Comparison of three FLAIR vascular hyperintensities methodologies in patients with acute ischemic stroke

BACKGROUND

Multiple methods have been used to analyze fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs) which may represent collaterals in patients with acute ischemic stroke (AIS); however, there is no consensus between methods.

PURPOSE

To compare three frequently used FVH methods for predicting early infarct volume and clinical outcome in patients with AIS.

MATERIAL AND METHODS

Patients with AIS in middle cerebral artery territory were recruited. FVHs were evaluated using extensive FVHs, FVH-diffusion-weighted imaging (DWI) mismatch, and FVH-in/out-DWI. Infarct volume at baseline and day 7 were measured. Early neurological improvement (ENI) was assessed. Good outcomes were defined by modified Rankin Scale scores of 0-2 at 90 days.

RESULTS

Fifty-one patients were included. ENI was 55.6% in patients with extensive FVHs and 23.3% in those without (P = 0.024). Patients with extensive FVHs had smaller infarct volume growth at seven days than those without (P = 0.041). ENI was 48.3% in patients with FVH-DWI mismatch and 15.8% in those without (P = 0.021). Patients with FVH-DWI mismatch had smaller infarct volumes at seven days than those without (P = 0.038). Patients with FVH-out-DWI had smaller baseline infarct volumes, smaller seven-day volumes, and smaller infarct growth than those with FVH-in-DWI (P<0.001, P<0.001, and P = 0.031, respectively). In multivariate logistic regression analysis, the infarct growth at seven days negatively independently predicted ENI (OR = 0.737, 95% CI 0.593-0.915, P = 0.006). However, none of the FVH classifications could predict a good 90-day outcome.

CONCLUSION

Patients with extensive FVHs or FVH-DWI mismatch tend to have early favorable clinical outcome. FVH-out-DWI being associated with smaller infarct growth may also indicate early favorable clinical outcome.

A proposed method for outlining occluded intracranial artery using 3D T2-weighted sampling perfection with application optimized contrasts using different flip angle evolution (SPACE)

High-resolution vessel wall imaging techniques have been developed for clinical use in various types of intracranial artery disease. Numerous studies have described techniques for evaluating remodeling patterns and plaque character, but few have reported a method for outlining obstructed vessels in intracranial artery occlusion. The course of the vessel affects the success of recanalization and can cause complications in mechanical thrombectomy for acute ischemic stroke. We propose imaging with 3D T2-weighted sampling perfection with application optimized contrasts using different flip angle evolution (SPACE) as a useful tool for describing the course of an occluded artery in ischemic stroke due to intracranial artery occlusion.

Long-term prognostic value of coronary computed tomography angiography in chest pain patients

BACKGROUND

Coronary computed tomography angiography (CCTA) is increasingly used to detect coronary artery disease (CAD), but long-term follow-up studies are still scarce.

PURPOSE

To evaluate the prognostic value of CCTA in patients with suspected CAD.

MATERIAL AND METHODS

A total of 1205 consecutive CCTA patients with chest pain were classified as normal coronary arteries, non-obstructive CAD, or obstructive CAD. The primary outcome was major adverse cardiac event (MACE), defined as a composite outcome including cardiac death, myocardial infarction, unstable angina pectoris, or late revascularization (after >90 days).

RESULTS

Over 7.5 years follow-up (median = 3.1 years), Kaplan-Meier estimates demonstrated a MACE in 1.0%, 4.6%, and 20.7% in normal coronary arteries, non-obstructive CAD, and obstructive CAD, respectively. Log rank test for pairwise comparisons showed significant differences between non-obstructive CAD and normal coronary arteries ( P = 0.023) and between obstructive CAD and normal coronary arteries ( P < 0.001). In a multivariable analysis, adjusting for classical risk factors, non-obstructive CAD and obstructive CAD were independent predictors of MACE, with hazard ratios (HR) of 3.22 ( P = 0.041) and 25.18 ( P < 0.001), respectively.

CONCLUSION

Patients with normal coronary arteries have excellent long-term prognosis, but the risk for MACE increases with non-obstructive and obstructive CAD. Both non-obstructive and obstructive CAD are independently associated with future ischemic events.

R2* Map by IDEAL IQ for Acute Cerebral Infarction: Compared with Susceptibility Vessel Sign on T2*-Weighted Imaging

BACKGROUND

To evaluate the detectability of arterial acute thrombus on R2* map by iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) IQ compared with T2*-weighted imaging (T2*WI).

METHODS

Twenty-six patients with acute cerebral infarction who underwent R2* map and T2*WI were reviewed. We performed visual assessment of each sequence regarding the visibility of susceptibility effect reflecting acute thrombus and quantitative evaluation of the thrombus on R2* map.

RESULTS

Both R2* map and T2*WI showed susceptibility effect reflecting acute thrombi at the occluded site of magnetic resonance angiography (MRA) in 9 patients. R2* map revealed positive while T2*WI showed equivocal findings in 3 patients due to the surrounding vessel signal intensity. Acute thrombus at distal internal carotid artery (ICA) on R2* map was more clearly detected than that on T2*WI without any apparent susceptibility artifact from the skull base in 4 patients. Most of cardiogenic embolic infarction (CEI) and artery-to-artery embolic infarction (A-to-A) demonstrated positive and most of atherothrombotic infarction (ATI) revealed negative findings on R2* map, although quantitative R2* values of thrombi did not show significant differences between CEI (136.6 /msec) and A-to-A (189.9 /msec) (P = 0.332).

CONCLUSION

The detectability of acute thrombus on R2* map is comparable to that on T2*WI. Regarding thrombus at distal ICA, its detectability on R2* map is superior to that on T2*WI. R2* map provide additional information to distinguish between embolic and atherothrombotic infarctions.

Positive Predictive Value of Abdominal Sonography in the Diagnosis of Ischemic Colitis

AIM

The aim was to prospectively evaluate the positive predictive value of ultrasound in the diagnosis of ischemic colitis, with colonoscopy as the reference standard.

METHODS

During a 2-year period we included consecutive patients over 50 years of age with sudden abdominal pain and/or rectal bleeding who underwent abdominal sonography in an emergency setting with a thickened segment of colon with a length of more than 10 cm. This clinical-sonographic triad was considered diagnostic for ischemic colitis. A thickened bowel location or color Doppler flow findings on ultrasound examination were evaluated but were not considered to make the diagnosis of ischemic colitis. Basic descriptive statistics were used to characterize the study patients. The positive predictive value was calculated as: number of patients with the definitive diagnosis of ischemic colitis (colonoscopic or follow-up)/number of patients with a sonographic diagnosis of ischemic colitis.

RESULTS

A total of 48 patients had the clinical-sonographic triad; mean age: 74.3 years (range 54-90 years). The most frequent clinical manifestation was rectal bleeding (83% of the cases) followed by abdominal pain (81%) and diarrhea (45%). A total of 42 cases of ischemic colitis were confirmed by endoscopy (n=35) and biopsy (n=34) or clinical evaluation (n=7). The positive predictive value of the clinical-sonographic diagnosis of ischemic colitis was 87.5%. Thickening of the colon wall was detected on the left side in 35 patients with ischemic colitis, on the right side in 3 and pancolitis was identified in 5 patients.

CONCLUSION

In an appropriate clinical setting, ultrasound has a high positive predictive value for the diagnosis of ischemic colitis.

Outcome of mechanical thrombectomy in the very elderly for the treatment of acute ischemic stroke: the real world experience

Background

Although initial studies of neuroendovascular intervention did not review benefit over intravenous thrombolytics (iv r-tPA), recent studies have suggested otherwise. Elderly patients (age ≥80 years) are typically excluded from clinical trials.

Purpose

To examine the utility of mechanical thrombectomy based on patient outcomes.

Material and Methods

All stroke-alert activations at our health system from January 2011 to June 2014 were examined. All patients aged ≥80 years who had undergone mechanical thrombectomy were identified. Clinical characteristics included physiologic imaging findings, use of intravenous thrombolytics, baseline and postoperative National Institute of Health Stroke Scale (NIHSS), thrombolysis in cerebral infarction scores (TICI), and discharge destination.

Results

Mean NIHSS on presentation was 18.2 (range, 6–31), and 13.3 (range, 3–30) post thrombectomy. Three (16.6%) patients received iv r-tPA, two (11.1%) had symptomatic intracranial hemorrhage. Eight (44.4%) died, eight (44.4%) were discharged to nursing homes, and two (11.7%) were discharged to inpatient rehab and subsequently home. Favorable outcome was achieved in five (27.7%) patients. Fourteen (77.7%) patients had physiologic imaging prior to intervention. Three (75%) of four patients who did not have physiologic imaging prior to thrombectomy died. Thirteen (66.6%) patients had TICI 3 recanalization.

Conclusion

Our study showed that although there remains a role of mechanical thrombectomy in the treatment of acute ischemic stroke in very elderly patients, it is associated with significant higher morbidity and mortality compared to younger patients, but should remain a very viable treatment option when quality of life is the most important consideration.

A new technique of in vivo synchrotron radiation coronary microangiography in the rat

BACKGROUND

Previously, in our laboratory, synchrotron radiation coronary microangiography (SRCA) using Langendorff-perfused rat hearts could visualize a coronary artery of 50 µm in diameter. However, in vivo rat SRCA poses the problem of compromised temporal resolution due to the rapid heart rate of rats.

PURPOSE

To establish a simple method of in vivo rat SRCA with bradycardia induced by intravenous injection of adenosine triphosphate disodium hydrate (ATP).

MATERIAL AND METHODS

SRCA was performed at the Photon Factory of the High Energy Accelerator Research Organization (Tsukuba, Japan). Eight male Wistar rats were anesthetized. A catheter for injecting the contrast material was inserted into the carotid artery. Temporary bradycardia was induced by an intravenous bolus injection of 5 mg of ATP, and SRCA was performed immediately thereafter.

RESULTS

After ATP administration, the average heart rate decreased from 388 to 73 beats per minute. As a result, we could detect a coronary artery as small as 45 µm in diameter.

CONCLUSION

Our SRCA system which has a high resolution of 9 µm per pixel could detect a coronary artery as small as 45 µm in diameter in the in vivo rat.