Electrocardiogram-Triggered Angiography Non-Contrast-Enhanced (TRANCE) Imaging to Assess Access Route Before Diagnostic Cerebral Angiography

Systemic immune-inflammation index in dural arteriovenous fistula: a feasible biomarker reflecting its clinical characteristics

PURPOSE

The systemic immune-inflammation index (SII), a marker of systemic inflammation, can be calculated using peripheral blood tests. Although the SII has been reported as a feasible biomarker in various cerebrovascular diseases, no studies have explored in dural arteriovenous fistula (DAVF). A retrospective cohort study was performed to test whether the SII reflects the clinical characteristics of DAVF and whether this index could serve as a feasible biomarker.

METHODS

This study included 28 patients who underwent endovascular treatment (39 sessions) for DAVF between 2014 and 2023. The SII was calculated using the following formula: platelet count multiplied by neutrophil count divided by lymphocyte count. We investigated the correlation between the SII and various clinical characteristics of DAVF, including symptom manifestation, and digital subtraction angiography findings. Additionally, we compared pre- and post-endovascular treatment changes in the SII.

RESULTS

A significantly higher SII was observed in patients with multiple lesions, clinical symptoms (particularly aggressive symptoms), pseudophelebitic pattern (PPP), and sinus occlusion. Multivariate regression analysis revealed that the presence of symptoms (coefficient 270.9, P = 0.021) and PPP (coefficient 272.4, P = 0.017) were independent factors contributing to SII elevation. Notably, following endovascular treatment, there was a significant decrease in the elevated SII in patients whose symptoms resolved (P = 0.039) and where the DAVF was angiographically cured (P = 0.012).

CONCLUSION

Elevation of the SII in patients with advanced DAVF and its decrease following endovascular treatment suggests that the SII reflects the disease condition and indicates its potential as a promising biomarker.

Comparison of Access Route for Endovascular Treatment by Time-Spatial Labeling Inversion Pulse (Time-SLIP) MRA and Contrast-Enhanced MRA

Objective

In endovascular treatment, it is important to evaluate the access route for placing a catheter into the common carotid artery (CCA) promptly and safely prior to the procedure. We examined whether non-contrast MRA using time-spatial labeling inversion pulse (Time-SLIP) can be used in patients prior to endovascular thrombectomy for acute ischemic stroke. We compared Time-SLIP MRA to contrast-enhanced (CE) MRA and evaluated the efficacy in the evaluation of access routes.

Methods

We retrospectively reviewed 31 patients admitted between October 2018 and December 2018 for cerebral infarction at our hospital. Blood vessels were imaged from the aortic arch to the CCA. A radiologist blindly evaluated quality score, stenosis, shape of the aorta, and degree of tortuosity.

Results

There were no "non-diagnostic" images. The sensitivity, specificity, positive predictive value, and negative predictive value for stenosis were 83%, 96%, 83%, and 96%, respectively. The sensitivity for the aorta type classification was 100%. The sensitivity for mild tortuosity was 93%, for moderate was 100%, and for severe was 100%.

Conclusion

Time-SLIP MRA can be an alternative to CE MRA in access route assessment for patients with cerebral infarction who are not eligible for acute thrombectomy therapy.

Noncontrast MRI in assessing venous reflux of legs using QFlow analysis and radial basis function neural network technique

Since venous reflux is difficult to quantify, triggered angiography non-contrast-enhanced (TRANCE)-magnetic resonance imaging (MRI) is a novel tool for objectively evaluating venous diseases in the lower extremities without using contrast media. This study included 26 pre-intervention patients with superficial venous reflux in the lower extremities and 15 healthy volunteers. The quantitative flow (QFlow) analyzed the phase shift information from the pixels within the region of interest from MRI. The fast and simple radial basis function neural network (RBFNN) learning model is constructed by determining the parameters of the radial basis function and the weights of the neural network. The input parameters were the variables generated through QFlow, while the output variables were morbid limbs with venous reflux and normal limb classification. The stroke volume, forward flow volume, absolute stroke volume, mean flux, stroke distance, and mean velocity of greater saphenous veins from QFlow analysis could be used to discriminate the morbid limbs of pre-intervention patients and normal limbs of healthy controls. The neural network successfully classified the morbid and normal limbs with an accuracy of 90.24% in the training stage. The classification of venous reflux using the RBFNN model may assist physicians in clinical settings.

A Simple Low-Cost Electrocardiogram Synchronizer

Electrocardiogram (ECG) synchronization is useful to avoid the effects of cardiac motion in medical measurements, and is widely used in standard medical imaging. A number of medical equipment include embedded commercial synchronizers. However, the use of independent synchronization modules is sometimes needed when several non-integrated instruments are used, or in the development of new medical instruments and procedures. We present a simple low-cost ECG synchronizer module based on an Arduino controller board that converts the ECG signal into a transistor-transistor-logic (TTL) one, allowing real-time medical measurements triggered at specific phases of the cardiac cycle. The device and conversion algorithm developed is optimized in vitro using synthetic and human ECG signals, and tested in vivo on three swine specimens. Error rates during the in vivo testing stage remain below the 2% of the cycles in all animals and critical false positives are less than 1%, which is sufficient for most applications. Possible algorithm updates are discussed if its performance needs to be improved.

Evaluation of static ulcer on lower extremities using wireless wearable near-infrared spectroscopy device: Effect of deep venous thrombosis on TRiggered Angiography Non-Contrast-Enhanced sequence magnetic resonance imaging

BACKGROUND

Venous leg ulcers, or static leg ulcers, are chronic wounds associated with ambulatory venous hypertension of the lower extremities as a consequence of venous valve reflux, reduce venous capacitance, poor calf venous pump, heart failure, or in conjunction with venous obstruction. A static ulcer with venous thrombosis in a pelvic or thigh vein responds favorably to anticoagulation agents. However, anticoagulation is less effective and even harmful when ambulatory venous hypertension has another cause such as venous reflux, poorly heart function, and poor calf venous pump.

METHOD

TRiggered Angiography Non-Contrast-Enhanced (TRANCE) magnetic resonance imaging (MRI) exploits differences in vascular signal intensity during the cardiac cycle for subsequent image subtraction, providing detailed radiation-free venograms without the use of contrast agents. The method is a new tool for evaluating the presence of thrombosis in the venous systems. TRANCE-MRI was employed to document the existence of venous thrombosis within the eight patients in this study. Subsequently, we used a wireless wearable near-infrared spectroscopy device to compare deep vein thrombosis-associated and non-deep vein thrombosis-associated static ulcers. The sampling depths were 5 and 10 mm, representing the dermis and subcutaneous tissue, respectively.

RESULT

There are four patients with venous leg ulcers proven with venous thrombosis by TRANCE-MRI and are classified as deep vein thrombosis group. Compared with the non-deep vein thrombosis group, the deep vein thrombosis group had less deoxyhemoglobin, less total hemoglobin, and a significantly lower H₂O signal in the 5-mm sampling depth (dermis level). And eight health participants were included as control group. Wounded patients (including deep vein thrombosis and non-deep vein thrombosis patients) have higher H₂O concentration on the 5-mm depth sampling than control group. In the 10-mm sampling depth (subcutaneous level), the deoxyhemoglobin and tissue oxygen saturation of the deep vein thrombosis group were lower than those of the non-deep vein thrombosis group, and the H₂O concentration was higher than non-deep vein thrombosis group. Patients with static foot ulcers and deep vein thrombosis had similar oxyhemoglobin, deoxyhemoglobin, total hemoglobin, and tissue oxygen saturation than did those without deep vein thrombosis in 5-mm depth sampling (dermis level). Notably, the H₂O signal of patients with non-deep vein thrombosis-associated static ulcers was higher for the 5-mm sampling depth.

CONCLUSION

In patients with static ulcers and deep vein thrombosis, the H₂O level may be higher in the 10-mm sampling depth, indicating that those patients had more subcutaneous water. In patients with non-deep vein thrombosis static foot ulcer, the near-infrared spectroscopy (NIRS) indicated worse fluid retention in the dermis level. The H₂O value in the NIRS may be different owing to underline the cause of the venous leg ulcers.

Novel Diagnostic Options without Contrast Media or Radiation: Triggered Angiography Non-Contrast-Enhanced Sequence Magnetic Resonance Imaging in Treating Different Leg Venous Diseases

OBJECTIVES

Venous diseases in the lower extremities long lacked an objective diagnostic tool prior to the advent of the triggered angiography non-contrast-enhanced (TRANCE) technique.

METHODS

An observational study with retrospective data analysis.

MATERIALS

Between April 2017 and June 2019, 66 patients were evaluated for venous diseases through TRANCE-magnetic resonance imaging (MRI) and were grouped according to whether they had occlusive venous (OV) disease, a static venous ulcer (SU), or symptomatic varicose veins (VV). The clinical appliance of TRANCE-MRI was analysed by groups.

RESULTS

In total, 63 patients completed the study. TRANCE-MRI could identify venous thrombosis, including that of the abdominal and pelvic vessels, and it enabled the timely treatment of underlying diseases in patients with OV disease. TRANCE-MRI was statistically compared with the duplex scan, the gold standard to exclude deep vein thrombosis (DVT) in the legs, with regard to their abilities to detect venous thrombosis by using Cohen's kappa coefficient at a compatible value of 0.711. It could provide the occlusion degree of the peripheral artery for treating an SU. Finally, TRANCE-MRI can be used to outline all collateral veins and occult thrombi before treating symptomatic or recurrent VV to ensure a perfect surgical plan and to avoid complications.

CONCLUSIONS

TRANCE-MRI is an innovative tool in the treatment of versatile venous pathology in the lower extremities and is widely used for vascular diseases in our institution.