Quantitative Imaging in Medicine and Surgery最新文献

Background: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease with a high prevalence. Recent data suggest that NAFLD may be an independent risk factor for cardiovascular disease (CVD). This study aimed to investigate the association between NAFLD and carotid high-risk plaque (HRP) as assessed by high-resolution magnetic resonance imaging (MRI), and to examine the diagnostic value of NAFLD.

Methods: A total of 125 patients with carotid plaques who underwent high-resolution MRI and unenhanced abdominal computed tomography (CT) examinations were included in this retrospective study. NAFLD was defined as a liver/spleen Hounsfield unit (HU) ratio <1.0 on a non-contrast CT scan. The criteria for defining HRP were at least one of the following features: fibrous cap rupture (FCR); a large lipid-rich necrotic core (LRNC) (occupying >40% of the wall area); or intraplaque hemorrhage (IPH). Univariable and multivariable logistic regression analyses were conducted to examined the association between HRP and NAFLD. The adjusted receiver operating characteristic (aROC) curve and the adjusted area under the curve (aAUC) with the 95% confidence interval (CI) were calculated for each model.

Results: Compared with the patients without NAFLD, those with NAFLD had a higher prevalence of IPH, large LRNC, and FCR (all P<0.001). HRP was more commonly observed in the plaques of the NAFLD patients than the non-NAFLD patients (P<0.001). The multivariate analyses showed that NAFLD was an independent predictor of carotid HRP [odds ratio (OR) =12.06, 95% CI: 3.66-39.76, P<0.001]. The aROC curve analysis showed that NAFLD had an outstanding diagnostic ability (aAUC =0.95) in identifying HRP after adjusting for risk factors.

Conclusions: NAFLD is associated with carotid HRP as assessed by high-resolution MRI. CT-defined NAFLD may be a novel and robust predictor for identifying HRP.

Background: The scanning trigger threshold affects image quality. The aim of this study was to investigate the effect of different scanning trigger thresholds on brain computed tomography angiography (CTA) image quality.

Methods: In this prospective study, 80 patients undergoing brain CTA examinations with dual-layer CT (DLCT) were randomly divided into group A and group B, with 40 patients in each group. In group A, the CT value of the internal carotid artery at the level of the fourth cervical vertebra was monitored, and the scan was initiated once the CT value reached 100 Hounsfield units (HU). In group B, the trigger threshold was set at 60 HU, with all other parameters kept consistent with those of group A. Finally, the image quality of the 50-keV virtual monoenergetic images (VMIs) was evaluated, including the CT values of the internal carotid artery (CT_ICA), middle cerebral artery (CT_MCA), sinus confluence (CT_SC), cerebral white matter (CT_CWM), background noise (BN), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective scoring.

Results: All images met the diagnostic imaging requirements. Group B showed significantly lower values than did group A for CT_ICA (371.97±51.81 vs. 442.64±83.39 HU), CT_MCA (345.80±50.72 vs. 405.87±82.81 HU), CT_SC (90.44±21.30 vs. 138.87±37.37 HU), CT_CWM (31.98±5.66 vs. 38.86±5.68 HU), SNR (108.64±21.05 vs. 126.79±30.87), and CNR (98.58±19.72 vs. 114.65±29.56) (all P values <0.05) but the value for BN was not significantly different (P>0.05). However, the subjective scores in group B were significantly higher than those in group A (χ²=19.013; P<0.05).

Conclusions: For brain CTA imaging in DLCT (50 keV VMIs), lowering the scan trigger threshold to 60 HU helped to reduce venous artifacts and improve image quality (as evidenced by improved subjective scores) and also suggests the potential for a further reduction of the contrast dose.

Background: Rapid eye movement sleep behavior disorder (RBD) is associated with pathological α-synuclein deposition and may have different damage directions due to α-synuclein spreading orientations. Recent functional imaging studies of Parkinson's disease (PD) with RBD have identified abnormalities in connectivity, but effective connectivity (EC) for this altered orientation is understudied. Here, we aimed to explore altered intrinsic functional connectivity (FC) and EC in PD patients with probable RBD (pRBD).

Methods: This was a cross-sectional study. A total of 31 PD patients with pRBD (PD-pRBD), 35 PD without pRBD (PD-npRBD), and 32 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (RS-fMRI) scans. The voxel-wise degree centrality (DC) calculation was first performed to investigate the inherent connectivity of the PD-pRBD patients. Subsequently, we applied Granger causality analysis (GCA) to probe the causal effects of anomalous brain regions. Finally, the support vector machine (SVM) method was executed to evaluate the DC values in identifying PD-pRBD.

Results: PD-pRBD patients exhibited reduced z-DC values in the right precentral gyrus relative to PD-npRBD (voxel-level P<0.001, cluster-level P<0.05), as well as decreased z-DC values in the right postcentral gyrus and the superior parietal lobule compared to HCs. Then, our GCA revealed that decreased EC was located predominantly from the right precentral gyrus to the right caudate nucleus in the PD-pRBD group. Additionally, the SVM results revealed that the z-DC values of the right precentral gyrus could discriminate PD-pRBD from the PD-npRBD group [area under the curve (AUC) =0.905].

Conclusions: The altered z-DC in the right precentral gyrus and the anomaly causal effects from the precentral motor cortex to the ipsilateral striatum represented by the caudate nucleus might play vital roles in the pathogenesis of PD-pRBD. It was speculated that the attenuation of FC from the precentral motor cortex to the subcortical striatum might be associated with nocturnal muscle dyskinesia and behavioral abnormalities in PD-pRBD patients. This disruption pattern may be a prospective imaging marker in the characterization of PD with pRBD.

Background: Data on overall survival (OS) and progression-free survival (PFS) after microwave ablation (MWA) for intrahepatic cholangiocarcinoma (ICC) are scarce. We conducted a systematic review of the safety and efficacy of MWA for ICC.

Methods: The PubMed, Embase, Web of Science, and Cochrane Library databases were searched for studies reporting the outcomes of MWA for ICC. Meta-analyses of the pooled OS, PFS, technical success, technical efficacy, and complication rates were conducted. Pooled hazard ratios (HRs) of common variables were calculated to identify the factors associated with OS.

Results: The analysis encompassed 168 entries, among which 8 observational studies comprising 
423 patients were deemed eligible. The pooled results were as follows: The median OS was 22.0 months [95% confidence interval (CI): 15.1-28.9], with the 1-, 3-, and 5-year OS rates being 83.7% (95% CI: 
75.8-91.6%), 51.0% (95% CI: 41.1-60.9%), and 33.3% (95% CI: 14.1-52.4%), respectively. The median PFS was 12.5 months (95% CI: 8.3-16.7), and the 1-year PFS rate was 61.2% (95% CI: 36.5-85.9%). The technical success, technical efficacy, and major complication rates were 100% (95% CI: 99.5-100%), 99% (95% CI: 92.1-100%), and 2.8% (95% CI: 1.1-5.2%), respectively. A cancer antigen 19-9 (CA 19-9) level >37 U/mL was associated with a shorter OS (HR =1.4; 95% CI: 1.2-1.7; P=0.001).

Conclusions: MWA is a safe and effective alternative to chemotherapy, radiotherapy, and radiofrequency ablation (RFA) treatments, especially for patients with a CA 19-9 level ≤37 U/mL, and potentially has advantages over RFA. However, further studies are required to validate these findings.

Background: It is well known that dysfunction of thalamocortical circuity generates the motor signs that lead to distinct disease processes and prognoses in Parkinson's disease (PD). This study aimed to leverage ultrahigh-field magnetic resonance imaging (MRI) to identify the connectivity alterations of thalamocortical circuity and clarify their relation to motor signs in early PD.

Methods: Patients with early-stage PD (n=55) and healthy controls (HCs, n=56) were recruited from March 2022 to July 2023. All participants underwent 7-Tesla MRI scans as the baseline. Sign scores were calculated from the Movement Disorder Society Unified Parkinson's Disease Rating Scale III. Significant differences in the functional connectivity between the thalamus subregions and cortex between the PD and HC groups were discovered. The association between altered thalamic functional connectivity and sign scores was evaluated using Spearman or Pearson correlation analysis with false discovery rate (FDR) correction.

Results: Compared to the HCs, the patients with early-stage PD exhibited a decreased functional connectivity between thalamic subregions (primary motor, sensory, occipital, premotor, and parietal thalamus regions) and the cortex [voxel-level P<0.001, cluster-level P_{family-wise error (FWE)} <0.05]. Further exploration of the connection pattern within thalamic subregions showed that the connection strength between the primary motor and sensory (t=2.055; P=0.042), sensory and occipital (t=2.173; P=0.032), and occipital and parietal (t=2.365; P=0.020) regions were reduced. Importantly, motor signs in early-stage PD were associated with the alterations of functional connectivity pattern between the parietal thalamus and left dorsolateral part of the superior frontal gyrus (r=-0.272; P_FDR =0.049) and the right thalamus (r=-0.267; P_FDR =0.048) .

Conclusions: These findings support the use of ultrahigh-field MRI for examining the thalamic subregions and clarifying their involvement in the neural mechanisms of various motor signs in early-stage PD.

Background: Dynamic chest radiography (DCR) is useful for detecting preoperative pleural adhesions, predicting operation time and blood loss, and determining the surgical approach. However, since DCR evaluations are subjective, an objective index was needed. Therefore, we focused on the low motion area (LMA) ratio derived from the objective data obtained through DCR. The purpose of this study was to examine the relationship between the LMA ratio and pleural adhesions, as well as to evaluate its cutoff values, detectability, and overall utility.

Methods: The study encompassed patients who received DCR prior to thoracic surgery from January 2020 to December 2023. The LMA ratio was calculated using an analysis workstation for DCR. Pleural adhesions were defined as adhesions extending to >20% of the thoracic cavity and/or taking >5 min to dissect. The relationship between the presence of pleural adhesions and the LMA ratio was analyzed retrospectively.

Results: A total of 338 patients were analyzed, of whom 65 had pleural adhesions. The median LMA ratio for patients with adhesions was 56.0%, while that of patients without adhesions was 41.5%, which amounted to a significant difference (P<0.001). This was also true in the group of patients with pulmonary comorbidities (56.0% vs. 41.0%, P<0.001). When the analysis was limited to the group of patients with a large lung field change rate (>28.2%; n=169), the power of detection using the LMA ratio improved [52.0% vs. 36.9%, area under the curve (AUC) =0.748]. When the two groups were further divided according to the extent of adhesion, the LMA ratio was significantly higher for extensive adhesions (49.8% in grade 1, the narrow adhesion, and 66.1% in grades 2-4, the extensive adhesion).

Conclusions: The LMA ratio is a useful objective index for detecting pleural adhesions. Adding the cutoff value of the LMA ratio (approximately 50%) to the conventional criteria may allow for a more reproducible preoperative assessment.

Background: Brain temperature signifies the thermal homeostasis of the tissue, and may serve as a marker for neuroprotective therapy. Currently, it remains challenging to map the human brain temperature with high spatial resolution. The thermal dependence of chemical exchange saturation transfer (CEST) effects of endogenous labile protons may provide a promising mechanism for the absolute brain temperature imaging. In this study, we aimed to investigate the temperature dependency of the CEST effect of creatine (CrCEST), and contemplate its feasibility for brain temperature mapping.

Methods: Creatine (Cr) was selected as the endogenous agent to probe the brain temperature. Proof-of-concept phantom experiments were first conducted using a 400 MHz nuclear magnetic resonance (NMR) spectrometer and a 5.0 T magnetic resonance (MR) scanner at various temperatures. A multi-pool Lorentzian fitting model was utilized to quantify the apparent chemical shift, amplitude, linewidth, and integral of CrCEST peak at around 2 ppm. Regression analysis was performed to estimate the thermal response of these CrCEST parameters. Finally, the temperature mapping of ex vivo swine brain tissues was conducted based on the CEST signal at 2 ppm (CEST@2ppm).

Results: A robust linear correlation between the apparent chemical shift of CrCEST and temperature was identified in the in vitro phantom experiments (+0.005 ppm/℃, P<0.001), based on which temperature maps of phantoms were generated. In the subsequent experiments on ex vivo swine brain tissue, a comparable temperature dependency of the apparent chemical shift of CEST@2ppm peak was found (+0.008 ppm/℃), confirming the utility of this approach for mapping brain temperature.

Conclusions: The CEST-based approach proposed in this study suggests a path toward label-free brain thermometry in vivo at high resolution and may be potentially applied in other tissues such as muscle and kidney.