Acta radiologica最新文献

Background: This study utilized quantitative susceptibility mapping (QSM) to evaluate magnetic susceptibility of brain nuclei in Parkinson's disease (PD).

Purpose: To explore iron deposition patterns in PD and ascertain if these patterns can distinguish between motor subtypes.

Material and methods: This study enrolled 30 healthy controls and 34 patients with PD categorized mainly into postural instability and gait disorder (PIGD) (n = 12) and tremor dominance (TD) (n = 16). A total of 18 regions of interest were delineated, and a comprehensive classification of nuclei was conducted, including the differentiation of globus pallidus (GP) into its external (GPe) and internal (GPi) segments. All participants underwent brain magnetic resonance imaging.

Results: Notable differences in magnetic susceptibility were identified in bilateral substantia nigra pars reticulate (SNr) and substantia nigra pars compacta (SNc) between PD and HC. Significant differences in QSM values of bilateral GPe, SNr, and SNc-R were found between TD and PIGD. The susceptibility values of bilateral putamen (PUT) were positively correlated with MDS-UPDRSIII score and Hoehn-Yahr scale in PD. QSM values of bilateral PUT and SNc-L showed associations with MDS-UPDRSIII score in TD. QSM values showed associations with MDS-UPDRSIII in bilateral PUT and Hoehn-Yahr scale in PUT-L and TH-L in PIGD.

Conclusion: Pathologic iron deposition exhibits variability across nuclei of PD, with age also influencing this distribution. SN may be meaningful in identifying different subtypes of PD, such as differentiating PD from HC in the future.

Background: Giving contrast material before ¹H-magnetic resonance spectroscopy (MRS) could enhance the precision of locating the lesion of interest. However, evidence indicates that contrast material might influence the outcomes of MRS.

Purpose: To verify the effect of gadolinium-based contrast agent (GBCA) on MRS in normal white matter.

Material and methods: A total of 34 patients were referred for brain magnetic resonance imaging (MRI) with GBCAs, and they underwent single-volume MRS before and after administering contrast material. Those patients had the MRS voxel placed at the right frontal normal white matter, which remained consistent across all examinations. Measurements were taken for the integral concerning N-acetyl aspartate (NAA), choline (Cho), creatine (Cr and Cr2), and myo-inositol (Ins) in all examinations.

Results: NAA (P = 0.0313) and Cho (P = 0.0094) had a significant decrease in their integral after intravenous GBCA administration. No significant differences were found between the pre- and post-contrast MRS studies for Cr, Cr2, and Ins.

Conclusion: Intravenous GBCA can alter NAA and Cho integrals in normal white matter. Therefore, brain ¹H-MRS should precede intravenous GBCA administration to avoid the potential impact of contrast material on peak integrals.

Background: Triple rule-out computed tomography angiography (CTA) provides imaging of the coronary arteries, pulmonary arteries, and thoracic aorta filled with contrast material (CM) to exclude or diagnose the pathologies of these three systems. Although dual rule-out adapted to exclude aortic and pulmonary pathologies. Iodinated CM may result in contrast-induced nephropathy, which lengthens hospital stay.

Purpose: To compare image quality of dual/triple rule-out CTA by reducing the radiation dose by using relatively high mAs with less contrast material and low kilovoltage without affecting the diagnostic value.

Methods: We acquired standard dual/triple rule-out CTA 120 kilovoltage peak (kVp) with 95 mL contrast material. The low-dose group acquired 80 Kvp with total 60 contrast material. There were 91 patients in the standard-dose group and 88 patients in the low-dose group.

Results: Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated separately. There was no significant difference in CNR values between the two groups in the aorta and pulmonary and coronary arteries; however, a significant difference was found in SNR values. In subjective image quality evaluation, no significant difference was found between the standard- and low-dose patients. The radiation dose was reduced by 63.80% and the contrast material by 31.5% in the low-dose group in comparison to the standard dose.

Conclusion: Our study showed that dual/triple rule-out CTA can be performed with low-dose radiation and low-volume contrast material. Low-dose CTA may be preferred in emergencies situations that patients with borderline renal function tests or the risk group.

Background: Radiomics and deep learning (DL) can individually and efficiently identify the pathological type of brain metastases (BMs).

Purpose: To investigate the feasibility of utilizing multi-parametric MRI-based deep transfer learning radiomics (DTLR) for the classification of lung adenocarcinoma (LUAD) and non-LUAD BMs.

Material and methods: A retrospective analysis was performed on 342 patients with 1389 BMs. These instances were randomly assigned to a training set of 273 (1179 BMs) and a testing set of 69 (210 BMs) in an 8:2 ratio. Eight machine learning algorithms were employed to construct the radiomics models. A DL model was developed using four pre-trained convolutional neural networks (CNNs). The DTLR model was formulated by integrating the optimal performing radiomics model and the DL model using a classification probability averaging approach. The area under the curve (AUC), calibration curve, and decision curve analysis (DCA) were utilized to assess the performance and clinical utility of the models.

Results: The AUC for the optimal radiomics and DL model in the testing set were 0.824 (95% confidence interval [CI]= 0.726-0.923) and 0.775 (95% CI=0.666-0.884), respectively. The DTLR model demonstrated superior discriminatory power, achieving an AUC of 0.880 (95% CI=0.803-0.957). In addition, the DTLR model exhibited good consistency between actual and predicted probabilities based on the calibration curve and DCA analysis, indicating its significant clinical value.

Conclusion: Our study's DTLR model demonstrated high diagnostic accuracy in distinguishing LUAD from non-LUAD BMs. This method shows potential for the non-invasive identification of the histological subtype of BMs.

Background: In this prospective study, we evaluated whether a sufficient number of glomeruli were achieved using the 8× magnification of smartphone cameras.

Purpose: To increase the percutaneous ultrasound-guided renal biopsy (PURB) diagnostic value with a method that has not been tried before and reduce the need for repetition of the procedure.

Material and methods: A total of 39 adult patients who underwent PURB were included in our study. After the PURB was applied to the patients, the biopsy specimen was placed on the previously prepared sterile gauze. At this stage, 8× magnification photos were taken of the biopsy samples using the smartphone camera. The glomeruli in the photograph were counted and recorded and compared with the number of glomeruli seen at the end of the histopathological examination.

Results: The mean number of glomeruli in the evaluated samples was counted as 6 ± 2.2 (range = 1-10) in the 8× magnification photograph. The mean number of glomeruli detected in the histopathological examination of these samples was 11 ± 5.7 (range = 2-30). A pathological glomeruli count of 10 was associated with more than five brown spots in the 8× magnification photograph (area under the curve = 0.977, P=0.0001).

Conclusion: To obtain more than 10 glomeruli in a PURB specimen, five or more brownish-red dots should be counted on the 8x magnification photograph. Using smartphones as an alternative tool for evaluating renal biopsy tissue adequacy can be practical and advantageous in terms of time and labor.

Background: The association of Mini-Mental State Examination (MMSE) with microstructure of individual regions across the entire brain remains unexplored.

Purpose: To investigate the relationship between cognitive function and the microstructure of each brain region in the gray matter using diffusion kurtosis imaging (DKI) in older adults with mild cognitive impairment (MCI), which is the transitional stage before the onset of dementia.

Material and methods: DKI and MMSE were obtained for 34 older adults with MCI and 16 cognitively normal (CN) individuals aged 65-85 years. The DKI parameters were measured from 31 distinct regions of interest in the gray matter. A multiple regression analysis was used to examine the association between DKI parameters and MMSE scores; subsequently, interactions between the DKI parameters and the groups (MCI and CN) were examined.

Results: The mean (±SD) MMSE score for the MCI group was 27.67 ± 1.90. Significant positive correlations were observed between MMSE score and mean kurtosis (MK) in the superior frontal, middle frontal, inferior frontal, precentral, postcentral, angular, middle temporal, and inferior occipital gyri, and superior parietal lobe for the MCI group. In addition, the interaction term of the MK in the middle frontal, precentral, postcentral, and angular gyri, and the groups was statistically significant.

Conclusion: Older adults with MCI may exhibit histological damage in certain regions of the brain, such as the middle frontal and angular gyri, as observed in this study. The findings could provide insights into understanding the pathophysiology of cognitive decline in this population group.

Background: Radiofrequency ablation (RFA) of subphrenic hepatocellular carcinomas (HCCs) using ultrasound (US) guidance presents a challenge.

Purpose: To evaluate local tumor progression (LTP) and overall survival (OS) after RFA of right posterior subphrenic HCCs, and to identify the risk factors for LTP and OS after RFA.

Material and methods: We screened patients who underwent US-guided RFA for a single HCC <3 cm in the right posterior subphrenic area. Cumulative rates of LTP and OS were compared between multiple- and single-electrode treatments and artificial pleural effusion versus no-effusion groups using Kaplan-Meier curves and the log-rank test. The risk factors for LTP and OS were assessed.

Results: A total of 36 patients were included. The cumulative 5-year and 10-year LTP rates were 32.9% and 39.6%, respectively, and the corresponding OS rates were 72.2% and 48.7%, respectively. The multiple-electrode group had significantly lower cumulative LTP rates compared to the single-electrode group (P < 0.001). The group receiving artificial pleural effusion showed a trend towards lower LTP rates than the no-effusion group (P = 0.076). The albumin-bilirubin (ALBI) grade was the only risk factor for LTP (hazard ratio [HR] = 4.17, 95% confidence interval [CI] = 1.26-14.55; P = 0.020). A lower albumin level was a risk factor for mortality (HR = 0.24, 95% CI = 0.07-0.79; P = 0.020).

Conclusion: US-guided RFA with multiple electrodes and artificial pleural effusion tends to be linked with lower LTP rates. The ALBI grade and serum albumin level are risk factors for LTP and OS, respectively.

Background: Individually tailored contrast medium (CM) may improve vascular image quality in chest computed tomography (CT).

Purpose: To evaluate vascular attenuation in chest CT by comparing CM dose calculations using lean body mass (LBM) and body surface area (BSA) with a fixed-dose protocol.

Material and methods: Patients referred for contrast-enhanced chest CT were categorized as either normal, muscular, or overweight. Patients were accordingly randomized into three CM dosing protocols: fixed-dose group (n = 87), LBM group (n = 92), and BSA group (n = 93).

Results: Of the patients, 94% in the fixed-dose group, 99% in the LBM group, and 98% in the BSA group achieved optimal vascular attenuation. In the overweight category, lower attenuation was demonstrated in the fixed-dose group compared to the LBM group (P = 0.032) and the BSA group (P = 0.010). In the fixed-dose group, vascular attenuation showed a negative correlation with total body weight for all body composition categories. In the LBM group, a positive correlation was observed between attenuation and total body weight in the muscular category (P = 0.041), while a negative correlation was noted for the overweight category in the BSA group (P = 0.049).

Conclusion: Fixed-dose CM protocol exhibited larger variations in vascular attenuation between patients of various body weights and body compositions compared to tailored CM doses based on LBM and BSA.

Background: Pelvic floor dysfunction (PVD), a prevalent clinical issue impacting quality of life, can be effectively assessed using magnetic resonance defecography (MRD) with the patient either supine or in the lateral decubitus position.

Purpose: To compare the measurement value and grading in dynamic MRD within the closed-magnet system of PFD patients performed in supine versus lateral decubitus position using the H line, M line, and organ prolapse (HMO) classification system.

Material and methods: During 2017-2019, 100 patients with PFD underwent MRD during defecation in both supine and lateral decubitus positions. MR images were measured and graded by two blinded radiologists. The mean value of each HMO parameter and grading severity were compared between supine and lateral positions. Image quality (IQ) between two positions was also evaluated. Paired t-test and Wilcoxon ranked test were performed for significant difference. P < 0.05 was considered statistically significant.

Results: For HMO measurement, M-line, levator plate angle (LPA), urethral hypermobility (UH), uterine prolapse, and peritoneocele had significantly higher mean values when measured in the lateral decubitus position than in the supine position. For grading, M-line, uterine prolapse, and peritoneocele also had more grading severity in the lateral decubitus than supine position with statistical significance (P = 0.002, 0.004, and 0.001, respectively). Only anterior rectocele had a mean value and grading severity in the supine more than the lateral position (P = 0.003 and P = 0.005). IQ in the supine was better than in the lateral decubitus position (P < 0.001).

Conclusion: MRD in lateral decubitus showed a more severe degree of PFD in most parameters based on the HMO grading system irrespective of inferior imaging quality.

Background: The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a semi-quantitative tool for evaluating the extent and distribution of early ischemic changes.

Purpose: To assess the value of ASPECTS on non-contrast CT (NCCT), arterial-phase CT (APCT), or venous-phase CT (VPCT) in predicting the final infarct core (IC) on follow-up diffusion-weighted imaging (DWI) and the clinical outcomes of patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT).

Material and methods: In total, 120 patients with AIS who underwent EVT in our center were retrospectively enrolled. Correlations between CT-ASPECTS and follow-up DWI-ASPECTS were analyzed using Spearman's rank correlation coefficient. Mean differences and limit of agreement (LoA) between CT-ASPECTS and follow-up DWI-ASPECTS were assessed using the Bland-Altman plots. Multivariate logistic regression and receiver operating characteristic curve analyses were used to identify independent factors and evaluate their performances in predicting the clinical outcomes.

Results: VPCT-ASPECTS exhibited the highest correlation with follow-up DWI-ASPECTS (r = 0.846, P < 0.001), followed by APCT-ASPECTS (r = 0.613, P < 0.001) and NCCT-ASPECTS (r = 0.557, P < 0.001). The mean difference between VPCT-ASPECTS and follow-up DWI-ASPECTS was 0.0 (limit of agreement = -2.1 to 2.1). National Institute of Health Stroke Scale (NIHSS) scores at admission (NIHSS_pre) (odds ratio [OR]=1.162, 95% confidence interval [CI]=1.063-1.270; P = 0.001) and VPCT-ASPECTS (OR=0.728, 95% CI=0.535-0.991; P = 0.044) were the independent factors associated with clinical outcomes. The combined model integrating NIHSS_pre and VPCT-ASPECTS exhibited an excellent performance in predicting good clinical outcomes (area under curve [AUC]=0.807; sensitivity=75.0%; specificity=72.3%).

Conclusion: VPCT-ASPECTS may be a promising imaging biomarker to predict the final IC and the clinical outcome of the patients with AIS after EVT.