Feasibility of Non-contrast-enhanced MR Angiography Using the Time-SLIP Technique for the Assessment of Pulmonary Arteriovenous Malformation

Abstract

Purpose:The purpose of this study was to evaluate the diagnostic performance of non-contrast-enhanced magnetic resonance angiography with time-spatial labeling inversion pulse (time-SLIP MRA) in the assessment of pulmonary arteriovenous malformation (PAVM).Methods:Eleven consecutive patients with 38 documented PAVMs underwent time-SLIP MRA with a 3-tesla unit. Eight patients with 25 lesions were examined twice, once before and once after embolotherapy. The lesions were divided into two groups—initial diagnosis (n = 35) and follow-up (n = 28)—corresponding to untreated and treated lesions, respectively, and were evaluated separately. To evaluate the initial diagnosis group, two reviewers assessed image quality for visualization of PAVMs by using a qualitative 4-point scale (1 = not assessable to 4 = excellent). The location and classification of PAVMs were also evaluated. The results were compared with those from digital subtraction angiography. For evaluation of the follow-up group, the reviewers assessed the status of treated PAVMs. Reperfusion and occlusion were defined respectively as visualization or disappearance of the aneurysmal sac. The diagnostic accuracy of time-SLIP MRA was assessed and compared with standard reference images. Interobserver agreement was evaluated with the κ statistic.Results:In the initial diagnosis group, time-SLIP MRA correctly determined the PAVMs in all but one patient with one lesion who had image degradation due to irregular breath. Image quality was considered excellent (median = 4) and the κ coefficient was 0.85. Additionally, both readers could correctly localize and classify the PAVMs on time-SLIP MRA images with both κ coefficient of 1.00. In the follow-up group, the sensitivity and specificity of time-SLIP MRA for reperfusion of PAVMs were both 100%, and the κ coefficient was 1.00.Conclusion:Time-SLIP MRA is technically and clinically feasible and represents a promising technique for noninvasive pre- and post-treatment assessment of PAVMs.

Ultra-short echo time magnetic resonance imaging for detection of pulmonary arteriovenous malformation recanalization after coil embolization: a case report and a phantom study

“…Assessment of PAVM patency after embolization is crucial because recanalization can occur in up to 50% of cases and cause neurologic events that are similar to those associated with untreated lesions ( 4 , 5 ). DSA remains the gold standard for identifying recanalization; however, in recent years, CT and MRA with or without contrast agents have been generally performed for the assessment of recanalization in embolized PAVMs because of their non-invasiveness ( 6 – 12 ). The detections of recanalization using unenhanced CT, contrast-enhanced CT, and TR-CEMRA have been reported to have sensitivities of 93%, 82%, and 93–100%, respectively, and specificities of 53%, 100%, and 93–100%, respectively ( 9 , 11 ).…”

“…More recently, Hamamoto et al. demonstrated the high sensitivity and specificity (both 100%) of unenhanced MRA utilizing the time-spatial inversion pulse technique (time-SLIP MRA) in the detection of PAVM recanalization ( 12 ). However, the diagnostic criteria for recanalization that were used in these studies were based on morphologic changes and hemodynamic information; therefore, the sufficiency of these modalities for detecting recanalization of embolized PAVMs was not confirmed.…”

Non–contrast-enhanced magnetic resonance angiography using time-spatial labeling inversion pulse technique for differentiation between pulmonary varix and arteriovenous malformation

“…Time-SLIP MRA was performed using a 3-tesla magnetic resonance imaging (MRI) system (Vantage Titan 3T; Toshiba Medical Systems, Tochigi, Japan) using 4- and 8-element-phased array body surface coil and receiver channels combined with parallel imaging capability (SPEEDER; Toshiba Medical Systems). Details of the procedures of this time-SLIP technique are described elsewhere [6] , [7] . Briefly, after acquisition of axial, coronal, and sagittal field echo images to localize the heart for time-SLIP pulse (tag) placement and to determine the acquisition area, combined respiratory- and ECG-triggered 3-dimensional (3D) single-shot half Fourier fast advanced spin echo (FASE; Toshiba Medical Systems) images with fat saturation were acquired in the axial plane using time-SLIP with an alternate tag-on/off subtraction technique.…”

“…Non–contrast-enhanced magnetic resonance angiography with the time-spatial labeling inversion pulse technique (time-SLIP MRA) is a relatively new non–contrast-enhanced MRA that facilitates the selective visualization of blood flow in a region of interest using an arterial spin labeling technique [6] . The utility of time-SLIP MRA for the evaluation of PAVM has been recently reported [7] . Here, we present the findings of time-SLIP MRA in case of pulmonary varix and PAVM and the utility of this method for differentiating between these diseases.…”

Quantification of the salivary volume flow rate in the parotid duct using the time‐spatial labeling inversion pulse (Time‐SLIP) technique at MRI: A feasibility study

“…Time‐SLIP is a technique based on arterial spin‐labeling methods; without the need for contrast material, it demonstrates the flow of blood, cerebrospinal fluid (CSF), pancreatic juice, and flow in the salivary gland duct . Although the Time‐SLIP technique can measure the travel distance of flow in 2D planes, we found no reports that quantified the volume flow rate (VFR, mm 3 /sec).…”