Interdisciplinary Management of Vascular Anomalies in the Head and Neck

Vascular anomalies in the head and neck area are usually rare diseases and pose a particular diagnostic and therapeutic challenge. They are divided into vascular tumours and vascular malformations. A distinction is made between benign tumours, such as infantile haemangioma, and rare malignant tumours, such as angiosarcoma. Vascular malformations are categorised as simple malformations, mixed malformations, large vessel anomalies and those associated with other anomalies. Treatment is interdisciplinary and various modalities are available. These include clinical observation, sclerotherapy, embolisation, ablative and coagulating procedures, surgical resection and systemic drug therapy. Treatment is challenging, as vascular anomalies in the head and neck region practically always affect function and aesthetics. A better understanding of the genetic and molecular biological basis of vascular anomalies has recently led to clinical research into targeted drug therapies. This article provides an up-to-date overview of the diagnosis, clinic and treatment of vascular anomalies in the head and neck region.

Drainage Pattern of Craniofacial Veins With Emphasis on its Influence on Facial Reconstruction Procedures

As the facial transplantation procedures are becoming more popular and frequent in recent years, for repairing facial trauma, variations in the veins of head and neck needs to be reported time and again. This study was undertaken to examine the course and drainage pattern of the facial vein and external jugular vein on this context and emphasize its surgical implications. The authors studied the head and neck region of 50 embalmed cadavers of both sexes to document normal and variant anatomy of facial, retromandibular, and external jugular veins. In 30% of the head and neck regions, different draining pattern of the above-mentioned veins were observed. One of the rare variation discovered was the splitting of the retromandibular vein to embrace the external carotid artery within the parotid gland. The data about variations in the termination of facial vein, retromandibular vein, and external jugular vein, as observed in the present study might be useful in avoiding accidental injury to these vessels during any surgical intervention in the face as well as neck. Level of Evidence: IV.

Domestic pig head and neck arteries from the viewpoint of imaging methods and experimental surgery

The aim of this paper is to summarize the current knowledge of the anatomy of domestic pig head and neck arteries for the needs of experimental surgery and imaging methods in biomedical research and translational medicine. The potential of this large animal model seems to be valuable also for the xenotransplantation of certain organs. Demands for the knowledge of morphological differences between analogous human structures and particular breeds are growing also in connection with the need for more precise planning of experiments or interpretation of the results. Deepening anatomical knowledge is allowed also by the development of imaging methods. The search was performed using the keywords “domestic pig” and “arteries of the head and neck“ in the MEDLINE database, PubMed interface.

Image-guided percutaneous sclerotherapy of venous malformations of the head and neck: Clinical and MR-based volumetric mid-term outcome

Objective

To report the clinical and MRI-based volumetric mid-term outcome after image guided percutaneous sclerotherapy (PS) of venous malformations (VM) of the head and neck.

Methods

A retrospective analysis of a prospectively maintained database was performed, including patients with VM of the head and neck who were treated with PS. Only patients with available pre- and post-interventional MRI were included into this study. Clinical outcome, which was subjectively assessed by the patients, their parents (for paediatric patients) and/or the physicians, was categorized as worse, unchanged, minor or major improvement. Radiological outcome, determined by MRI-based volumetric measurements, was categorized as worse (>10% increase), unchanged (≤10% increase to <10% decrease), minor (≥10% to <25% decrease), intermediate (≥25% to <50% decrease) or major improvement (≥50% decrease).

Results

Twenty-seven patients were treated in 51 treatment sessions. After a mean follow-up of 31 months, clinical outcome was worse for 7.4%, unchanged for 3.7% of the patients, while there was minor and major improvement for 7.4% and 81.5%, respectively. In the volumetric imaging analysis 7.4% of the VMs were worse and 14.8% were unchanged. Minor improvement was observed in 22.2%, intermediate improvement in 44.4% and major improvement in 11.1%. The rate of permanent complications was 3.7%.

Conclusion

PS can be an effective therapy to treat the symptoms of patients with VMs of the head and neck and to downsize the VMs. MRI-based volumetry can be used to objectively follow the change in size of the VMs after PS. Relief of symptoms frequently does not require substantial volume reduction.

Application of multiple injections of contrast agent in head and neck CT arteriovenous angiography in children: Study protocol clinical trial (SPIRIT Compliant)

OBJECTIVE

To investigate the application value of multiple injections of contrast agent in head and neck CT arteriovenous angiography in children.

METHODS

A total of 100 children aged 6 to 7 years who needed head and neck CT arteriovenous angiography were prospectively selected. They were randomly divided into a control group and a research group, with 50 children in each group. The same scanning parameters and reconstruction methods were used. The right median cubital vein was injected intravenously with the contrast agent Omnipaque (350 mg I/ml). For children in the control group, a bolus of undiluted contrast agent (dose was 2 ml/kg, upper limit was 50 ml) was injected 1 time. The arterial phase and vein phase of the head and neck vessels were scanned. For children in the research group, a contrast agent bolus diluted with saline to a concentration of 20% was first injected (dose was 1 ml/kg, upper limit was 25 ml), and then an undiluted contrast agent bolus (dose was 1 ml/kg, upper limit was 25 ml) was injected. Thresholds were used to trigger the scanning of the head and neck arterial phases. The CT image quality of the head and neck arteries and veins, radiation dose and contrast agent dose were compared between the 2 groups.

RESULTS

Subjective evaluation of CT image quality of arteries: there were 47 cases of 4 points and 3 cases of 3 points in the control group and 34 cases of 4 points and 16 cases of 3 points in the research group. Subjective evaluation of CT image quality of veins: there were 47 cases of 4 points and 3 cases of 3 points in the control group and 5 cases of 4 points, 42 cases of 3 points and 3 cases of 2 points in the research group. The CT value of brain arterial vessel enhancement was higher in the control group than the research group, and the difference was statistically significant (P < .05). The CT value of vein enhancement was higher in the control group than the research group, and the difference was statistically significant (P < .05). The X-ray dose in the research group was 51% lower than that in the control group; the contrast agent dose in the research group was 44% lower than that in the control group.

CONCLUSION

For the head and neck enhanced CT examination of children, the method of first bolus injection of 20% diluted contrast agent and later bolus injection of undiluted contrast agent can clearly demonstrate the head and neck arteries and veins one time, reducing the X-ray dose and contrast agent dose, which has clinical practical value in the enhanced CT examination of children with head and neck disease.

Assessment of image quality and dose in contrast-enhanced head and neck CT angiography of New Zealand rabbit

BACKGROUND

Although computed tomography (CT) is a powerful diagnostic imaging modality for diagnosing vascular diseases, it is some what risky to human health due to the high radiation dosage. Thus, CT vendors have developed low dose computed tomography (LDCT) aiming to solve this problem. Nowadays, LDCT has gradually become a main stream of CT examination.

OBJECTIVE

This study aimed to assess the feasibility of LDCTAin an animal model and compare the imaging features and doses in two clinical scanners.

METHODS

Twenty-two New Zealand rabbit head and neck CTA images pre- and post-contrast agent injection were performed using256-sliceand 64-slice CT scanners. The tube voltages used in the 256-slice and the 64-slice CTA were 70 kVp and 80 kVp, respectively. Quantitative images indices and radiation doses obtained from CTA in these two scanners were compared.

RESULTS

More neck arterial vessels could be visualized in multi-planar reconstruction (MPR) CTA on the 256-slice CT scanner than on the 64-slice CT scanner. After contrast agent injection, all observed neck arterial vessels had higher CT numbers in 256-slice CTA than in 64-slice CTA. There was no significant difference in contrast-to-noise (CNR) of CTA images between these two scanners. CT dose index (CTDI) and dose length product (DLP) for the 256-slice CTA were lower than those for the 64-slice CTA.

CONCLUSIONS

Low dose CTA of rabbits with 70 or 80 kVp is feasible in a 256-slice or a 64-slice CT scanner. The radiation dose from the 256-slice CTA was much lower than that from the 64-slice CTA with comparable SNR and CNR. The technique can be further applied in longitudinal monitoring of an animal stroke model in the future.

foxc1 is required for embryonic head vascular smooth muscle differentiation in zebrafish

Vascular smooth muscle of the head derives from neural crest, but developmental mechanisms and early transcriptional drivers of the vSMC lineage are not well characterized. We find that in early development, the transcription factor foxc1b is expressed in mesenchymal cells that associate with the vascular endothelium. Using timelapse imaging, we observe that foxc1b expressing mesenchymal cells differentiate into acta2 expressing vascular mural cells. We show that in zebrafish, while foxc1b is co-expressed in acta2 positive smooth muscle cells that associate with large diameter vessels, it is not co-expressed in capillaries where pdgfrβ positive pericytes are located. In addition to being an early marker of the lineage, foxc1 is essential for vSMC differentiation; we find that foxc1 loss of function mutants have defective vSMC differentiation and that early genetic ablation of foxc1b or acta2 expressing populations blocks vSMC differentiation. Furthermore, foxc1 is expressed upstream of acta2 and is required for acta2 expression in vSMCs. Using RNA-Seq we determine an enriched intersectional gene expression profile using dual expression of foxc1b and acta2 to identify novel vSMC markers. Taken together, our data suggests that foxc1 is a marker of vSMCs and plays a critical functional role in promoting their differentiation.

Craniocervical computed tomography angiography with adaptive iterative dose reduction 3D algorithm and automatic tube current modulation in patients with different body mass indexes

The aim of this study was to investigate the feasibility of head and neck computed tomography angiography (CTA) using the 80-kV tube voltage and the adaptive iterative dose reduction (AIDR) 3D algorithm in patients with different body mass indexes (BMIs).From November 2016 to January 2017, 128 consecutive patients scheduled for head and neck CTA examinations were randomized into the 100-kV group (n = 60) and the 80-kV group (n = 68). Both groups used the automatic tube current modulation technique and the AIDR 3D algorithm. The patients were further grouped as slender (BMI < 22 kg/m), normal weight (22 kg/m≤BMI < 25 kg/m), and overweight (BMI ≥25 kg/m). The image quality and the radiation dose of each subgroup were analyzed.The images of the head and neck vessels and the brain tissue obtained with 100 kV were all of diagnostic quality. Slender and normal weight patients imaged with 80 kV also produced images of diagnostic quality. However, 80 kV in the overweight patients failed to produce images of diagnostic quality. The radiation dose in the patients imaged with 80 kV was significantly decreased in comparison with those imaged with 100 kV. The effective dose was 0.36 ± 0.06 and 0.41 ± 0.05 mSv in the slender and normal weight patients imaged with 80 kV.Head and neck CTA scanning with 80 kV, automatic tube current modulation, and AIDR 3D algorithm can produce high quality images with reduced radiation dose in slender or normal weight patients.

Vascular Lesions of the Head and Oral Cavity – Diagnosis and Management

Vascular anomalies constitute a diffuse group of conditions which can range in their significance from being completely harmless and of little clinical relevance to being potentially life threatening. It is important that dentists have a good understanding of these conditions so that the risk of potential complications of dental treatment in affected patients is reduced as much as possible. This article focuses on the pathogenesis, diagnosis and treatment of these conditions, with explanation on their relevance to the practising dentist. Clinical relevance: The paper describes several vascular anomalies that may be encountered in clinical practice with information that is relevant to their diagnosis and management.

Evaluation of the effectiveness of 3D vascular stereoscopic models in anatomy instruction for first year medical students

The head and neck region is one of the most complex areas featured in the medical gross anatomy curriculum. The effectiveness of using three-dimensional (3D) models to teach anatomy is a topic of much discussion in medical education research. However, the use of 3D stereoscopic models of the head and neck circulation in anatomy education has not been previously studied in detail. This study investigated whether 3D stereoscopic models created from computed tomographic angiography (CTA) data were efficacious teaching tools for the head and neck vascular anatomy. The test subjects were first year medical students at the University of Mississippi Medical Center. The assessment tools included: anatomy knowledge tests (prelearning session knowledge test and postlearning session knowledge test), mental rotation tests (spatial ability; presession MRT and postsession MRT), and a satisfaction survey. Results were analyzed using a Wilcoxon rank-sum test and linear regression analysis. A total of 39 first year medical students participated in the study. The results indicated that all students who were exposed to the stereoscopic 3D vascular models in 3D learning sessions increased their ability to correctly identify the head and neck vascular anatomy. Most importantly, for students with low-spatial ability, 3D learning sessions improved postsession knowledge scores to a level comparable to that demonstrated by students with high-spatial ability indicating that the use of 3D stereoscopic models may be particularly valuable to these students with low-spatial ability. Anat Sci Educ 10: 34-45. © 2016 American Association of Anatomists.

Venous malformations of the head and neck: current concepts in management

Low-flow venous malformations are congenital lesions and they are the third most common vascular anomaly in the head and neck. In this paper, the third in a series of three educational reviews, we discuss current trends in their management, and include a summary of common sclerosant agents used in their control.

Role of BKCa Channels in Cephalic Vasodilation Induced by CGRP, NO and Transcranial Electrical Stimulation In The Rat

Both calcitonin gene-related peptide (CGRP) and nitric oxide (NO) are potent vasodilators that have been shown to induce headache in migraine patients. Their antagonists are effective in the treatment of migraine attacks. In the present study, we hypothesize that vasodilation induced by the NO donor glyceryltrinitrate (GTN) or by CGRP is partially mediated via large conductance calcium-activated potassium (BKCa) channels. The effects of the BKCa channel selective inhibitor iberiotoxin on dural and pial vasodilation induced by CGRP, GTN and endogenously released CGRP by transcranial electrical stimulation (TES) were examined. Iberiotoxin significantly attenuated GTN-induced dural and pial artery dilation in vivo and in vitro, but had no effect on vasodilation induced by CGRP and TES. Our results show that GTN- but not CGRP-induced dural and pial vasodilation involves opening of BKCa channels in rat.

Stereoscopic vascular models of the head and neck: A computed tomography angiography visualization

Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching anatomy includes use of computed tomography angiography (CTA) images of the head and neck to create clinically relevant 3D stereoscopic virtual models. These high resolution images of the arteries can be used in unique and innovative ways to create 3D virtual models of the vasculature as a tool for teaching anatomy. Blood vessel 3D models are presented stereoscopically in a virtual reality environment, can be rotated 360° in all axes, and magnified according to need. In addition, flexible views of internal structures are possible. Images are displayed in a stereoscopic mode, and students view images in a small theater-like classroom while wearing polarized 3D glasses. Reconstructed 3D models enable students to visualize vascular structures with clinically relevant anatomical variations in the head and neck and appreciate spatial relationships among the blood vessels, the skull and the skin.

Right arm injection of contrast medium reduces venous artifacts in head and neck multislice spiral computed tomography angiography

OBJECTIVE

We tested whether injection of contrast medium via right or left arm would affect venous artifacts on head and neck multislice spiral computed tomography (CT) angiography.

PATIENTS AND METHODS

326 patients were enrolled. Each patient was injected with 10 ml of contrast medium at 5 ml/sec. Time of peak contrast value plus an additional 1 sec was defined as delay time. Another 40 ml of contrast medium were injected with the same injection speed. The scanning area ranged from the aortic arch to the top of the head. Left and right forearms were used for intravenous injections of contrast medium in, respectively, 151 and 175 patients. Comparative analyses of image quality included determining contrast medium residues remaining in the superior vena cava, brachiocephalic vein, or subclavian vein, and comparisons of quality of three-dimensional CT angiography.

RESULTS

In 75% of head and neck angiographies, the delay time of the common carotid artery ranged from 16 to 22 sec. In 60% of the images, the quality was graded as excellent, with the left arm injection resulting in delay time of > 23 sec and the right arm delay time of > 18 sec. The CT imaging quality after contrast injections via left or right arms was statistically significant (p < 0.05). The image quality after right arm injection was better than after left arm injection.

CONCLUSIONS

Intravenous injection of contrast medium via right arm reduces artifacts from contrast medium residues and improves the image quality of head and neck CT angiography.

Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange

Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature, as well as pathways that would bypass neurosensory tissues. The orbital region houses a large venous sinus that receives cooled blood from the nasal region. Blood vessels from the nasal region and orbital sinus show anastomotic connections to the dural sinus system, allowing for the direct modulation of brain temperatures. The generality of the vascular patterns discovered in iguanas were assessed by firsthand comparison with other squamates taxa (e.g., via dissection and osteological study) as well as the literature. Similar to extant archosaurs, iguanas and other squamates have highly vascularized sites of thermal exchange that likely support physiological thermoregulation that "fine tunes" temperatures attained through behavioral thermoregulation.

Noncontact diffuse optical assessment of blood flow changes in head and neck free tissue transfer flaps

Knowledge of tissue blood flow (BF) changes after free tissue transfer may enable surgeons to predict the failure of flap thrombosis at an early stage. This study used our recently developed noncontact diffuse correlation spectroscopy to monitor dynamic BF changes in free flaps without getting in contact with the targeted tissue. Eight free flaps were elevated in patients with head and neck cancer; one of the flaps failed. Multiple BF measurements probing the transferred tissue were performed during and post the surgical operation. Postoperative BF values were normalized to the intraoperative baselines (assigning "1") for the calculation of relative BF change (rBF). The rBF changes over the seven successful flaps were 1.89 ± 0.15, 2.26 ± 0.13, and 2.43 ± 0.13 (mean ± standard error), respectively, on postoperative days 2, 4, and 7. These postoperative values were significantly higher than the intraoperative baseline values (p<0.001), indicating a gradual recovery of flap vascularity after the tissue transfer. By contrast, rBF changes observed from the unsuccessful flaps were 1.14 and 1.34, respectively, on postoperative days 2 and 4, indicating less flow recovery. Measurement of BF recovery after flap anastomosis holds the potential to act early to salvage ischemic flaps.

Head and Neck Veins of the Mouse. A Magnetic Resonance, Micro Computed Tomography and High Frequency Color Doppler Ultrasound Study

To characterize the anatomy of the venous outflow of the mouse brain using different imaging techniques. Ten C57/black male mice (age range: 7-8 weeks) were imaged with high-frequency Ultrasound, Magnetic Resonance Angiography and ex-vivo Microcomputed tomography of the head and neck. Under general anesthesia, Ultrasound of neck veins was performed with a 20MHz transducer; head and neck Magnetic Resonance Angiography data were collected on 9.4T or 7T scanners, and ex-vivo Microcomputed tomography angiography was obtained by filling the vessels with a radiopaque inert silicone rubber compound. All procedures were approved by the local ethical committee. The dorsal intracranial venous system is quite similar in mice and humans. Instead, the mouse Internal Jugular Veins are tiny vessels receiving the sigmoid sinuses and tributaries from cerebellum, occipital lobe and midbrain, while the majority of the cerebral blood, i.e. from the olfactory bulbs and fronto-parietal lobes, is apparently drained through skull base connections into the External Jugular Vein. Three main intra-extracranial anastomoses, absent in humans, are: 1) the petrosquamous sinus, draining into the posterior facial vein, 2) the veins of the olfactory bulb, draining into the superficial temporal vein through a foramen of the frontal bone 3) the cavernous sinus, draining in the External Jugular Vein through a foramen of the sphenoid bone. The anatomical structure of the mouse cranial venous outflow as depicted by Ultrasound, Microcomputed tomography and Magnetic Resonance Angiography is different from humans, with multiple connections between intra- and extra- cranial veins.

MIDA: A Multimodal Imaging-Based Detailed Anatomical Model of the Human Head and Neck

Computational modeling and simulations are increasingly being used to complement experimental testing for analysis of safety and efficacy of medical devices. Multiple voxel- and surface-based whole- and partial-body models have been proposed in the literature, typically with spatial resolution in the range of 1-2 mm and with 10-50 different tissue types resolved. We have developed a multimodal imaging-based detailed anatomical model of the human head and neck, named "MIDA". The model was obtained by integrating three different magnetic resonance imaging (MRI) modalities, the parameters of which were tailored to enhance the signals of specific tissues: i) structural T1- and T2-weighted MRIs; a specific heavily T2-weighted MRI slab with high nerve contrast optimized to enhance the structures of the ear and eye; ii) magnetic resonance angiography (MRA) data to image the vasculature, and iii) diffusion tensor imaging (DTI) to obtain information on anisotropy and fiber orientation. The unique multimodal high-resolution approach allowed resolving 153 structures, including several distinct muscles, bones and skull layers, arteries and veins, nerves, as well as salivary glands. The model offers also a detailed characterization of eyes, ears, and deep brain structures. A special automatic atlas-based segmentation procedure was adopted to include a detailed map of the nuclei of the thalamus and midbrain into the head model. The suitability of the model to simulations involving different numerical methods, discretization approaches, as well as DTI-based tensorial electrical conductivity, was examined in a case-study, in which the electric field was generated by transcranial alternating current stimulation. The voxel- and the surface-based versions of the models are freely available to the scientific community.

[Combined treatment of arteriovenous malformations of the head and neck]

An arteriovenous malformation (AVM) is a vascular developmental abnormality conditioned by impaired embryonic morphogenesis and characterized by the development of an abnormal connection between arteries and veins. More than 50% of the total number of patients suffering from this pathology are those having the pathological foci localizing in the area of the head and neck. At present, a combined method is both a generally accepted and the most radical one used for treatment for AVM. However, in the majority of cases, excision of the malformation leaves an extensive and complicated defect of tissues, whose direct closure leads to coarse cicatricious deformities. Over the period from 2004 to 2012, we followed up a total of 37 patients presenting with arteriovenous malformations of the head and neck. At admission the patients underwent preoperative examination including clinical tests, ultrasound duplex scanning, arteriography, MRT, and computed tomography. 24-72 hours prior to the operative intervention the patients were subjected to embolisation of the main vessels supplying the vascular malformation. Excision of the AVM was in 8 cases followed by primary closure of the postoperative wound, in 17 patients the defect was closed by transposition of the axial flaps, and 12 subjects underwent free transplantation of composite complexes of tissues. Relapse of the disease was revealed in 17 patients. In the majority of cases, relapses developed during the first year after the operative intervention (10 cases). The control of the disease's course was obtained in 20 patients. In 8 of the 12 patients with free transplantation of flaps we managed to obtain long-term control over the disease's course (more than 5 years). Hence, free microsurgical transplantation of compound complexes of tissues may be considered as a method of choice for closing the defect after excising an AVM in the area of the head and neck. Replacement of the defect with a well-vascularized tissue complex considerably improves regional haemodynamics, decreases tissue ischaemia, and is capable of providing longterm control over the disease's course.

Image reconstruction algorithm for in-line phase contrast imaging computed tomography with an improved anisotropic diffusion model

Phase contrast imaging (PCI) is a new physical and biochemical technique. Practical biomedical applications combine PCI with computer tomography (CT), Phase contrast CT (PC-CT) can reconstruct 3D images of samples. How to reconstruct high quality image at a low radiation dose level is a hot topic for PC-CT. In order to reduce radiation dose, a strategy is to collect incomplete projection data by few-view projection data. This work presents a reconstruction method for incomplete data PC-CT. It is based on an algebraic iteration reconstruction algorithm and combined with an anisotropic diffusion model to reduce aliasing distortions.To validate the availability of this method, the research carried out a computer-simulated and real experimental synchrotron data. The computer-simulated and real data results demonstrate that the presented method can improve the convergence speed of image reconstruction and reduce the aliasing distortions by incomplete projection data for PC-CT. However, there is no proof that this is true for all kinds of structures.

[Efficacy of suture ligation combined with super-wet tumescent techniques in resection of peripheral arteriovenous malformations of head and neck]

OBJECTIVE

To evaluate the feasibility and effectiveness of suture ligation combined with super-wet tumescent technique to replace embolization before surgical resection of peripheral arteriovenous malformations (AVMs) of the head and neck.

METHODS

Between July 2007 and November 2010, 9 patients with peripheral AVMs of the head and neck were treated, including 4 males and 5 females with a median age of 21 years (range, 8 months to 55 years). The causes were congenital malformation in 6 cases, trauma in 2 cases, and unknown origin in 1 case. The lesions were located at the frontotemporal region in 2 patients, cheek in 2 patients, occipitocervical region in 2 patients, temporoparietal region in 1 patient, upper lip in 1 patient, and lower lip in 1 patient. The size of the AVMs lesions ranged from 2.2 cm x 1.2 cm to 13.0 cm x 10.0 cm. Of 9 cases, 8 were classified as Schobinger grade II and I as grade III. The AVMs involved 2 to 7 main nutrient arteries, with a diameter range of 1.7-3.1 mm. At one-stage operation, AVMs was removed and direct suture, skin graft or flaps were used for repair in 6 cases; the skin was expanded at one-stage operation, and then AVMs removal and repair were performed at two- stage operation in 3 cases. Before resection of AVMs, No.7 silk suture was used to ligate the main nutrient vessels, and then annular interrupted suture of soft tissue was performed with the silk sutures around the lesions, at least two rings. Tumescent anesthetic solution was injected into lesions, and super wet end-point achieved.

RESULTS

Partial incision dehiscence occurred in 1 patient; the flaps and grafting skin survived, and primary healing of incision was obtained in the other patients. The mean operation time was 136 minutes (range, 42-367 minutes). The mean intraoperative blood loss was 268 mL (range, 15-1,000 mL). Only 1 patient received 3 units of blood transfusion. All patients were followed up for 4.2 years on average (range, 2 years to 6 years and 6 months); there was no recurrence case. The self-assessment cosmetic results were excellent or good in 5 cases and fair in 4 cases.

CONCLUSION

Intensive suture ligation followed by super-wet tumescent techniques might partially substitute preoperative embolization to facilitate surgical resection of peripheral AVMs of the head and neck, due to simple operation and less bleeding.

Diagnostic yield of delayed phase imaging in CT angiography of the head and neck: a retrospective study

PURPOSE

To evaluate how often delayed images, obtained during neurovascular CTA, provide unique information relative to early phase imaging alone.

MATERIALS AND METHODS

Informed consent was waived by the institutional review body for this study. Neurovascular CTAs from January through June 2009 were searched to identify those with delayed phase imaging. Reports were reviewed to identify cases where delayed images provided potentially unique information. The studies with potentially unique information were re-interpreted to determine if the information was indeed unique.

RESULTS

645 CTAs with delayed phase imaging were identified. There were 324 men and 310 women (median age 67 years; range 20-96 years). 59 studies (59/645: 9.1%) had findings on the delayed images. There were 13 cases with hemorrhage, with 4 showing progression on delayed views. Of the remaining 46 cases, 28 had occlusion of a vessel that did not reconstitute on the delayed images, 6 had occlusion of a vessel that did reconstitute on the delayed images, 7 had a string sign which was unchanged on the delayed views and 5 had no abnormal findings. Thus in 10 cases the findings were unique to the delayed images (10/645: 1.55%). Four showed active bleeding, three showed proximal occlusion with distal internal carotid filling from ophthalmic collaterals, two showed pial vessels filling distal to proximal MCA occlusion, and one showed retrograde vertebral artery filling due to subclavian steal. 95% confidence limits of the expected incidence of unique information from the delayed phase images are 0.6%-2.5%.

CONCLUSION

Obtaining delayed phase imaging for neurovascular CTA should be an active decision and not the default protocol. This avoids imaging with little, if any value. If delayed images had not been obtained in our cohort, no detriment in patient management would have occurred.

+Gz tolerance, with and without muscle tensing, following loss of anti-G trouser pressure

BACKGROUND

Fast jet aircrew are heavily reliant on anti-G trousers (AGT) and failure of the garment or its pressure supply would expose them to high levels of +Gz acceleration without protection. A previous study demonstrated the severity of this event at high +Gz, but no data exists as to the maximum +Gz level which could be tolerated.

METHODS

: While relaxed and with lower body muscle tensing, 10 experienced centrifuge subjects had their AGT deflated after 5 and 30 s of +Gz exposure. Discrete +Gz exposures of increasing intensity were performed until deflation resulted in central light loss (CLL). Visual symptoms, eye-level systolic BP (SBPeye), and mean blood flow velocity in the middle cerebral artery (MCAVmean) were recorded.

RESULTS

The mean +Gz level at CLL following AGT deflation was comparable to that without AGT inflation (+4.07 Gz) and increased by muscle tensing (+0.53 G) independent of exposure duration. Initial visual symptoms occurred more rapidly in the shorter +Gz exposures, while progression to CLL was quicker with muscle tensing compared with relaxed, but never less than 6.7 s. At CLL, the nadir in SBPeye was higher (+17 mmHg) with muscle tensing compared with relaxed, while MCAVmean was decreased by about 50% in all conditions.

DISCUSSION

+Gz tolerance following AGT deflation is comparable to that without inflation and only modestly increased by muscle tensing. Although vision is maintained for several seconds following AGT deflation, progression of light loss symptoms can be rapid, possibly resulting in insufficient time to respond before G-induced loss of conciousness (G-LOC) ensues.

128-slice acceletated-pitch dual energy CT angiography of the head and neck: comparison of different low contrast medium volumes

BACKGROUND

Our study aims to evaluate the image quality and feasibility of 128-slice dual-energy CTA (DE-CTA) for supra-aortic arteries using reduced amounts of contrast medium (CM).

METHODS

A prospective study was performed in 54 patients receiving CTA of the head and neck with a 128-slice dual-source CT system. Patients were randomized into two groups with a volume of either 40 mL of CM (Group I) or 50 mL of CM (Group II). Arterial and venous enhancements were recorded for quantitative assessment. Qualitative assessments for images without bone removal (BR) were based on a) the visualization of the circle of Willis and b) streak artifacts due to residual CM in the subclavian or internal jugular veins ipsilateral to injection of CM. Qualitative assessment of dual-energy images using BR was based on the presence of bone remnants and vessel integrity. Quantitative data was compared using the Student t test. The χ(2) test was used for the qualitative measurements of streak artifacts in veins while the Mann-Whitney U test was used for the qualitative measurements of images with BR.

RESULTS

Arterial and venous attenuation was significantly higher in Group II (P=0.000). Image quality regarding the circle of Willis was excellent in both groups (3.90±0.30 for Group I and 4.00±0 for Group II) . Imaging of the internal jugular veins was scored higher in Group I (1.87±0.72) compared with Group II (1.48±0.51) (P=0.021). Within Group I using BR, mean scores for bone remnants did not differ significantly (P>0.05) but mean scores of vessel integrity (P<0.05) did.

CONCLUSIONS

Contrast-enhanced head and neck CTA is feasible using a scan protocol with low amounts of contrast medium (40 mL) on a 128-slice dual-energy CTA. The 40-mL protocol provides satisfactory image quality before and after dual-energy bone-removal post-processing.

General equation for the differential pathlength factor of the frontal human head depending on wavelength and age

Continuous-wave near-infrared spectroscopy and near-infrared imaging enable the measurement of relative concentration changes in oxy- and deoxyhemoglobin and thus hemodynamics and oxygenation. The accuracy of determined changes depends mainly on the modeling of the light transport through the probed tissue. Due to the highly scattering nature of tissue, the light path is longer than the source-detector separation (d). This is incorporated in modeling by multiplying d by a differential pathlength factor (DPF) which depends on several factors such as wavelength, age of the subject, and type of tissue. In the present work, we derive a general DPF equation for the frontal human head, incorporating dependency on wavelength and age, based on published data. We validated the equation using different data sets of experimentally determined DPFs from six independent studies.

Time resolved imaging of contrast kinetics (TRICKS) MR angiography of arteriovenous malformations of head and neck

PURPOSE

To evaluate vasculature of arteriovenous malformations (AVMs) of head and neck with time resolved imaging of contrast kinetics (TRICKS) MR angiography (MRA).

MATERIAL AND METHODS

Prospective study was conducted upon 19 patients (age range, 12-29 years; mean age 18 years; 10 males and 9 females) with AVM of head and neck. TRICKS-MRA of head and neck was performed during injection of contrast medium. Post processing with reconstruction of the images was done. Two independent readers assessed the overall TRICKS-MRA image quality score using a 5-point scale and depiction of the main arterial feeders, nidus, and venous drainage using 3 points scale. The Kappa test for interobserver agreement was done. The AVMs were evaluated morphologically in terms of number and origin of the main arterial feeders, the location and size of nidus either small (>2 cm) or large (>2 cm) and the draining veins into the superficial or deep venous drainage.

RESULTS

The average TRICKS-MRA image quality score as judged by reader 1 was 3.89 ± 1.15 and that as judged by reader 2 was 3.89 ± 0.10, which yielded excellent interobserver agreement (k=0.77, 95% CI=0.53-0.98, r=0.78, P=0.001). The interobserver agreement of both readers was excellent for the arterial feeders (k=0.81, 95% CI=0.57-1.00, r=0.83, P=0.001), excellent for the nidus (k=0.91, 95% CI=0.75-1.00, r=0.92, P=0.001), and good for the venous drainage (k=0.77, 95% CI=0.53-0.98, r=0.78, P=0.001). The arterial feeders were single (n=14) or multiple (n=5), the nidus was large (n=16) or small (n=3) and the venous drainage was into the internal jugular (n=17) or the external jugular (n=2) veins. Three patients with small nidus and single arterial feeder were treated with sclerotherapy. Eleven patients with large nidus and single arterial feeder were referred for embolization. Combined embolization and surgery were done for five patients with large nidus and multiple arterial feeders.

CONCLUSION

We concluded that TRICKS-MRA is a reliable non invasive tool for evaluation of the feeding arteries, the nidus and the draining veins of AVMs of head and neck. TRICKS-MRA can be used for evaluation and treatment planning of AVMs of head and neck.

Detection of an unstable and/or a weak probe contact in a multichannel functional near-infrared spectroscopy measurement

Multichannel functional near-infrared spectroscopy measurements involve the placement of many probes on a subject's head. A stable close contact between the probe and head surface is essential. We propose a way to detect two types of problematic probe contacts from the measurement data: an unstable contact whose light transmission easily fluctuates with body motion, and a weak contact whose light transmission is constantly small. An unstable contact causes large baseline fluctuation, whereas a weak contact causes large noise. Because absorbance changes caused by body motion and noise show different spectroscopic properties from the tissue hemoglobin absorption, they have a component orthogonal to the plane spanned by hemoglobin molar extinction coefficient vectors. We use this information to detect unstable and/or weak contacts. Probes are shared by different channels, and this sharing configuration is determined by the probe arrangement. Thus, the baseline fluctuation and noise of the channels are related to contact instability and weakness of the probe according to the probe arrangement. Unstable and/or weak probes are determined by solving an inverse problem of this relation. Problematic probes can be effectively determined using the proposed method.

[Application of computed tomographic angiography in repairing skin defect after scalp avulsion with free latissimus dorsi flap transplantation]

OBJECTIVE

To investigate the clinical value of computed tomographic angiography (CTA) and three-dimensional reconstruction technique in repairing scalp avulsion wound with large skull exposure by the free latissimus dorsi flap transplantation.

METHODS

Between October 2007 and June 2012, 9 female patients with serious scalp avulsion and large skull exposure were treated, aged 23-54 years (mean, 38 years). The injury causes included machine twist injury in 6 cases, traffic accident injury in 2 cases, and falling from height injury in 1 case. Before admission, 3 patients had scalp necrosis after scalp in situ replantation, and 6 patients underwent debridement and dressing. The time from injury to admission was 8 hours to 7 days (mean, 1 day). The avulsed scalp area ranged from 75% to 90% of the scalp area (mean, 81%); the exposed skull area ranged from 55% to 70% of the scalp area (mean, 63%). Two patients had unilateral auricle avulse. CTA was used to observe the superficial temporal artery and vein, facial artery, external jugular vein, dorsal thoracic artery and vein, and measure the blood vessel diameter before operation. According to the CTA results, the latissimus dorsal skin flaps were desinged to repair wounds in 7 cases, the latissimus dorsal muscle flaps combined with skin graft were used to repair wounds in 2 cases. According to preoperative design, operation was successfully completed in 7 cases; great saphenous vein was used as vascular graft in 2 cases having poor images of superficial temporal vessels. The size of latissimus dorsal skin flaps ranged from 20 cm x 14 cm to 25 cm x 20 cm; the donor site was repaired with skin graft. The size of latissimus dorsal muscle flaps were 23 cm x 16 cm and 16 cm x 10 cm; the donor site was directly sutured.

RESULTS

The blood vessel diameter measured during operation was close to the value measured before operation. The operation time was 6-8 hours (mean, 6.5 hours). The latissimus dorsal muscle (skin) flap and skin graft survived, with primary healing of wound or incision at donor site. The patients were followed up 3 months-2 years (mean, 6 months). The flap had soft texture and skin had no ulceration.

CONCLUSION

The free latissimus dorsi flaps can repair scalp avulsion with large skull exposure. Preoperative CTA can get the vessel anatomical structure and diameter at donor and recipient sites, which will guide the operation program design and implementation so as to shorten the operation time and improve the accuracy rate of vascular anastomosis.

Head and neck vessel size by angiography predicts neo-aortic arch obstruction after Norwood/Sano operation for hypoplastic left heart syndrome

OBJECTIVES

To identify and predict neo-aortic arch obstruction (NAAO) in children after Norwood/Sano operation (NO) for hypoplastic left heart syndrome (HLHS).

BACKGROUND

NAAO is associated with morbidity and mortality after NO for HLHS and no objective measure has predicted the initial occurrence of NAAO. Computational flow models of aortic coarctation demonstrate increased wall shear stress (WSS) in vessels proximal to the coarctation segment, which we believe also occurs with NAAO. These vessels respond by increasing their luminal diameter to maintain normal WSS. We hypothesized that the relative increase in diameters of head and neck vessels to the isthmus, as measured by angiography, would identify hemodynamically significant NAAO and predict future NAAO.

METHODS

Retrospective review of patients with HLHS and at least one catheterization with aortic angiography after NO. Diameters of head and neck vessels were totaled and divided by the isthmus diameter to give a head and neck index (HNI), which was compared to coarctation index (CI) for identifying and predicting future NAAO.

RESULTS

Forty-four patients were identified, 17 with and 27 without NAAO. Receiver operator characteristic analysis using a value for CI ≤0.5 showed a sensitivity of 47% and specificity of 89%. For HNI, a value >2.65 gave a sensitivity of 77% and specificity of 93%. Three patients who developed NAAO after their initial catheterization had CI >0.5, but abnormally high HNI >2.65.

CONCLUSIONS

HNI is a more robust indicator of hemodynamically significant NAAO than CI and may predict its future occurrence after NO for HLHS.

[Angiodysplasias of the head and neck: present-day principles of treatment using elements of plastic surgery]

The authors assessed the outcomes of treatment of fifty-one patients presenting with angiodysplasias of the head and neck. Of these, 24 patients suffered from the venous form and 27 had the arteriovenous form. The 51 patients accounted for 23.5% of the total number of patients with congenital vascular malformations over a five-year period. The topicity and angioarchitectonics of the lesion were specified by means of the standard diagnostic complex (i. e., duplex scanning of the vessels, ultrasonographic study of the soft tissues and osseous structures, computed and magnetic resonance tomography, echocardiography, and angiography). Radical excision of the angiomatous tissues was performed in 15 patients and palliative one - in 36 cases. Eight patients were subjected to stagewise resection interventions, ten patients underwent stagewise sessions of laser coagulation, and seven patients endured stagewise roentgenoendovascular embolisations of the afferent arteries. Two patients with the venous form were postoperatively subjected to sessions of sclerotherapy of the residual venous caverns. Two patients in the remote period (7-10 days) underwent autodermoplasty with a free perforated cutaneous flap. This technique was used while closing the wound surface after removing the angiomatous tissues of the parotid region and hairy portion of the head. In five patients the wound surface was closed with a mobilized cervical fat-cutaneous flap. Taking into consideration the importance of the cosmetic outcome after excising the angiomatous tissues on the face and neck, it is necessary to seek for wide application of plastic methods of closing the wound. These methods simultaneously allow of making operative interventions for angiodysplasias more radical.

Double external jugular vein and other rare venous variations of the head and neck

Superficial veins of the head and neck are utilised for central venous cannulation, oral reconstruction and parenteral nutrition in debilitated patients. Clinical and sonological examinations of these veins may provide clues toward underlying cardiac pathology. Hence, although variations in these vessels are common, a sound knowledge of such variations becomes clinically important to surgeons, radiologists and interventional anaesthetists. We report a rare case of a left-sided double external jugular vein where the common facial vein continued as the second external jugular vein, and where there was a communicating channel between the internal jugular vein on the same side and the anterior jugular vein.

Effect of head posture on the healthy human carotid bifurcation hemodynamics

Head and neck postures may cause morphology changes to the geometry of the carotid bifurcation (CB) that alter the low and oscillating wall shear stress (WSS) regions previously reported as important in the development of atherosclerosis. Here the right and left CB were imaged by MRI in two healthy subjects in the neutral head posture with the subject in the supine position and in two other head postures with the subject in the prone position: (1) rightward rotation up to 80°, and (2) leftward rotation up to 80°. Image-based computational models were constructed to investigate the effect of posture on arterial geometry and local hemodynamics. The area exposure to unfavorable hemodynamics, based on thresholds set for oscillatory shear index (OSI), WSS and relative residence time, was used to quantify the hemodynamic impact on the wall. Torsion of the head was found to: (1) cause notable changes in the bifurcation and internal carotid artery angles and, in most cases, on cross-sectional area ratios for common, internal and external carotid artery, (2) change the spatial distribution of wall regions exposed to unfavorable hemodynamics, and (3) cause a marked change in the hemodynamic burden on the wall when the OSI was considered. These findings suggest that head posture may be associated with the genesis and development of atherosclerotic disease as well as complications in stenotic and stented vessels.

Phantom with pulsatile arteries to investigate the influence of blood vessel depth on pulse oximeter signal strength

This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm). The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of real tissues and blood. The amplitude of the pulsating component of the light returning from the phantom tissues was measured at each artery depth mentioned above. The build-up of the in-house-developed pulse oximeter used for performing the measurements and the physical layout of the measuring head are described. The radiant flux generated by the LED on the measuring head was measured to be 1.8 mW at 910 nm. The backscattered radiant flux was measured, and found to be 0.46 nW (0.26 ppm), 0.55 nW (0.31 ppm), and 0.18 nW (0.10 ppm) for the 1.2 mm, 3.7 mm and 6.8 mm arteries, respectively. In the case of the 9.6 mm and 11.8 mm arteries, useful measurement data were not obtained owing to weak signals. We simulated the phantom with the arteries at the above-mentioned five depths and at two additional ones (2.5 mm and 5.3 mm in depth) using the Monte Carlo method. The measurement results were verified by the simulation results. We concluded that in case of 11 mm source-detector separation the arteries at a depth of about 2.5 mm generate the strongest pulse oximeter signal level in a tissue system comprising three layers of thicknesses: 1.5 mm (skin), 5.0 mm (skull), and >50 mm (brain).

Diagnostic methods, treatment modalities, and follow-up of extracranial arteriovenous malformations

OBJECTIVE

Arteriovenous malformations (AVMs) are an uncommon vascular pathology that remains challenging to accurately diagnose and successfully treat. This study introduces a novel way to evaluate AVM treatment outcomes using transarterial lung perfusion scintigraphy (TLPS) and reports our treatment results.

MATERIAL AND METHODS

The patients treated for extracranial AVMs were studied retrospectively. Diagnosis and outcomes were based on clinical data, ultrasonography, magnetic resonance imaging, computed tomography, angiography, and TLPS studies. The influence of gender; location, form, and stage of AVMs; first attempt at treatment; and treatment modalities was analyzed. Outcomes were defined as positive (cure, improvement, and remission) or negative (no remission and aggravation).

RESULTS

Of the 324 patients with congenital vascular malformations, 129 (39.8%) presented with AVMs, and the data of 56 treated patients with AVMs were analyzed. Of the 29 patients in the endovascularly treated group, 15 in the surgically treated group, and 12 in the combined treatment group, 24 (82.8%), 14 (93.3%), and 10 patients (83.3%), respectively, had positive outcomes (P>0.05). All outcomes were positive in surgically treated patients with extratruncular limited AVMs, and these patients were more likely to be cured as compared with those who had other forms of AVMs (OR, 5.8; 95% CI, 1.1-29; P=0.02). The patients with more advanced AVMs (stages III and IV) and with AVMs in the gluteal and pelvic region were more likely to have the worst outcomes than those with stage II AVMs (OR, 8.2; 95% CI, 1-72; P=0.03) and with AVMS in other locations (OR, 5.8; 95% CI, 1.1-29; P=0.02), respectively. Gender and age did not significantly influence treatment results (P>0.05). The TLPS data of 17 patients showed AV shunting ranging from 0% to 92%, which combined with other results helped identify 9 patients who needed further interventions, 6 who were treated successfully, and 2 who had insignificant shunting.

CONCLUSIONS

The best outcomes were achieved in surgically treated patients with localized lesions and less advanced AVMs. For the first time in Lithuania, a modified TLPS method has been introduced that enhances a hemodynamic assessment of AV shunting and provides with a more accurate evaluation of AVMs to better serve in planning future treatments.

[Multidisciplinary approach to diagnostics of extensive vascular head and neck malformations]

The article summarizes the experience of diagnostics in 60 patients with large face and neck angiodysplasia. Compression test, cytology, Doppler ultrasound with color Doppler mapping, X-ray computed tomography and angiography with intravenous contrast, magnetic resonance imaging with angiography and selective carotid angiography of branches of external carotid arteries were used for adequate diagnostics. The efficiency of a multidisciplinary approach in diagnosis and treatment of extensive face and neck angiodysplasias is shown in the study.

Arrangement and prevalence of branches in the external carotid artery in humans

The external carotid artery originates branches to face structures. The superior thyroid, lingual and facial arteries are originated from this vessel as artery trunks or separately. The aim of this study was to determinate the arrangement frequency of these artery branches. For this, thirty six (36) hemi-heads of adult cadavers from both genders were studied. The anatomic parts were fixed in 10% of formalin and dissected. The superior thyroid, lingual and facial arteries were analyzed in terms of their origins. The superior thyroid, lingual and facial arteries originated separately from the external or common carotid artery in 77.8% of the cases. A linguofacial trunk was observed in 19.9% of the cases and a thyrolingual trunk in 2.8%. A thyrolinguofacial trunk was not observed. In 51.2% cases the superior thyroid artery originated directly from the external carotid artery, in 45.3% from the bifurcation of the common carotid artery, and in 3.5% from the common carotid artery. Thus, the superior thyroid, lingual and facial arteries more frequently showed a separate origin from the external or common carotid artery. Among the combined artery trunks, the linguofacial trunk was most frequently observed, followed by the thyrolingual trunk. The superior thyroid artery originated more frequently from the external or common carotid artery; however, it also could emerge from the bifurcation of the common carotid artery.

Interpretation errors in CT angiography of the head and neck and the benefit of double reading

BACKGROUND AND PURPOSE

CTA provides high-resolution imaging of the head and neck vasculature but also of the soft tissues and bones. This results in a large volume of information to be interpreted. This study examines interpretation errors with head and neck CTAs and assesses whether double reading reduces miss rates.

MATERIALS AND METHODS

Consecutive CTAs of the neck and intracranial circulation were retrospectively identified and reviewed for vascular and nonvascular findings by a consensus of 2 neuroradiologists. The results were compared with the official report. Significant discrepancies were considered those that would have influenced follow-up or management.

RESULTS

We reviewed 503 studies; 144 were originally reported by a staff neuroradiologist alone, 209 by staff and diagnostic radiology resident, and 150 by staff and neuroradiology fellow. Twenty-six significant discrepancies were discovered in 20 studies, corresponding to 4.0% of studies with at least 1 miss, and an overall miss rate per study of 5.2%. There was at least 1 miss in 6.3% of studies interpreted by a staff neuroradiologist alone, 3.3% by staff and resident, and 2.7% by staff and fellow. The miss rate differences were not statistically significant. The most common misses were small aneurysms (50% of misses).

CONCLUSIONS

CTA neck and head datasets are now large, and there is a potential for missed findings. Significant discrepancies can occur with a low but not insignificant rate. Arterial pathology accounted for most discrepancies. This study emphasizes the need for careful systematic scrutiny for both vascular and nonvascular pathology regardless of indication. Double reading reduces error rates.

Reduction of image artifacts induced by change in the optode coupling in time-resolved diffuse optical tomography

Tomographic images of the optical properties can be reconstructed using inversion algorithms for diffuse optical tomography (DOT); however, changes in the optode coupling that occurs while obtaining an object's measurements may often lead to the presence of artifacts in the reconstructed images. To reduce the number of artifacts induced by optode coupling, previous studies have introduced (unknown) coupling coefficients in reconstruction algorithms, which were found to be effective for continuous wave- and frequency-domain DOT. This study aims to investigate the effects of optode calibration on the reconstructed images of time-domain DOT. Here, coupling coefficients are incorporated into the time-domain DOT algorithm based on a modified generalized pulse spectrum technique. The images of the absorption coefficient are reconstructed in various numerical simulations, phantom experiments, and in vivo experiments of time-domain DOT. As a result, the artifacts resulting from changes in optode coupling are reduced in the reconstructed images of the absorption coefficient, thereby demonstrating that introduction of coupling coefficients is effective in time-domain DOT. Moreover, numerical simulations, phantom experiments, and in vivo studies have validated this algorithm.

Treatment of high-flow arteriovenous malformations (AVMs) of the head and neck with embolization and surgical resection

AIM

Arteriovenous malformations (AVMs) with a high flow of the head and neck are quite rare compared to their low-flow counterparts, but when they do occur they are often accompanied by massive bleeding or present with significant esthetic defects. The treatment of these high-flow vascular anomalies is often highly risky. The multidisciplinary approach required for the assessment and treatment of these lesions should include angioradiology with preoperative superselective embolization, followed by surgical resection of the lesion within 24 hours and esthetic reconstruction.

MATERIALS OF STUDY

We studied a series of 55 patients with AVMs of the head and neck that were treated surgically between 1999 and 2009.

RESULTS

Of the 55 patients with AVMs, 7 had hemangiomas and 48 had vascular malformations, of which 28 were low-flow lesions and 20 were high-flow lesions (AVMs). The high-flow lesions were most commonly located on the lip. All 48 AVMs underwent surgical resection for concerning symptoms, diagnostic purposes, or esthetic problems. Of the 20 high-flow AVMs, 20% were classified as Schöbinger stage I, 55% as stage II, and 25% as stage III. A combined treatment of embolization and resection was used to resolve 13 of the high-flow AVMs (stages II and III), of which 4 required a flap reconstruction.

CONCLUSION

Recent advances in microsurgery and interventional angioradiology have greatly improved the prognosis for patients with these malformations. Combined embolization-resection is the treatment of choice for high-flow AVMs, and esthetic reconstruction with flaps can prevent their recurrence.

[Penetrating needling on head points for vertigo caused by vertebral-basilar arterial blood-supply insufficiency]

OBJECTIVE

To observe the differences in therapeutic effect between penetrating needling on head points and acupuncture of syndrome division in the treatment of vertigo caused by vertebral-basilar arterial blood-supply insufficiency.

METHODS

Sixty cases of vertigo caused by vertebral-basilar arterial blood-supply insufficiency were divided into 2 groups: a penetrating needling on head points group (group A) and an acupuncture of syndrome division group (group B), 30 cases in each one. In group A, penetrating needling technique was applied from Baihui (GV 20) towards Qianding (GV 21), Shuaigu (GB 8) towards Qubin (GB 7) and Yuzhen (BL 9) towards Tianzhu (BL 10). Electric stimulation was added. In group B, the acupoints were selected according to syndromes. For example, upper disturbance of wind yang: Ganshu (BL 18), Xingjian (LR 2),etc. were selected; upper disturbance of turbid phlegm: Yinlingquan (SP 9), Fenglong (ST 40), etc. were selected; qi and blood deficiency: Baihui (GV 20), Xuehai (SP 10), etc. were selected; liver and kidney yin deficiency: Ganshu (BL 18), Shenshu (BL 23), etc. were selected. Electric stimulation and needling manipulation were conducted on those acupoints. Ten treatments made one session. After continuous 2 sessions of treatment, the efficacy, symptom score and physical sign score were compared between two groups. Transcranial Doppler (TCD) examination was done to observe hemodynamic changes of anterior cerebral artery (ACA), middle cerebral artery (MCA) and posterior cerebral artery (PCA) before and after treatment.

RESULTS

The total effective rate in group A was 96.7% (29/30) that was obviously better than 83.3% (25/30) in group B (P<0.05). The scores of vertigo degree, vertigo frequency, duration and accompanied symptoms after treatment were lower obviously as compared with those before treatment in two groups (all P<0.05). The improvements in group A were much significant (all P<0.05). The highest mean velocity(Vm) of bilateral MCA, ACA and PCA were apparently reduced after treatment in two groups (P< 0.05, P<0.01). The improvements in group A were much more apparently (all P<0.05).

CONCLUSION

The penetrating needling on head points can effectively relieve vertigo caused by vertebral-basilar arterial blood-supply insufficiency, reduce the attack frequency and improve in its accompanied symptoms. Its clinical efficacy is significantly superior to that in acupuncture of syndrome division group.

[Analysing causes of low efficacy of ultrasonographic diagnosis of stenosing major arteries of the head in hypertensive patients]

The authors analyse herein the reasonable use of ultrasonographic methods of examination of carotid arteries for diagnosis of stenosing pathology in hypertensive patients. At the stage of primary medical care of the city of Chelyabinsk, a non-selective referral of patients presenting with elevated arterial pressure to duplex ultrasonography of the carotid artery is not uncommon. Doubtful criteria of selecting the hypertensive patients who really require undergoing ultrasonography of the carotid artery result in low efficacy of the examination.

Characterization of congenital lymphatic and blood vascular malformations in the head and neck using blood pool scintigraphy and spect

The purpose of this study was to investigate the usefulness and diagnostic efficacy of blood pool (BP) scintigraphy and SPECT for characterizing congenital vascular malformations (CVMs) in the head and neck area. A total of 154 patients suspected of having head and neck CVMs underwent whole-body BP scintigraphy and head and neck BP SPECT using 99mTc-labeled red blood cells. Based on SPECT findings, CVMs were classified into lymphatic malformation/ non-(blood) vascular disease (LM/NVD, no distinct uptake), arterio-venous malformation (AVM, abnormal uptake in lesions and asymmetrically increased jugular vein uptake on ipsilateral side), venous malformation (VM, strong uptake in lesions with symmetric jugular vein uptake), and veno-lymphatic malformation (VLM, no or mild uptake on lesions with symmetric jugular vein uptake). The sensitivities and specificities of BP SPECT for diagnosing each subtype of head and neck CVM were 100% (13/13) and 97.1% (137/141) for LM/NVD, 61.1% (22/36) and 99.1% (117/118)for AVM, 91.7% (88/96) and 79.3% (46/58) for VM, and 55.6% (5/9) and 93.7% (136/145) in VLM, respectively. The overall accuracy for characterizing CVMs by head and neck BP SPECT was 83.1% (128/154). In conclusion, BP SPECT is a useful method for classifying CVMs in the head and neck area due to its high diagnostic efficacy.

Malformation of certain brain blood vessels caused by TCDD activation of Ahr2/Arnt1 signaling in developing zebrafish

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). The AHR also plays important roles in normal development in mice, and AHR(-/-) mice show abnormal development of vascular structures in various blood vessels. Our previous studies revealed that Ahr type 2 (Ahr2) activation by TCDD and beta-naphthoflavone (BNF) caused a significant decrease in blood flow in the dorsal midbrain of zebrafish embryos. Here we report effects of TCDD exposure on the morphology of some blood vessels in the head of developing zebrafish. TCDD caused concentration-dependent anatomical rearrangements in the shape of the prosencephalic artery in zebrafish larvae. In contrast, no major vascular defects were recognized in the trunk and tail regions following exposure to TCDD at least at the concentrations used. Essentially, the same observations were also confirmed in BNF-exposed larvae. Knock-down of either Ahr2 or Ahr nuclear translocator type 1 (Arnt1) by morpholino oligonucleotides (MOs) protected larvae against abnormal shape of the prosencephalic artery caused by TCDD and BNF. On the other hand, knock-down of Ahr2 or Arnt1 in vehicle-exposed zebrafish larvae had no clear effect on morphology of the prosencephalic artery or trunk vessels. Ascorbic acid, an antioxidant, protected against the TCDD-induced decrease in blood flow through the prosencephalic artery, but not the abnormal morphological changes in the shape of this artery. These results indicate that activation of Ahr2/Arnt1 pathway by TCDD and BNF affects the shape of certain blood vessels in the brain of developing zebrafish.

[Ultrasound duplex scanning of head and neck vessels with the aim of preoperational preparation of the patients with inherent microtia of the III degree]

For surgical treatment of patients with inherent microtia of the III degree we use one stage method of otoplasty with silicone implant and parietotemporal fascial flap. In order to receive most full picture of the status of superficial temporal artery and its branches the additional diagnostic study is necessary. Method of ultrasound duplex scanning let to study any vessel in real time regimen under monitor screen control. Received by us results of ultrasound duplex scanning of superficial temporal artery branches in patients with inherent microtia of the III degree let us to conclude about the status of the vessel wall, to determine diameter and vessel occlusion, to evaluate and measure blood flow parameters. It is diagnostically necessary criteria for answering the question about flap vitality and in such a way let to avoid possible complications.

Internal jugular vein valves: an assessment of prevalence, morphology and competence by color Doppler echography in 240 healthy subjects

The presence of valves in the head and neck veins is known since classical anatomical dissections. Previous studies have investigated whether jugular veins show constant valves at their ostium and whether these valves are physiologically competent, but, unluckily, these studies have reported conflicting results. Further, recent observations have raised the question whether the incompetence of jugular vein valves might play a pivotal role in neurological disorders related to venous engorgement of the brain. In this study we examined 462 internal jugular veins by using an echocolorodoppler apparatus. In particular, we assessed the presence, morphology and competence of valves at their ostium. Unilateral jugular vein valves were present in 406 cases (88%), mainly on the right side. The most frequently observed morphology (75%, 305 cases) was the two-leaflet valve, and jugular vein valves were incompetent in the huge majority of cases (365 cases, 90%). Our findings confirm the anatomical variability predicted from classical anatomical studies but, unluckily, do not provide additional evidence on the possible role of jugular vein valves in physiology and pathology. Further studies are strongly needed to determine whether these valves actually play an important role in counteracting chest venous pressure and in preventing reflux towards the brain.

Vascular anatomy: the head, neck, and skull base

Knowledge of the anatomy of the vasculature of the head and neck from the thorax to the skull base is critical to the approach to diagnosis and treatment of cerebrovascular disease. Awareness of the anatomic variations that may be encountered, common and uncommon, is necessary to avoid diagnostic pitfalls and to avert therapeutic disasters. Careful anatomic analysis and understanding of collateral pathways and dangerous anastomoses facilitates cross-sectional and angiographic diagnosis and the development of surgical and endovascular treatment strategies.

An anatomical study of the arterial and nerve supply of the infrahyoid muscles

A precise knowledge of the sources of the arterial and neural supply of the sternohyoid (SH), sternothyroid (STM), and superior belly of omohyoid (OM) is of value to surgeons using the infrahyoid muscles in reconstruction procedures of the head and neck. This study was designed to define the anatomical bases of the variable sources of the arterial and neural supply of these muscles. Fourteen cadavers were unilaterally dissected in the neck region, and the arterial pedicles of these muscles were followed and accurate measurements were taken. For the SH, two arterial pedicles (superior and inferior) originated from the superior thyroid artery ST and supplied the muscle in 57.1% of cases. The inferior pedicle was absent in 42.9% of cases. As regards the STM, one arterial pedicle from the ST supplied its upper end by multiple branches in 57.1% of cases. In 14.3% of cases, branches from the inferior thyroid artery (IT) supplied the STM in addition to its supply from the ST. As regards the OM, two arterial pedicles originated from the ST and supplied its upper and lower ends in 57.1% of cases. The main artery from the ST to the superior belly of OM entered at its superior portion. The ansa cervicalis (AC) innervated the infrahyoid muscles. SH usually had a double nerve supply. In 57.1% of cases, its superior part was innervated by the nerve to the superior belly of OM. Its inferior part received branches from the AC. In 35.7% of cases, its superior part received direct branches from the AC. As regards the STM, in (71.4%) of cases, a common trunk arose from the loop and supplied the inferior part of both the SH and STM. The nerve supply to the superior belly of OM originated from the AC below the loop in 64.3% of cases. These data will be useful for preserving the neuro-vascular supply of the infrahyoid muscles during flap preparation.