Waxing and Waning Presentation of Isolated Cardiac Sarcoidosis on Sequential 18F-FDG PET Examinations.

We describe the case of a patient who had suspected myocardial ischemia, showed normal findings on multiple perfusion scans, and showed isolated cardiac sarcoidosis on 18F-FDG-PET. Also discussed are the diagnosis and the monitoring of disease response using imaging follow-up.

Effect of Elevated Calcium Score on Normal Myocardial Perfusion Study on Clinician Management of Coronary Artery Disease Risk Factors.

Elevated coronary artery calcification (CAC) scores are associated with higher cardiovascular (CV) risk even with normal stress myocardial perfusion imaging (MPI). Whether referring providers appropriately manage subclinical CV disease is unclear. We hypothesized that ordering clinicians would intensify medical therapy for CV disease in response to normal MPI and CAC ≥ 300. We conducted a cohort study on patients without known CV disease who underwent MPI and CAC scoring. Medical management of CV disease and clinical outcomes were assessed. Of 299 patients who underwent stress MPI, 62 patients had normal MPI and CAC ≥ 300. Documentation of elevated CAC score was noted in the final interpretation for 52% (n = 32) of MPI reports. During follow-up, treatment change in aspirin, cholesterol medications, and/or antihypertensive medication was made in 40% of these patients. Aspirin use increased from 71% to 82% (P < 0.001); statin use increased from 68% to 76% (P < 0.001). Several patients remained on suboptimal lipid or antiplatelet regimens without documented contraindication. Among patients with normal MPI, many have CAC ≥ 300. Not all MPI reports adequately call attention to this finding associated with elevated CV risk. Despite the elevated CAC score, some patients were not optimized medically.

Multimodality Imaging of Dementia: Clinical Importance and Role of Integrated Anatomic and Molecular Imaging.

Neurodegenerative diseases are a devastating group of disorders that can be difficult to accurately diagnose. Although these disorders are difficult to manage owing to relatively limited treatment options, an early and correct diagnosis can help with managing symptoms and coping with the later stages of these disease processes. Both anatomic structural imaging and physiologic molecular imaging have evolved to a state in which these neurodegenerative processes can be identified relatively early with high accuracy. To determine the underlying disease, the radiologist should understand the different distributions and pathophysiologic processes involved. High-spatial-resolution MRI allows detection of subtle morphologic changes, as well as potential complications and alternate diagnoses, while molecular imaging allows visualization of altered function or abnormal increased or decreased concentration of disease-specific markers. These methodologies are complementary. Appropriate workup and interpretation of diagnostic studies require an integrated, multimodality, multidisciplinary approach. This article reviews the protocols and findings at MRI and nuclear medicine imaging, including with the use of flurodeoxyglucose, amyloid tracers, and dopaminergic transporter imaging (ioflupane). The pathophysiology of some of the major neurodegenerative processes and their clinical presentations are also reviewed; this information is critical to understand how these imaging modalities work, and it aids in the integration of clinical data to help synthesize a final diagnosis. Radiologists and nuclear medicine physicians aiming to include the evaluation of neurodegenerative diseases in their practice should be aware of and familiar with the multiple imaging modalities available and how using these modalities is essential in the multidisciplinary management of patients with neurodegenerative diseases.©RSNA, 2020.

Phase-Contrast MRI: Physics, Techniques, and Clinical Applications.

With phase-contrast imaging, the MRI signal is used to visualize and quantify velocity. This imaging modality relies on phase data, which are intrinsic to all MRI signals. With use of bipolar gradients, degrees of phase shift are encoded and in turn correlated directly with the velocity of protons. The acquisition of diagnostic-quality images requires selection of the correct imaging plane to ensure accurate measurement and selection of the encoding velocity and thus prevent aliasing and achieve the highest signal-to-noise ratio. Multiple applications of phase-contrast imaging are actively used in clinical practice. One of the most common clinical uses is in cardiac valvular flow imaging, at which the data are used to assess the severity of valvular disease and quantify the shunt fraction. In neurologic imaging, phase-contrast imaging can be used to measure the flow of cerebrospinal fluid. This measurement can aid in the diagnosis and direct management of normal pressure hydrocephalus or be used to evaluate the severity of stenosis, such as that in Chiari I malformations. At vascular analysis, phase-contrast imaging can be used to visualize arterial and venous flow, and this application is used most commonly in the brain. Three-dimensional imaging can yield highly detailed flow data in a technique referred to as four-dimensional flow. A more recently identified application is in MR elastography. Shear waves created by using an impulse device can be velocity encoded, and this velocity is directly proportional to the stiffness of the organ, or the shear modulus. This imaging modality is most commonly used in the liver for evaluation of cirrhosis and steatosis, although research on the assessment of other organs is being performed. Phase-contrast imaging is an important tool in the arsenal of MRI examinations and has many applications. Proper use of phase-contrast imaging requires an understanding of the many practical and technical factors and unique physics principles underlying the technique.©RSNA, 2020.

Recurrent metastatic breast cancer manifesting as pulmonary tumor thrombotic microangiopathy with interstitial pulmonary fibrosis and infarcts: A clinicopathological correlation.

Pulmonary Tumor Thrombotic Microangiopathy (PTTM) is a fatal complication of malignancy characterized by embolization of tumor cells to the pulmonary vasculature leading to a vascular reaction resulting in stenosis and pulmonary hypertension. Because the clinical manifestations of PTTM overlap with those of other entities, premortem diagnosis is challenging. We describe an unusual case of PTTM as the only clinical manifestation of recurrent metastatic breast cancer. A 50 year-old woman presented with hypoxemia and echocardiographic findings consistent with pulmonary hypertension and cor pulmonale. Correlation of premortem pulmonary imaging with autopsy histopathologic findings revealed that ill-defined ground-glass opacities identified on CT angiogram corresponded to areas of cellular interstitial fibrosis and widespread intrapulmonary tumor emboli involving predominantly small-sized arteries with associated florid intimal fibrosis. The radiologic nodularities and scattered peripheral wedge-shaped consolidations corresponded to evolving pulmonary infarcts on histopathology. Although retrospectively, the imaging findings were concordant with a spectrum of increasing severity of tumor embolization and vascular remodeling, the diagnosis of PTTM was not made premortem. PTTM is a rare entity that must be considered in cancer patients with unexplained hypoxemia, pulmonary hypertension and lung opacities on imaging.

Image Quality and Patient-Specific Organ Doses in Stone Protocol CT: A Comparison of Traditional CT to Low Dose CT with Iterative Reconstruction.

OBJECTIVE: To compare organ specific radiation dose and image quality in kidney stone patients scanned with standard CT reconstructed with filtered back projection (FBP-CT) to those scanned with low dose CT reconstructed with iterative techniques (IR-CT). MATERIALS AND METHODS: Over a one-year study period, adult kidney stone patients were retrospectively netted to capture the use of noncontrasted, stone protocol CT in one of six institutional scanners (four FBP and two IR). To limit potential CT-unit use bias, scans were included only from days when all six scanners were functioning. Organ dose was calculated using volumetric CT dose index and patient effective body diameter through validated conversion equations derived from previous cadaveric, dosimetry studies. Board-certified radiologists, blinded to CT algorithm type, assessed stone characteristics, study noise, and image quality of both techniques. RESULTS: FBP-CT (n=250) and IR-CT (n=90) groups were similar in regard to gender, race, body mass index (mean BMI = 30.3), and stone burden detected (mean size 5.4 ± 1.2 mm). Mean organ-specific dose (OSD) was 54-62% lower across all organs for IR-CT compared to FBP-CT with particularly reduced doses (up to 4.6-fold) noted in patients with normal BMI range. No differences were noted in radiological assessment of image quality or noise between the cohorts, and intrarater agreement was highly correlated for noise (AC2=0.873) and quality (AC2=0.874) between blinded radiologists. CONCLUSIONS: Image quality and stone burden assessment were maintained between standard FBP and low dose IR groups, but IR-CT decreased mean OSD by 50%. Both urologists and radiologists should advocate for low dose CT, utilizing reconstructive protocols like IR, to reduce radiation exposure in their stone formers who undergo multiple CTs.

Coronary artery bypass graft pseudoaneurysm from saphenous vein graft stent fracture.

Saphenous venous graft (SVG) pseudoaneurysms are a rare complication of coronary artery bypass grafting (CABG). An 85-year-old man with CABG and a distal SVG stent presented with dyspnea. Chest computed tomography (CT) revealed a large partially thrombosed pseudoaneurysm at the distal SVG with stent fracture. Endoluminal exclusion of the distal SVG pseudoaneurysm using a covered stent was performed. Follow-up chest CT and angiography showed persistent pseudoaneurysm filling and enlargement. The SVG proximal to the pseudoaneurysm was embolized with coils to reduce rupture risk. Following embolization, the patient's left ventricular ejection fraction was moderately depressed but the patient remained stable and was discharged. .

Comparative accuracy of supine-only and combined supine-prone myocardial perfusion imaging in men.

BACKGROUND: Combined supine-prone myocardial perfusion imaging (CSP MPI) has been shown to reduce attenuation artifact in comparison to supine-only (SU) MPI in mixed-gender populations with varying risk for coronary artery disease (CAD), often where patients served as their own controls. However, there is limited direct comparison of these imaging strategies in men. METHODS: 934 male patients underwent CSP or SU MPI. Diagnostic certainty of interpretation was compared. Within the cohort, 116 were referred for left heart catheterization (LHC) to assess for CAD. Sensitivity, specificity, and area under the curve (AUC) were compared with additional analysis based on body mass index (BMI). RESULTS: 597 patients completed the SU protocol and 337 patients completed the CSP protocol. Equivocal studies were seen more frequently in the SU group (13%) than in the CSP group (4%, P < .001). At catheterization, the specificity for CSP MPI of 70% was higher than 40% for SU MPI (P = .032). The CSP AUC (0.80 ± 0.06) was significantly larger than SU AUC (0.57 ± 0.05, P = .004). CSP specificity was significantly higher in obese patients. CONCLUSIONS: CSP MPI increases diagnostic certainty and improves test accuracy for CAD detection in men with CAD risk factors, especially obese patients, compared to SU MPI.

Fluorodeoxyglucose-positron-emission tomography/computed tomography imaging for adrenal masses in patients with lung cancer: review and diagnostic algorithm.

BACKGROUND AND PURPOSE: Positron-emission tomography/computed tomography (PET/CT) with fluorine-18 fluorodeoxyglucose (FDG) is used as first-line staging for patients with newly diagnosed non-small cell lung cancer (NSCLC). Our purpose was to review the accuracy of FDG-PET/CT to predict adrenal gland metastasis, explain the causes for false-positive PET, and provide a diagnostic algorithm. PATIENTS AND METHODS: Two patients with incidentally discovered lung masses were found to have hypermetabolic adrenal activity by FDG-PET/CT with maximal standard uptake value (SUV) of 4.5 and 6.5. A MEDLINE search was performed on the topic of FDG-PET/CT, adrenal gland metastasis, and NSCLC. Literature was reviewed with regard to diagnosis, accuracy, outcomes, and alternative imaging or diagnostic strategies. RESULTS: Both patients underwent transabdominal laparoscopic adrenalectomy and were found to have nodular hyperplasia without evidence of adrenal tumor. A total of seven articles containing 343 patients were identified as having pertinent oncologic information for NSCLC patients with adrenal lesions. Sensitivity and specificity of PET/CT for distant metastasis was 94% and 85%, respectively, but only 13% (44/343) of these patients had histologically confirmed adrenal diagnoses. Based on this, a diagnostic algorithm was created to aid in decision making. CONCLUSIONS: Although PET/CT has high sensitivity and specificity for adrenal metastasis in the setting of NSCLC, adrenal biopsy or other secondary imaging should be considered to confirm the finding. Adrenalectomy in lieu of biopsy may have both diagnostic and therapeutic benefit in cases where the adrenal mass is ≥10 mm with high PET maximum SUV (≥3.1) and SUV ratios (>2.5), where washout CT or chemical shift MRI is positive, or where percutaneous biopsy is deemed too difficult or unsafe.

Case of persistent left superior vena cava draining via the left atrium with a normal coronary sinus utilizing cardiac CT.

With an estimated incidence of ≈ 0.5%-2% of the population and 10% of patients with congenital heart disorders, persistent LSVC is the most common venous anomaly of the chest. Most drain via the right atrium. Rarely (7.5% of cases), the persistent LSVC may drain directly into the left atrium. These are typically seen with a coronary sinus type atrial septal defect with many investigators believing that, embryologically, a normal coronary sinus cannot exist in the setting of a persistent LSVC draining into the left atrium. There have been few case reports of this in the setting of a normal coronary sinus. With the assistance of cardiac CT, we were able to show the existence of this rare entity. The CT images provided guidance for a successful endovascular repair.

Immediate computed tomography coronary angiography versus delayed outpatient stress testing for detecting coronary artery disease in emergency department patients with chest pain.

Noninvasive testing for coronary artery disease (CAD) is warranted for symptomatic patients with intermediate pretest likelihood of CAD. Accomplishing testing in an emergency department (ED) environment is challenging. We compared two strategies of CAD testing in ED patients: immediate computed tomography coronary angiography (CTCA) versus delayed outpatient stress testing. We conducted a historical control cohort study comparing symptomatic ED patients without an acute coronary syndrome who warranted noninvasive CAD testing. Two cohorts (50 patients each) were defined by CAD testing strategy, immediate CTCA versus delayed stress testing. Outcomes were duration of ED stay, detection of CAD, and 3-month rates of readmission, myocardial infarction, (MI) or death. Median duration of stay was 417.5 minutes (interquartile range [IQR] 359.0-581.0) in the CT cohort and 400.0 minutes (IQR 338.0-471.0) in the control cohort (P = 0.53). CAD was detected in 14 CT cohort patients versus 1 in control (P = 0.0004), due to low follow-up in the control cohort (18 of 50, 36%). Obstructive CAD was diagnosed in 6 CT cohort patients versus 1 in control (P = 0.11). During 3 months of follow-up, four patients in each cohort were reevaluated in the ED for chest pain; no patients suffered MI or death. A strategy of immediate CTCA is superior to a delayed stress testing strategy for detecting CAD in ED patients with chest pain and prompting appropriate referrals for further management. Delayed stress testing was primarily ineffective due to low follow-up. Immediate CTCA can be used safely without altering the ED duration of stay.

Toll-like receptor 3 ligands induce CD80 expression in human podocytes via an NF-κB-dependent pathway.

BACKGROUND: Recent studies suggest that CD80 (also known as B7.1) is expressed on podocytes in minimal-change disease (MCD) and may have a role in mediating proteinuria. CD80 expression is known to be induced by Toll-like receptor (TLR) ligands in dendritic cells. We therefore evaluated the ability of TLR to induce CD80 in human cultured podocytes. METHODS: Conditionally immortalized human podocytes were evaluated for TLR expression. Based on high expression of TLR3, we evaluated the effect of polyinosinic-polycytidylic acid (polyIC), a TLR3 ligand, to induce CD80 expression in vitro. RESULTS: TLR1-6 and 9 messenger RNA (mRNA) were expressed in podocytes. Among TLR ligands 1-9, CD80 mRNA expression was significantly induced by polyIC and lipopolysaccharide (TLR4 ligand) with the greatest stimulation by polyIC (6.8 ± 0.7 times at 6 h, P < 0.001 versus control). PolyIC induced increased expression of Cathepsin L, decreased synaptopodin expression and resulted in actin reorganization which suggested a similar injury pattern as observed with lipopolyssaccharide. PolyIC induced type I and type II interferon signaling, nuclear factor kappa B (NF-κB) activation and the induction of CD80 expression. Knockdown of CD80 protected against actin reorganization and reduced synaptopodin expression in response to polyIC. Dexamethasone, a corticosteroid commonly used to treat MCD, also blocked both basal and polyIC-stimulated CD80 expression, as did inhibition of NF-κB. CONCLUSIONS: Activation of TLR3 on cultured human podocytes induces CD80 expression and phenotypic change via an NF-κB-dependent mechanism and is partially blocked by dexamethasone. These studies provide a mechanism by which viral infections may cause proteinuria.

Hyperuricemia as a mediator of the proinflammatory endocrine imbalance in the adipose tissue in a murine model of the metabolic syndrome.

OBJECTIVE: Hyperuricemia is strongly associated with obesity and metabolic syndrome and can predict visceral obesity and insulin resistance. Previously, we showed that soluble uric acid directly stimulated the redox-dependent proinflammatory signaling in adipocytes. In this study we demonstrate the role of hyperuricemia in the production of key adipokines. RESEARCH DESIGN AND METHODS: We used mouse 3T3-L1 adipocytes, human primary adipocytes, and a mouse model of metabolic syndrome and hyperuricemia. RESULTS: Uric acid induced in vitro an increase in the production (mRNA and secreted protein) of monocyte chemotactic protein-1 (MCP-1), an adipokine playing an essential role in inducing the proinflammatory state in adipocytes in obesity. In addition, uric acid caused a decrease in the production of adiponectin, an adipocyte-specific insulin sensitizer and anti-inflammatory agent. Uric acid-induced increase in MCP-1 production was blocked by scavenging superoxide or by inhibiting NADPH oxidase and by stimulating peroxisome-proliferator-activated receptor-γ with rosiglitazone. Downregulation of the adiponectin production was prevented by rosiglitazone but not by antioxidants. In obese mice with metabolic syndrome, we observed hyperuricemia. Lowering uric acid in these mice by inhibiting xanthine oxidoreductase with allopurinol could improve the proinflammatory endocrine imbalance in the adipose tissue by reducing production of MCP-1 and increasing production of adiponectin. In addition, lowering uric acid in obese mice decreased macrophage infiltration in the adipose tissue and reduced insulin resistance. CONCLUSIONS: Hyperuricemia might be partially responsible for the proinflammatory endocrine imbalance in the adipose tissue, which is an underlying mechanism of the low-grade inflammation and insulin resistance in subjects with the metabolic syndrome.

Responsible use of computed tomography in the evaluation of coronary artery disease and chest pain.

Many options are available to clinicians for the noninvasive evaluation of the cardiovascular system and patient concerns about chest discomfort. Cardiac computed tomography (CT) is a rapidly advancing field of noninvasive imaging. Computed tomography incorporates coronary artery calcium scoring, coronary angiography, ventricular functional analysis, and information about noncardiac thoracic anatomy. We searched the PubMed database and Google from inception to September 2009 for resources on the accuracy, risk, and predictive capacity of coronary artery calcium scoring and CT coronary angiography and have reviewed them herein. Cardiac CT provides diagnostic information comparable to echocardiography, nuclear myocardial perfusion imaging, positron emission tomography, and magnetic resonance imaging. A cardiac CT study can be completed in minutes. In patients with a nondiagnostic stress test result, cardiac CT can preclude the need for invasive angiography. Prognostic information portends excellent outcomes in patients with normal study results. Use of cardiac CT can reduce health care costs and length of emergency department stays for patients with chest pain. Cardiac CT examination provides clinically relevant information at a radiation dose similar to well-established technologies, such as nuclear myocardial perfusion imaging. Advances in technique can reduce radiation dose by 90%. With appropriate patient selection, cardiac CT can accurately diagnose heart disease, markedly decrease health care costs, and reliably predict clinical outcomes.

Does surgical closure technique affect early mammographic detection of tumor recurrence after breast-conserving therapy?

PURPOSE: Scarring in the tumor bed may mask or mimic local recurrence of tumor on surveillance mammography. Type of surgical closure technique used during lumpectomy may impact the pattern or density of scar tissue apparent in the tumor bed on mammography. This study sought to determine whether surgical closure type affects tumor-bed scar formation and impacts interpretation of surveillance mammography in women treated with breast-conserving therapy for early-stage breast cancer. MATERIALS AND METHODS: One hundred women who received breast-conserving therapy were selected; 99 of them had 2-year post-treatment mammograms for the treated breast. Craniocaudal and mediolateral oblique views were reviewed by 3 subspecialty radiologists who routinely read mammograms. The mammograms were scored on 5-point scales for overall breast density and scarring within the tumor bed. RESULTS: The analyses did not demonstrate greater scarring or density in breast status post superficial closure compared with breast status post full-thickness closure, or vice versa (P > 0.05 for scarring and density). There were no detectable differences between the 2 closure techniques either within the data from individual reviewers, within the composite data for the entire group of reviewers, or in instances where 2 of 3 reviewers agreed (P > 0.05). There was significant interobserver variability in scoring among the mammographers for both scarring (P = 0.001) and density (P < 0.0001). CONCLUSION: Based on our study of the 2-year post-treatment mammograms, there was no evidence that closure technique impacts degree of scarring in the tumor bed. However, striking interobserver variability in scoring density and scarring was noted.

Detecting infiltrating lobular carcinoma using scintimammographic breast specific gamma imaging.

UNLABELLED: This study evaluated the effectiveness of scintimammography performed with gamma cameras optimized for breast imaging in the detection of infiltrating lobular carcinoma. This new procedure, Breast Specific Gamma Imaging (BSGI), was conducted on 105 patient presenting with 113 breast lesions. Studies were conducted at two medical centers using three prototype cameras [14, 16]. Biopsy and pathology reports were obtained for all cases and, of the 34 detected carcinomas, 6 were determined to be infiltrating lobular type without mixed component other than lobular carcinoma in situ. Of the 6 lesions, 4 were smaller than 1 cm, the smallest moasuring 3 mm at biopsy. BSGI detected all 6 of the lobular carcinomas and correctly identified the secondary lesion in the only multifocal case. The BSGI foci sizes matched the lesion size at biopsy to within +/-5.5 mm, with about an equal number of cases ovar and under estimated. CONCLUSION: BSGI provides an effective tool for the detection of lobular carcinoma and in the determination of lesion size and multifocality.