Comparison of pulmonary artery sarcoma and pulmonary thromboembolism according to clinical and computed tomography pulmonary angiography and magnetic resonance imaging characteristics: a single-center retrospective study.

Background: Pulmonary artery sarcoma (PAS) is a very rare malignancy with a poor prognosis; however, its clinical manifestations and imaging findings are often indistinguishable from pulmonary thromboembolism (PTE). We thus aimed to accurately diagnose PAS by comparing the clinical and computed tomography pulmonary angiography (CTPA) and magnetic resonance imaging (MRI) imaging characteristics of PAS and PTE. Methods: This case-control study retrospectively enrolled 20 patients with PAS (from March 2017 to September 2022), 40 patients with central acute PTE, and 40 patients with central chronic PTE (from January 2021 to December 2022) in the China-Japan Friendship Hospital. The following clinical and imaging findings were compared between the three groups: initial symptoms; D-dimer, C-reactive protein, and N-terminal pro B-type natriuretic peptide levels; wall-eclipsing sign (WES); scope of lesion involvement; and morphological characteristics. Signal intensity was also observed on different MRI sequences. Results: The D-dimer level in PAS was significantly lower than that in central acute PTE (P<0.001). The WES was present in 17 cases of PAS (85.0%), which was a greater proportion than that of the central acute PTE and chronic PTE groups (all P values <0.001). The involvement of the pulmonary valve or right ventricular outflow tract was observed in five PAS cases but none of the central acute PTE or chronic PTE cases (all P values =0.001). In 19 PAS cases (95.0%), the lesions grew expansively in the central pulmonary artery. The proximal margin of 18 patients with PAS (90.0%) was bulging or lobulated. Nine cases of PAS (45.0%) showed aneurysm-like dilatation (grape-like sign) of the distal pulmonary artery, representing significantly greater proportion than that of the central acute PTE and chronic PTE groups (all P values <0.001). In 37 patients with central acute PTE (92.5%), the clots were observed to be floating in the pulmonary artery lumen with saddle, tubular or polypoid shape. Eccentric filling defects attached to the pulmonary artery wall were observed in 32 cases of central chronic PTE (80.0%). On MRI, PAS lesions were hyperintense on fat-suppressed T2-weighted imaging and diffusion-weighted imaging, demonstrating heterogeneous enhancement. Conclusions: Comprehensive analysis of the clinical data and imaging features on CTPA and MRI can aid in the accurate differential diagnosis of PAS and PTE.

Effect of dominant vertebral artery angle on basilar artery curvature and plaque.

Background: Quantification of vertebral arteries can provide insights into basilar curvature and plaque. Therefore, this retrospective study aimed at identifying the dominant vertebral artery (VA) causing basilar artery (BA) curvature and to further quantify the effect of dominant VA angle on BA curvature and BA plaque using high-resolution magnetic resonance imaging (HRMRI) and 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA). Methods: This retrospective analysis included 521 participants who underwent HRMRI in the China-Japan Friendship Hospital from November 2015 to October 2021 for neurological symptoms or signs. The VA angle more related to BA curvature was defined as the dominant VA angle. Multivariable linear regression analysis was used to evaluate the relationship between the dominant VA angle and mid-BA angle, while multivariable logistics regression was used to evaluate the influence of the dominant VA angle and clinical risk factors on BA plaque. Results: In total, 259 participants were included in this study (mean age 53.71±13.12 years; 146 males). The balanced-type participants had a significantly lower probability of BA plaques (P<0.001). The Chi-squared test showed that the BA curvature direction was significantly associated with the side with larger VA diameter (P<0.001) and larger VA angle (P<0.001). As a result, the VA angle on the side with the larger diameter or the larger VA angle when the diameters were similar was considered to be the dominant VA angle. The dominant VA angle was independently correlated with the mid-BA angle (P<0.001). In addition, the dominant VA angle was also an independent risk factor for BA plaque. Additionally, 80° was the cutoff value of the dominant VA angle, and when the dominant VA angle was greater than 80°, the risk of BA plaque increased about 18-fold [odds ratio, 18.951; 95% confidence interval (CI): 4.545-79.026; P<0.001]. Conclusions: The dominant VA angle was independently associated with BA plaque, and a dominant VA angle greater than 80° may be a marker for a high risk of posterior circulation atherosclerosis.

Studying the imaging features and infarction mechanism of vertebrobasilar dolichoectasia with high-resolution magnetic resonance imaging.

The mechanisms underlying ischemic infarction in patients with vertebrobasilar dolichoectasia (VBD) remain unclear. In this study, we retrospectively analyzed the imaging characteristics of high-resolution magnetic resonance imaging (HR-MRI) in patients with VBD to explore the possible mechanisms of ischemic stroke (IS) in patients with VBD. Patients with VBD were recruited from the HR-MRI database between July 2017 and June 2021. HR-MRI was used to evaluate the diameter, bifurcation height, laterality, arterial dissection, and atherosclerotic plaques of the basilar artery (BA). Transcranial Doppler was used to measure the vertebrobasilar mean velocity (Vm), peak systolic velocity (Vs), end-diastolic velocity (Vd), and pulsatile index. Twenty-six patients with VBD were enrolled, of which 15 had IS and 11 did not. The incidence of classical vascular risk factors, including age, sex, hypertension, diabetes, and hypercholesterolemia, did not differ significantly between the two groups. The BA diameters of the stroke group were significantly higher than that of the nonstroke group (6.57 ± 1.00 mm vs. 5.06 ± 0.50 mm, p = 0.000). The height of the BA bifurcation in the stroke and nonstroke groups was statistically significant (p = 0.002). Compared with the nonstroke group, the Vm, Vs, and Vd of the BA in the stroke group were lower, but the difference was not significant. In the 16 patients with atherosclerotic stenosis, 30 atherosclerotic plaques were found in the BA, 18 (60%) in the greater curvature, and 12 (40%) in the lesser curvature. In addition, one artery dissection (on the lesser curvature) and two dissecting aneurysms (on the greater curvature) were found in the BA of three patients, respectively. The BA diameter and bifurcation height are factors related to IS in patients with VBD. The mechanism of stroke in patients with VBD may involve abnormal hemodynamics, artery dissection, and atherosclerosis. HR-MRI is a useful method for evaluating the risk and underlying mechanism of stroke in patients with VBD.

Effect of Mid-Basilar Artery Angle and Plaque Characteristics on Pontine Infarction in Patients with Basilar Artery Plaque.

AIMS: The basilar artery (BA) geometry and plaque characteristics may play an important role in the development of atherosclerosis. This study was performed to explore the relationship between the mid-BA angle and plaque characteristics and its effect on pontine infarction using high-resolution magnetic resonance imaging and three-dimensional time-of-flight magnetic resonance angiography. METHODS: In total, 77 patients with BA plaques were included in this study. According to the presence of acute pontine infarction on diffusion-weighted imaging, the patients were divided into a pontine infarction group and pontine non-infarction group. The mid-BA angle, plaque burden, stenosis ratio, positive remodeling, and intraplaque hemorrhage were evaluated to investigate their effects on stroke. RESULTS: The pontine infarction group had a greater plaque burden, stenosis ratio, positive remodeling, and mid-BA angle than the pontine non-infarction group. The correlation between the plaque burden and mid-BA angle was the highest (r=0.441, P＜0.001). Multivariate logistic regression analysis showed that the plaque burden (odds ratio, 1.164; 95% confidence interval, 1.093-1.241; P＜0.001) was an independent risk factor for pontine infarction. CONCLUSION: The mid-BA angle may increase the incidence of pontine infarction by increasing the plaque burden.

Three-Dimensional High-Resolution Magnetic Resonance Imaging for the Assessment of Cervical Artery Dissection.

Background and Purpose: Diagnosing cervical artery dissection (CAD) is still a challenge based on the current radiographic criteria. This study aimed to assess the value of three-dimensional high-resolution magnetic resonance imaging (3D HRMRI) in the detection of the signs of CAD and its diagnosis. Materials and Methods: Patients with CAD from January 2016 to January 2021 were recruited from our 3D HRMRI database. The signs of dissection (intramural hematomas, intimal flap, double lumen), length and location of the dissection, thickness of the intramural hematoma, intraluminal thrombus, and percentage of dilation of the outer contour of the dissection on 3D HRMRI were assessed. Results: Fourteen patients with 16 CADs, including 12 carotid CADs and 4 vertebral CADs, were finally diagnosed in this study. On 3D HRMRI, intramural hematomas were detected in 13/16 (81.3%) lesions with high sensitivity (100%) and high specificity (100%). Intimal flaps were found in 9/16 (56.3%) lesions with moderate sensitivity (64.3%) and high specificity (88.9%). Double lumen signs were observed in 4/16 (25.0%) lesions with high sensitivity (80.0%) and high specificity (100%). In addition, concomitant intraluminal thrombus were detected in 4/16 (25.0%) lesions with high sensitivity (80.0%) and high specificity (100%). The mean length of dissection was (25.1 ± 13.7) mm. The mean thickness of the intramural hematoma was (4.3 ± 2.3) mm. The mean percentage of dilation for the outer contour of the dissection was (151.3 ± 28.6)%. Conclusion: The 3D HRMRI enables detection of the dissecting signs, such as intramural hematoma, intimal flap, double lumen, and intraluminal thrombus with high sensitivity and specificity, suggesting a useful, and non-invasive tool for definitively diagnosing CAD.

Case Report: Advantages of High-Resolution MRI in Evaluating the Efficacy of Drug Therapy for Intracranial Atherosclerotic Plaques.

Intracranial atherosclerotic stenosis is one of the main causes of ischemic stroke and transient ischemic attack. High-resolution magnetic resonance imaging allows us to directly observe the intracranial artery wall, accurately assess the condition of the vascular wall, and quantitatively analyze the vascular wall and intracranial atherosclerotic plaque load. We report a case of acute cerebral infarction with left middle cerebral artery stenosis. During the first 3 weeks, the patient was treated with aspirin 100 mg and clopidogrel 75 mg daily. Afterwards, the patient continued to be given aspirin, and cilostazol 100 mg twice daily was given instead of clopidogrel. After 24 months of follow-up, we observed a significant reversal of intracranial atherosclerotic plaque using high-resolution MRI (HR-MRI) and discussed the advantages of HR-MRI in evaluating drug therapy for intracranial atherosclerotic plaque.

Relationship Between Computed Tomography Imaging Features and Clinical Characteristics, Masaoka-Koga Stages, and World Health Organization Histological Classifications of Thymoma.

Objectives: Computed tomography (CT) is an important technique for evaluating the condition and prognosis of patients with thymomas, and it provides guidance regarding treatment strategies. However, the correlation between CT imaging features, described using standard report terms, and clinical characteristics, Masaoka-Koga stages, and World Health Organization (WHO) classifications of patients with thymomas has not been described in detail nor has risk factor analysis been conducted. Methods: Overall, 159 patients with thymomas who underwent preoperative contrast-enhanced CT between September 2011 and December 2018 were retrospectively reviewed. We assessed the clinical information, CT imaging features, and pathological findings for each patient. A total of 89 patients were specially used to evaluate postoperative recurrence or metastasis between September 2011 and December 2015 to obtain an appropriate observation period. The relationship between CT imaging features and clinical characteristics, Masaoka-Koga stage, and WHO histological classification were analyzed, and related risk factors based on CT imaging features were identified. Results: CT imaging features did not significantly differ based on sex or age. Some imaging features demonstrated significant differences between the groups with and without related clinical characteristics. Contour (odds ratio [OR] = 3.711, P = 0.005), abutment ≥50% (OR = 4.277, P = 0.02), and adjacent lung abnormalities (OR = 3.916 P = 0.031) were independent risk factors for relapse or metastasis. Among all imaging features, there were significant differences between stage I/II and III/IV lesions in tumor size, calcification, infiltration of surrounding fat, vascular invasion, pleural nodules, elevated hemidiaphragm, and pulmonary nodules. Tumor size (odds ratio = 1.261, P = 0.014), vascular invasion (OR = 2.526, P = 0.023), pleural nodules (OR = 2.22, P = 0.048), and pulmonary nodules (OR = 3.106, P = 0.006) were identified as independent risk factors. Tumor size, contour, internal density, infiltration of surrounding fat, and pleural effusion significantly differed between low- and high-risk thymomas. Tumor size (OR = 1.183, P = 0.048), contour (OR = 2.288, P = 0.003), internal density (OR = 2.192, P = 0.024), and infiltration of surrounding fat (OR = 2.811 P = 0.005) were independent risk factors. Conclusions: Some CT imaging features demonstrated significant correlations with clinical characteristics, Masaoka-Koga clinical stages, and WHO histological classifications in patients with thymomas. Familiarity with CT features identified as independent risk factors for these related clinical characteristics can facilitate preoperative evaluation and treatment management for the patients with thymoma.

Differences in functional brain alterations driven by right or left facial nerve efferent dysfunction: Evidence from early Bell's palsy.

BACKGROUND: Bell's palsy is defined as idiopathic unilateral facial nerve palsy. Early Bell's palsy is characterized by emerging asymmetric motor conduction of the facial nerve and obvious imbalance of facial muscle movement, which can result in a substantial psychological impact on patients and trigger brain cortical functional reorganization. However, the differences between the brain functional alterations were driven by right or left facial nerve efferent dysfunction in patients with early Bell's palsy are not fully understood. The neuroimage study in patients with different-sided Bell's palsy in the early stage will help to understand the different mechanisms involved in functional integration driven by unilateral facial efferent nerve dysfunction and to provide the theoretical foundation for the choice of suitable treatment strategy. METHODS: Sixty-seven patients and 37 age- and sex-matched healthy controls were recruited to undergo resting-state functional magnetic resonance imaging (R-fMRI). Regional brain activity was analyzed by comparing the fractional amplitude of low-frequency fluctuations (fALFF) between right palsy and healthy control, left palsy and healthy control, and right and left palsy groups. The altered brain regions were further selected as seeds in subsequent functional connectivity (FC) analysis, and the correlations between the Toronto Facial Grading System (TFGS) scores and the connectivity alterations were also analyzed. RESULTS: The right and left Bell's palsy groups showed fALFF alterations compared with the healthy control group, and several brain regions with different fALFF values between the right and left palsy groups were identified. In the right palsy group, overall inter-regional FC increased in the right supramarginal gyrus (SMG), bilateral superior frontal gyrus (SFG), and left precentral gyrus (PreCG), compared with the left palsy group. Furthermore, the brain region pairs with higher FC in the right palsy group were left temporal pole of the superior temporal gyrus (TPOsup) and right SMG, left TPOsup and middle cingulate cortex (MCC), left TPOsup and left PreCG, right SMG and SFG, MCC and left PreCG, left and right SFG, and right SFG and left PreCG. In the right palsy group, the left TPOsup and PreCG showed a negative correlation with the TFGS score, while the right SFG and left PreCG showed a positive correlation with the TFGS scores. In the left palsy group, the left TPOsup and right SMG, and the right SMG and SFG region pairs showed a negative correlation with the TFGS score. CONCLUSIONS: The fALFF and FC analyses revealed the remodeling of different brain functional networks driven by right or left facial nerve efferent dysfunction in patients with early Bell's palsy. The reintegration mechanisms differed between patients with right and left Bell's palsy. Additionally, the severity of the disease showed different associations with altered FC.

Morphologic characteristics of severe basilar artery atherosclerotic stenosis on 3D high-resolution MRI.

BACKGROUND: Two-dimensional high-resolution MRI (2D HRMRI) faces many technical challenges for fully assessing morphologic characteristics of inherent tortuous basilar arteries. Our aim was to investigate remodeling mechanisms and plaque distribution in symptomatic patients with basilar artery stenosis on three-dimensional (3D) HRMRI. METHODS: Forty-six consecutive patients with symptomatic basilar artery atherosclerotic stenosis on MRA (70-99%) were enrolled. The remodeling index (RI) was the ratio of vessel area at the maximal-lumen-narrowing (MLN) site to reference vessel area. RI ≥ 1.05 was defined as positive remodeling (PR), RI ≤ 0.95 as negative remodeling (NR), and 0.95 < RI < 1.05 as intermediate remodeling (IR). The remodeling patterns were divided into two groups (PR and non-PR [NR and IR]). The cross-sectional and longitudinal distribution of BA plaques were evaluated. RESULTS: Two patients were excluded because of poor-quality images. Images of 44 patients were available for measurements. PR was found in 23 (52.3%) patients, and non-PR in 21 (47.7%) patients. At the MLN sites, vessel area, wall area, plaque size and percentage of plaque burden of PR group were significantly greater than non-PR group (p < .001). Most plaques (90.9%) of the 44 patients were located at the dorsal, left and right walls. For the longitudinal distribution of plaque, 8 (18.2%) and 36 (81.8%) plaques were located in BA proximal and distal to AICA, respectively. Most plaques (68.2%) were eccentrically distributed. CONCLUSIONS: 3D HRMRI with postprocessing multiple planar reconstruction is able to evaluate the remodeling pattern and plaque distribution of basilar artery atherosclerotic stenosis, which might be used to guide intracranial intervention.

Altered Brain Fraction Amplitude of Low Frequency Fluctuation at Resting State in Patients With Early Left and Right Bell's Palsy: Do They Have Differences?

Purpose: Bell's palsy refers to acute idiopathic unilateral facial nerve palsy. It is a common disorder of the main motor pathway to the facial muscles. This study aimed to investigate the abnormal fraction amplitude of low frequency fluctuation (fALFF) of the brain in patients with early left and right Bell's palsy. Materials and Methods: Sixty-seven patients (left 33, right 34) and 37 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging (R-fMRI) examination. The fALFF values were measured from all subjects and were compared among the left palsy, right palsy, and control groups. Then, correlations between the Toronto Facial Grading System (TFGS) scores of the patients and the fALFF values of abnormal brain regions were analyzed. Results: Significant group differences in fALFF values among the three groups were observed mainly in the cerebral cortical, subcortical, and deep gray matter regions. Compared with the right Bell's palsy group, the left Bell's palsy group showed significantly decreased fALFF values in the left temporal pole of the superior temporal gyrus (TPOsup), right supramarginal, left and right middle cingulate cortex (MCC), left superior frontal gyrus (SFG), and left precentral gyrus (PreCG), and increased fALFF values were observed in the right SFG and PreCG. Furthermore, altered fALFF values correlated positively with the TFGS scores in the left superior TPO, bilateral MCC, and right PreCG, and correlated negatively with the TFGS scores in the right SFG of the left Bell's palsy group. Altered fALFF values correlated positively with the TFGS scores in the bilateral MCC and right PreCG and correlated negatively with the TFGS scores in the left superior TPO and SFG of the right Bell's palsy group. Conclusion: Regulatory mechanisms seem to differ between patients with left and right early Bell's palsy. The severity of the disease is associated with these functional alterations.

Increased Iron Deposition on Brain Quantitative Susceptibility Mapping Correlates with Decreased Cognitive Function in Alzheimer's Disease.

The excessive accumulation of iron in deep gray structures is an important pathological characteristic in patients with Alzheimer's disease (AD). Quantitative susceptibility mapping (QSM) is more specific than other imaging-based iron measurement modalities and allows noninvasive assessment of tissue magnetic susceptibility, which has been shown to correlate well with brain iron levels. This study aimed to investigate the correlations between the magnetic susceptibility values of deep gray matter nuclei and the cognitive functions assessed by mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) in patients with mild and moderate AD. Thirty subjects with mild and moderate AD and 30 age- and sex-matched healthy controls were scanned with a 3.0 T magnetic resonance imaging (MRI) scanner. The magnetic susceptibilities of the regions of interest (ROIs), including caudate nucleus (Cd), putamen (Pt), globus pallidus (Gp), thalamus (Th), red nucleus (Rn), substantia nigra (Sn), and dentate nucleus (Dn), were quantified by QSM. We found that the susceptibility values of the bilateral Cd and Pt were significantly higher in AD patients than the controls ( P < 0.05). In contrast, bilateral Rn had significantly lower susceptibility values in AD than the controls. Regardless of gender and age, the increase of magnetic susceptibility in the left Cd was significantly correlated with the decrease of MMSE scores and MoCA scores ( P < 0.05). Our study indicated that magnetic susceptibility value of left Cd could be potentially used as a biomarker of disease severity in mild and moderate AD.

The reduction of volume and fiber bundle connections in the hippocampus of EGR3 transgenic schizophrenia rats.

BACKGROUND AND OBJECTIVE: There is a growing consensus that schizophrenia is ultimately caused by abnormal communication between spatially disparate brain structures. White matter fasciculi represent the primary infrastructure for long distance communication in the brain. In this study, we aimed to investigate the white matter connection in schizophrenia susceptible brain regions of early growth response factor 3 (EGR3) expressing rats. METHODS: A rat model of schizophrenia was created by the transfection of the EGR3 gene into rat hippocampus. All animals were placed in a fixation system using a commercial rat-dedicated coil. Schizophrenia susceptible brain regions were scanned using in vivo diffusion tensor magnetic resonance imaging. The volume, quantity, average length of fiber bundles, fractional anisotropy, apparent diffusion coefficient, the relative heterosexual fraction, and volume ratio were collected in the whole brain and schizophrenia related brain areas (the hippocampus, thalamus, and prefrontal lobe). MedINRIA software was used for data processing of diffusion tensor and fiber bundles tracking. The fibronectin in relevant brain regions was also analyzed. RESULTS: There was a significant decrease in the volume of the fiber beam through the left hippocampus dentate in the schizophrenia model group in comparison to the control group and the risperidone treatment group (P<0.05). A significant reduction in the volume and number of the fiber bundles was also observed in left prefrontal-left hippocampus, left hippocampus-left thalamus, left prefrontal-left hippocampus-left thalamus areas in the model group (all P<0.05). CONCLUSION: The volume of hippocampus and the number of fiber bundles were reduced in EGR3 transgenic schizophrenia rats, and are the most sensitive indicators in schizophrenia. The diffusion tensor imaging technique plays an important role in the evaluation of patients with schizophrenia.

Splenic littoral cell hemangioendothelioma: report of a case with hepatic metastases and review of the literature.

Littoral cell tumors are unique to the spleen and are different from all other primary splenic tumors. These tumors may be divided into three types: "littoral cell angioma," "littoral cell hemangioendothelioma," and "littoral cell angiosarcoma." We present a patient with splenic littoral cell hemangioendothlioma accompanied by hepatic metastases.