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Background and Purpose: To reduce the door-to-puncture time, which is a prognostic factor for the clinical outcome after intra-arterial recanalization therapy, we established a prehospital telecommunication strategy between neurointerventionalists and emergency medical technicians, namely, the critical stroke call pathway. We retrospectively evaluated the clinical significance of the critical stroke call pathway by comparing the door-to-puncture time and clinical outcome of the critical stroke call pathway with those of the routine stroke pathway., Materials and Methods: From January 2018 to June 2020, one hundred seventy-one patients with anterior circulation occlusion who underwent arterial recanalization therapy via the emergency department were included in this study. Patients were divided into the critical stroke call pathway group ( n = 75, 43.9%) and the routine stroke pathway group ( n = 96, 56.1%)., Results: The critical stroke call pathway group exhibited a shorter door-to-puncture time than the routine stroke pathway group (median, 87 minutes; interquartile range, 63-107 minutes; P < .001). On multivariable analysis, a good clinical outcome (3-month mRS, 0-2) was independently associated with a shorter door-to-puncture time (adjusted OR, 0.998; adjusted 95% CI, 0.996-1.000; P = .027). In patients with an NIHSS score on admission of ≤11, an excellent clinical outcome (3-month mRS, 0-1) was more frequently achieved in the critical stroke call pathway group than in the routine stroke pathway group (22/33, 66.7%, versus 21/48, 43.8%; P = .042)., Conclusions: In our study, compared with the routine stroke pathway, the critical stroke call pathway remarkably reduced the door-to-puncture time for arterial recanalization therapy, with better clinical outcomes, especially in patients with a relatively good clinical status., (© 2022 by American Journal of Neuroradiology.)

Background and Purpose: High-resolution postcontrast 3D T1WI is a widely used sequence for evaluating brain metastasis, despite the long scan time. This study aimed to compare highly accelerated postcontrast 3D T1-weighted sampling perfection with application-optimized contrasts by using different flip angle evolution by using wave-controlled aliasing in parallel imaging (wave-T1-SPACE) with the commonly used standard high-resolution postcontrast 3D T1-SPACE for the evaluation of brain metastases., Materials and Methods: Among the 387 patients who underwent postcontrast wave-T1-SPACE and standard SPACE, 56 patients with suspected brain metastases were retrospectively included. Two neuroradiologists assessed the number of enhancing lesions according to lesion size, contrast-to-noise ratio lesion/parenchyma , contrast-to-noise ratio white matter/gray matter , contrast ratio lesion/parenchyma , and overall image quality for the 2 different sequences., Results: Although there was no significant difference in the evaluation of larger enhancing lesions (>5 mm) between the 2 different sequences ( P = .66 for observer 1, P = .26 for observer 2), wave-T1-SPACE showed a significantly lower number of smaller enhancing lesions (<5 mm) than standard SPACE (1.61 [SD, 0.29] versus 2.84 [SD, 0.47] for observer 1; 1.41 [SD, 0.19] versus 2.68 [SD, 0.43] for observer 2). Furthermore, mean contrast-to-noise ratio lesion/parenchyma and overall image quality of wave-T1-SPACE were significantly lower than those in standard SPACE., Conclusions: Postcontrast wave-T1-SPACE showed comparable diagnostic performance for larger enhancing lesions (>5 mm) and marked scan time reduction compared with standard SPACE. However, postcontrast wave-T1-SPACE showed underestimation of smaller enhancing lesions (<5 mm) and lower image quality than standard SPACE. Therefore, postcontrast wave-T1-SPACE should be interpreted carefully in the evaluation of brain metastasis., (© 2022 by American Journal of Neuroradiology.)

Background and Purpose: Contrast-enhanced T1-weighted sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) with the delay alternating with nutation for tailored excitation (DANTE) pulse could suppress the blood flow signal and provide a higher contrast-to-noise ratio of enhancing lesion-to-brain parenchyma than the MPRAGE sequence. The purpose of our study was to evaluate the usefulness of SPACE with DANTE compared with MPRAGE for detecting brain metastases., Materials and Methods: Seventy-one patients who underwent contrast-enhanced SPACE with DANTE and MPRAGE sequences and who were suspected of having metastatic lesions were included. Two neuroradiologists determined the number of enhancing lesions, and diagnostic performance was evaluated using figure of merit, sensitivity, positive predictive value, interobserver agreement, and reading time. Contrast-to-noise ratio lesion/parenchyma and contrast-to-noise ratio white matter/gray matter were also assessed., Results: SPACE with DANTE (observer one, 328; observer two, 324) revealed significantly more small (<5 mm) enhancing lesions than MPRAGE (observer one, 175; observer two, 150) ( P < 0.001 for observer 1, P ≤ .0001 for observer 2). Furthermore, SPACE with DANTE showed significantly higher figure of merit and sensitivity and shorter reading time than MPRAGE for both observers. The mean contrast-to-noise ratio lesion/parenchyma of SPACE with DANTE (52.3 ± 43.1) was significantly higher than that of MPRAGE (17.5 ± 19.3) ( P ≤ .0001), but the mean contrast-to-noise ratio white matter/gray matter of SPACE with DANTE (-0.65 ± 1.39) was significantly lower than that of MPRAGE (3.08 ± 1.39) ( P ≤ .0001)., Conclusions: Compared with MPRAGE, SPACE with DANTE significantly improves the detection of brain metastases., (© 2019 by American Journal of Neuroradiology.)

Background and Purpose: Time-of-flight MR angiography, though widely used after coil embolization, is associated with limitations owing to magnetic susceptibility and radiofrequency shielding following stent-assisted coil embolization. We evaluated the pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based MRA (qMRA) using an ultrashort TE relative to TOF-MRA during the follow-up of stent-assisted coil embolization for anterior circulation aneurysms., Materials and Methods: Twenty-five patients (3 men and 22 women; mean age, 59.1 ± 14.0 years) underwent stent-assisted coil embolization for anterior circulation aneurysms and were retrospectively evaluated using TOF-MRA and PETRA qMRA data from the same follow-up session. Two neuroradiologists independently reviewed both MRA findings and subjectively graded flow within the stents (relative to the latest DSA findings) and occlusion status (complete occlusion or neck/aneurysm remnant). Interobserver and intermodality agreement for TOF-MRA and PETRA qMRA were evaluated., Results: The mean score for flow visualization within the stents was significantly higher in PETRA qMRA than in TOF-MRA ( P < .001 for both observers), and good interobserver agreement was reported (κ = 0.63). The aneurysm occlusion status of PETRA qMRA (observer 1, 92.0%; observer 2, 88.0%) was more consistent with DSA than with TOF-MRA (observer 1, 76.0%; observer 2, 80.0%), and there was a better intermodality agreement between DSA and PETRA qMRA than between DSA and TOF-MRA., Conclusions: These findings indicate that PETRA qMRA is a useful follow-up technique for patients who have undergone stent-assisted coil embolization for anterior circulation aneurysms., (© 2019 by American Journal of Neuroradiology.)

Background and Purpose: Surgical revision of recurrent cerebral aneurysms is technically difficult. Therefore, coil embolization has been used as an alternative in these cases. The aim of this study was to evaluate the clinical and angiographic outcomes of coil embolization in patients with recurrent cerebral aneurysms after microsurgical clipping., Materials and Methods: Between May 1999 and February 2016, nineteen patients with 19 recurrent aneurysms who previously underwent surgical clipping were treated by coil embolization., Results: Nine patients presented with subarachnoid hemorrhage (47.4%). The interval between surgical clipping and coil embolization was 143.5 ± 66.1 months (range, 43-276 months). Single- or double-catheter coil embolization was performed in 16 patients. A balloon ( n = 1) and stents ( n = 2) were used to assist the coil embolization in 3 patients. Immediate radiologic findings after coil embolization showed complete occlusion in 10 patients, a residual neck in 8 patients, and a residual sac in 1 patient. Procedure-related permanent morbidity occurred in 1 patient. The mean clinical follow-up was 58.3 ± 38.8 months. Poor clinical outcomes (modified Rankin Scale score = ≥3) at the end of the clinical follow-up were reported in 5 patients (26.3%). Angiographic follow-up was available for 12 patients (63.2%). Major recurrence was detected in 5 patients (41.7%), and a tendency for aneurysm regrowth rather than coil compaction was noted in all cases., Conclusions: In our series, coil embolization for recurrent aneurysms after surgical clipping was feasible but had a high recurrence rate and tended to result in aneurysm regrowth rather than coil compaction., (© 2019 by American Journal of Neuroradiology.)