Apeksha Chaturvedi

Pediatric Distal Forearm and Wrist Injury: An Imaging Review

Injuries to the pediatric distal forearm and wrist have myriad manifestations. Growth plate injuries can occur in the skeletally immature child. An unfused growth plate is less robust than ligamentous complexes and therefore is more easily injured. The Salter-Harris fracture classification system is used to grade physeal injuries based on their imaging appearance. This grading has prognostic significance: higher grades imply an increased likelihood of eventual growth disturbance. A disrupted distal radioulnar joint characterizes Galeazzi-type injuries at all ages; however, before skeletal maturity is attained, a disrupted radioulnar joint can manifest as a distal ulnar physeal separation with associated epiphysiolysis of the distal ulna, termed a Galeazzi-equivalent fracture. Bone contusions can be diagnosed using fluid-sensitive fat-suppressed magnetic resonance imaging, and their detection can alter the prognosis. The unique cartilaginous cushion of the developing bony carpus imparts resilience to fracture and dislocation until carpal maturity is reached. Chronic compressive forces to the wrist in a skeletally immature gymnast can result in a distinct pattern of bone and soft-tissue injury referred to as gymnast wrist. If the distal radial physis fuses prematurely, ulnar growth will outpace radial growth, leading to positive ulnar variance and consequent chronic wrist pain from ulnar impaction.

MRI of Pediatric Patients: Part 2, Normal Variants and Abnormalities of the Knee

OBJECTIVE The purpose of this article is to discuss MRI of the pediatric knee and familiarize the reader with conditions encountered in the pediatric population. Clinical scenarios are included to convey important concepts and to orient the learner to normal variants and abnormalities of the pediatric knee. The conditions discussed include, but are not limited to, distal femoral metaphysial irregularity, isolated popliteus tendon avulsion, juvenile idiopathic arthritis, and discoid meniscus. CONCLUSION The knee is the joint that is most commonly imaged by MRI in children. Injury patterns and signs of other pathologic processes seen in skeletally immature patients are different from those seen in adults. Interpreting pediatric knee MRI studies may be a challenge for those unfamiliar with the evolving patterns of normal development and of the signs of conditions that are more prevalent in children. Through case scenarios, this article describes and provides images that depict conditions commonly encountered in the pediatric knee. Most of the described normal findings and abnormalities are more prevalent in the pediatric population than in adults, and a few of the conditions are, in fact, unique to pediatric patients.

Imaging Bithalamic Pathology in the Pediatric Brain: Demystifying a Diagnostic Conundrum

OBJECTIVE The thalami are subject to multiple insults including metabolic and toxic phenomena, acute demyelination, infection, infarction, hemorrhage and neoplastic involvement. The purpose of this article is to review the neuroimaging approach, classification, and imaging of bilateral thalamic lesions with histopathology correlation and application of advanced techniques. CONCLUSION Neuroimaging of abnormal pediatric thalami uses conventional MRI sequences and advanced techniques to characterize lesions. Although there is considerable imaging overlap, a tailored approach can facilitate diagnosis and management.

Looking beyond the thrombus: essentials of pulmonary artery imaging on CT.

AbstractBackgroundPulmonary arteries are not just affected by thrombus. Congenital and acquired conditions can also involve the pulmonary arteries. An awareness of these conditions is important for the radiologist interpreting chest computed tomography (CT).MethodsThe anatomy of the pulmonary arteries was reviewed. CT and magnetic resonance (MR) acquisition protocols for imaging the pulmonary arteries were discussed. The imaging appearances of congenital and acquired anomalies involving the pulmonary arteries, using CT and other modalities, were presented.ResultsImaging features of congenital anomalies presented include pulmonary agenesis, partial pulmonary artery agenesis, patent ductus arteriosus, pulmonary artery sling, congenital pulmonary artery stenosis and coronary to pulmonary artery fistula. Acquired pulmonary artery anomalies discussed include arteritis, infected aneurysm and sarcoma. Pulmonary artery filling defects besides thromboembolism are also discussed, including foreign body emboli. Imaging features of bronchogenic carcinoma and mediastinal fibrosis demonstrating compression of the pulmonary arteries are presented, followed by a brief discussion of post repair appearance of the pulmonary arteries for congenital heart disease.ConclusionsCongenital and acquired pulmonary artery anomalies have a characteristic appearance on a variety of imaging modalities. An acquaintance with the imaging features of these anomalies is needed to avoid misinterpretation and reach the correct diagnosis. Teaching Points • Discuss a variety of congenital and acquired anomalies of the pulmonary arteries.• Discuss the imaging appearance of the presented congenital or acquired pulmonary artery anomalies.• Describe CT and MR acquisition protocols for imaging the pulmonary arteries.• Review the anatomy of the pulmonary arteries.

MRI evaluation prior to Transcatheter Aortic Valve Implantation (TAVI): When to acquire and how to interpret

AbstractTranscatheter Aortic Valve Implantation (TAVI) is increasingly being used in patients with severe aortic stenosis who are not candidates for surgery. ECG-gated CT angiography (CTA) plays an important role in the preoperative planning for these devices. As the number of patients undergoing these procedures increases, a subset of patients is being recognized who have contraindications to iodinated contrast medium, either due to a prior severe allergic type reaction or poor renal function. Another subgroup of patients with low flow and low gradient aortic stenosis is being recognized that are usually assessed for severity of aortic stenosis by stress echocardiography. There are contraindications to stress echocardiography and some of these patients may not be able to undergo this test. Non-contrast MRI can be a useful emerging modality for evaluating these patients. In this article, we discuss the emerging indications of non-contrast MRI in preoperative assessment for TAVI and describe the commonly used MRI sequences. A comparison of the most important measurements obtained for TAVI assessment on CTA and MRI from same subjects is included. Teaching Points • MRI can be used for preoperative assessment of aortic annulus. • MRI is an alternate to CTA when iodinated contrast is contraindicated. • Measurements obtained by non-contrast MRI are similar to contrast enhanced CTA. • MRI can be used to assess severity of aortic stenosis.

Traumatic Rib Injury: Patterns, Imaging Pitfalls, Complications, and Treatment

The ribs are frequently affected by blunt or penetrating injury to the thorax. In the emergency department setting, it is vital for the interpreting radiologist to not only identify the presence of rib injuries but also alert the clinician about organ-specific injury, specific traumatic patterns, and acute rib trauma complications that require emergent attention. Rib injuries can be separated into specific morphologic fracture patterns that include stress, buckle, nondisplaced, displaced, segmental, and pathologic fractures. Specific attention is also required for flail chest and for fractures due to pediatric nonaccidental trauma. Rib fractures are associated with significant morbidity and mortality, both of which increase as the number of fractured ribs increases. Key complications associated with rib fracture include pain, hemothorax, pneumothorax, extrapleural hematoma, pulmonary contusion, pulmonary laceration, acute vascular injury, and abdominal solid-organ injury. Congenital anomalies, including supernumerary or accessory ribs, vestigial anterior ribs, bifid ribs, and synostoses, are common and should not be confused with traumatic pathologic conditions. Nontraumatic mimics of traumatic rib injury, with or without fracture, include metastatic disease, primary osseous neoplasms (osteosarcoma, chondrosarcoma, Ewing sarcoma, Langerhans cell histiocytosis, and osteochondroma), fibrous dysplasia, and Paget disease. Principles of management include supportive and procedural methods of alleviating pain, treating complications, and stabilizing posttraumatic deformity. By recognizing and accurately reporting the imaging findings, the radiologist will add value to the care of patients with thoracic trauma. Online supplemental material is available for this article. ©RSNA, 2017.

Contrast opacification on thoracic CT angiography: challenges and solutions

AbstractContrast flow and enhancement patterns seen on thoracic CT angiography (CTA) can often be challenging and may often reveal more than is immediately apparent. A non-diagnostic CTA following the initial contrast injection can be secondary to many causes; these include both extrinsic factors, such as injection technique/equipment failure (iv cannula, power injector), and intrinsic, patient-related factors. Contrast pressure and flow graphs often contain useful information regarding the etiology of a non-diagnostic scan. Understanding these graphs will help the radiologist plan a repeat contrast injection to overcome the deficiencies of the first injection and thus obtain a diagnostic scan. The current review article outlines normal and abnormal intravenous contrast dynamics, discusses how to recognize etiologies of non-diagnostic scans, and ultimately addresses techniques to overcome obstacles towards obtaining normal contrast opacification of the target vessel. In addition, there are some life-threatening findings, which unless sought for, may remain hidden in plain sight. Key Points • Using contrast enhancement and flow patterns to identify the cause of a non-diagnostic CTA.• Recognize life threatening causes of altered contrast dynamics such as cardiac asystole.• Non-target vessel opacification may hold key to underlying pathophysiology.

Lesions involving the outer surface of the bone in children: a pictorial review

AbstractBackgroundLesions involving the outer cortical surface of the bone occur quite often among children. Broadly, these include benign cortical, juxtacortical and periarticular lesions, dysplasias affecting the cortical bone, regional and diffuse periosteal pathology and malignant tumours. Some of these lesions are unique to the paediatric population; others are more frequently seen among children than adults — yet others have an adult predilection but can occasionally be seen in children.MethodsA complete list of differential considerations for lesions involving the outer cortical surface of the bone in children is presented. Imaging characteristics on plain film radiography and MR are described in association with multiple examples and illustrations.ConclusionA pictorial review detailing the imaging features of surface lesions of the bone in children will be a useful aide for both radiologists and their clinical colleagues, and will help them sort their way through the maze of differential diagnoses for these abnormalities. Teaching Points• Surface lesions of bones in children comprise a distinct entity and differ from those in adults. • Imaging plays an important role towards classifying surface lesions of bones in children. • MRI features may be characteristic and aid precise diagnosis, thus guiding further management.

Emergency Pediatric Ear, Nose, and Throat Imaging

Pediatric ear, nose, and throat emergencies broadly comprise infection, trauma, and airway obstruction secondary to a multitude of etiologies. Imaging occupies center stage in the diagnosis of many of these conditions and their complications, making it imperative for radiologists and other physicians covering the pediatric emergency department to familiarize themselves with the imaging appearances of these entities. Toward this goal, this article describes the imaging features of common pediatric ear, nose, and throat emergencies. Differential considerations, potential fallacies, and complications have been discussed when appropriate. Because a sound knowledge of the most relevant, efficient, time, and cost-effective imaging modality is of undisputable value in the acute setting, the preferred modality for each specific condition has been outlined. Finally, in alignment with our commitment to using radiation judiciously, we have suggested using ultrasonography and magnetic resonance instead of computed tomography, where possible, to optimize cost-benefit ratio for our young patients.

Imaging of acquired transdiaphragmatic fistulae and communications

Acquired diaphragmatic defects occur secondary to trauma, infection, surgery or neoplasm. These defects can lead to abnormal thoraco-abdominal fistulous communications also. Examples of surgically created diaphragmatic defects are omental, colonic interposition and vascular grafts. Regardless of etiology, these transdiaphragmatic communications provide a direct path for spread of pathology between the abdomen and thorax. If left untreated and unrecognized, these fistulae portend a high morbidity and mortality. Subtle but important diagnostic clues can be present on imaging. This pictorial essay describes commonly encountered imaging findings seen with acquired transdiaphragmatic communications. This knowledge will improve diagnostic confidence of the interpreting radiologist in acute situations and confounding clinical scenarios.