Left Internal Jugular Vein Research Articles

Microgravity-induced reduced jugular vein flow is more pronounced on the non-dominant side

An astronaut developed a left-sided internal jugular vein (IJV) thrombosis while in orbit, likely due to reduced IJV blood flow. We hypothesized that microgravity-induced flow reductions would be greatest on the non-dominant (usually left) side thereby increasing thrombosis risk. A Simulink®-based lumped parameter model (LPM) was used to explore causes of jugular flow reduction and asymmetric thrombosis risk. Vessel behavior is described by combinations of four discrete components: hydrostatic gradients, vessel compliance, flow resistance, and flow inertia. The cranial venous system features drainage pathways through the right IJV, the left IJV and the vertebral plexus. The right jugular vein was modeled as the dominant jugular pathway (60% of total undeformed jugular cross-sectional area). The left side accounted for the remaining 40% of jugular flow. Multiple variables were adjustable in the LPM: body position (supine, prone, head-down tilt), and gravity. A key feature of this LPM is the incorporation of extravascular pressure on the vessels by the weight of tissues.Relative to a supine baseline, simulated total IJV flow changed from an average of 10.7 to 1.7 mL/s in weightlessness. The left and right IJV flow in microgravity was 0.6 and 1.2 mL/s, respectively (33.3% and 66.6% of total jugular venous flow, respectively). Not only was average flow reduced, but the flow pulsatility in the left IJV matched the observations made by Marshall-Goebel et al. in microgravity, where blood flowed forward, but with periodic zero-velocity flow. In microgravity, simulated left IJV was reduced to 33.3% from 40% of total jugular flow because the reduction in vein diameter in response to the transmural pressure changes is non-linear.

LEMIERRE'S SYNDROME: THE FORGOTTEN DISEASE

TYPE: Case Report TOPIC: Chest Infections INTRODUCTION: Septic thrombophlebitis of the internal jugular vein (IJV) is a rare complication of anaerobic oropharyngeal infection. We present a case of Lemierre’s syndrome which was managed without systemic anticoagulation therapy. CASE PRESENTATION: A 63 year old female presented to the hospital with left jaw pain for one week. The admission labs were pertinent for leukocytosis, lactic acidosis, acute kidney injury and thrombocytopenia. Oral physical exam was significant for submandibular tenderness, ulcerative pharyngitis and tonsillitis. She was initiated on broad spectrum antibiotics. A venous ultrasound of the left upper extremity revealed an acute deep vein thrombosis in her left IJV and an acute superficial venous thrombosis in the right cephalic vein. The blood culture later grew an anaerobic gram negative bacteremia, identified to be part of the Fusobacterium species. The patient was managed on IV Unasyn for two weeks; she improved and her abnormal labs resolved. She was discharged with Amoxicillin for two weeks. DISCUSSION: The typical clinical picture of Lemierre’s syndrome is an acute oropharyngeal infection, anaerobic gram negative bacterial infection and an acute thrombosis of the internal jugular vein. Antibiotics are currently the primary treatment of this condition. Despite thrombosis of IJV, treatment with anticoagulation therapy remains unclear. CONCLUSIONS: We wish to highlight the importance of recognising Lemierre’s syndrome due to its increasing resurgence and high mortality rate (25%) if not treated adequately with antibiotics. This case also emphasises septic thrombophlebitis in the hospital setting and the need for further controlled studies to establish the role of anticoagulation therapy. DISCLOSURE: Nothing to declare. KEYWORD: lemierre's syndrome

1307-P: Leptin Action in the Nucleus of the Solitary Tract

Obesity and diabetes are characterized by a disruption in energy balance and glucose homeostasis in association with leptin resistance. Leptin action in the hypothalamus regulates glucose levels and body weight, but whether other brain regions facilitate leptin action remain unclear. Here, we investigate whether the nucleus of the solitary tract (NTS) of the brainstem is a crucial site for leptin action in regulating glucose homeostasis in 3d high-fat (HF) -fed male rats, as recent studies report leptin activates leptin receptor in the NTS to regulate feeding. In this study, we performed brain stereotaxic bilateral surgery targeting the NTS followed one week later by catheterization of the left carotid artery and right internal jugular vein for infusion/sampling purposes. Rats that attained >90% of presurgical weight received 3d of Lard oil enriched HF diet and were fasted 4-6 hr before undergoing a 2min pancreatic (basal insulin) -euglycemic clamp studies together with tracer glucose infusion to assess glucose metabolism independent of changes in plasma insulin and glucagon levels. Leptin (91.7 ng/uL at 0.33 ul/hr) or saline was infused into the NTS throughout the duration of the clamp studies. Correct placement of the NTS catheter was verified by infusion of bromophenol blue dye through the brain cannula. For the first time, we found that leptin vs. saline infusion into the NTS markedly increased the exogenous glucose infusion [lep: 4.6±0.2 vs. sal: 1.3±0.4 mg/kg/min; p<0.005; n=12, 5] required to maintain euglycemia [lep: 137.5±2.2 vs. sal: 145±3.1 mg/dl; p>0.05; n=12, 5], during the clamps. The drop in plasma glucose levels was due to an inhibition of glucose production [lep: 4.9±0.1 vs. sal: 8.4±0.7 mg/kg/min; p<0.01; n=12, 5], but not an increase in glucose uptake [lep: 10.4±0.5 vs. sal: 9.7±0.3 mg/kg/min; p>0.05; n=12, 5]. These findings demonstrate that the NTS mediates leptin action on glucose homeostasis. Future studies are needed to investigate the NTS leptin signaling cascade in glucose homeostasis in obesity and diabetes. Disclosure K.Bruce: None. R.Li: None. Y.Lim: None. J.T.Yue: None. T.K.Lam: None. Funding Canadian Institutes of Health Research Foundation Grant (FDN-143204)

Left internal jugular vein thrombosis secondary to pacemaker insertion.

Venous thrombosis associated with pacemaker implant is a known phenomenon. We present a clinical video emphasizing on an important physical examination finding suggesting propagation of thrombus in internal jugular vein secondary to pacemaker insertion, which would be educational and help readers visualize the sign on physical examination.

Abstract No. 603 Safety and feasibility of transjugular intrahepatic portosystemic shunt creation via a left internal jugular vein approach

Abstract No. 603 Safety and feasibility of transjugular intrahepatic portosystemic shunt creation via a left internal jugular vein approach

VARIANT OF FETAL TOPOGRAPHY OF THE JUGULAR VEINS

An atypical case of the topography of the left external jugular vein and some extracranial tributaries of the left internal jugular vein in a 7-month-old human fetus is presented. The left external jugular vein is formed by two tributaries: the anterior (submandibular vein) and the posterior (posterior auricular vein), it fl ows into the left subclavian vein. The confl uence of the left lateral saphenous vein into the left external jugular vein, the absence of the left anterior jugular and occipital veins, and the absence of the anastomosis of the mandibular and the deep facial vein were found. The described case of the fetal topography of the left jugular veins will be of interest to both morphologists and fetal surgeons.

Surveillance for jugular venous thrombosis in astronauts

Thrombosis of the left internal jugular vein in an astronaut aboard the International Space Station was recently described, incidentally discovered during a research study of blood flow in neck veins in microgravity. Given this event, and the high incidence of flow abnormalities, the National Aeronautics and Space Administration (NASA) instituted an occupational surveillance program to evaluate astronauts for venous thrombosis. Duplex ultrasound of the bilateral internal jugular veins was conducted on all NASA astronauts terrestrially, and at three points during spaceflight. Respiratory maneuvers were performed. Images were analyzed for thrombosis and certain hemodynamic characteristics, including peak velocity and degree of echogenicity. Eleven astronauts were evaluated with matching terrestrial and in-flight ultrasounds. No thrombosis was detected. Compared to terrestrial ultrasound measurements, in-flight peak velocity was reduced and lowest in the left. Six of 11 astronauts had mild-moderate echogenicity in the left internal jugular vein during spaceflight, but none had more than mild echogenicity in the right internal jugular vein. Two astronauts developed retrograde blood flow in the left internal jugular vein. Abnormal flow characteristics in microgravity, most prominent in the left internal jugular vein, may signal an increased risk for thrombus formation in some individuals.

PO-717-02 TRANS-HEPATIC ‘BODY-FLOSSING’ TO OBTAIN ACCESS IN A PATIENT WITH VENOUS OCCLUSIONS FOR SUPRAVENTRICULAR TACHYCARDIA ABLATION

Trans-hepatic access (THA) can be performed for ablations in patients with femoral venous occlusions. In the setting of additional superior vena cava (SVC) occlusion, obtaining a second access can be challenging. To describe retrograde crossing of a chronic total venous occlusion (CTVO) followed by superior snaring after THA. n/a A 45-year-old female with a history of end-stage renal disease presented with recurrent supraventricular tachycardia refractory to medications. She had dialysis performed at different times via all 4 extremities and had known inferior CTVO. THA was obtained to gain access into the heart (A, blue arrows). Right internal jugular vein (IJV) was occluded; the left IJV vein was accessed, however, there was evidence of SVC stenosis (B, yellow dotted line), and a wire could not be advanced antegradely. Using a Glidewire from the THA, the stenosis was crossed retrogradely (C, yellow arrows). From the left IJV sheath, the wire tip was snared (D, white arrow), and pulled out (Figure 1E, green arrows). Once through-and-through access was obtained, a long sheath was advanced over the wire into the right atrium (F, red arrows) through which another decapolar catheter (G-H, orange arrow) was placed and with the help of the THA decapolar coronary sinus catheter (G, asterisk), the diagnosis of typical atrioventricular node reentrant tachycardia was confirmed. Following this, the THA decapolar catheter was replaced by an ablation catheter (H, red arrow) for successful slow pathway modification. Obtaining venous access in addition to the THA can be challenging in patients with superior and inferior venous stenosis. Retrograde crossing of CTVO scan be performed after THA, and with the help of snaring, additional access can be obtained.

Correlation Between Ultrasound-Measured Diameter and Blood Flow Velocity of the Internal Jugular Veins with the Preoperative Blood Volume in Elderly Patients

The study aimed to explore the correlation of the diameter and blood flow velocity of the internal jugular vein with the preoperative blood volume in elderly patients and to providence for rapid evaluation of preoperative blood volume with ultrasound in elderly patients. Thirty patients over 65 years old were recruited in the study. Patient’s central venous pressure (CVP) was recorded before anesthesia. The maximum diameter (Dmax) and the minimum diameter (Dmin) of the left internal jugular vein were measured by M type ultrasound and the respiratory variation index (RVI), defined as (Dmax − Dmin) / Dmax × 100%, was calculated. The maximum blood flow velocity (BVmax) and the minimum blood flow velocity (BVmin) were measured by Doppler ultrasound, and the blood flow variation index (BVI), defined as (BVmax − BVmin) / BVmax × 100%, was calculated. Then, each of the patients was given with 5 ml/kg crystalloid solution, and the relevant data were measured again and compared to that before infusion. The correlation between each measurement index and CVP, and their efficiency in predicting CVP > 6 mmHg were statistically evaluated. No matter before or after infusion, Dmax, Dmin, BVmax, and BVmin were positively correlated with CVP (Correlation is significant at the 0.01 level (2-tailed)); and RVI was negatively correlated with CVP (Correlation is significant at the 0.01 level (2-tailed)); however, BVI is negatively correlated with the CVP with no statistically significant difference. Through the analysis of ROC curve, Dmax, Dmin, RVI, BVmax, and BVmin could be used to predict the CVP > 6 mmHg in these patients, and the best index was BVmax; BVI diagnosis was not effective. Ultrasonic measurements of internal jugular vein diameter, respiratory variability, and blood flow velocity were correlated with preoperative CVP in elderly patients, indicating that these indexes could potentially be used to evaluate the preoperative blood volume in elderly patients.

Feasibility and safety of guidewire-balloon entrapment technique for recanalization of thoracic central vein occlusion in hemodialysis patients.

To explore the feasibility and safety of Guidewire-Balloon Entrapment Technique (GBET) for the recanalization of thoracic central vein occlusions (TCVOs) in hemodialysis patients. A retrospective observational study was conducted using data from 28 patients who required the establishment or maintenance of hemodialysis access and were treated with GBET for the recanalization of right-sided TCVOs from January 2017 to April 2021. Of the patients, 27 required tunneled cuffed catheter (TCC) placement or exchange, and 1 had an outflow tract occlusion of the Brescia-Cimino radio cephalic arteriovenous fistula (AVF). A total of 26 patients successfully underwent TCC exchange and placement using GBET; 1 patient underwent successful recanalization of an occlusion of the outflow tract of the right Brescia-Cimino AVF; and 1 patient underwent successful TCC placement in the left internal jugular vein (LIJV) after the failure of TCC placement in the right internal jugular vein (RIJV). The success rate for GBET was 27/28 (96.43%), and there were no major complications. GBET is a safe and effective method for the recanalization of right-sided TCVOs, especially for TCC exchange and placement, and can be used as a safe and easy approach for TCVO recanalization.

Ultrasound Guided Central Chemotherapy Port Insertion by Surgeon in Cancer Patients.

Purpose: The aim of the study is to report early experience in ultrasound guided central chemo port insertion by surgeons in cancer patients who required chemotherapy. Materials and methods: The procedure was carried out in operation theatre under local anesthesia with intravenous sedation. Linear high frequency ultrasound probe was used to visualize and cannulate left or right internal jugular vein in the neck. The reservoir was kept through a separate incision over anterior chest wall. Results: Fifty patients with mean age of 48 years underwent chemo port insertion. The indications were neoadjuvant, adjuvant and palliative chemotherapy in 30%, 58% and 12%, respectively. Cannulation was successful in 100% of cases. Two patients (4%) required port removal due to wound infection (one patient) and blockade (one patient). One patient (2%) had kinking of the catheter which required repositioning. Conclusion: Ultrasound guided central chemo port insertion by surgeons is a safe procedure with 100% success rate and minimal complications.

Internal Jugular Vein Geometry Under Multiple Inclination Angles with 3D Low-Field MRI in Healthy Volunteers.

Cerebral venous pathways are subjected to geometrical and patency changes due to body position. The internal jugular veins (IJVs) are the main venous drainage pathway in supine position. Their patency and geometry should be evaluated under different body inclination angles over a three-dimensional (3D) volume in the healthy situation to better understand pathological cases. To investigate whether positional changes in the body can affect the geometrical properties and patency of the venous system. Prospective. 15 healthy volunteers, of which seven males and median age 22 years in a range of 19-59. A 0.25-T tiltable MRI system was used to scan volunteers in 90° (sitting position), 69°, 45°, 21°, and 0° (supine position) in the transverse plane with the top at vertebra C2. A gradient echo sequence was used. Three observers assessed IJVs on patency and created automatic centerlines from which diameter and patency were analysed perpendicular to the vessel at every 4 mm starting at the level of C2. A Student's t test was used to find statistical difference (p < 0.05) in average IJV diameters per inclination angle. The amount of fully collapsed IJVs increased from 33% to 93% (left IJV) and 14% to 80% (right IJV) when increasing the inclination angle from 0° to 90°. In both IJVs, the mean diameter (±SD) of the open vessels was significantly higher at 0° than 90° with 6.3 ± 0.5 mm vs. 4.4 ± 0.1 mm (left IJV) and 6.6 ± 0.6 mm vs. 4.3 ± 0.4 mm (right IJV). Tiltable low-field MRI can be used to assess IJV geometry and its associated venous pathways in 3D under multiple inclination angles. Next to a higher amount of collapsed vessels, the average diameter of noncollapsed vessels decreases with increasing inclination angles for both left and right IJVs. 2 TECHNICAL EFFICACY STAGE: 1.

Placement of cuffed tunnelled permanent hemodialysis catheter in patients with end stage renal disease: A cross sectional study

BackgroundEnd-Stage Renal Disease (ESRD) is a significantly increasing condition warranting renal replacement therapy. Gaining vascular access for catheter placement for this procedure is of paramount importance. These can be done by temporary and permanent cuffed tunnelled catheters. The present study aims to analyze the outcome of permanent hemodialysis catheters and their efficacy in the case of patients suffering from end-stage renal disease. Materials and methodsA cross-sectional study was conducted on 32 patients who underwent permanent tunnelled catheter intervention along with details of follow-up from January 1st, 2021 till December 31st, 2021. ResultsAmong 32 patients, the mean age of the patient was 50.25 ± 18.10 years with 62.5% females. The site of insertion was right 27(84.37%) and left internal jugular vein in 4 (12.50%) and 1 patient (3.12%) in the left common femoral vein. Bleeding the peri-catheter site was observed in 4 (12.5%), infection was found among 2 patients (6.25%), thrombosis in the catheter in 7 (21.87%) patients. Indication for the procedure was due to failure of arteriovenous fistula in 21 (65.62%), lack of maturation of the AVF in 9 (28.12%) and patients awaiting transplantation in 2 (6.25%). The mean months of follow-up of the patients were 5.9 months (SD 4.4 months, range 1 month–12 months). Total 25 (78.1%) of the catheters were patent till the time of follow-up. Seven (21.9%) of the patients required manipulation once after which they also had functioning permanent catheters. The mean month on which manipulation was required was 4.1 months (SD 2.3months, range one month to seven months). ConclusionPermanent cuffed tunnelled catheter has good patency and can be an alternative to an arteriovenous fistula.

A Trilogy of Submassive Pulmonary Embolism, Non-Small Cell Lung Cancer with Brain Metastasis, Kartagener's Syndrome and its Management with Aspiration Thrombectomy.

Venous thromboembolism is a common cause of morbidity and mortality in cancer patients. Given the bleeding risks, determining treatment for malignancy-related thrombosis is challenging, especially in the case of submassive pulmonary embolism (PE) because the risk-benefit ratio in terms of bleeding risk is uncertain. Here we discuss the case of a 53-year-old man with Kartagener syndrome with situs inversus totalis and stage IV non-small cell lung cancer with a recent brain mass resection, presenting with dyspnoea and palpitations. The patient was diagnosed with a submassive PE and only underwent suction thrombectomy through the left internal jugular vein with excellent response. In conclusion, when treating submassive PE, aspiration thrombectomy without thrombolysis is preferable to thrombolysis, which may be contraindicated due to the higher risk of bleeding.LEARNING POINTSAnticoagulation and thrombolysis should be started after carefully weighing the risks and benefits in cancer patients.In some patients with submassive pulmonary embolism (PE), thrombolysis may be contraindicated due to the increased risk of bleeding, but aspiration thrombectomy can be a preferred treatment modality.Further research evaluating the risks and benefits of different therapeutic approaches for submassive PE could aid in determining the best course of action and establishing treatment guidelines.

Lemierre's syndrome complicated by cerebral venous sinus thrombosis: A life threatening and rare disease successfully treated with empiric antimicrobial therapy and conservative approach.

Lemierre's syndrome (LS) is a "forgotten" condition characterized by septic thrombophlebitis of the jugular vein that follows an otolaryngological infection. Fusobacterium necrophorum is the aetiological agent responsible for the syndrome in adolescents and young adults whereas in older people even common bacteria are involved. Complications arise from spreading of septic emboli distally, i.e. to the brain, lungs, bones and internal organs everywhere in the body. We report a middle-aged woman who presented with headache and bilateral sixth cranial nerve palsy following a sphenoidal sinusitis and left mastoiditis. Imaging revealed thrombotic involvement of the left internal jugular vein as well as of several cerebral venous sinuses thrombosis (CVT). Currently, precise management protocols of LS with CVT complication do not exist although a combination of macrolides and second or third-generation cephalosporins, as well as anti-coagulants represent the mainstream of therapeutics. Surgical drainage is associated to remove septic foci but is burdened by severe complications and side effects. Complete recovery was achieved following pharmacological treatment in our patient. This report adds further evidence that LS complicated by CVT may be effectively treated adopting a conservative approach thus avoiding surgical drainage and severe complications.

A Rare Cardiac Complication of Left-Sided Tunneled Hemodialysis Catheter Insertion

Left atrial perforation during central venous catheter insertion is an extremely rare complication which can have catastrophic outcomes if left unrecognized. We describe a rare case of the left atrial catheter malposition during tunneled hemodialysis catheter insertion from the left internal jugular vein, which was managed successfully by surgical reposition and simultaneously vascular access was secured by salvaging the same catheter in a patient with poor arteriovenous anatomy for surgical arteriovenous fistula.

The Right Internal Jugular at the Cricoid Cartilage Level May Represent the Optimal Central Vein Puncture Site in Pediatric Patients

ObjectiveInternal jugular vein puncture or cannulation is far more difficult in children compared with adults. Anthropometric measures of the internal jugular vein acquired by two-dimensional ultrasound are useful in the practice of puncture and catheterization. The aim of this study is to measure anthropometric parameters of bilateral internal jugular veins in children and to determine the best puncture site based on these parameters.MaterialsA total of 107 pediatric patients undergoing elective operation were included. Ultrasound-visible evaluation of bilateral internal jugular veins was used to obtain the depth from skin, maximum antero-posterior diameter, and cross-sectional area at the levels of the superior border of thyroid cartilage and cricoid cartilage. Statistical analysis was performed using these anthropometric data and demographic variables of all studied pediatric patients, such as age, height, and weight.ResultsA very weak correlation was noted between the depth, maximal antero-posterior diameter, and cross-sectional area of both internal jugular veins and the age, height, weight, and body surface index of all included children. All Pearson's R correlation coefficients were <0.45. The largest diameter and cross-sectional area were in the right internal jugular vein at the cricoid cartilage level (p < 0.01) followed by the left internal jugular vein at this level (p < 0.01). In addition, the internal jugular vein at the cricoid cartilage level was more superficial than that of the superior border of the thyroid cartilage (p < 0.01).ConclusionThe right internal jugular vein at the cricoid cartilage level is the best site for puncture. The most appropriate alternative site is the left internal jugular vein on the same level. Better correlation was not observed between the anthropometric parameters of the internal jugular vein and children's biological characteristics. This finding should be confirmed in a larger-scale demographical study in the future.

Fatal bleeding following left internal jugular vein cannulation associated with type A1 endoleak, false aneurysm and aortobronchopulmonary fistula

Fatal bleeding following left internal jugular vein cannulation associated with type A1 endoleak, false aneurysm and aortobronchopulmonary fistula

Anticoagulation in the Treatment of Pulsatile Tinnitus Caused by Internal Jugular Vein Stenosis: A Rare Case Report

Background: Anticoagulation is considered as a first line treatment of pulsatile tinnitus caused by internal jugular vein thrombosis. We present a case of non-thrombotic internal jugular vein occlusion which responded to Apixaban (Eliquis) therapy. Case Presentation: A 54-year-old female with no significant past medical history presented with debilitating pulsatile tinnitus for two months. Her symptoms included inability to sleep, lower appetite, and intense pressure and throbbing in the face and ears. She described it as a ‘whooshing sound’ exacerbated in the supine position. She admitted to occasional episodes of neck throbbing and forceful heart beat over the years and had undergone multiple workups including Echocardiograms and Holter monitoring, with no apparent abnormalities. The recent workup, including coagulation studies, Computed Tomography (CT) scans and Magnetic Resonance Imaging (MRI) of the head and neck, yielded negative findings. However, a CT angiogram revealed an isolated non-thrombotic occlusion of the most proximal aspect of the left Internal Jugular Vein (IJV), with extensive occipital and sub occipital collateral flow. She had been taking antihypertensive and diuretic medications without much effect. She was then prescribed anticoagulation therapy initially with IV enoxaparin (30 milligrams for two weeks) and then oral Apixaban (5 milligrams b.i.d.). Eliquis 5 milligrams bid was continued for 8 months and tapered down to 2.5 milligrams bid for 4 months to completely off in 12 months. Her symptoms improved after eight weeks and were completely gone within a year. Repeat MR angiography showed improved flow in the jugular venous system. Conclusions: A trial of anticoagulation is warranted and can be beneficial in patients with non-thrombotic internal jugular vein occlusion causing pulsatile tinnitus refractory to other treatments.

Simultaneous dual‐contrast imaging using energy‐integrating detector multi‐energy CT: An in vivo feasibility study

To demonstrate the feasibility of simultaneous dual-contrast imaging in a large animal using a newly developed dual-source energy-integrating detector (EID)-based multi-energy computed tomography (MECT) system. Two imaging tasks that may have potential clinical applications were investigated: head/neck (HN) CT angiography (CTA)/CT venography (CTV) with iodine and gadolinium, and small bowel imaging with iodine and bismuth in domestic swine. Dual-source X-ray beam configurations of 70kV + Au120/Sn120 kV and 70kV + Au140/Sn140 kV were used for the HN-CTA/CTV and small bowel imaging studies, respectively. A test bolus scan was performed for each study. The regions of interest (ROIs) in the carotid artery and jugular vein for HN-CTA/CTV imaging and abdominal aorta for small bowel imaging were used to determine the time-attenuation curves, based on which the timing for contrast injection and the CT scan was determined. In the HN-CTA/CTV study, an MECT scan was performed at the time point corresponding to the optimal arterial enhancement by iodine and the optimal venous enhancement by gadolinium. In the small bowel imaging study, an MECT scan was performed at the optimal time point to simultaneously capture the mesenteric arterial enhancement of iodine and the enteric enhancement of bismuth. Image-based material decomposition was performed to decompose different materials for each study. To quantitatively characterize contrast material separation and misclassification, two ROIs on left common carotid artery and left internal jugular vein in HN-CTA/CTV imaging and three ROIs on superior mesenteric artery, ileal lumen, and collapsed ileum (ileal wall) in small bowel imaging were placed to measure the mean concentration values and the standard deviations. In the HN-CTA/CTV study, common carotid arteries containing iodine and internal/external jugular veins containing gadolinium were clearly delineated from each other. Fine vessels such as cephalic veins and branches of external jugular veins were noticeable but clear visualization was hindered by image noise in gadolinium-specific (CTV) images, as reviewed by a neuroradiologist. In the small bowel imaging study, the mesenteric arteries and collapsed bowel wall containing iodine and the small bowel loops containing bismuth were clearly distinctive from each other in the iodine- and bismuth-specific images after material decomposition, as reviewed by an abdominal radiologist. Quantitative analyses showed that the misclassifications between the two contrast materials were less than 1.7 and 0.1mg/ml for CTA/CTV and small bowel imaging studies, respectively. Feasibility of simultaneous CTA/CTV imaging in head and neck with iodine and gadolinium and simultaneous imaging of arterial and enteric phases of small bowel with iodine and bismuth, using a dual-source EID-MECT system, was demonstrated in a swine study. Compared to iodine and gadolinium in CTA/CTV, better delineation and classification of iodine and bismuth in small bowel imaging were achieved mainly due to wider separation between the corresponding two K-edge energies.