Developmental or Procedural Vena Cava Interruption and Venous Thromboembolism: A Review.

The inferior vena cava (IVC) and superior vena cava are the main conduits of the systemic venous circulation into the right atrium. Developmental or procedural interruptions of vena cava might predispose to stasis and deep vein thrombosis (DVT) distal to the anomaly and may impact the subsequent rate of pulmonary embolism (PE). This study aimed to review the various etiologies of developmental or procedural vena cava interruption and their impact on venous thromboembolism. A systematic search was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines per each clinical question. For management questions with no high-quality evidence and no mutual agreements between authors, Delphi methods were used. IVC agenesis is the most common form of congenital vena cava interruption, is associated with an increased risk of DVT, and should be suspected in young patients with unexpected extensive bilateral DVT. Surgical techniques for vena cava interruption (ligation, clipping, and plication) to prevent PE have been largely abandoned due to short-term procedural risks and long-term complications, although survivors of prior procedures are occasionally encountered. Vena cava filters are now the most commonly used method of procedural interruption, frequently placed in the infrarenal IVC. The most agreed-upon indication for vena cava filters is for patients with acute venous thromboembolism and coexisting contraindications to anticoagulation. Familiarity with different forms of vena cava interruption and their local and systemic adverse effects is important to minimize complications and thrombotic events.

Multimodality imaging to assess diagnosis and evaluate complications of large vesselarteritis.

Different types of vasculitis can be distinguished according to the blood vessel's size that is preferentially affected: large-vessel, medium-vessel, and small-vessel vasculitides. Giant cell arteritis (GCA) and Takayasu's arteritis (TAK) are the main forms of large-vessel vasculitis, and may lead to lumen narrowing. Clinical manifestations of arterial narrowing on the short- and long term include vision loss, stroke, limb ischemia, and heart failure. Imaging tools are well established diagnostic tests for large-vessel vasculitis and may aid therapy monitoring in selected cases while providing important information regarding the occurrence of vascular damage, tissue and organ complications. This review aims to provide the current status of multimodality imaging for the diagnosis and identification of vascular complications in the field of large vessel vasculitis.

Multimodality imaging to distinguish between benign and malignant cardiac masses.

BACKGROUND: To compare the diagnostic accuracy of CMR and FDG-PET/CT and their complementary role to distinguish benign vs malignant cardiac masses. METHODS: Retrospectively assessed patients with cardiac mass who underwent CMR and FDG-PET/CT within a month between 2003 and 2018. RESULTS: 72 patients who had CMR and FDG-PET/CT were included. 25 patients (35%) were diagnosed with benign and 47 (65%) were diagnosed with malignant masses. 56 patients had histological correlation: 9 benign and 47 malignant masses. CMR and FDG-PET/CT had a high accuracy in differentiating benign vs malignant masses, with the presence of CMR features demonstrating a higher sensitivity (98%), while FDG uptake with SUVmax/blood pool ≥ 3.0 demonstrating a high specificity (88%). Combining multiple (> 4) CMR features and FDG uptake (SUVmax/blood pool ratio ≥ 3.0) yielded a sensitivity of 85% and specificity of 88% to diagnose malignant masses. Over a mean follow-up of 2.6 years (IQR 0.3-3.8 years), risk-adjusted mortality were highest among patients with an infiltrative border on CMR (adjusted HR 3.1; 95% CI 1.5-6.5; P = .002) or focal extracardiac FDG uptake (adjusted HR 3.8; 95% CI 1.9-7.7; P < .001). CONCLUSION: Although CMR and FDG-PET/CT can independently diagnose benign and malignant masses, the combination of these modalities provides complementary value in select cases.

Multimodality Imaging of Large-Vessel Vasculitis, From the AJR Special Series on Inflammation.

Large-vessel vasculitis (LVV) is a noninfectious inflammation of the large vessels, including the aorta and its main branches. Imaging plays an essential role in diagnosing LVV given the challenges of tissue biopsy. This article reviews the types of LVV and the multimodality imaging tools available to establish its diagnosis. The cornerstone of imaging diagnosis is morphologic assessment using gray-scale ultrasound (US), gray-scale US combined with color Doppler US, CTA, or MRA. In the last decade, substantial progress has been made in functional and molecular imaging with FDG PET/CT for the diagnosis of LVV. Investigation is ongoing to develop novel MRA techniques and new PET tracers to assess disease activity and to differentiate the various vasculitides. An algorithm is provided to guide imaging technique selection based on the patient's specific clinical presentation.

Comparison of myocardial fibrosis quantification methods by cardiovascular magnetic resonance imaging for risk stratification of patients with suspected myocarditis.

BACKGROUND: Although the presence of late gadolinium enhancement (LGE) using cardiovascular magnetic resonance imaging (CMR) is a significant discriminator of events in patients with suspected myocarditis, no data are available on the optimal LGE quantification method. METHODS: Six hundred seventy consecutive patients (48 ± 16 years, 59% male) with suspected myocarditis were enrolled between 2002 and 2015. We performed LGE quantitation using seven different signal intensity thresholding methods based either on 2, 3, 4, 5, 6, 7 standard deviations (SD) above remote myocardium or full width at half maximum (FWHM). In addition, a LGE visual presence score (LGE-VPS) (LGE present/absent in each segment) was assessed. For each of these methods, the strength of association of LGE results with major adverse cardiac events (MACE) was determined. Inter-and intra-rater variability using intraclass-correlation coefficient (ICC) was performed for all methods. RESULTS: Ninety-eight (15%) patients experienced a MACE at a medium follow-up of 4.7 years. LGE quantification by FWHM, 2- and 3-SD demonstrated univariable association with MACE (hazard ratio [HR] 1.05, 95% confidence interval [CI]:1.02-1.08, p = 0.001; HR 1.02, 95%CI:1.00-1.04; p = 0.001; HR 1.02, 95%CI: 1.00-1.05, p = 0.035, respectively), whereas 4-SD through 7-SD methods did not reach significant association. LGE-VPS also demonstrated association with MACE (HR 1.09, 95%CI: 1.04-1.15, p < 0.001). In the multivariable model, FWHM, 2-SD methods, and LGE-VPS each demonstrated significant association with MACE adjusted to age, sex, BMI and LVEF (adjusted HR of 1.04, 1.02, and 1.07; p = 0.009, p = 0.035; and p = 0.005, respectively). In these, FWHM and LGE-VPS had the highest degrees of inter and intra-rater reproducibility based on their high ICC values. CONCLUSIONS: FWHM is the optimal semi-automated quantification method in risk-stratifying patients with suspected myocarditis, demonstrating the strongest association with MACE and the highest technical consistency. Visual LGE scoring is a reliable alternative method and is associated with a comparable association with MACE and reproducibility in these patients. TRIAL REGISTRATION NUMBER: NCT03470571 . Registered 13th March 2018. Retrospectively registered.

Common First-Pass CT Angiography Findings Associated With Rapid Growth Rate in Abdominal Aorta Aneurysms Between 3 and 5 cm in Largest Diameter.

OBJECTIVE: The purpose of this study was to describe CT angiography (CTA) findings of lumen contrast heterogeneity and intraluminal thrombus volume and to evaluate their relationship with rapid aneurysm growth in patients with abdominal aortic aneurysms (AAA) between 3 and 5 cm. MATERIALS AND METHODS: This institutional review board-approved and HIPAA-compliant single-center retrospective study included CTA studies obtained between January 2004 and December 2014 in 140 patients with AAA (101 men, 39 women; mean age ± SD, 70 ± 9 years old; age range, 22-87 years old). Standardized measurements for aneurysm intraluminal thrombus volume and a relatively new metric termed "lumen contrast heterogeneity" were obtained from the CTA images. AAA growth rate data were acquired from all subsequent cross-sectional studies. The association between the imaging findings and rapid aneurysm growth (> 0.4 cm/y) was evaluated using multivariate logistic regression. Patient comorbidities and medications were added to the regression model to assess for further associations with rapid growth rate. RESULTS: Using a baseline logistic regression model, lumen contrast heterogeneity (odds ratio [OR], 1.16; 95% CI, 1.05-1.32), intraluminal thrombus volume (OR, 2.15; 95% CI, 1.26-3.86), and maximum AAA diameter (OR, 1.69; 95% CI, 1.03-2.84) were independently associated with increased likelihood of rapid aneurysm growth. None of the patient comorbidities or medications were significantly associated with the outcome when added to the baseline model. CONCLUSION: Both intraluminal thrombus and lumen contrast heterogeneity are seen on AAA CTA studies and can be quantified; both of these metrics are independently associated with rapid growth rate and should be recognized by radiologists evaluating patients with AAA during surveillance.

Artifactual Appearance of Thrombosis on Using Metal Artifact Reduction Software Reconstruction in Computed Tomographic Angiography.

The authors attempted to use metal artifact reduction software in 2 computed tomographic angiogram studies to decrease beam hardening. Although the beam hardening artifacts were reduced in the postprocessed images, there was an artifactual appearance of thrombosis in the adjacent arteries in the first case and in the inflow cannula of a left ventricular assist device in the second case. Comparison of the reconstructed images with the original images is therefore essential to avoid a misdiagnosis.

Sonography and Magnetic Resonance Imaging Characteristics of Testicular Adrenal Rest Tumors.

BACKGROUND: The aim of this study was to describe the gray-scale and color Doppler ultrasonography (US) and magnetic resonance (MR) imaging features of testicular adrenal rest tumors (TART) in patients with congenital adrenal hyperplasia. MATERIAL/METHODS: Forty-one patients with congenital adrenal hyperplasia were evaluated by gray-scale and color Doppler ultrasonography. Totally eighteen adrenal rest tumors in 9 patients were diagnosed TART on US and MR imaging. Gray-scale and color Doppler US and MR findings of the patients were documented. RESULTS: A total of eighteen masses were evaluated in nine patients. The mean age of these patients was 14.3±4.5 (range 10.1-23.3) years. US revealed hypoechoic lesions around the mediastinum testis with hypervascularity dispersing in ten patients and hypovascularity in two patients. In six patients, the lesions were hyperechoic with poor vascularity. Lesions exhibited homogeneous (n=8) and heterogeneous (n=10). Testicular microlithiasis was present in 4 of 9 patients with TART. Doppler ultrasound showed normal testicular vessels passing through the mass which were undisturbed, not displaced and not change in caliber. MRI features were the following: all lesions were hypointense on T2- and hyperintense (n=12) and isointense (n=6) on T1-weighted images. All masses revealed homogeneous contrast enhancement on postcontrast T1-weighted images. CONCLUSIONS: Ultrasonography and MRI are good methods for detecting and monitoring TART. US is the first preferable modality because it is quick and cheap than MRI. Bilateral mostly hypoechoic lesions depicted around the mediastinum testis with no mass effect is highly suggestive for the diagnosis of testicular adrenal rest tissues on ultrasonography. Normal testicular vessels coursing through the lesions undisturbed and not change in caliber is described specific for this kind of tumors.

Implementation and Performance of Automated Software for Computing Right-to-Left Ventricular Diameter Ratio From Computed Tomography Pulmonary Angiography Images.

OBJECTIVE: The aim of this study was to prospectively test the performance and potential for clinical integration of software that automatically calculates the right-to-left ventricular (RV/LV) diameter ratio from computed tomography pulmonary angiography images. METHODS: Using 115 computed tomography pulmonary angiography images that were positive for acute pulmonary embolism, we prospectively evaluated RV/LV ratio measurements that were obtained as follows: (1) completely manual measurement (reference standard), (2) completely automated measurement using the software, and (3 and 4) using a customized software interface that allowed 2 independent radiologists to manually adjust the automatically positioned calipers. RESULTS: Automated measurements underestimated (P < 0.001) the reference standard (1.09 [0.25] vs1.03 [0.35]). With manual correction of the automatically positioned calipers, the mean ratio became closer to the reference standard (1.06 [0.29] by read 1 and 1.07 [0.30] by read 2), and the correlation improved (r = 0.675 to 0.872 and 0.887). The mean time required for manual adjustment (37 [20] seconds) was significantly less than the time required to perform measurements entirely manually (100 [23] seconds). CONCLUSIONS: Automated CT RV/LV diameter ratio software shows promise for integration into the clinical workflow for patients with acute pulmonary embolism.

Estimation of single-kidney glomerular filtration rate without exogenous contrast agent.

PURPOSE: Measurement of single-kidney filtration fraction and glomerular filtration rate (GFR) without exogenous contrast is clinically important to assess renal function and pathophysiology, especially for patients with comprised renal function. The objective of this study is to develop a novel MR-based tool for noninvasive quantification of renal function using conventional MR arterial spin labeling water as endogenous tracer. THEORY AND METHODS: The regional differentiation of the arterial spin labeling water between the glomerular capsular space and the renal parenchyma was characterized and measured according to their MR relaxation properties (T1ρ or T2 ), and applied to the estimation of filtration fraction and single-kidney GFR. The proposed approach was tested to quantify GFR in healthy volunteers at baseline and after a protein-loading challenge. RESULTS: Biexponential decay of the cortical arterial spin labeling water MR signal was observed. The major component decays the same as parenchyma water; the minor component decays much slower as expected from glomerular ultra-filtrates. The mean single-kidney GFR was estimated to be 49 ± 9 mL/min at baseline and increased by 28% after a protein-loading challenge. CONCLUSION: We developed an arterial spin labeling-based MR imaging method that allows us to estimate renal filtration fraction and singe-kidney GFR without use of exogenous contrast.

Computed Tomography Angiography After Transcatheter and Surgical Aortic Interventions.

This comprehensive article reviews the complex realm of aortic surgical and endovascular interventions, focusing on the aortic root, ascending aorta, aortic arch, descending aorta, and abdominal aorta. It outlines the nuances of various procedures, emphasizing the importance of computed tomography angiography acquisition for an accurate assessment. Detailed discussions encompass expected postsurgical/endovascular findings and complications, covering various scenarios, from hematoma and infection to pseudoaneurysms and graft-related issues. This article serves as a crucial resource for radiologists, offering invaluable insights into the complexities of aortic interventions and their subsequent imaging, fostering a comprehensive understanding of diagnostic and management strategies.