Head and neck vascular malformations: time-resolved MR projection angiography

The utility of time resolved magnetic resonance angiography in differentiating vascular malformations

PURPOSE

The objective is to show that TR-MRA is a useful non-invasive technique without ionizing radiation of traditional angiography in evaluating VMs.

MATERIALS AND METHODS

Retrospective search utilizing M-Power for MRA studies done at 3 T (Trio, Siemens) with both 3D contrast enhanced TR-MRA and 3D CE-MRA sequences from 2009 to 2018 were obtained after IRB approval. The images were blindly reviewed by two experienced cardiovascular radiologists for informations regarding vascular malformations with the ability to separate arteries and veins without any overlay or contamination in real time. Both TR-MRA and 3D CE-MRA images were carefully evaluated. The following characteristics: flow rate, size, type, feeding vessels, draining vessels and clots were evaluated. The findings were then compared to the Catheter Angiography for the patients that had catheter angiography study.

RESULTS

The M-Power search resulted a total of 69 patients (24 males, 45 females, age range 11 days to 74 years). Of those 69, there were 25 patients with confirmatory Catheter Angiography study. The radiologists characterized VMs as 19 high flow VMs, 47 slow flow VMs, 2 lymphatic malformations and 1 no flow VM. Of those with Cath, there was 100% concordance with the TR-MRA.

CONCLUSION

TR-MRA provides functional characterization of a VM that cannot be determined with CE-MRA alone. This is critical in treatment planning with high-flow VMs.

Vascular anomalies: nomenclature, classification, and imaging algorithms

There is a lot of ambiguity in the usage of correct terminology in the description of vascular malformations and tumors. Hemangioma and arteriovenous malformation (AVM) are the most commonly used terms and are the mostly incorrectly used as well! The aim of this review article was to lay out the correct nomenclature and describe the correct usage for the physicians and radiologists involved in diagnosing and managing these lesions. We describe the various classification systems which have been devised to define the multiple entities included under vascular anomalies. The latest classification system that should be adhered to is per the International Society for the Study of Vascular Anomalies, approved at the 20th ISSVA Workshop held in Melbourne in April 2014, last revised in May 2018. The main features of the latest revision have been highlighted. This classification, however, does not list the diagnostic clinico-radiological features for each entity. In addition, guidelines regarding the appropriate use of available imaging modalities are lacking in the literature. We, hereby, aim to address these pertinent issues in this review article.

Role of ultrasound in diagnosis and differential diagnosis of deep infantile hemangioma and venous malformation

OBJECTIVE

For vascular anomalies, when clinical findings are not sufficient, auxiliary examination is essential. In this study, we characterize and differentiate the ultrasound (US) findings of deep infantile hemangioma (DIH) and venous malformation (VM).

METHODS

A total of 135 patients (140 lesions) with clinically proven DIH and VM were analyzed. The following US characteristics were assessed: size, shape, border, echogenicity, echotexture, vascularity, and lesion softness. One-way analysis of variance, nonparametric test, χ² test, Fisher exact test, and paired sample t-test were used to analyze the US results.

RESULTS

On gray-scale US images, DIH and VM were more common in subcutaneous soft tissue, but VM could invade the muscle. Most DIHs were expressed as hyperechoic structures (47.0%), had a well-defined border (74.2%), and were homogeneous (53%), whereas the majority of VMs showed mixed echoic with anechoic structures (87.8%), had an ill-defined border (58.1%), and were heterogeneous (100%). On color Doppler US, most DIHs (90.9%) showed high vascular density, whereas only a few blood flow signals were found in most VMs (98.6%). On elastic US, VM was softer than DIH (2.9 ± 0.8 vs 2.6 ± 0.5; P = .048). After DIH involution, the distance from the body surface increased (P = .015); the lesion's vertical diameter, peak arterial systolic velocity, and Vmax were significantly decreased (P = .006, P = .047, and P = .026, respectively). Also, early VM (<18 months) has the typical US performance of VM. Compared with elastic US, gray-scale and Doppler US provided stronger evidence for differential diagnosis.

CONCLUSIONS

DIH and VM have different US manifestations that can provide evidence for diagnosis and differential diagnosis of DIH and early VM.

Visualization of Soft Tissue Venous Malformations of Head and Neck with 4D Flow Magnetic Resonance Imaging

Evaluation of hemodynamics in venous malformation (VM) in the head and neck area is done by direct puncture venography before alcohol sclerotherapy, but it is difficult due to a variable degree of filling in from the artery and filling out into the draining vein. We present our preliminary experience of 4D MRI to evaluate VM hemodynamics. Four patients with venous malformation in the maxillofacial area underwent both 4D MRI and direct puncture venography before alcohol sclerotherapy. To find out appropriate velocity encoding (VENC) for VM, we applied 5-50 cm/sec VENC. Significant high-flow foci demonstrated by phase changes in magnitude images were compared with lesion types shown on a direct puncture venogram. Detection of flow in VM was possible in magnitude images or phase-difference images when VENC was set to less than 30 cm/sec. Appropriate VENC for VM was regarded as less than 5 cm/sec. High-flow areas in the dilated venous sac demonstrated focal spots or linear band-like areas on phase changes of 4D MRI. Appropriate VENC application was mandatory to detect flow in VM. Flow information on 4D MRI provided flow information in VM which was not detected on a direct puncture venogram in the compartmentalized lesion and thus can make alcohol sclerotherapy safer.

Four-dimensional computed tomographic angiography of an arteriovenous fistula in the neck

Arteriovenous fistula (AVF), a type of vascular anomaly, is a relatively uncommon disease characterized by abnormal connections between the arterial and venous systems. Recently, remarkable advances in four-dimensional computed tomographic angiography (4D-CTA) have enabled detailed analysis of the hemodynamic features of vascular anomalies, which cannot be achieved by conventional imaging modalities. We report a case of AVF in a 59-year-old female presenting as a right neck mass. Using reconstructed animations from various viewing angles, 4D-CTA could clearly visualize not only a mass but the feeding artery and draining vein from the mass. 4D-CTA was useful for the diagnosis of AVF and to determine the surgical strategy preoperatively.

Periodontal manifestations and management of a patient with AV malformation

Arterio-venous malformation (AVM) is an abnormal communication between an artery and a vein. The incidence of its occurrence in oral and maxillofacial region is rare, and if present, the most common sign is gingival bleeding. A 12-year-old female patient presented with an extra oral swelling in relation with upper lip. Intra oral examination showed non tender gingival swelling with spontaneous bleeding associated with maxillary arch. On initiation of phase I therapy using hand instruments, spontaneous brisk bleeding was encountered which was difficult to control. Because of severe nature of hemorrhage encountered, some type of vascular abnormality was suspected. Ultrasonography followed by angiography confirmed AVM in relation with upper lip. Embolization of lesion was followed by gingivectomy procedure and no recurrence was reported during one year of follow-up. Thus, proper recognition and therapeutic intervention is essential to avoid serious complications and potentially tragic outcome in such situations.

Arteriovenous malformation of the mandible and parotid gland

Arteriovenous malformations (AVMs) of the jaws are relatively rare, with fewer than 200 cases reported in the literature. Their real importance lies in their potential to result in exsanguination, which usually follows an unrelated treatment, such as tooth extraction, surgical intervention, puncture wound or blunt injury in involved areas, with the dentist unaware of the existence of the AVM. The present case illustrates an AVM in an 18-year-old female with swelling on the right side of the face. This case report is unique because although there was no history of bleeding episodes, thorough examination and investigation diagnosed it as high-flow vascular malformation. We ascertain the importance of dentists' awareness of the fatal outcome of these lesions and emphasize that, prior to performing any procedure, necessary investigations should always be done.

Direct sac puncture and glue embolization of intraosseous AVM of the maxilla

The authors report an intraosseous maxillary arteriovenous malformation (AVM) treated with direct sac injection of n-butyl-2-cyanoacrylate and transarterial embolization. The case is presented because of its rarity and the efficacy of direct puncture glue embolization.

Current concepts in the classification, diagnosis and treatment of vascular anomalies

Patients with extended vascular anomalies may suffer from significant aesthetic and functional impairment and represent a challenge to therapeutic planning, which is best met by an interdisciplinary concept. In agreement with the International Society for the Study of Vascular Anomalies (ISSVA), vascular lesions are classified into haemangiomas as proliferating endothelial tumours on the one hand and congenital vascular malformations on the other. According to the preponderant vascular channels and hemodynamic characteristics, malformations are subdivided into low flow (venous, lymphatic and capillary) lesions and high-flow malformations. Diagnostic imaging should be targeted at the specific structural and functional informations required for treatment planning. The imaging modality of choice to provide these informations is magnetic resonance imaging (MRI) supplemented by magnetic resonance angiography (MRA) with high spatial and temporal resolution. Treatment indications for haemangiomas depend on the proliferative behaviour of the lesion and comprise beta-blockers in order to induce involution as well as cryotherapy, laser and open surgery. Interventional radiological procedures have evolved as an essential element in an interdisciplinary treatment plan for vascular malformations and include percutaneous sclerotherapy with ethanol and OK-432 for venous and lymphatic malformations and transarterial embolization for high-flow lesions.

Diffusion-weighted imaging and ADC mapping of head-and-neck paragangliomas: initial experience

BACKGROUND

Paragangliomas are rare, hypervascularized benign tumors. In some cases a clear differentiation of paragangliomas and other entities is impossible.

PATIENTS AND METHODS

The authors evaluated ten patients with skull base lesions (paraganglioma n = 7, meningioma n = 1, giant cell tumor n = 1, and neurinoma n = 1) in addition to conventional magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI), and calculation of apparent diffusion coefficient (ADC).

RESULTS

Mean ADC values +/- standard deviation of the paragangliomas were 1.304 +/- 0.257 x 10(-3) mm(2)/s and differed from ADC values of the other jugular fossa tumors with 0.743 +/- 0.108 x 10(-3) mm(2)/s and measurement derived from the cerebellum with 0.802 +/- 0.075 x 10(-3) mm(2)/s.

CONCLUSION

Due to the difference of ADC values, the authors propose that DWI and ADC mapping could be a promising tool in the diagnostic work-up of paragangliomas.

Head and neck vascular lesions: characterization of the flow pattern by the use of three-phase CT

Objective

This study was designed to evaluate the usefulness of three-phase CT to characterize the hemodynamics of vascular lesions in the head and neck area.

Materials and Methods

We analyzed vascular malformations of head and neck regions in 21 patients with the use of three-phase CT, including pre-contrast phase, vascular phase (scan delay: 20-35 seconds after intravenous contrast material injection) and equilibrium phase (scan delay: 3-5 minutes) imaging. The flow characteristic of each lesion was determined and categorized as either a high- or a low-flow lesion according to findings on selective arteriography and/or direct puncture venography. The CT number was acquired from two areas in a vascular lesion, sorted by the enhancement pattern: area 1, a highly enhanced area seen on the vascular phase; area 2, a delayedly enhanced area seen on the equilibrium phase. The CT numbers of each phase were compared between high- and low-flow lesions with use of the unpaired t-test. The flow patterns of high- and low-flow lesions were analyzed by assessment of time-density curves of three phase CT.

Results

High-flow lesions were detected in nine patients and low-flow lesions were detected in 12 patients. On the vascular phase, the CT number of areas 1 and 2 of high-flow lesions was significantly higher than for low-flow lesions (p < 0.05). Contrary to early peaks seen in time-density curves of high-flow lesions, low-flow lesions showed a delayed peak.

Conclusion

Three-phase CT seems to be a valuable non-invasive method to differentiate a high-flow lesion from a low flow lesion of head and neck vascular lesions.

Preoperative evaluation of spinal vascular malformation by MR angiography: how reliable is the technique: case report and review of literature

Contrast-enhanced MR angiography (MRA) has been increasingly used in the evaluation of spinal vascular malformations. Even though MR spinal angiography has several advantages over catheter spinal angiography (DSA), however, spinal DSA must never be omitted before operation, even if the vascular malformation is nicely demonstrated by MR angiography. We report a case of spinal vascular malformation in which MR angiography provided great images which almost convinced everyone about the type and site of malformation/fistula. The images were so convincing that it was almost decided to skip catheter based angiography, citing reason of disadvantages of catheter based angiography over MR angiography. However, spinal DSA was luckily done which completely changed the type and site of malformation and helped in avoiding failed surgery. We conclude that even though catheter based spinal angiography has disadvantages over MRA, it should never be omitted from the diagnostic protocol.

Assessment of blood supply to intracranial pathologies in children using MR digital subtraction angiography

BACKGROUND

MR digital subtraction angiography (MR-DSA) is a contrast-enhanced MR angiographic sequence that enables time-resolved evaluation of the cerebral circulation.

OBJECTIVE

We describe the feasibility and technical success of our attempts at MR-DSA for the assessment of intracranial pathology in children.

MATERIALS AND METHODS

We performed MR-DSA in 15 children (age range 5 days to 16 years) referred for MR imaging because of known or suspected intracranial pathology that required a dynamic assessment of the cerebral vasculature. MR-DSA consisted of a thick (6-10 mm) slice-selective RF-spoiled fast gradient-echo sequence (RF-FAST) acquired before and during passage of an intravenously administered bolus of Gd-DTPA. The images were subtracted and viewed as a cine loop.

RESULTS

MR-DSA was performed successfully in all patients. High-flow lesions were shown in four patients; these included vein of Galen aneurysmal malformation, dural fistula, and two partially treated arteriovenous malformations (AVMs). Low-flow lesions were seen in three patients, all of which were tumours. Normal flow was confirmed in eight patients including two with successfully treated AVMs, and in three patients with cavernomas.

CONCLUSION

Our early experience suggests that MR-DSA is a realistic, non-invasive alternative to catheter angiography in certain clinical settings.