Low dose time-resolved CT-angiography in pediatric patients with venous malformations using 3rd generation dual-source CT: Initial experience

Vascular Malformations and Tumors: A Review of Classification and Imaging Features for Cardiothoracic Radiologists

The International Society for the Study of Vascular Anomalies (ISSVA) classification is a comprehensive histology-based scheme that was updated in 2018. It is important for cardiothoracic imagers to understand this classification to ensure that accurate terminology is used and that archaic terms are avoided when vascular lesions are described. Knowledge of the various malformations (including common conditions, such as venous malformation, arteriovenous fistula, and arteriovenous malformation) and vascular tumors allows for timely diagnosis and appropriate management. This review describes various vascular anomalies, in accordance with ISSVA classification and terminology; highlights key imaging features associated with each; and discusses the role of different imaging modalities. Keywords: Pulmonary, Soft Tissues/Skin, Vascular, Arteriovenous Malformation © RSNA, 2023.

Imaging of peripheral vascular malformations - current concepts and future perspectives

Vascular Malformations belong to the spectrum of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic vasculature. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) is of major importance to guide proper treatment. Imaging plays a crucial role to classify vascular malformations according to their dominant vessel type, anatomical extension, and flow pattern. Several imaging concepts including color-coded Duplex ultrasound/contrast-enhanced ultrasound (CDUS/CEUS), 4D computed tomography angiography (CTA), magnetic resonance imaging (MRI) including dynamic contrast-enhanced MR-angiography (DCE-MRA), and conventional arterial and venous angiography are established in the current clinical routine. Besides the very heterogenous phenotypes of vascular malformations, molecular and genetic profiling has recently offered an advanced understanding of the pathogenesis and progression of these lesions. As distinct molecular subtypes may be suitable for targeted therapies, capturing certain patterns by means of molecular imaging could enhance non-invasive diagnostics of vascular malformations. This review provides an overview of subtype-specific imaging and established imaging modalities, as well as future perspectives of novel functional and molecular imaging approaches. We highlight recent pioneering imaging studies including thermography, positron emission tomography (PET), and multispectral optoacoustic tomography (MSOT), which have successfully targeted specific biomarkers of vascular malformations.

Diagnostic radiology findings and spectrum of therapeutic interventions in gynaecological and urogenital vascular anomalies

Vascular anomalies represent a rare congenital disease with manifestation at diverse anatomical sights and presenting with heterogenous symptoms. Undetected, they can progress and create acute and chronic complications with functional impairment. The manifestation in the female and male pelvis and the urogenital tract represents a multidisciplinary challenge for physicians. Especially outpatient management in gynaecology and urology is affected. Diagnostic Radiology holds an important supportive role in early diagnosis of the underlying urogenital vascular anomaly and referral to interventional radiology, either for minimal invasive treatment, or to surgery for further assessment. This pictorial review creates awareness for the spectrum of vascular anomalies of the gynaecological and urogenital tract, their characteristic imaging findings and dedicated interventional treatment options. The individual description of vascular anomalies, based on an appropriate nomenclature and classification standard, is a guide for radiologists to distinguish the underlying vascular anomaly from other vascular disorders and to accelerate diagnosis as well as therapeutic proceedings. In consequence, interdisciplinary management of patients with vascular anomalies of the female and male pelvis will benefit.

Updates in Vascular Computed Tomography

Computed tomography angiography (CTA) has become a mainstay for the imaging of vascular diseases, because of high accuracy, availability, and rapid turnaround time. High-quality CTA images can now be routinely obtained with high isotropic spatial resolution and temporal resolution. Advances in CTA have focused on improving the image quality, increasing the acquisition speed, eliminating artifacts, and reducing the doses of radiation and iodinated contrast media. Dual-energy computed tomography provides material composition capabilities that can be used for characterizing lesions, optimizing contrast, decreasing artifact, and reducing radiation dose. Deep learning techniques can be used for classification, segmentation, quantification, and image enhancement.

Spectrum of Imaging Manifestations of Vascular Malformations and Tumors Beyond Childhood: What General Radiologists Need to Know

Vascular anomalies encompass a collection of diagnoses that differ greatly in terms of clinical presentation, natural history, imaging findings, and management. The purpose of this article is to review diagnostic imaging findings of vascular malformations and vascular tumors, excluding the central nervous system, that occur beyond childhood. A widely accepted classification system created by the International Society for the Study of Vascular Anomalies provides a framework for this review, focusing on the entities most likely to be encountered by general radiologists, although several rare but clinically important entities are also reviewed.

CT angiography with 15 mL contrast material injection on time-resolved imaging for endovascular abdominal aortic aneurysm repair

PURPOSE

To assess the utility of whole-aorta CT angiography (CTA) with 15 mL contrast material (CM) on time-resolved imaging for endovascular abdominal aortic repair (EVAR).

METHODS

Twenty-six patients with a high-risk of post-contrast acute kidney injury (PC-AKI) underwent CTA with 15 mL CM using temporal maximum intensity projection (tMIP-CTA) generated from time-resolved imaging. The aortoiliac CT values were measured. Two observers measured the arterial diameters in unenhanced CT and tMIP-CTA images, and image quality was evaluated on a 5-point scale. The presence of the accessory renal artery, inferior mesenteric artery (IMA) occlusion, and instructions for use (IFU) of EVAR were evaluated.

RESULTS

CT examinations were successfully performed, and no patients developed PC-AKI. The mean CT values of the whole aorta were 267.5 ± 51.4 HU, which gradually decreased according to the distal levels of the aorta. Bland-Altman analysis revealed excellent agreement for the external arterial diameter measurements between unenhanced CT and tMIP-CTA. Excellent interobserver agreement was achieved for the measurements of the external (ICCs, 0.910-0.992) and internal arterial diameters (ICCs, 0.895-0.993). Excellent or good overall image quality was achieved in 24 (92 %) patients. The presence of the accessory renal artery, IMA occlusion and the assessment of IFU were in 100 % agreement. Multivariate analysis revealed aortic volume as the most significant independent factor associated with strong aortic enhancement (p = 0.004).

CONCLUSIONS

Whole-aorta tMIP-CTA on time-resolved imaging is useful for maintaining contrast enhancement and image quality for EVAR planning, and can substantially reduce the amount of CM.

Prediction of venous malformations with localized intravascular coagulopathy with diffusion-weighted magnetic resonance imaging

Background

Venous malformations may be complicated by localized intravascular coagulopathy which is a serious condition with hematological sequel. Prediction of localized intravascular coagulopathy is mandatory for prompt anticoagulation therapy. Laboratory and routine magnetic resonance imaging can predict localized intravascular coagulopathy in venous malformations; however, the results are variable.

Purpose

To predict venous malformations with localized intravascular coagulopathy with diffusion-weighted magnetic resonance imaging.

Material and methods

A retrospective analysis was performed on 55 patients (34 male, 21 female aged 14–64 years: mean 39 years) with venous malformations that underwent diffusion-weighted magnetic resonance imaging. The apparent diffusion coefficient value of venous malformations was calculated.

Results

The mean apparent diffusion coefficient value of venous malformations with localized intravascular coagulopathy (n = 26) (1.28 ± 0.18 × 10−3 mm2/s) was significantly different ( P = 0.001) from venous malformations without localized intravascular coagulopathy (n = 29) (1.60 ± 0.18 × 10−3 mm2/s). When apparent diffusion coefficient value of 1.454 × 10−3 mm2/s was used as a threshold value for the prediction of venous malformations with localized intravascular coagulopathy, the best result was obtained with an accuracy of 83.6%, sensitivity of 84.6%, specificity of 82.8%, and area under the curve of 0.895. The apparent diffusion coefficient value of venous malformations was correlated with D-dimer level ( r = −0.59, P = 0.006) and fibrinogen level ( r = 0.73, P = 0.001).

Conclusion

The apparent diffusion coefficient value is a non-invasive imaging parameter that can be used to predict venous malformations with localized intravascular coagulopathy.

Interdisciplinary Management of Head and Neck Vascular Anomalies: Clinical Presentation, Diagnostic Findings and Minimalinvasive Therapies

OBJECTIVES

Vascular anomalies are included in the 30 000 rare diseases worldwide affecting less than 5/10 000 people. Depending on their morphology and biological properties, they can cause varied disorders with organ involvement. Almost 60% of vascular anomalies have a predilection for the head and neck region in children. Clinical and scientific effort to establish interdisciplinary management concepts for vascular anomalies is increasing worldwide.

METHODS

Especially in the head and neck region, clinical impairment and organ dysfunction is associated with cosmetic issues that may represent a physical and psychological issue for the patient. Correct diagnosis, based on clinical presentation and symptoms, is a prerequisite for appropriate therapy, ranging from conservative management to a spectrum of minimally invasive treatment options. We searched PubMed for German and English language published data until December 2016 with focus on clinical studies, review articles and case reports on vascular anomalies with a focus on the head and neck region.

RESULTS

The last ISSVA update in 2014 has contributed to a better understanding of vascular anomalies, classifying them in vascular tumors and vascular malformations. The predominant representatives of vascular tumors are congenital and infantile hemangiomas. Infantile hemangiomas have the ability of spontaneous regression in more than 80%. Patients with symptomatic growing hemangiomas with ulcerations, bleeding complications and restriction of hearing, swallowing disorder, impairment of vision, or cosmetic dysfigurement require treatment. Therapies include oral propanolol, transcatheter embolization and surgery. Vascular malformations tend to progress with patientś age and are subdivided in slow flow and fast flow lesions. Symptomatic slow flow lesions, e.g. venous and lymphatic malformations, benefit from percutaneous sclerotherapy. Fast flow lesions, as arteriovenous malformations, are rare but undoubtedly therapeutically the most challenging vascular anomaly. Depending on location and size, they may require multiple transcatheter embolization procedures for successful occlusion of the AVM.

CONCLUSIONS

This review provides knowledge on the current ISSVA classification of vascular anomalies, their clinical presentation, diagnostic evaluation and minimally invasive therapy options to encourage the establishment of a comprehensive interdisciplinary management for head and neck vascular anomalies.