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2.
Cureus ; 16(2): e55140, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38558741

ABSTRACT

Cerebral vasospasm is a frequent complication of subarachnoid hemorrhage. We report a case of chronic subdural hematoma complicated by cerebral vasospasm after burr hole evacuation. A 74-year-old woman underwent burr hole evacuation of a chronic subdural hematoma. She developed left hemiparesis and disturbance of consciousness on postoperative day 3. Magnetic resonance imaging showed a right parietal infarct and decreased cerebral blood flow signal in the right middle cerebral artery territory. Digital subtraction angiography showed multiple segmental narrowings of the right middle cerebral artery. Her neurological symptoms recovered with conservative treatment. Follow-up angiography showed improvement in the arterial narrowing, which finally led to a diagnosis of cerebral vasospasm. Cerebral vasospasm can occur after burr hole evacuation of chronic subdural hematoma. Magnetic resonance angiography is useful for determining the cause of postoperative neurological worsening in chronic subdural hematoma patients.

3.
Quant Imaging Med Surg ; 14(4): 2788-2799, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38617180

ABSTRACT

Background: Color Doppler ultrasonography (CDUS) is feasible to detect arteriovenous fistula (AVF) dysfunction in hemodialysis patients but is not sufficient to map the structure of fistula required for interventions. This study is designed to evaluate the diagnostic accuracy of three-dimensional time-of-flight magnetic resonance angiography (TOF-MRA) at 3.0T versus CDUS for AVF dysfunction, by using digital subtraction angiography (DSA) as reference. Methods: This prospective study enrolled 68 consecutive patients with dysfunctional AVF who underwent both CDUS and TOF-MRA at Shanghai Sixth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. The analysis of the dysfunctional AVFs was divided into three regions: the feeding artery, fistula and draining veins. In the whole- and per-regional-based analyses, two observers who were blinded to the clinical and DSA results independently analyzed all CDUS and TOF-MRA datasets. The image quality and stenosis severity of the lesions on TOF-MRA were evaluated. A receiver operating characteristic curve was applied to analyze the detection of AVF dysfunction with TOF-MRA. Results: A total of 204 vessel regions were evaluated. The whole-region-based image quality of TOF-MRA was poorer in patients with a total occlusion (1.8±0.8) than in those with stenosis (2.7±0.6, P<0.001). In the whole-region analyses, TOF-MRA had higher sensitivity [99.1% (94.6-100.0%) vs. 82.9% (74.6-89.0%), P<0.001] and similar specificity [93.1% (85.0-97.1%) vs. 94.3% (86.5-97.9%), P=0.755] than CDUS. The per-region-based analyses showed that TOF-MRA yielded higher sensitivity [fistula region, 98.1% (88.4-99.9%) vs. 80.8% (67.0-89.9%); P=0.004; draining vein region, 100.0% (92.5-100.0%) vs. 85.0% (72.9-2.5%); P=0.003] and similar specificity [fistula region, 88.2% (62.3-97.8%) vs. 88.2% (62.3-97.9%); P>0.99; draining vein region, 100.0% (59.8-100.0%) vs. 87.5% (46.7-99.3%); P>0.99] than CDUS. Sensitivity and specificity of TOF-MRA were comparable to those of CDUS in feeding artery region. Conclusions: TOF-MRA is a feasible and accurate method to display AVF dysfunction in hemodialysis patients, and this method might fulfill the endovascular treatment planning requirements.

4.
Magn Reson Imaging ; 110: 43-50, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38604346

ABSTRACT

PURPOSE: Lower extremity magnetic resonance angiography (MRA) without electrocardiography (ECG) or peripheral pulse unit (PPU) triggering and contrast enhancement is beneficial for diagnosing peripheral arterial disease (PAD) while avoiding synchronization failure and nephrogenic systemic fibrosis. This study aimed to compare the diagnostic performance of turbo spin-echo-based enhanced acceleration-selective arterial spin labeling (eAccASL) (TSE-Acc) of the lower extremities with that of turbo field-echo-based eAccASL (TFE-Acc) and triggered angiography non-contrast enhanced (TRANCE). METHODS: Nine healthy volunteers and a patient with PAD were examined on a 3.0 Tesla magnetic resonance imaging (MRI) system. The artery-to-muscle signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) were calculated. The arterial visibility (1: poor, 4: excellent) and artifact contamination (1: severe, 4: no) were independently assessed by two radiologists. Phase-contrast MRI and digital subtraction angiography were referenced in a patient with PAD. Friedman's test and a post-hoc test according to the Bonferroni-adjusted Wilcoxon signed-rank test were used for the SIR, CNR, and visual assessment. p < 0.05 was considered statistically significant. RESULTS: No significant differences in nearly all the SIRs were observed among the three MRA methods. Higher CNRs were observed with TSE-Acc than those with TFE-Acc (anterior tibial artery, p = 0.014; peroneal artery, p = 0.029; and posterior tibial artery, p = 0.014) in distal arterial segments; however, no significant differences were observed upon comparison with TRANCE (all p > 0.05). The arterial visibility scores exhibited similar trends as the CNRs. The artifact contamination scores with TSE-Acc were significantly lower (but within an acceptable level) compared to those with TFE-Acc. In the patient with PAD, the sluggish peripheral arteries were better visualized using TSE-Acc than those using TFE-Acc, and the collateral and stenosis arteries were better visualized using TSE-Acc than those using TRANCE. CONCLUSION: Peripheral arterial visualization was better with TSE-Acc than that with TFE-Acc in lower extremity MRA without ECG or PPU triggering and contrast enhancement, which was comparable with TRANCE as the reference standard. Furthermore, TSE-Acc may propose satisfactory diagnostic performance for diagnosing PAD in patients with arrhythmia and chronic kidney disease.


Subject(s)
Contrast Media , Lower Extremity , Magnetic Resonance Angiography , Peripheral Arterial Disease , Spin Labels , Humans , Magnetic Resonance Angiography/methods , Peripheral Arterial Disease/diagnostic imaging , Male , Female , Lower Extremity/diagnostic imaging , Lower Extremity/blood supply , Adult , Middle Aged , Electrocardiography , Aged , Artifacts , Image Enhancement/methods , Reproducibility of Results
5.
Cureus ; 16(1): e51677, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38318545

ABSTRACT

OBJECTIVE: Although risk factors for intracranial aneurysm growth have been reported, studies investigating the influence of the parent artery angle are limited. In this study, we examined the relationship between intracranial aneurysm growth and parent artery angle narrowing by analyzing long-term follow-up magnetic resonance angiography data. METHODS: We retrospectively reviewed data of patients with untreated aneurysms and those treated by simple coil embolization, who were followed up by magnetic resonance angiography for over 24 months at the Steel Memorial Yawata Hospital between August 2007 and March 2023. We investigated the relationship of aneurysm growth with parent artery angle narrowing, age, sex, follow-up duration, previous subarachnoid hemorrhage, hypertension, smoking, aneurysm location, aneurysm type, maximum size, and neck size. RESULTS: A total of 180 aneurysms of 162 patients (women, n=113; untreated, n=136) were included. The median age at aneurysm diagnosis was 71 (63.8-76) years and the median follow-up duration was 69 (45-120) months. Among the 180 aneurysms, 41 (untreated, n=30; treated by simple coil embolization, n=11) showed growth during the follow-up period, with a risk of 4.4%/patient-year. In the univariable analysis, the parent artery angles on the initial and last follow-up images and angle change were significantly associated with aneurysm growth. However, in the multivariable analysis, the association remained significant only for angle change (odds ratio, 2.21; 95% confidence interval, 1.42-3.45). The cutoff value of parent artery angle change for intracranial aneurysm growth was -3.4°. CONCLUSION: Parent artery angle narrowing was significantly associated with intracranial aneurysm growth. This parameter may be useful for the monitoring of patients with unruptured intracranial aneurysms and may contribute to discerning the mechanism of intracranial aneurysm growth.

6.
Cureus ; 15(8): e42823, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37664282

ABSTRACT

Intimate partner violence (IPV) is a growing public health concern, with millions of individuals experiencing IPV each year. Consequences of IPV include psychological disturbances, changes in physical health, and in extreme cases, severe disablement or death. Here, we describe a case of a patient who experienced IPV, leading to a variety of neurological symptoms, and was diagnosed with a posterior cerebral artery (PCA) cerebrovascular accident (CVA) 10 days later. While cases of traumatic brain injury leading to CVA, or stroke, have been documented, there is currently limited reported literature on the neurological complications, specifically stroke, secondary to IPV in adults. Due to this limited reporting, future studies on IPV will be needed to fully understand the long-term neurological complications that may occur.

7.
Surg Radiol Anat ; 45(10): 1287-1293, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37615700

ABSTRACT

PURPOSE: As the lenticulostriate arteries (LSAs) perfuse neurologically important areas, it is necessary to accurately assess the origin and number of the LSAs before surgery. Although three-dimensional time-of-flight MR angiography (3D-TOF MRA) is a non-invasive procedure, it requires high-resolution (HR) images to depict the LSAs with a small diameter. Therefore, we performed 3D-TOF MRA with the maximum HR (HR-MRA) using a 3 T scanner to examine whether a good depiction of the LSAs, equivalent to that of digital subtraction angiography (DSA), could be obtained. METHODS: Our study group comprised 16 consecutive patients who underwent HR-MRA and 3D-DSA. In both studies, we evaluated the localization of the origin from M1, M2, or A1 segments, their number of stems, and depiction. RESULTS: There was no significant difference in the visualization of the LSAs between HR-MRA and 3D-DSA (P values; M1, M2, and A1 = 0.39, 0.69, and 0.69, respectively), and both the number of stems and the localization of the origin of the LSAs corresponded between the two examinations. CONCLUSION: HR-MRA at 3 T can depict the LSA well. It reveals the number of the LSA stems and the LSA origin comparatively with DSA.


Subject(s)
Cerebral Arteries , Magnetic Resonance Angiography , Humans , Cerebral Arteries/diagnostic imaging , Magnetic Resonance Angiography/methods , Angiography, Digital Subtraction , Middle Cerebral Artery , Imaging, Three-Dimensional
8.
Magn Reson Imaging Clin N Am ; 31(3): 373-394, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37414467

ABSTRACT

Aortic pathologic conditions represent diverse disorders, including aortic aneurysm, acute aortic syndrome, traumatic aortic injury, and atherosclerosis. Given the nonspecific clinical features, noninvasive imaging is critical in screening, diagnosis, management, and posttherapeutic surveillance. Of the commonly used imaging modalities, including ultrasound, computed tomography, and MR imaging, the final choice often depends on a combination of factors: acuity of clinical presentation, suspected underlying diagnosis, and institutional practice. Further research is needed to identify the potential clinical role and define appropriate use criteria for advanced MR applications such as four-dimenional flow to manage patients with aortic pathologic conditions.


Subject(s)
Aortic Diseases , Magnetic Resonance Imaging , Humans , Magnetic Resonance Imaging/methods , Magnetic Resonance Angiography , Aortic Diseases/diagnostic imaging , Tomography, X-Ray Computed , Ultrasonography
9.
Eur J Radiol ; 165: 110941, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37354772

ABSTRACT

PURPOSE: To investigate the association of tortuosity of the main cerebral arteries with intracranial aneurysm (IA) occurrence and rupture. To investigate the relationship between arterial tortuosity and aneurysm morphology as well as conventional risk factors of vascular diseases. METHODS: Three subject groups were analyzed in this study: Patients with ruptured IAs, patients with unruptured IAs, and healthy subjects. The groups were matched by sex and age using tendency score matching. Their intracranial magnetic resonance angiography (MRA) images were collected retrospectively. The intracranial arterial structures were segmented from the MRA images. Arterial tortuosity was measured and statistically compared between the different subject groups and different vessels. Correlation analysis was conducted between arterial tortuosity and clinical risk factors as well as aneurysm morphology. RESULTS: 120 patients were included in the study (average age: 67.5 years; 60% female), 40 for each group after matching. The tortuosity of the aneurysm-bearing artery was significantly greater than that of the contralateral artery in both the ruptured and unruptured IA groups (p < 0.001). There was no significant association between clinical risk factors (history of hypertension, hyperlipidemia, diabetes, smoking, and alcohol use) and arterial tortuosity. There were significant negative correlations between aneurysm-bearing artery tortuosity and aneurysm morphological features such as maximal diameter (p = 0.0011), neck diameter (p < 0.0001), maximum height (p = 0.0024), and size ratio (p = 0.0269). CONCLUSION: The occurrence of cerebral aneurysms correlates to increased unilateral arterial tortuosity, but the risk of aneurysm enlargement/rupturing decreases with greater arterial tortuosity. Abnormal tortuosity may be congenital as tortuosity has no clear connection with acquired common risk factors of vascular diseases.


Subject(s)
Aneurysm, Ruptured , Intracranial Aneurysm , Humans , Female , Aged , Male , Retrospective Studies , Intracranial Aneurysm/complications , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/epidemiology , Aneurysm, Ruptured/diagnostic imaging , Aneurysm, Ruptured/pathology , Cerebral Arteries/diagnostic imaging , Risk Factors , Cerebral Angiography/methods
10.
Diagnostics (Basel) ; 13(8)2023 Apr 19.
Article in English | MEDLINE | ID: mdl-37189578

ABSTRACT

Atherosclerotic plaque in the carotid artery is the main cause of ischemic stroke, with a high incidence rate among people over 65 years. A timely and precise diagnosis can help to prevent the ischemic event and decide patient management, such as follow up, medical, or surgical treatment. Presently, diagnostic imaging techniques available include color-Doppler ultrasound, as a first evaluation technique, computed tomography angiography, which, however, uses ionizing radiation, magnetic resonance angiography, still not in widespread use, and cerebral angiography, which is an invasively procedure reserved for therapeutically purposes. Contrast-enhanced ultrasound is carving out an important and emerging role which can significantly improve the diagnostic accuracy of an ultrasound. Modern ultrasound technologies, still not universally utilized, are opening new horizons in the arterial pathologies research field. In this paper, the technical development of various carotid artery stenosis diagnostic imaging modalities and their impact on clinical efficacy is thoroughly reviewed.

11.
Cureus ; 15(1): e34229, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36852359

ABSTRACT

PURPOSE: There have been several reports of central nervous system impairments associated with severe coronavirus disease 2019 (COVID-19) infection on head magnetic resonance imaging and angiography (MRI/A). However, head MRI/A is rarely performed in mild cases, and there have been few reports on intracranial changes after COVID-19 infection in these cases. Here, we report a comparative examination of the findings seen in common head MRI/A sequences in mild cases of COVID-19. METHODS: Of the 15,376 patients who underwent head MRI/A examination called "Brain Dock" between June 2020 and June 2021, 746 patients who received a COVID-19 antibody test were evaluated. Positive and negative patients were comparatively examined for head MRI/A findings such as cerebral white matter lesions, ischemic changes, cerebral microbleeds, cerebral aneurysms, arterial stenosis, sinusitis, and other abnormal findings. RESULTS: Overall, 31 (4.2%) patients were COVID-19 positive, and all of them had mild infections not requiring hospitalization. There was no significant difference in patient characteristics and head MRI/A findings between positive and negative patients. All positive patients showed no particular abnormalities in the nasal findings such as olfactory bulb atrophy or thickening of the olfactory mucosa. CONCLUSION: Intracranial lesions in mild patients do not show a clear difference from those in negative patients. This indicates that findings seen in common MRI/A sequences of severe patients are not likely in mild patients, supporting that there is relatively no damage to the central nervous system in mild patients.

12.
Quant Imaging Med Surg ; 13(2): 1009-1022, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36819290

ABSTRACT

Background: Moyamoya disease (MMD) is a rare cerebrovascular occlusive disease with progressive stenosis of the terminal portion of internal cerebral artery (ICA) and its main branches, which can cause complications, such as high risks of disability and increased mortality. Accurate and timely diagnosis may be difficult for physicians who are unfamiliar to MMD. Therefore, this study aims to achieve a preoperative deep-learning-based evaluation of MMD by detecting steno-occlusive changes in the middle cerebral artery or distal ICA areas. Methods: A fine-tuned deep learning model was developed using a three-dimensional (3D) coordinate attention residual network (3D CA-ResNet). This study enrolled 50 preoperative patients with MMD and 50 controls, and the corresponding time of flight magnetic resonance angiography (TOF-MRA) imaging data were acquired. The 3D CA-ResNet was trained based on sub-volumes and tested using patch-based and subject-based methods. The performance of the 3D CA-ResNet, as evaluated by the area under the curve (AUC) of receiving-operator characteristic, was compared with that of three other conventional 3D networks. Results: With the resulting network, the patch-based test achieved an AUC value of 0.94 for the 3D CA-ResNet in 480 patches from 10 test patients and 10 test controls, which is significantly higher than the results of the others. The 3D CA-ResNet correctly classified the MMD patients and normal healthy controls, and the vascular lesion distribution in subjects with the disease was investigated by generating a stenosis probability map and 3D vascular structure segmentation. Conclusions: The results demonstrated the reliability of the proposed 3D CA-ResNet in detecting stenotic areas on TOF-MRA imaging, and it outperformed three other models in identifying vascular steno-occlusive changes in patients with MMD.

13.
Front Neurol ; 13: 1018529, 2022.
Article in English | MEDLINE | ID: mdl-36530638

ABSTRACT

Background: Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is one of the most common maternally inherited mitochondrial diseases which rarely affects elderly people. Case presentation: We reported the case of a 61-year-old male patient with MELAS. He was experiencing acute migraine-like headaches as the first symptoms. Laboratory data showed elevated lactate and creatine kinase levels. Brain magnetic resonance imaging (MRI) found a high signal intensity lesion in the left occipital-temporal-parietal lobe on diffusion-weighted imaging (DWI). Magnetic resonance angiography (MRA) revealed reversible vasoconstriction of the middle cerebral arteries and superficial temporal arteries. A muscle biopsy suggested minor muscle damage. A genetic study revealed a mitochondrial DNA A3243G mutation. Conclusion: Elderly onset of MELAS is rare and easily misdiagnosed as an ischemic stroke. MELAS with the onset of stroke-like episodes should be considered in adult or elderly patients with imaging findings that are atypical for cerebral infarction. The use of multimodal MRI in the clinical diagnosis of MELAS could be extremely beneficial.

14.
Radiol Case Rep ; 17(12): 4828-4833, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36238206

ABSTRACT

Solitary fibrous tumors are rare mesenchymal tumors originally described in the pleura that infrequently metastasize. We present a 71-year-old male complaining of hemoptysis and a mass with the characteristic appearance of a hemangioma in the floor of the mouth. The mass had nonspecific imaging features on CT and MRI. After unsuccessful fine needle aspiration, surgical excision and biopsy with histological analysis revealed a solitary fibrous tumor, high risk variant. CT Imaging and lymph node biopsy showed gross total resection and no metastatic adenopathy. Given the high risk for malignancy, the patient received adjuvant radiation without subsequent clinical or imaging signs of recurrence. This case report demonstrates the presentation of this rare entity that can often be confused with other tumors in this region, given its nonspecific clinical and imaging findings.

15.
Clin Neurol Neurosurg ; 222: 107471, 2022 11.
Article in English | MEDLINE | ID: mdl-36265242

ABSTRACT

Moyamoya angiopathy (MMA) is a rare condition characterized by steno-occlusion of terminal portions of the internal carotid arteries and/or their proximal branches with the formation of collateral vessels network (moyamoya vessels). These changes result in chronic ischemia of the brain parenchyma with subsequent serious cerebrovascular accidents. The prognosis of MMA could be dramatically improved if the diagnosis and assessment are prompt and accurate. It is also crucial to define the indications, optimal timing, volume, and tactics of revascularization surgery, as well as longitudinal observation after treatment. It is therefore necessary to use strict criteria for decision making, including radiological criteria. In today's world, neuroimaging is a valuable diagnostic tool that continually evolves and provides us with more and more information about structural and functional changes in different pathological conditions. However, due to MMA's rarity, its neuroimaging can be challenging. The purpose of this review is to summarize a contemporary knowledge regarding neuroimaging in patients with MMA and to discuss the main difficulties associated with visualizing this condition.


Subject(s)
Moyamoya Disease , Humans , Angiography, Digital Subtraction , Moyamoya Disease/diagnostic imaging , Moyamoya Disease/surgery , Moyamoya Disease/complications , Cerebral Angiography/methods , Neuroimaging , Brain/diagnostic imaging , Magnetic Resonance Angiography
16.
Cureus ; 14(8): e28456, 2022 Aug.
Article in English | MEDLINE | ID: mdl-36176849

ABSTRACT

The agenesis of the left common carotid artery, with independent origins of the external and internal carotid arteries from the aortic arch, is a well-described but extremely rare congenital anomaly. We present a case of agenesis of the left common carotid artery with the independent origin of the left internal and left external arteries from the arch of the aorta in a patient with ankylosing spondylitis which was depicted by CT angiogram and magnetic resonance angiography. The diagnosis of this anatomical variant especially before interventional procedures is of great importance, as it could complicate the catheterization of these arteries.

17.
Front Neurol ; 13: 958037, 2022.
Article in English | MEDLINE | ID: mdl-36090850

ABSTRACT

Objectives: The role of three-dimensional (3D) TOF-MRA in patients with cognitive impairment is not well established. We evaluated the diagnostic yield of 3D TOF-MRA for detecting incidental extra- or intracranial artery stenosis and intracranial aneurysm in this patient group. Methods: This retrospective study included patients with cognitive impairment undergoing our brain MRI protocol from January 2013 to February 2020. The diagnostic yield of TOF-MRA for detecting incidental vascular lesions was calculated. Patients with positive TOF-MRA results were reviewed to find whether additional treatment was performed. Logistic regression analysis was conducted to identify the clinical risk factors for positive TOF-MRA findings. Results: In total, 1,753 patients (mean age, 70.2 ± 10.6 years; 1,044 women) were included; 199 intracranial aneurysms were detected among 162 patients (9.2%, 162/1,753). A 3D TOF-MRA revealed significant artery stenoses (>50% stenosis) in 162 patients (9.2%, 162/1,753). The overall diagnostic yield of TOF-MRA was 16.8% (294/1,753). Among them, 92 patients (31.3%, 92/294) underwent either medical therapy, endovascular intervention, or surgery. In total, eighty-one patients with stenosis were prescribed with either antiplatelet medications or lipid-lowering agent. In total, fifteen patients (aneurysm: 11 patients, stenosis: 4 patients) were further treated with endovascular intervention or surgery. Thus, the "number needed to scan" was 19 for identifying one patient requiring treatment. Multivariate logistic regression analysis showed that being female (odds ratio [OR] 2.05) and old age (OR 1.04) were the independent risk factors for intracranial aneurysm; being male (OR 1.52), old age (OR 1.06), hypertension (OR 1.78), and ischemic heart disease history (OR 2.65) were the independent risk factors for significant artery stenosis. Conclusions: Our study demonstrated the potential benefit of 3D TOF-MRA, given that it showed high diagnostic yield for detecting vascular lesions in patients with cognitive impairment and the considerable number of these lesions required further treatment. A 3D TOF-MRA may be included in the routine MR protocol for the work-up of this patient population, especially in older patients and patients with vascular risk factors.

18.
Radiol Phys Technol ; 15(4): 311-322, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36002782

ABSTRACT

The quality of visualization in inflow magnetic resonance angiography (MRA) depends highly on the excitation state of the longitudinal magnetization obtained using specified imaging parameters. In addition, signal intensity changes controlled by the preparation pulse-such as inversion recovery (IR) and saturation recovery (SR)-can potentially be used as quantitative physiological values. Although having practitioners understand these relationships both qualitatively and quantitatively is important, handling clinical equipment in practical learning or experiments involves limited opportunities. The simulator corresponds to a three-dimensional spoiled gradient echo sequence and allows users to freely input multiple virtual excitation effects in space and time. The purpose of this study was to quantitatively evaluate the agreement between the measured MRAs obtained in flow phantom tests and virtual MRAs simulated under similar conditions. We imaged two vascular flow phantoms on a 3.0 T MR system using three-dimensional (3D) time-of-flight (TOF) MRA and 3D inversion recovery tissue signal suppression (IR-suppression) MRA protocols. We evaluated quantitative values for consistency between the measured and virtual MRAs images with matched spatial resolution. Then we assessed the coincidence by reformatting maximum-intensity projection images with 1 mm isotropic pixels, with it ranging from 89.6 to 92.0% and 89.1 to 92.9% for TOF MRA and IR-suppression MRA, respectively. These results may be useful as a reference index for the theoretical study of MRA images by practitioners, for complementary validation by phantom testing, or for the development of MRI-related simulators.


Subject(s)
Magnetic Resonance Angiography , Magnetic Resonance Imaging , Magnetic Resonance Angiography/methods , Phantoms, Imaging , Imaging, Three-Dimensional/methods
19.
Front Vet Sci ; 9: 819627, 2022.
Article in English | MEDLINE | ID: mdl-35782562

ABSTRACT

Arterial thromboembolism is associated with high morbidity and mortality rates in cats. Definitive diagnosis requires advanced imaging modalities, such as computed tomography angiography (CTA) and contrast-enhanced (CE) magnetic resonance angiography (MRA). However, CTA involves exposure to a large amount of ionized radiation, and CE-MRA can cause systemic nephrogenic fibrosis. Non-contrast-enhanced (NE) MRA can help accurately diagnose vascular lesions without such limitations. In this study, we evaluated the ability of NE-MRA using three-dimensional electrocardiograph-gated fast spin-echo (3D ECG-FSE) and 3D time-of-flight (3D TOF) imaging to visualize the aorta and external iliac arteries in clinically healthy cats and compared the results with those obtained using CE-MRA. All 11 cats underwent 3D ECG-FSE, 3D TOF, and CE-MRA sequences. Relative signal intensity (rSI) for quantitative image analysis and image quality scores (IQS) for qualitative image analysis were assessed; the rSI values based on the 3D TOF evaluations were significantly lower than those obtained using 3D ECG-FSE (aorta 3D TOF: 0.57 ± 0.06, aorta 3D ECG-FSE: 0.83 ± 0.06, P < 0.001; external iliac arteries 3D TOF: 0.45 ± 0.06, external iliac arteries 3D ECG-FSE:0.80 ± 0.05, P < 0.001) and similar to those obtained using CE-MRA (aorta: 0.58 ± 0.05, external iliac arteries: 0.57 ± 0.03). Moreover, IQS obtained using 3D TOF were significantly higher than those obtained using 3D ECG-FSE (aorta 3D TOF: 3.95 ± 0.15, aorta 3D ECG-FSE: 2.32 ± 0.60, P < 0.001; external iliac arteries 3D ECG-FSE: 3.98 ± 0.08, external iliac arteries 3D ECG-FSE: 2.23 ± 0.56, P < 0.001) and similar to those obtained using CE-MRA (aorta: 3.61 ± 0.41, external iliac arteries: 3.57 ± 0.41). Thus, 3D TOF is more suitable and produces consistent image quality for visualizing the aorta and external iliac arteries in clinically healthy cats and this will be of great help in the diagnosis of FATE.

20.
Cureus ; 14(4): e23828, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35530922

ABSTRACT

Certain clinical scenarios should alert a physician to take a deeper look into causative pathological processes. This was evident in the case of a 41-year-old man who presented for recurrent micro thromboembolic strokes, which is atypical for the patient's age. Our desire to explain the pathological process led to the rare finding of a plasminogen activator inhibitor-1 polymorphism, which has been associated with an increased risk of cerebrovascular thrombosis. A defect in this pathway leads to the inhibition of the tissue plasminogen activator protein. This genetic polymorphism has relatively been unexplored in recent medical literature, and we are hoping that our case may inspire future research that could help potential targets of risk factor stratifications as well as the development of novel pharmacological options.

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