatic rate. Diagnostic imaging aids with staging and surgical planning of these tumours; however, identification is unpredictable across modalities. High-grade human pancreatic neuroendocrine tumours display increased avidity on 18 F-fluorodeoxyglucose positron emission tomography-CT. Materials and methods Dogs with clinicopathologic findings consistent with pancreatic insulinoma were prospectively enrolled. Patients underwent 18 F-fluorodeoxyglucose positron emission tomography-CT and CT angiography, followed by exploratory laparotomy. Results Three patients met the inclusion criteria and had histologically confirmed insulinomas. Both metastatic lesions in patient 1 were mildly avid (SUVmax 2.79 and 3.01). In patient 2, the primary pancreatic insulinoma was minimally avid (SUVmax 2.16). The primary pancreatic lesion in patient 3 had similar avidity to normal pancreatic parenchyma (SUVmax 1.54) and was undetected on 18 F-fluorodeoxyglucose positron emission tomography-CT. Insulinomas demonstrated variable attenuation and contrast enhancement patterns on CT angiography and certain lesions were more conspicuous than on 18 F-fluorodeoxyglucose positron emission tomography-CT. Two metastatic lesions not visible on either imaging modality were discovered in patient 2 at surgery. Clinical significance Canine insulinomas were inconsistently avid on 18 F-fluorodeoxyglucose positron emission tomography-CT. This finding is likely attributable to the confounding clinicopathological features and multifaceted transformation of these tumours, in addition to the influence of variable tumour size, composition and vascularity. Unpredictable tumoural avidity limits the value of 18 F-fluorodeoxyglucose positron emission tomography-CT for staging canine insulinomas.

Stroke is among the first pathologies that kill the most in the world, ranking second in deaths from illness. Each year, around 16 million people worldwide are victims of this disease, with approximately 38 % of cases brought to death. Computed Tomography (CT) is a super effective method to aid the medical diagnosis of stroke. But the analysis is subject to variations in the perception of specialists about its characteristics. Faced with the challenge of diagnosing stroke on CT images, this study proposes a fully automatic system based on Health of Things capable of classifying CT images of the skull through deep learning networks, classifying them into (Uninjured or Hemorrhagic stroke). After the image classification, Mask R-CNN segments the stroke through a learning transfer process, combined with machine learning methods. Our innovative method selected excellent results, both for classification with 100 % accuracy, and for segmentation in our best model (Mask + kNN) that reached 99.93% specificity and 99.73 accuracy, with segmentation time of 4.00 seconds, surpassing literature methods based on automatic models.

Previous studies explored the feasibility of using gamma-ray as an alternative to X-ray in medical imaging. The feasibility studies reported that gamma radiography could be an effective alternative to X-ray radiography. Exposure is the factor that decides noise level and contrast quality in the produced image; the two crucial factors for the diagnosis and patient safety. This research aims to foster the feasibility of gamma-ray mammography by proposing a method for exposure determination. Geant4 Application for Tomographic Emission toolkit was used to simulate the required exposure on the American College of Radiology Mammography phantom using photon energies of 17.5, 19, 20, 22, 23.5, 25, 26, 27.5, and 30 keV. The quality of the produced image was evaluated against a reference experimental X-ray mammographic image. A visual assessment procedure was adopted to determine the minimum contrast-to-noise ratio required to detect the various sets of phantom features. Based on the visual assessment, a method for exposure determination was established and verified. The results will support the application of radioisotopes for mammography.

Background Contrast-enhanced CT is the reference standard used in diagnostic imaging for acute appendicitis in adults. The radiation dose has been of concern. This study aimed to assess whether a lower radiation dose would affect the diagnostic accuracy of CT. Methods This was a prospective single-centre cohort study of patients (aged over 16 years) with suspected appendicitis evaluated for enrolment in concurrent APPAC II–III trials. The diagnostic accuracy of contrast-enhanced low- and standard-dose CT was compared with study protocols guiding imaging based on BMI; this enabled direct CT imaging comparison only in patients with a BMI below 30 kg/m2. The on-call CT diagnosis was compared with the final clinical diagnosis. Results Among all 856 patients investigated, the accuracy of low-dose (454 patients) and standard-dose (402 patients) CT in identifying patients with and without appendicitis was 98·0 and 98·5 per cent respectively. In patients with a BMI under 30 kg/m2, respective values were 98·2 per cent (434 patients) and 98·6 per cent (210 patients) (P = 1·000). The corresponding accuracy for differentiating between uncomplicated and complicated acute appendicitis was 90·3 and 87·6 per cent in all patients, and 89·8 and 88·4 per cent respectively among those with a BMI below 30 kg/m2 (P = 0·663). The median radiation dose in the whole low- and standard-dose CT groups was 3 and 7 mSv respectively. In the group with BMI below 30 kg/m2, corresponding median doses were 3 and 5 mSv (P Conclusion Low- and standard-dose CT were accurate both in identifying appendicitis and in differentiating between uncomplicated and complicated acute appendicitis. Low-dose CT was associated with a significant radiation dose reduction, suggesting that it should be standard clinical practice at least in patients with a BMI below 30 kg/m2.

The present paper aims at reviewing different shielding methods used for patients in medical imaging and investigating their merits and demerits. These techniques are generally classified into two groups including in-plane and out-of-plane shielding. Bismuth (Bi) shielding is a conventional in-plane shielding method used during CT examinations to protect radiosensitive organs. This method has reduced radiosensitive organs dose by about 34–68% during different CT examinations. However, it causes considerable degrading effects on image quality and for this reason AAPM recommended against its application in 2017. Recently, another in-plane shielding, named Saba shielding, introduced wherein all the shortcomings and deficits of Bi shielding have been resolved or fixed. Saba shielding reduces radiosensitive organs dose by about 50% without degrading image quality. Out-of-plane shields can decrease the patient dose by more than 55%. However, due to the low dose of the scattered radiation received by out-of-plane organs, in the case of applying out-of-plane shields such as gonad or thyroid shields, the risk and benefit of their usage should be evaluated.

To compare detection rates of NET liver metastases of MRI and Ga-68-DOTATATE PET/CT to provide more clarity when selecting diagnostic imaging tests for NET staging. In this IRB-approved single-institution retrospective study, all patients with pathology-proven NET who underwent Ga-68-DOTATATE and MRI scans within 8 weeks of each other (3/2017–2/2020) were reviewed. Number of metastases for each patient on diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) MRI, and Ga-68 DOTATATE were recorded by two blinded radiologists, followed by consensus review with two separate blinded readers for MRI and nuclear medicine. Per-lesion and -modality scoring at each lesion location were then performed in consensus. Per-patient linear regression was performed comparing MRI and Ga-68 DOTATATE detection rates for each reader and in consensus, and per-lesion-matched pair difference means were used to compare detection frequency between modalities. 32 patients (mean age 59 years, 59.4% male) and 90 liver metastases were analyzed. Intraclass coefficients (ICC) [95% CI] between the two readers were 0.97 [0.95, 0.99], 0.89 [0.82, 0.94], and 0.98 [0.97, 0.99] for Ga-68 DOTATATE, DWI, and DCE, respectively. Matched per-lesion mean differences were + 0.17 ± 0.07 (p = 0.01) and + 0.22 ± 0.06 (p =

Background Evidence suggests severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may be associated with appendicitis or clinical symptoms that mimic appendicitis, but it is not clear if the findings or utility of imaging in pediatric patients with suspected appendicitis have changed since the onset of the coronavirus disease 2019 (COVID-19) pandemic. Objective To evaluate for potential differences in SARS-CoV-2 positive and SARS-CoV-2 negative pediatric patients imaged for suspected appendicitis to determine the reliability of the existing medical imaging approach for appendicitis in a population that contains both SARS-CoV-2 positive and SARS-CoV-2 negative pediatric patients. Materials and methods Patients imaged for suspected appendicitis Apr. 1, 2020, to Dec. 31, 2020, were identified via an electronic medical records search. Differences in ultrasound (US) diagnostic performance, use of computed tomography (CT) following US, rates of appendicitis, imaging findings of appendicitis and perforation were compared between SARS-CoV-2 positive and SARS-CoV-2 negative tested patients, using pathology and surgery as reference standards for appendicitis and perforation, respectively. Fisher exact test and Student’s t-test were used for statistical analysis. Results One thousand, six hundred and ninety-three patients

Zusammenfassung Hintergrund Bei steigender Zahl von Magnetresonanztomographie(MRT)-Untersuchungen in der deutschen Gesamtbevölkerung gibt es keine Daten zum Untersuchungsbedarf von Patienten mit implantiertem Neurostimulator in Deutschland. Publizierte Daten aus den USA legen einen hohen Bedarf nahe. Die eingeschränkte MRT-Zulassung der Implantate ist in der täglichen Praxis ein häufiges Problem. Ziel Im Fokus steht der MRT-Bedarf dieser Schmerzpatienten und die Vorhersagbarkeit zum Zeitpunkt der Implantation. Material und Methoden Es erfolgte eine retrospektive Auswertung der Datenbank unseres Klinikinformationssystems. Gesucht wurden alle im Zeitraum November 2011 bis März 2019 in unserem Klinikum angeforderten MRT-Untersuchungen für Patienten mit implantiertem Neurostimulator. Zudem erfolgte ein Abgleich mit den im gleichen Zeitraum durchgeführten Implantationen derartiger Stimulationssysteme. Ergebnisse Es konnten 171 durchgeführte MRT-Untersuchungen und 22 Anforderungen ohne nachfolgende Untersuchung ausgewertet werden. Bei 83 von 294 Patienten, die in unserem Zentrum mit implantierten Neurostimulatoren versorgt wurden, erfolgte mindestens eine MRT-Untersuchung in unserem Klinikum. Wir beobachten eine stetig steigende Nachfrage. In 111 von 171 durchgeführten Untersuchungen (65 %) bestand kein Zusammenhang zwischen der zur Implantation führenden Indikation und der Indikation für die MRT. Eine Vorhersagbarkeit konnte nur bei 43 von 193 MRT-Anforderungen (22 %) unterstellt werden. Diskussion Patienten mit implantiertem Neurostimulator haben auch in Deutschland einen hohen Bedarf an MRT-Diagnostik, welcher zum Zeitpunkt der Implantation nicht vorhersagbar ist. Daher sollten ausschließlich MRT-taugliche Systeme implantiert werden. Die Industrie ist aufgefordert, die Implantate und deren Zulassungen an den Bedarf anzupassen.

Ultrasound and microbubbles are useful for both diagnostic imaging and targeted drug delivery, making them ideal conduits for theranostic interventions. Recent reports have indicated the preclinical success of microbubble cavitation for enhancement of chemotherapy in abdominal tumors; however, there have been limited studies and variable efficacy in clinical implementation of this technique. This is likely because in contrast to the high pressures and long cycle lengths seen in successful preclinical work, current clinical implementation of microbubble cavitation for drug delivery generally involves low acoustic pressures and short cycle lengths to fit within clinical guidelines. To translate the preclinical parameter space to clinical adoption, a relevant safety study in a healthy large animal is required. Therefore, the purpose of this work was to evaluate the safety of ultrasound cavitation treatment (USCTx) in a healthy porcine model using a modified Philips EPIQ with S5-1 as the focused source. We performed USCTx on eight healthy pigs and monitored health over the course of 1 wk. We then performed an acute study of USCTx to evaluate immediate tissue damage. Contrast-enhanced ultrasound exams were performed before and after each treatment to investigate perfusion changes within the treated areas, and blood and urine were evaluated for liver damage biomarkers. We illustrate, through quantitative analysis of contrast-enhanced ultrasound data, blood and urine analyses and histology, that this technique and the parameter space considered are safe within the time frame evaluated. With its safety confirmed using a clinical-grade ultrasound scanner and contrast agent, USCTx could be easily translated into clinical trials for improvement of chemotherapy delivery. This represents the first safety study assessing the bio-effects of microbubble cavitation from relevant ultrasound parameters in a large animal model.

Objective: Longitudinal neuroimaging data have been widely used to predict clinical scores for automatic diagnosis of Alzheimer’s Disease (AD) in recent years. However, incomplete temporal neuroimaging records of the patients pose a major challenge to use these data for accurately diagnosing AD. In this paper, we propose a novel method to learn an enriched representation for imaging biomarkers, which simultaneously captures the information conveyed by both the baseline neuroimaging records of all the participants in a studied cohort and the progressive variations of the available follow-up records of every individual participant. Methods: Taking into account that different participants usually take different numbers of medical records at different time points, we develop a robust learning objective that minimizes the summations of a number of not-squared $\ell _2$ -norm distances, which, though, is difficult to efficiently solve in general. Thus we derive a new efficient iterative algorithm with rigorously proved convergence. Results: We have conducted extensive experiments using the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. Clear performance gains have been achieved when we predict different cognitive scores using the enriched biomarker representations learned by our new method. We further observe that the top selected biomarkers by our proposed method are in perfect accordance with the known knowledge in existing clinical AD studies. Conclusion: All these promising experimental results have demonstrated the effectiveness of our new method. Significance: We anticipate that our new method is of interest to biomedical engineering communities beyond AD research and have open-sourced the code of our method online. 1 1 The code package of this paper have been made publicly available online at https://github.com/lyujian/Improved-Prediction-of-Cognitive-Outcomes

Conventional tissue sampling can lead to misdiagnoses and repeated biopsies. Additionally, tissue processed for histopathology suffers from poor nucleic acid quality and/or quantity for downstream molecular profiling. Targeted micro-sampling of tissue can ensure accurate diagnosis and molecular profiling in the presence of spatial heterogeneity, especially in tumors, and facilitate acquisition of fresh tissue for molecular analysis. In this study, we explored the feasibility of performing 1–2 mm precision biopsies guided by high-resolution reflectance confocal microscopy (RCM) and optical coherence tomography (OCT), and reflective metallic grids for accurate spatial targeting. Accurate sampling was confirmed with either histopathology or molecular profiling through next generation sequencing (NGS) in 9 skin cancers in 7 patients. Imaging-guided 1–2 mm biopsies enabled spatial targeting for in vivo diagnosis, feature correlation and depth assessment, which were confirmed with histopathology. In vivo 1-mm targeted biopsies achieved adequate quantity and high quality of DNA for next-generation sequencing. Subsequent mutational profiling was confirmed on 1 melanoma in situ and 2 invasive melanomas, using a 505-gene mutational panel called Memorial Sloan Kettering-Integrated mutational profiling of actionable cancer targets (MSK-IMPACT). Differential mutational landscapes, in terms of number and types of mutations, were found between invasive and in situ melanomas in a single patient. Our findings demonstrate feasibility of accurate sampling of regions of interest for downstream histopathological diagnoses and molecular pathology in both in vivo and ex vivo settings with broad diagnostic, therapeutic and research potential in cutaneous diseases accessible by RCM-OCT imaging.

Spine infection is both a clinical and diagnostic imaging challenge due to its relatively indolent and nonspecific clinical presentation. The diagnosis of spine infection is based upon a combination of clinical suspicion, imaging evaluation and, when possible, microbiologic confirmation performed from blood cultures or image-guided percutaneous or open spine biopsy. With respect to the imaging evaluation of suspected spine infection, MRI without and with contrast of the affected spine segment is the initial diagnostic test of choice. As noncontrast MRI of the spine is often used in the evaluation of back or neck pain not responding to conservative medical management, it may show findings that are suggestive of infection, hence this procedure may also be considered in the evaluation of suspected spine infection. Nuclear medicine studies, including skeletal scintigraphy, gallium scan, and FDG-PET/CT, may be helpful in equivocal or select cases. Similarly, radiography and CT may be appropriate for assessing overall spinal stability, spine alignment, osseous integrity and, when present, the status of spine instrumentation or spine implants. 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.

Traditionally, patients with newly diagnosed invasive breast cancer underwent axillary US to assess for suspicious axillary lymph nodes (LNs), which were then targeted for image-guided needle biopsy to determine the presence of metastasis. Over the past decade, there has been a shift towards axillary preservation. For patients with palpable lymphadenopathy, the decision to perform axillary imaging with documentation of the number and location of abnormal LNs in preparation for image-guided LN sampling is straightforward. Since LN involvement correlates with cancer size, it is reasonable to image the axilla in patients with tumors larger than 5 cm; however, for tumors smaller than 5 cm, axillary imaging is often deferred until after the tumor molecular subtype and treatment plan are established. Over the last decade, neoadjuvant chemotherapy (NACT) is increasingly used for smaller cancers with more aggressive molecular subtypes. In most cases, detecting axillary metastasis is critical when deciding whether the patient would benefit from NACT. There is increasing evidence that abnormal axillary US findings correlates with LN metastases and reliably establishes a baseline to monitor response to NACT. Depending on hormone receptor status, practices may choose to image the axilla in the setting of clinical stage T1 and T2 cancers to evaluate nodal status and help determine further steps in care. Radiologists should understand the nuances of axillary management and the scope and challenges of LN marking techniques that significantly increase the precision of limited axillary surgery.

In the United States, acute low back pain, with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life-years. Uncomplicated acute low back pain and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, fracture, or infection. 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.