MRI as a first-line imaging modality in acute ischemic stroke: a sustainable concept

 I thought speed was  the most important factor is diagnosing stroke'.

TIME IS BRAIN!

So why aren't you using these much much faster methods? Only 4 years old.

Maybe you want these much faster objective diagnosis options.

Hats off to Helmet of Hope - stroke diagnosis in 30 seconds; February 2017

 

Microwave Imaging for Brain Stroke Detection and Monitoring using High Performance Computing in 94 seconds March 2017

 

New Device Quickly Assesses Brain Bleeding in Head Injuries - 5-10 minutes April 2017

Ski-Mask Design AIR Coil Offers Whole-Brain Imaging Without Claustrophobia

The latest here:

 

MRI as a first-line imaging modality in acute ischemic stroke: a sustainable concept

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Katharina Althaus, Jens Dreyhaupt, Sonja Hyrenbach, ...

First Published August 27, 2021 Research Article 

https://doi.org/10.1177/17562864211030363

Article information

Abstract

Background:

Computed tomography (CT) scans are the first-line imaging technique in acute stroke patients based on the argument of rapid feasibility. Using magnetic resonance imaging (MRI) as the first-line imaging technique is the exception to the rule, although it provides much more diagnostic information and avoids exposure to radiation. We evaluated whether an MRI-based acute stroke concept is fast, suitable, and useful to improve recanalization rates and patient outcomes.

Methods:

We performed a retrospective observational cohort study comparing patients treated at a comprehensive stroke center (Ulm/Germany) applying an MRI-based acute stroke concept with patients recorded in a large comprehensive stroke registry in Baden-Württemberg (Germany). We analyzed the quality indicators of acute stroke treatment, patient’s outcome, and the rate of transient ischemic attack (TIA) at discharge.

Results:

A total of 2182 patients from Ulm and 82,760 patients from the Baden-Württemberg (BW) stroke registry (including 29,575 patients of comprehensive stroke centers (BWc)) were included. Intravenous thrombolysis rate was higher in Ulm than in BW or the BWc stroke centers (Ulm 27.4% versus BW 20.9% versus BWc 26.1; p < 0.01), while a door-to-needle time <30 min(Is that fast enough to get 100% recovered? If not, what is the time limit? Why the fuck don't you know that? I'm sure the time is actually prior to door.) could be achieved more frequently (Ulm 73.6% versus BW 44.1% versus BWc 47.1%; p < 0.01). Thrombectomy rate in patients with a proximal vascular occlusion was higher (Ulm 69.2% versus BW 50.7% versus BWc 59.3; p < 0.01). The number of TIA diagnoses was lower (Ulm 16.2% versus BW 24.6% versus BWc 19.9%; p < 0.01). More patients showed a shift to a favorable outcome (Ulm 21.1% versus BW 16.9% versus BWc 15.3; p < 0.01). Complication rates were similar.

Conclusions:

The MRI-based acute stroke concept is suitable, fast(Your definition of fast is wrong. Fast enough would be 100% recovery, NOT your fucking tyranny of low expectations! Recanalization.) and seems to be beneficial. The time-dependent quality indicators were better both in comparison to all stroke units and to the comprehensive stroke units in the area. Based on the MRI concept, high rates of recanalization procedures and fewer TIA diagnoses could be observed. In addition, there was a clear trend towards an improved clinical outcome. A clinical trial comparing the effects of CT and MRI as the primary imaging technique in otherwise identical stroke unit settings is warranted.

Keywords

stroke, MRI, thrombolysis, thrombectomy, stroke imaging, DWI, FLAIR, stroke mimics, stroke chameleons

Introduction

Ischemic stroke is one of the most common diseases worldwide and a leading cause of morbidity and mortality.¹ Alteplase (recombinant tissue plasminogen activator, rtPA) is the only approved drug for patients with acute ischemic stroke. It is recommended as an initial treatment within 4.5 hours after stroke onset and also shows therapeutic effects in a longer time window, if this is based on differentiated stroke imaging.^1,2 Its safe routine use is documented by data analyses from large thrombolysis registers.³ In addition, since 2015, several studies have shown the efficacy of mechanical thrombectomy (MT) in strokes caused by occlusions of large vessels.^4,5

Native noncontrast cerebral computed tomography (CT) imaging was used in the initial studies of intravenous thrombolysis (IVT) and is established as the standard in acute stroke care worldwide, in particular to exclude cerebral bleedings.⁶ A decision regarding IVT and MT is based on the patient’s symptoms and the clinical decision in the emergency room.^7,8 Possible misdiagnoses are ‘stroke mimics’ (SMs) resulting in false-positives and ‘stroke chameleons’ (SCs) resulting in a false-negative stroke diagnoses.

The majority of SMs are conditions that simulate stroke, such as migraine and seizures. The proportion of patients with SMs who are misdiagnosed as stroke decreases with the use of magnetic resonance imaging (MRI) at baseline. Studies on the proportion of SMs treated as ischemic stroke vary from 0% (when MRI is utilized prior to thrombolysis) to 25%, if standard procedures are used.⁹ SM patients may receive IVT and are exposed to side effects of this therapy, in addition the underlying cause is recognized and treated late. Patients presenting with SCs are not identified as stroke patients and are not appropriately treated.^10,11

Additional imaging modalities have been optimized in recent years and help to define potential tissue at risk according to the mismatch concept.¹² Important tools are CT angiography (CT-A) for detection of larger arterial occlusions and CT perfusion (CT-P) analysis to define the penumbra and the infarct core. Advanced imaging technologies with MRI or CT-P can guide effective acute reperfusion treatment with MT and IVT.¹³

CT-based procedures are radiation-intensive. The radiation exposure of a single examination with CT-A and CT-P may be up to 1500 mGy surface dose. Compared with CT scans, the advantages of MRI include higher sensitivity for smaller lacunar or embolic lesions and ischemia in the posterior cranial fossa, easier assessment of the age of the infarction, and the reduction of SMs and SCs. These advantages add to the absence of radiation exposure.¹⁴ Nevertheless, CT is predominantly used in acute diagnostics and therapy in acute stroke patients based on the arguments of a faster imaging and shorter door-to-needle times (DNTs) as one of the most important quality parameters.¹⁵ To date, less than 20% of stroke units reportedly use MRI for acute diagnosis, although the number of available MRI scanners is constantly increasing worldwide.¹² In Baden-Württemberg (BW), a federal state with 10.8 million inhabitants in southwest Germany, only 16% of all stroke patients received an MRI as their first imaging modality in 2017.¹⁶

It is our hypothesis that, within a high-standard-organization setting, MRI can be carried out quickly and easily, thereby resulting not only in an increased rate of acute reperfusion treatments using IVT and MT but also in an improved patient outcome.