Imaging of systemic vasculitis in childhood

Myocardial Functional Imaging in Pediatric Nuclear Cardiology

The role of nuclear medicine in pediatric cardiology has grown rapidly over the years, providing useful functional and prognostic information and playing a complementary role to morphological imaging in the evaluation of myocardial perfusion, cardiovascular inflammation and infections, and cardiac sympathetic innervation. The aim of this narrative review is to summarize and highlight the most important evidence on pediatric nuclear cardiology, describing clinical applications and the possibilities, advantages, and limitations of nuclear medicine techniques. Moreover, a special focus will be given to the minimization of radiation exposure in pediatric nuclear cardiology imaging, a critical topic in children.

SCMR expert consensus statement for cardiovascular magnetic resonance of acquired and non-structural pediatric heart disease

Cardiovascular magnetic resonance (CMR) is widely used for diagnostic imaging in the pediatric population. In addition to structural congenital heart disease (CHD), for which published guidelines are available, CMR is also performed for non-structural pediatric heart disease, for which guidelines are not available. This article provides guidelines for the performance and reporting of CMR in the pediatric population for non-structural ("non-congenital") heart disease, including cardiomyopathies, myocarditis, Kawasaki disease and systemic vasculitides, cardiac tumors, pericardial disease, pulmonary hypertension, heart transplant, and aortopathies. Given important differences in disease pathophysiology and clinical manifestations as well as unique technical challenges related to body size, heart rate, and sedation needs, these guidelines focus on optimization of the CMR examination in infants and children compared to adults. Disease states are discussed, including the goals of CMR examination, disease-specific protocols, and limitations and pitfalls, as well as newer techniques that remain under development.

Pediatric cardiothoracic vasculitis: multimodality imaging review

The pediatric vasculitides are a relatively uncommon and heterogeneous group of disorders characterized by vessel inflammation, often with cardiothoracic involvement. Diagnosis and monitoring are often clinically challenging because of the nonspecific symptoms and laboratory markers. Thus, imaging has assumed increasing importance for early detection of disease activity, extent and complications as well as long-term monitoring pre- and post-treatment. Herein, we review the major pediatric vasculitides with frequent chest manifestations, including Takayasu arteritis, Kawasaki disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis, Behçet disease and potential mimics. We highlight key clinical features and management considerations, emphasizing the central role of imaging.

Multisystem Imaging Manifestations of Kawasaki Disease

Kawasaki disease (KD) is a common pediatric vasculitis syndrome involving medium- and small-sized arteries that is especially prevalent in early childhood (ie, age 6 months to 5 years). The diagnosis of KD is made on the basis of clinical features, such as fever, characteristic mucocutaneous changes, and nonsuppurative cervical lymphadenopathy. However, early diagnosis is often challenging because many children with KD present with atypical symptoms. The most serious complication of KD is coronary artery aneurysm caused by coronary arteritis. Prompt intravenous immunoglobulin therapy reduces the risk of cardiac morbidity. In addition, the systemic extension of KD-related vasculitis during the acute phase causes a variety of multisystem manifestations, including encephalopathy, stroke, retropharyngeal edema, pericarditis, myocarditis, KD shock syndrome, pulmonary lesions, intestinal pseudo-obstruction, gallbladder hydrops, arthritis, and myositis. These complications tend to be more common in affected children with atypical presentation. Radiologists can play an important role in the timely identification of diverse KD-associated morbidities and thus may contribute to the early diagnosis of atypical KD. Online supplemental material is available for this article. ^©RSNA, 2021.

Vessel Wall MR Imaging in the Pediatric Head and Neck

Vessel wall MR imaging (VWI) is a technique that progressively has gained traction in clinical diagnostic applications for evaluation of intracranial and extracranial vasculopathies, with increasing use in pediatric populations. The technique has shown promise in detection, differentiation, and characterization of both inflammatory and noninflammatory vasculopathies. In this article, optimal techniques for intracranial and extracranial VWI as well as applications and value for pediatric vascular disease evaluation are discussed.

Ultrasonography as a Diagnostic Support Tool for Childhood Takayasu Arteritis Referred to as Fever of Unknown Origin: Case Series and Literature Review

Introduction

Childhood Takayasu arteritis (c-TA) often shows nonspecific symptoms, such as fever of unknown origin (FUO). Delay of diagnosis may result in organ dysfunction by arterial occlusion; therefore, early diagnosis is very important. Although ultrasonography is the first-line screening tool for children with FUO, its diagnostic efficacy of evaluation of systemic arteries in c-TA that presents as FUO remains unclear. We evaluated the suitability of ultrasonography evaluation that included systemic vessels for the early diagnosis of c-TA initially presenting as FUO.

Methods

We review five patients who received a diagnosis of c-TA in our institution and also performed a literature review regarding TA cases with FUO and diagnosed on the basis of initial ultrasonography.

Results

As in our cases, the median period from onset to diagnosis was 25 days (interquartile range [IQR], 21-35). Comparing the initial ultrasonography findings with later contrast-enhanced computed tomography (CECT) findings in the abdominal aorta, celiac artery, superior mesenteric artery, bilateral renal arteries, and bilateral common carotid arteries, the concordance rate between ultrasonography and CECT was moderate (Kappa coefficient was 0.50). All the patients were successfully treated without severe vascular damage. The literature review revealed 12 articles; although 9 of the 13 patients did not show the characteristic features (such as blood pressure discrepancy, bruit, or pulse deficiency), the median time to diagnosis was still 5 months (IQR, 3-12).

Conclusions

During initial screening for patients with FUO, ultrasonography including evaluation of systemic vessels could contribute to earlier diagnosis of c-TA.

Pediatric Cardiac PET/CT Imaging

With the routine availability of PET/CT imaging for oncologic purposes, there has been renewed interest in and acceptance of cardiac and neurologic applications of PET/CT. As our understanding of the pathophysiology underlying various pediatric heart diseases has improved, there has been a parallel advance in imaging modalities. Cardiac MR imaging and cardiac PET continue to improve in the pediatric domain. Molecular imaging holds promise to provide a more robust assessment of the cardiac pathophysiology in a 1-stop setting with less radiation exposure to the patient, an important consideration for the pediatric patient population.

The importance of FDG PET/CT in the diagnostic process of the middle aortic syndrome in a 15-year-old boy patient with suspected systemic vasculitis and final diagnosis of Williams-Beuren syndrome

The differential diagnosis in children with the systemic vasculopathy is still a challenge for clinicians. The progress in vascular imaging and the latest recommendations improve the diagnostic process, but only single reports describe the use of new imaging tests in children. The publication aims to demonstrate the important role of 18F-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography combined with anatomical computed tomography angiography (PET/CTA) imaging in the case of a 15-year-old boy with chest pain, intermittent claudication, hypertension and features of middle aortic syndrome in computed tomography angiography (CTA). The patient was suspected to have Takayasu arteritis, but was finally diagnosed with Williams–Beuren syndrome. The case indicates that the FDG PET/CT imaging might be essential in the diagnostic process of middle aortic syndrome in children. We suggest that this imaging technique should be considered in the diagnostic process of systemic vasculopathy particularly in children.

Prolonged Fever, Diarrhea, Abdominal Pain, and Joint Pain in a 9-Year- Old Boy

A 9-year-old African American boy was admitted to hospital with a 12-day history of fevers, diarrhea, abdominal pain and a 1-day history of joint pain. His abdominal pain and diarrhea resolved within the first few days of admission, but he continued with high-grade fevers and intermittent joint pain. The joints affected included the right first interphalangeal joint, right wrist, right elbow, and left knee joint. His initial laboratory tests revealed normal complete blood count, comprehensive metabolic panel, and C-reactive protein. Consequently, he developed fatigue, lower back pain, and bicytopenias. After 19 days of fevers, a multispecialty collaborative evaluation arrived at a final diagnosis and treatment plan. In this article, we discuss the child's hospital course and our clinical thought process. Written consent was obtained from the family.

A case of Henoch-Schonlein Purpura with dilated coronary arteries

BACKGROUND

Henoch-Schonlein Purpura (HSP) is one of the most common vasculitides of childhood, with 10-20 cases per 100,000 children. It frequently occurs following an infectious trigger and involves IgA and C3 deposition in small vessel walls. HSP is characterized by palpable purpura plus IgA deposition on biopsy, arthritis/arthralgia, renal involvement (hematuria and/or proteinuria), and/or abdominal pain. It is not generally recognized as a cause of dilated coronary arteries.

CASE PRESENTATION

We describe the first reported case of HSP presenting with dilated coronary arteries. This patient is a nine-year-old previously healthy Caucasian male who presented with 1 week of petechiae on his lower legs, knee and ankle arthritis, and abdominal pain without fever, consistent with HSP. An echocardiogram revealed coronary dilation, including the left main (5.32 mm, Z score + 4.25) and left anterior descending (LAD) (3.51 mm, Z score + 2.64) coronary arteries. He received high dose aspirin, IVIG, and infliximab with normalization of the LAD. Skin biopsy revealed leukocytoclastic vasculitis with positive IgA staining. He was Rhinovirus/Enterovirus positive with Group A Streptococcus on throat culture.

CONCLUSION

Cardiac findings, while rare, can exist in HSP. Coronary dilation appeared to respond to our hospital protocol's Kawasaki Disease (KD) therapy, possibly indicating an overlap in HSP and KD pathophysiology. This case, along with prior reports of dilated coronaries in systemic juvenile idiopathic arthritis (SJIA), highlights the importance of considering other sources of systemic inflammation, in addition to KD, when coronary dilation is identified. The appropriate therapy, follow-up, and prognosis for our patient are not clear, as further studies are needed to determine the natural course of these findings.

Comparison of Power Versus Manual Injection in Bolus Shape and Image Quality on Contrast-Enhanced Magnetic Resonance Angiography: An Experimental Study in a Swine Model

OBJECTIVE

The aim of this study was to compare power versus manual injection in bolus shape and image quality on contrast-enhanced magnetic resonance angiography (CE-MRA).

MATERIALS AND METHODS

Three types of CE-MRA (head-neck 3-dimensional [3D] MRA with a test-bolus technique, thoracic-abdominal 3D MRA with a bolus-tracking technique, and thoracic-abdominal time-resolved 4-dimensional [4D] MRA) were performed after power and manual injection of gadobutrol (0.1 mmol/kg) at 2 mL/s in 12 pigs (6 sets of power and manual injections for each type of CE-MRA). For the quantitative analysis, the signal-to-noise ratio was measured on ascending aorta, descending aorta, brachiocephalic trunk, common carotid artery, and external carotid artery on the 6 sets of head-neck 3D MRA, and on ascending aorta, descending aorta, brachiocephalic trunk, abdominal aorta, celiac trunk, and renal artery on the 6 sets of thoracic-abdominal 3D MRA. Bolus shapes were evaluated on the 6 sets each of test-bolus scans and 4D MRA. For the qualitative analysis, arterial enhancement, superimposition of nontargeted enhancement, and overall image quality were evaluated on 3D MRA. Visibility of bolus transition was assessed on 4D MRA. Intraindividual comparison between power and manual injection was made by paired t test, Wilcoxon rank sum test, and analysis of variance by ranks.

RESULTS

Signal-to-noise ratio on 3D MRA was statistically higher with power injection than with manual injection (P < 0.001). Bolus shapes (test-bolus, 4D MRA) were represented by a characteristic standard bolus curve (sharp first-pass peak followed by a gentle recirculation peak) in all the 12 scans with power injection, but only in 1 of the 12 scans with manual injection. Standard deviations of time-to-peak enhancement were smaller in power injection than in manual injection. Qualitatively, although both injection methods achieved diagnostic quality on 3D MRA, power injection exhibited significantly higher image quality than manual injection (P = 0.001) due to significantly higher arterial enhancement (P = 0.031) and less superimposition of nontargeted enhancement (P = 0.001). Visibility of bolus transition on 4D MRA was significantly better with power injection than with manual injection (P = 0.031).

CONCLUSIONS

Compared with manual injection, power injection provides more standardized bolus shapes and higher image quality due to higher arterial enhancement and less superimposition of nontargeted vessels.

A 15-Year-Old with Aphasia and Right Hemiparesis

Takayasu arteritis (TA) is the third most common vasculitis in childhood, peaking in the second to third decades of life but affecting patients as young as 6 months of age. It often presents with nonspecific systemic symptoms, although at late stages, it may present with cardiac, renal, or focal neurologic sequelae of vascular compromise. In this case, we describe a 15-year-old patient who presented acutely with stroke. In the absence of more classic rheumatological symptoms and significant laboratory abnormalities on initial testing, the diagnosis of TA was only reached through extensive vascular imaging following consultation with multiple subspecialty teams. This case demonstrates the need to maintain a high index of suspicion for vasculitis in pediatric patients presenting with new onset stroke in the absence of known predisposing factors. Doing so may reduce the time to diagnosis, hasten treatment, and optimize outcomes.

The Utility of MRI in the Diagnosis of Takayasu Arteritis

Takayasu Arteritis (TA) is an inflammatory disorder involving the thoracoabdominal aorta and its branches and the pulmonary arteries, with eventual vascular stenosis, occlusion, or aneurysm formation. Conventional angiography has been the reference imaging standard for diagnosis of TA. The purpose of this case report is to demonstrate the utility of MR imaging and MR angiography in the diagnosis of Takayasu Arteritis in a pediatric patient. The patient is a 15-year-old female patient presenting with anemia, hypertension, and acute kidney injury. Initial chest CT demonstrated ectasia of the ascending and focal stenosis of the descending thoracic aorta, prompting further evaluation with MRI and MRA. MRI/MRA demonstrated mural thickening with luminal stenosis of the aorta and aortic branch vessels. These imaging findings were suggestive of a large vessel arteritis and along with the clinical presentation and laboratory abnormalities the diagnosis of Takayasu Arteritis was suggested. Several case series in adults have described the cross-sectional findings of TA. However, this case report demonstrates the utility of MRI/MRA in the evaluation of TA in children and in the course of follow-up, as it provides a noninvasive method for evaluating a child without ionizing radiation or iodinated contrast.

Fludeoxyglucose positron emission tomography-computed tomography scan showing polyarthritis in a patient with an atypical presentation of Henoch-Schönlein vasculitis without clinical signs of arthritis: a case report

Background

Henoch-Schönlein vasculitis is the most common systemic vasculitis in children. Arthritis or arthralgia occurs in 80 % of patients. We believe this to be the first case report to describe the finding of polyarthritis in a fludeoxyglucose positron emission tomography-computed tomography scan in a patient with Henoch-Schönlein vasculitis without clinical signs of arthritis.

Case presentation

A 4.5-year-old Caucasian boy presented with fever of 4 days’ duration followed by debilitating migratory arthralgia and inflammation. He underwent a fludeoxyglucose positron emission tomography-computed tomography scan to exclude a possible malignant cause or to detect any infectious or autoimmune focus of his symptoms. Fludeoxyglucose uptake was observed in multiple large joints and in multiple tendons. These findings suggested active polyarthritis and polytendinitis. However, physical and ultrasound evaluations did not show any signs of arthritis in our patient, despite his evident arthralgia.

Conclusions

Fludeoxyglucose positron emission tomography-computed tomography might be able to detect inflammatory activity in painful joints that cannot yet be detected clinically or with ultrasound evaluation in a patient with Henoch-Schönlein vasculitis. Therefore, fludeoxyglucose positron emission tomography-computed tomography can be of additional value in the diagnostic workup of patients with an unresolved diagnosis of suspected autoimmune disease, especially in patients with unresolved arthralgia and fever of unknown cause.

Updates in Pathophysiology, Diagnosis and Management of Takayasu Arteritis

BACKGROUND

Takayasu arteritis (TA) is a rare, systemic, inflammatory vasculitis of granulomatous nature, and still of unknown etiology. It mainly involves the aorta and its major branches and is more commonly seen in women of childbearing age and Asians. TA leads to stenosis, occlusion, or aneurysmal degeneration of large arteries, and its pathogenesis seems to be mainly due to an abnormal cell-mediated immunity, although other molecular and genetic abnormalities may contribute. The diagnosis and treatments lie on clinical and arteriographic findings. Because of its fluctuating course, both clinical scores and biomarkers are currently evaluated. The aim of this review is to report a comprehensive and methodologically robust state of the art about Takayasu arteritis, including the latest data and evidences in the definition, epidemiology, pathogenesis and etiology, clinical manifestations and classification, diagnosis, assessment of disease activity and progression, biomarkers, and treatment.

METHODS

We searched all publications addressing definition, epidemiology, pathogenesis, etiology, classification, diagnosis, biomarkers, and treatment of TA. Randomized trials, cohort studies, and reviews were contemplated to give a breadth of clinical data. PubMed and Scopus were searched from August 2010 to November 2015.

RESULTS

Of the 3,056 records found, 267 matched our inclusion criteria. After reading the full-text articles, we decided to exclude 169 articles because of the following reasons: (1) no innovative or important content; (2) no multivariable analysis; (3) insufficient data; (4) no clear potential biases or strategies to solve them; (5) no clear end-points; and (6) inconsistent or arbitrary conclusions. The final set included 98 articles.

CONCLUSIONS

This review presents the last updates in all fields of Takayasu arteritis. Still today, large areas of TA pathogenesis and disease-activity assessment need to be further investigated to better treat patients with TA.

Body MR angiography in children: how we do it

Vascular pathology is ubiquitous in children. Common indications for angiographic imaging in the body include congenital anomalies, portal hypertension, assessing resectability of neoplasms, renovascular hypertension, vascular malformations, vasculitis, systemic vein thrombosis, and trauma. MR angiography, with or without the use of intravenous contrast agents, is therefore a mainstay in the repertoire of MR imaging in children. Pediatric contrast-enhanced MR angiography has benefited from several innovations in recent years, including improved hardware options like high-field-strength scanners and integrated high-density coil arrays, new sequences that combine parallel imaging, innovative k-space sampling and Dixon fat suppression with time-resolved imaging, new contrast agents with longer blood-pool residence time, and advanced post-processing solutions like image fusion. This article focuses on the principles of contrast-enhanced MR angiography of the body as it pertains to the physiologies and pathologies encountered in children. It also discusses tools to adapt the MR angiographic technique to the clinical indication, as well as pitfalls of post-processing and interpretation in commonly encountered vascular imaging scenarios in the pediatric body.