Coronary Artery Involvement in Idiopathic Retroperitoneal Fibrosis: Computed Tomographic Findings

Series of myocardial FDG uptake requiring considerations of myocardial abnormalities in FDG-PET/CT

Distinct from cardiac PET performed with preparation to control physiological FDG uptake in the myocardium, standard FDG-PET/CT performed with 4-6 h of fasting will show variation in myocardial FDG uptake. For this reason, important signs of myocardial and pericardial abnormality revealed by myocardial FDG uptake tend to be overlooked. However, recognition of possible underlying disease will support further patient management to avoid complications due to the disease. This review demonstrates the mechanism of FDG uptake in the myocardium, discusses the factors affecting uptake, and provides notable image findings that may suggest underlying disease.

Multimodality Imaging of Focal and Diffuse Fibrosing Mediastinitis

Fibrosing mediastinitis is a rare benign but potentially life-threatening process that occurs because of proliferation of fibrotic tissue in the mediastinum. The focal subtype is more common and typically is associated with an abnormal immunologic response to Histoplasma capsulatum infection. Affected patients are typically young at presentation, but a wide age range has been reported, without a predilection for either sex. The diffuse form may be idiopathic or associated with autoimmunity, usually affects middle-aged and/or elderly patients, and is more common in men. For both subtypes, patients present with signs and symptoms related to obstruction or compression of vital mediastinal structures. The most common presenting signs and symptoms are cough, dyspnea, recurrent pneumonia, hemoptysis, and pleuritic chest pain. Patients with the diffuse subtype may have additional extrathoracic symptoms depending on the other organ systems involved. Because symptom severity is variable, treatment should be individualized with therapies tailored to alleviate compression of the affected mediastinal structures. Characteristic imaging features of fibrosing mediastinitis include infiltrative mediastinal soft tissue (with or without calcification) with compression or obstruction of mediastinal vascular structures and/or the aerodigestive tract. When identified in the appropriate clinical setting, these characteristic features allow the radiologist to suggest the diagnosis of fibrosing mediastinitis. Careful assessment is crucial at initial and follow-up imaging for exclusion of underlying malignancy, assessment of disease progression, identification of complications, and evaluation of treatment response. Online supplemental material is available for this article. ^©RSNA, 2019.

Immunoglobulin G4-related Coronary Periarteritis and Luminal Stenosis in a Patient with a History of Autoimmune Pancreatitis

Immunoglobulin G4 (IgG4)-related disease is a systemic inflammatory disorder that was first described in patients with autoimmune pancreatitis. Although IgG4-related disease is thought to involve the cardiovascular system, case reports describing coronary artery involvement are relatively rare. We describe a patient who was previously diagnosed with autoimmune pancreatitis and found to have coronary periarteritis and luminal narrowing. After the initiation of steroid treatment, the patient's coronary periarteritis and luminal stenosis were both ameliorated with an improvement in the serum IgG4 concentration. The present findings collectively suggest that IgG4-related immuno-inflammation may have a role in the development of coronary periarteritis and luminal atherosclerosis.

Unique angiographic findings in a patient with myocardial ischemia and immunoglobulin G4-related disease

Immunoglobulin G4-related disease characteristically involves multiple organs including the heart and coronary arteries. Immunoglobulin G4-related coronary artery disease is thought to be due to periarteritis and histopathologically is characterized by marked thickening of the adventitia and periarterial fat with infiltration of immunoglobulin G4-positive plasma cells. Although comprehensive diagnostic criteria require a biopsy for a definite or probable diagnosis of immunoglobulin G4-related disease, obtaining a coronary artery biopsy is difficult and risky. However, imaging findings including coronary angiography and intravascular ultrasound might be useful tools to establish a diagnosis of immunoglobulin G4-related coronary artery disease. We report a case of a 63-year-old man with a history of immunoglobulin G4-related disease who presented with exertional chest pain. We found unique angiographic and intravascular ultrasound features of immunoglobulin G4-related coronary artery disease that distinguished it from those of arteriosclerotic coronary artery disease and suggest that coronary angiography and intravascular ultrasound might be useful tools in the diagnosis of immunoglobulin G4-related coronary artery disease.

Pulmonary hypertension associated with combined fibrosing mediastinitis and bronchial anthracofibrosis: A retrospective analysis in a single Chinese hospital

INTRODUCTION

Both fibrosing mediastinitis (FM) and bronchial anthracofibrosis (BAF) are unique diseases. The combined appearance of FM and BAF is extremely rare.

OBJECTIVES

The aim of this study was to investigate the clinical features of patients with coexisting FM and BAF.

METHOD

Between January 2003 and December 2015, a total of eight patients were diagnosed at the Peking Union Medical College Hospital as having combined FM and BAF. The clinical presentations, radiographic features and bronchoscopic findings of the eight patients were reviewed.

RESULTS

The patients were five women and three men with a median age of 64 years (range 56-86 years). Symptoms included dyspnea (eight patients), cough (seven patients), chest pain (two patients), hemoptysis (two patients) and so on. Chest CT of all eight patients showed mediastinal soft-tissue lesions, with multiple narrowed or obliterated lobar or segmental bronchi and arteries. Bronchoscopy showed that all of the patients had multiple stenoses of lobar or segmental bronchi with anthracotic pigmentation on the mucosa. Echocardiography showed that all of the patients had elevated pulmonary arterial systolic pressure (median 81 mm Hg, range 51-107 mm Hg). Each of the eight patients had a history of exposure to, or infection with, tuberculosis, although there was no evidence of active disease. All of the eight patients had long-term exposure to indoor coal or biomass fuel smoke.

CONCLUSIONS

FM can coexist with BAF, characterized by prominent pulmonary hypertension. The possible etiological factors are tuberculosis and coal or biomass fuel exposure.

Coronary Artery Manifestation of Ormond Disease: The "Mistletoe Sign"

A 69-year-old woman presented with symptoms of presumed cardiac involvement of idiopathic retroperitoneal fibrosis, otherwise known as Ormond disease. Distinct pericoronary tissue proliferations were depicted at cardiac magnetic resonance (MR) imaging and coronary computed tomographic (CT) angiography. On images, the coronary manifestation was termed the "mistletoe sign." The presence of the mistletoe sign on cardiac MR and coronary CT angiographic images is probably rare, but it might be a characteristic manifestation of retroperitoneal fibrosis. With the increasing number of noninvasive cardiac imaging tests performed worldwide, the recognition of the mistletoe sign could be helpful in diagnosing retroperitoneal fibrosis. ^© RSNA, 2016 Online supplemental material is available for this article.

Relationship between serum IgG4 concentrations and atherosclerotic coronary plaques assessed by computed tomographic angiography

BACKGROUND

Immunoglobulin G4 (IgG4)-related immuno-inflammation has been suggested to affect the development of coronary artery atherosclerosis. The aim of this study was to analyze the association of serum IgG4 concentrations with calcified and non-calcified coronary plaques.

METHODS

Serum IgG4 concentrations were measured in 263 patients who underwent 320-slice coronary computed tomographic (CT) angiography. Vulnerable coronary plaques were evaluated for CT plaque characteristics, including low-density plaque (LDP), positive remodeling, and spotty calcification.

RESULTS

Serum concentrations of IgG4 were significantly higher in patients with non-calcified plaque (NCP) than in those without (32.2mg/dL vs. 23.7mg/dL, p=0.029). By contrast, the median serum IgG4 concentrations in patients with and without calcified plaque were 31.2mg/dL and 26.2mg/dL, respectively (p=0.107). Serum IgG4 concentrations were significantly elevated in patients with LDP (33.5mg/dL vs. 26.9mg/dL, p=0.002) and in those with positive remodeling (31.4mg/dL vs. 28.4mg/dL, p=0.039) than in those without. Patients with spotty calcification also had significantly higher serum IgG4 concentrations than those without (32.1mg/dL vs. 24.9mg/dL, p=0.049). In age- and gender-adjusted logistic regression analysis, the highest IgG4 quartile (≥56.7mg/dL) was significantly associated with LDP with an odds ratio of 2.49 (95% CI, 1.15-5.36, p=0.020).

CONCLUSIONS

Serum IgG4 concentrations were significantly associated with NCP, especially with LDP, suggesting that IgG4-related immuno-inflammation may play a role in coronary plaque vulnerability.

Coronary periarteritis in a patient with multi-organ IgG4-related disease

Immunoglobulin G4-related disease is a recently described systemic clinicopathological entity characterized by immunoglobulin G4-producing plasmacytic infiltration of tissue and frequently by elevated serum immunoglobulin G4 concentration. Manifestations of this disease have been documented in nearly all organs and locations, but coronary artery involvement is not widely recognized. We report the coronary findings of a patient with multi-organ immunoglobulin G4-related disease. Non-electrocardiogram-gated computed tomography of the chest demonstrated nodular and rind-like periarterial soft tissue thickening along the proximal coronary artery segments with improvement following steroid therapy.

Retroperitoneal fibrosis

Retroperitoneal fibrosis (RPF) is a rare disease that is marked by systemic inflammation and the development of a periaortic fibroinflammatory mass. The fibroinflammatory infiltration can encase the abdominal aorta, ureters, and other abdominal organs. The clinical presentation often includes constitutional symptoms, abdominal pain, and signs of renal insufficiency or renal failure related to ureteral obstruction. Less frequently, RPF may present with vascular complications, such as venous thrombosis or claudication. The idiopathic form of RPF is most common but secondary forms have been described and are associated with malignancy and a variety of different medications. The pathophysiology is uncertain, but RPF has been linked with periaortitis and IgG4-related disease. Treatment centers on the relief of symptoms and complications associated with mass effects. Corticosteroids and other immunosuppressant therapies can improve constitutional symptoms, reduce infiltrate mass, and achieve disease remission, but a chronic relapsing course is not uncommon.