Showing papers in "Seminars in Ultrasound Ct and Mri in 2020"
TL;DR: The risks and benefits of GBCA administration are reviewed and there is no solid evidence of negative clinical effect from the retention of macrocyclic agents in the brain while there is evidence that they wash out of the brain over time.
Abstract: The responsible use of gadolinium-based contrast agents (GBCAs) requires a balance between safety and clinical utility. While nephrogenic systemic fibrosis (NSF) has been associated with most linear GBCAs few, if any, new cases have been verified since the successful implementation of screening programs to detect renal impairment and prevent susceptible patients from receiving these higher-risk agents. The likelihood of developing nephrogenic systemic fibrosis has been shown to be negligible with macrocyclic agents, prompting the American College of Radiology and other regulatory agencies to suggest that no screening is necessary when they are used. There is no solid evidence of negative clinical effect from the retention of macrocyclic agents in the brain while there is evidence that they wash out of the brain over time. GBCAs have many important clinical uses that can help prevent morbidity or death. This article reviews the risks and benefits of GBCA administration.
16 citations
TL;DR: This review will introduce single photon emission computed tomography and positron emission tomographic imaging of the brain, including the history of their development, technical considerations, and a brief overview of pertinent radiopharmaceuticals and their applications.
Abstract: Advances in nuclear medicine have revolutionized our ability to accurately diagnose patients with a wide array of neurologic pathologies and provide appropriate therapy. The development of new radiopharmaceuticals has made possible the identification of regional differences in brain tissue composition and metabolism. In addition, the evolution of 3-dimensional molecular imaging followed by fusion with computed tomography and magnetic resonance imaging have allowed for more precise localization of pathologies. This review will introduce single photon emission computed tomography and positron emission tomographic imaging of the brain, including the history of their development, technical considerations, and a brief overview of pertinent radiopharmaceuticals and their applications.
13 citations
TL;DR: The widespread use of cross-sectional imaging with magnetic resonance imaging (MRI) and computed tomography (CT) has greatly increased the radiological diagnosis in conditions where US may be limited.
Abstract: Musculoskeletal soft tissue infections are not uncommonly encountered in both the clinic and Emergency Department setting. The clinical diagnosis is not always evident as these infections can have variable presentations depending on the duration and depth of disease extension through the soft-tissue layers. Imaging often plays an important role in diagnosing the infection, defining the extent of involvement, directing tissue sampling, and in monitoring treatment response. After initial radiographs, ultrasound (US) is often the next modality utilized to evaluate patients with suspected soft tissue infections given its low cost, availability, portability, and potential for real-time guidance of fluid aspiration. The widespread use of cross-sectional imaging with magnetic resonance imaging (MRI) and computed tomography (CT) has greatly increased the radiological diagnosis in conditions where US may be limited. In addition, CT and MRI allow a thorough evaluation of disease extension, including assessment of joint spaces, tendons, and osseous changes indicative of bone involvement. This review will focus on the radiological findings of soft tissue infections on US, CT, and MRI.
13 citations
TL;DR: A thorough review of radiologic findings in common infections of the brain, from primarily compartmentalized infections of multimicrobial etiologies, to CNS manifestations of specific immunocompromised-selective pathogens, of herpes simplex virus, and of tuberculosis are provided.
Abstract: Acute infections of the intracranial central nervous system (CNS) often present as neurological emergencies, where missed or delayed diagnosis and treatment can be catastrophic to the patient. Accurate and timely identification of the underlying etiologies, which are critical in directing life-saving therapies, can be achieved through neuroimaging. This article will provide a thorough review of radiologic findings in common infections of the brain, from primarily compartmentalized infections of multimicrobial etiologies, to CNS manifestations of specific immunocompromised-selective pathogens, of herpes simplex virus, and of tuberculosis. We also briefly discuss the epidemiology, etiology, clinical features, treatment guidelines, complications, and long-term sequelae of these infections.
11 citations
TL;DR: This article reviews the typical clinical and imaging findings of the most common and relevant benign, intermediate and malignant pediatric soft-tissue tumors in the following categories of the 2013 World Health Organization (WHO) classification: adipocytic tumors (lipoma, lipoblastoma, and liposarcoma).
Abstract: There is a broad spectrum of soft-tissue masses in children that can be challenging to diagnose clinically and on imaging. This article reviews the typical clinical and imaging findings of the most common and relevant benign, intermediate and malignant pediatric soft-tissue tumors in the following categories of the 2013 World Health Organization (WHO) classification: adipocytic tumors (lipoma, lipoblastoma, and liposarcoma), fibroblastic/myofibroblastic tumors (nodular fasciitis, myositis ossificans, fibrous hamartoma of infancy, fibromatosis colli, desmoid-type fibromatosis, lipofibromatosis, and infantile fibrosarcoma), pericytic tumors (myofibroma/myofibromatosis), skeletal muscle tumor (rhabdomyosarcoma), nerve sheath tumors (neurofibroma, malignant peripheral nerve sheath tumor), and uncertain differentiation (synovial sarcoma). In general, ultrasound and magnetic resonance imaging are used as first- and second-line imaging modalities, with limited roles for plain radiographs, computed tomography, and fluorodeoxyglucose-positron emission tomography. Many of these tumors have nonspecific imaging findings although there are some key imaging clues that in conjunction with the clinical information allow a specific diagnosis or a narrow differential diagnosis. However, in many instances, histology is required for final diagnosis.
10 citations
TL;DR: This article provides a foundation for evaluating deep neck infections through a review of essential anatomy and a discussion of important diseases that interact with these spaces.
Abstract: Identifying infections of the deep neck spaces and understanding how they spread can be a diagnostic challenge that is complicated by complex anatomy and far-reaching clinical implications. Deep neck infections have the potential to quickly spread throughout the neck and chest, leading to widespread disease that can be rapidly fatal and resistant to treatment. This article provides a foundation for evaluating deep neck infections through a review of essential anatomy and a discussion of important diseases that interact with these spaces.
10 citations
TL;DR: Current strategies of brain tumor imaging are discussed, specifically detailing the role of nuclear medicine single-photon emission computed tomography and positron emission tomography with utilization of both common and uncommon radiotracers in tumor grading, diagnosis, and treatment response.
Abstract: Neuroimaging plays a vital role in the diagnosis and post-treatment assessment of brain tumors, aiding in treatment optimization, prognostication, and patient management. New clinical treatments have resulted in increased complexity of imaging interpretation, thus integrating complementary information from multiple imaging modalities (computed tomography, magnetic resonance imaging, and nuclear medicine) contributes to a thorough and more accurate evaluation. In review, we discuss current strategies of brain tumor imaging, specifically detailing the role of nuclear medicine single-photon emission computed tomography and positron emission tomography with utilization of both common and uncommon radiotracers in tumor grading, diagnosis, and treatment response.
10 citations
TL;DR: It is important for the clinical neuroradiologist to understand the underlying patterns of Aβ and tau deposition in the context of AD (across its clinical continuum) and in other causes of dementia, as well as understand the implications of current research.
Abstract: Although diagnosing the syndrome of dementia is largely a clinical endeavor, neuroimaging plays an increasingly important role in accurately determining the underlying etiology, which extends beyond its traditional role in excluding other causes of altered cognition. New neuroimaging methods not only facilitate the diagnosis of the most common neurodegenerative conditions (particularly Alzheimer Disease [AD]) after symptom onset, but also show diagnostic promise even in the very early or presymptomatic phases of disease. Positron emission tomography (PET) is increasingly recognized as a key clinical tool for differentiating normal age-related changes in brain metabolism (using 18F-fluorodeoxyglucose [FDG]) from those seen in the earliest stages of specific forms of dementia. However, FDG PET only demonstrates nonspecific changes in altered parenchymal glucose uptake and not the specific etiologic proteinopathy causing the abnormal glucose uptake. A growing class of radiotracers targeting specific protein aggregates for amyloid-β (Aβ) and tau are changing the way AD is diagnosed, as these radiotracers directly label the underlying disease pathology. As these pathology-specific radiotracers are currently making their way to the clinic, it is important for the clinical neuroradiologist to understand the underlying patterns of Aβ and tau deposition in the context of AD (across its clinical continuum) and in other causes of dementia, as well as understand the implications of current research.
10 citations
TL;DR: It is important for radiologists to be aware of the imaging features that can help make the diagnosis of OO utilizing MRI, given that the majority of these lesions occur in younger patients, in whom there is greater concern to limit ionizing radiation.
Abstract: Osteoid osteoma (OO) is a benign bone neoplasm consisting of a central prostaglandin-secreting nidus surrounded by a zone of reactive sclerosis. The diagnosis is suspected in children and young adults with longstanding nighttime pain that is relieved by salicylates or nonsteroidal anti-inflammatory drugs. Early studies suggested that computed tomography had a higher sensitivity and specificity in the diagnosis of OO compared to magnetic resonance imaging (MRI). More recent literature suggests MRI done with dynamic postcontrast imaging to be equal to or slightly better at detecting the nidus of OOs, particularly the ones in atypical locations. Being able to evaluate for OO utilizing MRI is important given that the majority of these lesions occur in younger patients, in whom there is greater concern to limit ionizing radiation. Furthermore, patients with atypical OOs often receive an MRI if radiographs are not suggestive of the diagnosis. Therefore, it is important for radiologists to be aware of the imaging features that can help make the diagnosis on MRI.
9 citations
TL;DR: The basics of acquisition, postprocessing, and thoracic applications of DECT are reviewed with a focus on pulmonary blood volumes as a surrogate for perfusion imaging, including pulmonary embolism, hypoplastic lung, pulmonary hypertension in bronchopulmonary dysplasia, and pediatric lung masses.
Abstract: Dual-energy computer tomography (DECT) technology has experienced rapid growth in recent years, now allowing for the collection of 2 CT data sets and opening the potential for functional data acquisition. Data from a single postcontrast phase are deconstructed and Iodine can be subtracted to create a virtual noncontrast image, or selectively represented as a contrast map that allows for the qualification and quantification of lung perfusion. Virtual monoenergetic images can also be used to reduce beam-hardening artifact from concentrated contrast or metal implants. In children, DECT is of particular interest because it has been shown to be dose neutral in most applications, dose-reducing in multiphase studies, and to increase the contrast to noise ratio in suboptimal studies. We review the basics of acquisition, postprocessing, and thoracic applications of DECT with a focus on pulmonary blood volumes as a surrogate for perfusion imaging. The discussed applications include pulmonary embolism, hypoplastic lung, pulmonary hypertension in bronchopulmonary dysplasia, and pediatric lung masses.
8 citations
TL;DR: Important elements to running a safe PAE practice including careful patient selection, exclusion criteria, complications, and efficacy of PAE compared to other techniques are reviewed.
Abstract: Prostate artery embolization (PAE) is a minimally invasive technique in managing men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). BPH is one of the commonest causes of LUTS in men, associated with high morbidity and economic burden. Patients suffering from LUTS secondary to BPH, severe enough to warrant intervention traditionally underwent transurethral resection of the prostate or open prostatectomy. PAE is an emerging alterative technique with promising data. In this paper we review important elements to running a safe PAE practice including careful patient selection, exclusion criteria, complications, and efficacy of PAE compared to other techniques. This paper also reviews the basic anatomy and techniques relevant to PAE, including common anatomical variants.
TL;DR: Renal masses are common incidental findings on cross-sectional imaging and newer modalities like dual energy CT scan obviate need for repeat imaging by generation of iodine-overlay image and also help in eliminating artifactual pseudoenhancement which can be problematic, especially in small endophytic cysts.
Abstract: Renal masses are common incidental findings on cross-sectional imaging. Accurate characterization of renal masses is essential to guide management. Renal mass CT protocol comprises of a good quality noncontrast, corticomedullary and nephrographic phases, with each phase providing complementary information for diagnosis. Attenuation measurements in different phases are central to the 'golden-rules' in renal mass imaging in the characterization of renal masses. Newer modalities like dual energy CT scan obviate need for repeat imaging by generation of iodine-overlay image and also help in eliminating artifactual pseudoenhancement which can be problematic, especially in small endophytic cysts. Contrast- enhanced ultrasound (CEUS) is extremely sensitive in identification of enhancing components in indeterminate masses, especially in the setting of renal failure as the microbubbles are not excreted via the renal route. The Bosniak classification for renal cystic masses has been revised in 2019 to standardize terminology and further improve upon the original version. The current version includes CT and MRI, although CEUS is yet to be included. Image- guided biopsy of renal mass helps confirm the diagnosis and also gives information regarding the subtype and grading and is useful in avoiding overtreatment of benign entities, and in active surveillance. Multiparametric MRI can potentially help avoid needle biopsy in a subset of patients by accurate characterization through a previously validated algorithm.
TL;DR: MRI, computed tomography and bone scan remain the preferred modalities for evaluation of nodal, soft tissue, and bone metastases, respectively and the utility of individual modalities is described.
Abstract: Prostate cancer (PCa) is the most common noncutaneous malignancy in men and the second leading cause of cancer related death in the United States. Men with clinical suspicion of PCa undergo tissue sampling and based on features including the Gleason score, Prostate Specific antigen (PSA) levels and clinical tumor (T) stage, patients are risk stratified into 6 major groups based on National Comprehensive Cancer Network (NCCN) guidelines. This forms the basis for deciding imaging and management. Active surveillance is the preferred approach for less aggressive tumors. Surgery or radiation +/- androgen deprivation therapy continue to be the primary treatment options for localized disease. Imaging plays a critical role in the diagnosis, staging and management of PCa. Multiparametric magnetic resonance imaging (mpMRI) is currently the imaging modality of choice for locoregional staging. MRI, computed tomography and bone scan remain the preferred modalities for evaluation of nodal, soft tissue, and bone metastases, respectively. Advanced positron emission tomography imaging using novel radiotracers are being developed but are not yet integrated in the diagnostic guidelines for initial staging. In this review, we will discuss the imaging and treatment algorithms based on the NCCN risk groups, describe the utility of individual modalities, review Prosate Imaging and Reporting and Data System (PIRADS) version 2.1 for the reporting of mpMRI of the prostate.
TL;DR: A multimodality approach using ultrasound, computed tomography, and magnetic resonance imaging is described that distinguish a number of infectious etiologies that affect the bowel, as well as differentiate from ischemic and inflammatory bowel processes.
Abstract: Although radiologic imaging of bowel infections is often a precursor to definitive diagnosis by endoscopy, biopsy, or stool cultures, imaging can provide critical information for diagnosis and management. Many infectious entities such as viral, bacterial, and parasitic infections can be discovered on imaging. Furthermore, imaging characterizes the extent of infection, involvement of specific bowel segments, and presence of complications in the abdomen. Utilizing a multimodality approach using ultrasound, computed tomography, and magnetic resonance imaging, we describe the spectrum of imaging findings that distinguish a number of infectious etiologies that affect the bowel, as well as differentiate from ischemic and inflammatory bowel processes.
TL;DR: Increased awareness of the abilities and limitations of IR physicians in clinical scenarios needs to be implemented, to allow multispecialty input in efforts to decrease morbidity and mortality.
Abstract: Interventional radiology (IR) is plays a crucial role in the management of localized infections, utilizing percutaneous access to loculated fluid collections for drainage and source control. Interventions have been developed in multiple organs and systems and used over decades, allowing the IR physician to provide patient care in many cases where surgical options are not optimal. In this review, we will examine the emergent, urgent, and routine nature of various IR procedures in the infectious context and timelines for each in regards to the decision making process. An algorithmic approach should guide the clinician's decision making for IR procedures in both large academic centers and smaller community hospitals. This approach and the pertinent procedural technique are described for multiple systems and organs including the biliary tree, gallbladder, genitourinary tract, and thoracic, abdominal, and pelvic abscesses. Increased awareness of the abilities and limitations of IR physicians in clinical scenarios needs to be implemented, to allow multispecialty input in efforts to decrease morbidity and mortality.
TL;DR: In this article, ultrasound and CT imaging findings of acute and chronic urinary tract infections are reviewed.
Abstract: Acute urinary tract infection diagnosis is primarily performed on clinical grounds. Diagnostic imaging is, however, often necessary as part of the workup for poor response to treatment, to evaluate causative or contributory factors, complicated infections and chronic presentations. Appropriate knowledge of the most relevant radiological findings in urinary tract infections provides pertinent differential diagnosis and guides clinical management, including emergent and aggressive interventions. In this article we review ultrasound and CT imaging findings of acute and chronic urinary tract infections.
TL;DR: Cerebral 2-deoxy-2-[F-18]fluoroglucose (FDG) positron emission tomography allows for qualitative and quantitative characterization of major dementia syndromes and variants by means of detecting distinct patterns of cortical hypometabolism.
Abstract: Dementia syndromes present a diagnostic challenge given their overlapping clinical features and insidious presentations. Cerebral 2-deoxy-2-[F-18]fluoroglucose (FDG) positron emission tomography (PET) is a functional imaging modality commonly used in the evaluation of dementia. While its role in the clinical assessment of dementia is evolving, FDG PET allows for qualitative and quantitative characterization of major dementia syndromes and variants by means of detecting distinct patterns of cortical hypometabolism. Familiarity with these “metabolic signatures” in dementia syndromes can be helpful when interpreting cerebral FDG PET.
TL;DR: While CT of the head is the first modality of choice for assessment of an infant with AHT, magnetic resonance imaging examination of the brain and spine should follow due to its higher sensitivity for detection of these findings.
Abstract: Abusive head trauma (AHT) is the leading cause of fatal head injuries in infants. The mechanism of injury usually involves vigorous shaking of the infant, impact, or a combination of the 2. There are characteristic imaging findings of which the most common are subdural hemorrhages. Parenchymal injuries to the brain are common as well, including hypoxic ischemic injury, diffuse axonal injury, and cerebral contusions. Retinal hemorrhages are common with AHT and are best evaluated by fundoscopy, however, high grade retinal hemorrhages may be detected on cross-sectional imaging. Skull fractures are not specific to AHT but are present in third of the cases and tend to be complex in association with AHT. Injuries to the spine are more common than previously thought and typically involve soft tissues rather than bones, with the most common being ligamentous injuries in the craniocervical junction. In the setting of AHT, an affected infant would typically exhibit multiple findings. While CT of the head is the first modality of choice for assessment of an infant with AHT, magnetic resonance imaging examination of the brain and spine should follow due to its higher sensitivity for detection of these findings.
TL;DR: Familiarity with the strengths of individual imaging modalities in the radiologists' arsenal is imperative to guide the appropriate utilization of resources, particularly in the emergent time sensitive setting.
Abstract: Hepatobiliary infections account for a small but clinically important proportion of emergency department presentations. They present a clinical challenge due to the broad range of imaging characteristics on presentation. Recognition of complications is imperative to drive appropriate patient care and resource utilization to avoid diagnostic pitfalls and avert adverse patient outcomes. A thorough understanding of anatomy infectious pathology of hepatobiliary system is essential in the emergency setting to confidently diagnose and guide medical intervention. Many presentations of hepatobiliary infection have characteristic imaging features on individual imaging modalities with others requiring the assimilation of findings of multiple imaging modalities along with incorporating the clinical context and multispecialist consultation. Familiarity with the strengths of individual imaging modalities in the radiologists' arsenal is imperative to guide the appropriate utilization of resources, particularly in the emergent time sensitive setting. Accurate identification and diagnosis of hepatobiliary infections is vital for appropriate patient care and management stratification.
TL;DR: A broad overview of the imaging and management of pancreatic cancer with a focus on diagnosis and staging, operative and nonoperative treatments, and post-therapeutic appearances after surgery and chemoradiation therapy is provided.
Abstract: Pancreatic cancer is an aggressive disease with rising incidence and high mortality despite advances in imaging and therapeutic options. Surgical resection is currently the only curative treatment, with expanding roles for adjuvant and neoadjuvant chemoradiation. Accurate detection, staging, and post-treatment monitoring of pancreatic cancer are critical to improving survival and imaging plays a central role in the multidisciplinary approach to this disease. This article will provide a broad overview of the imaging and management of pancreatic cancer with a focus on diagnosis and staging, operative and nonoperative treatments, and post-therapeutic appearances after surgery and chemoradiation therapy.
TL;DR: Familiarity with the postoperative anatomy is essential for early identification of postoperative complications and detection of tumor recurrence in urinary diversion post cystectomy patients.
Abstract: Various surgical techniques exist for urinary diversion post cystectomy and each have different imaging features. This diverse range of surgical procedures can make imaging interpretation difficult and so familiarity with the postoperative anatomy is essential. Multiple imaging modalities and techniques are available for the radiologist's assessment including fluoroscopic studies, computed tomography, magnetic resonance, and radionuclide imaging. Knowledge of when each of these modalities is indicated and the typical imaging appearances is essential for early identification of postoperative complications and detection of tumor recurrence. This information enables the radiologist to make an accurate and early diagnosis and subsequently guide the management pathway for these patients.
TL;DR: The epidemiology of RCC and the role of imaging in diagnosis and follow-up is described.
Abstract: Kidney lesions are commonly an incidental finding on cross sectional studies carried out for a variety of reasons. The detection of renal cell carcinoma (RCC) has increased accordingly. There are a variety of different contrast-enhanced CT imaging protocols that have been developed to help diagnose and stage RCC. More recently, renal MRI and contrast-enhanced ultrasound have also been used as problem-solving tools. This paper describes the epidemiology of RCC and the role of imaging in diagnosis and follow-up.
TL;DR: This review details common and uncommon brain tumor mimics in specific context of PET and SPECT imaging of the brain, including the multimodality imaging appearance of tumor mimICS and the potential roles these modalities may play in providing diagnostic clarity.
Abstract: Several non-neoplastic processes, including infection, inflammation, demyelination, vasculitis, autoimmune disease, and post-treatment changes (radiation therapy or chemoradiation) can result in a mass-like, space-occupying lesion on conventional computed tomography (CT) or magnetic resonance (MR) imaging of the brain. Additionally, non-neoplastic processes can produce imaging findings that mimic nontumoral neoplastic involvement of the central nervous system. Such instances pose a substantial diagnostic dilemma for interpreting radiologists, as well as clinicians tasked with determining the appropriate diagnostic tests and therapeutic strategies for these patients. Nuclear medicine studies, including single positron emission computed tomography (SPECT) and positron emission tomography (PET), as well as hybrid SPECT/CT, PET/CT, and PET/MRI may offer important diagnostic insights into these challenging cases, often helping to differentiate these mimics from true brain neoplasms. In this review, we detail common and uncommon brain tumor mimics in specific context of PET and SPECT imaging of the brain, including the multimodality imaging appearance of tumor mimics and the potential roles these modalities may play in providing diagnostic clarity.
TL;DR: Initial experience with mpUS from selected specialist centers shows promise for lesion characterization, and potential for affecting management and improving outcomes, and outlines the clinical context from a urological and histopathological perspective.
Abstract: Indeterminate nonpalpable focal testicular lesions have emerged as a clinical problem with the increasing use of scrotal ultrasound, particularly in the context of infertility. Conventional morphological ultrasound and color Doppler have been unreliable at differentiating benign from malignant lesions. Multiparametric ultrasound (mpUS) comprises real-time elastography and contrast-enhanced ultrasound as adjunctive tools, and is ready for use in most state-of-the-art ultrasound systems. Initial experience with mpUS from selected specialist centers shows promise for lesion characterization, and potential for affecting management and improving outcomes. This article provides a summary of the existing literature on testicular mpUS, and outlines the clinical context from a urological and histopathological perspective.
TL;DR: Improvements in scanning techniques and development of highly sensitive functional sequences have improved the detection of clinically significant prostate cancer as well as treatment planning and follow up, leading to a recent NICE recommendation to use prostate MRI as the initial investigation in men with clinically suspected localized disease.
Abstract: Multiparametric MRI has a changing role in prostate cancer diagnosis. Internationally recognized consensus documents such as prostate imaging reporting and data system version have been developed and adapted to standardize the acquisition and reporting of prostate MRI. The improvement in scanning techniques and development of highly sensitive functional sequences have improved the detection of clinically significant prostate cancer as well as treatment planning and follow up. This has led to a recent NICE recommendation to use prostate MRI as the initial investigation in men with clinically suspected localized disease. The results of several recent international MRI prostate trials are influencing the way imaging is used to stratify which patients require a prostate biopsy as well as how MRI guidance is used to target biopsies.
TL;DR: The role of imaging of the thyroid gland in children is discussed, highlighting pearls and pitfalls, and knowledge of unique features of thyroid imaging in the pediatric population is critical for accurate diagnosis and management recommendations.
Abstract: This article discusses the role of imaging of the thyroid gland in children, highlighting pearls and pitfalls. In the pediatric age group, thyroid imaging is mainly performed for the evaluation of congenital hypothyroidism, diffuse thyroid enlargement, and thyroid nodules. Permanent congenital hypothyroidism is most often caused by thyroid dysgenesis. Diffuse thyroid enlargement is mainly seen in teenage girls, and most often caused by Hashimoto disease, nodular hyperplasia, Graves disease, or diffuse papillary carcinoma. Thyroid nodules are less common in children than they are in adults, but more likely to be malignant; TI-RADS criteria may underestimate the risk of malignancy in children, and lead to erroneous classification downgrading. Knowledge of unique features of thyroid imaging in the pediatric population is critical for accurate diagnosis and management recommendations.
TL;DR: High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations, and helps in individualizing treatment inrectal cancer.
Abstract: High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a "watch and wait" approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.
TL;DR: General features of soft tissue sarcomas and some of the common tumors from WHO category 1-4 found in abdomen and pelvis are discussed and knowledge of the WHO classification, pathologic features and available treatment options will help the radiologist make a meaningful contribution in multidisciplinary discussions of such cases and overall patient care.
Abstract: Soft-tissue sarcomas are a diverse group of rare mesenchymal malignancies accounting for only 1% of all solid adult malignancies. These have been categorized in 12 broad groups by the World Health Organization (WHO) with their recent update in 2013. Majority of them lack specific imaging features serving as imaging conundrums for a radiologist. These are often large masses at presentation as they are asymptomatic or cause vague clinical symptoms. These tumors are challenging for surgeons as well as they find it difficult to achieve complete resection because of complex intra-abdominal anatomy and their close relationship with critical structures. Often, a multidisciplinary approach is required to decide on the most appropriate management for these complex cases so as to provide optimal patient care. Knowledge of the WHO classification, pathologic features and available treatment options will help the radiologist make a meaningful contribution in multidisciplinary discussions of such cases and overall patient care. Liposarcoma (well-differentiated and dedifferentiated liposarcomas), leiomyosarcoma, and gastrointestinal stromal tumor are the 3 most common primary intra-abdominal sarcomas. In part 1 of this article, general features of soft tissue sarcomas and some of the common tumors from WHO category 1-4 found in abdomen and pelvis are discussed. Part 2 will focus on common tumors from remainder of the WHO categories.
TL;DR: The pathophysiology and the latest NMOSD diagnostic criteria are summarized and imaging findings beyond optic neuritis and transverse myelitis are focused on.
Abstract: Neuromyelitis optica (NMO) is a rare and chronic disabling autoimmune astrocytopathy of the central nervous system. Current advances regarding aquaporin-4 antibody function facilitate the understanding of clinical manifestations and imaging findings beyond optic neuritis and transverse myelitis. The current definition of NMO spectrum disorder (NMOSD) includes both aquaporin-4-IgG seropositive and seronegative patients who present with characteristic findings. This review will briefly summarize the pathophysiology and the latest NMOSD diagnostic criteria and focus on the NMOSD imaging findings and its differential diagnosis.
TL;DR: Technical considerations in the performance of MR enterography in children and adolescents, as well as "do not miss" findings on MR enterographic findings that will impact clinical management and potential problems encountered with MREnterography that may limit its diagnostic utility in some patients are focused on.
Abstract: Magnetic resonance (MR) enterography is now the preferred modality for evaluation of acute and chronic presentations of Crohn disease in pediatric patients. There has been increasing standardization in the performance and interpretation of these studies, given the growth in volume and impact on clinical management. This article will focus on technical considerations in the performance of MR enterography in children and adolescents, as well as "do not miss" findings on MR enterography that will impact clinical management and potential problems encountered with MR enterography that may limit its diagnostic utility in some patients.