ACTA Radiologica (Test)

Acta Radiologica, Ahead of Print. <br/>BackgroundPatellar instability (PI) or patellar dislocation (PD) is challenging to diagnose accurately based on medical history and clinical manifestations alone. While X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) are commonly employed for detecting PI or PD, computer vision has not yet been widely utilized for this purpose.PurposeTo explore the feasibility of computer vision, specifically the You Only Look Once (YOLO) algorithm, in identifying patellar instability or dislocation.Material and MethodsA total of 550 patients (190 diagnosed with patellar instability or dislocation) were divided into a training set (n = 360), validation set (n = 90), and external test set (n = 100). Four indicators were measured on transverse knee MRI scans to determine the presence of patellar instability, and 450 images were labeled using Labelme software. YOLO version 8 (YOLOv8) was refined using these labeled images and validated on 100 unlabeled images. The diagnostic accuracy of YOLOv8 was compared with that of a junior radiologist.ResultsThe sensitivity, specificity, and accuracy of the refined YOLO model and the junior radiologist were 62%, 97%, and 83%, and 62%, 82%, and 74%, respectively. Although the YOLO model demonstrated slightly higher accuracy, the difference did not reach statistical significance (P = 0.093). The YOLO model required approximately 14.01 ± 10.34 ms to interpret each image, significantly shorter than the 9.55 ± 2.39 s required by the radiologist (P < 0.001).ConclusionThe refined YOLOv8 model is not inferior to junior radiologists in identifying patellar instability or dislocation and offers a significantly faster interpretation time.

Acta Radiologica, Ahead of Print. <br/>BackgroundCongenital coronary artery to pulmonary artery fistulas (CPAFs) are extremely rare congenital vascular malformations.PurposeTo give a practical approach and consider technical challenges and pitfalls for endovascular embolization of CPAF.Material and MethodsAnatomic, technical, and pathophysiologic considerations are given and demonstrated for antegrade and retrograde endovascular embolization of CPAF.ResultsAntegrade embolization is easier to perform, saves radiation exposure, and is recommended especially in younger patients. In case of a single dominant feeder, antegrade embolization of this feeder might sufficiently treat the CPAF. Retrograde embolization from the pulmonary orifice is technically more challenging but leads to a complete and definite closure of the fistula in one single step.ConclusionPatient age and fistula configuration must be taken into consideration for appropriate treatment approach in CPAF. Prerequisite for successful embolization of CPAF is profound clinical and interventional experience, why we highly recommend to both plan and carry out embolization of CPAF as interdisciplinary procedure.

Acta Radiologica, Ahead of Print. <br/>Background68Ga-labled fibroblast activating protein inhibitor (68Ga-FAPI) represents a new and exciting positron emission tomography-computed tomography/magnetic resonance (PET-CT/MR) radiotracer.PurposeTo compare the diagnostic efficacy of 68Ga-FAPI PET CT/MR and 18F-fluorodeoxyglucose (18F-FDG) PET/CT in metastatic lesions of gynecological cancers (GCs).Material and MethodsThe PubMed, Embase, and Web of Science databases were thoroughly investigated from inception until 22 December 2023. A head-to-head contrast between 18F-FDG PET/CT as well as 68Ga-FAPI PET CT/MR for the assessment of GCs was presented by the included studies. A random variable model was employed to examine the sensitivity in detection of lymph node (LN) and peritoneal metastases (PM).ResultsThe pooled sensitivity for 68Ga-FAPI PET CT/MR and 18F-FDG PET/CT in lymph node metastases (LNM) of GC were 0.98 (95% confidence interval [CI] = 0.86–1) and 0.85 (95% CI = 0.65–0.98), respectively, while the results about peritoneal metastases in ovarian cancer were 0.98 (95% CI = 0.93–1) and 0.71 (95% CI = 0.55–0.86). Compared with 18F-FDG PET/CT, 68Ga-FAPI PET CT/MR exhibited a better sensitivity in peritoneal involvement of ovarian cancer with a relative risk of 0.24 (95% CI = 0.09–0.40) and P = 0.002.Conclusion68Ga-FAPI PET CT/MR displayed a superior sensitivity over 18F-FDG PET/CT in detecting metastatic lesions of ovarian cancer. However, there was insufficient evidence to favor the superiority of 68Ga-FAPI PET CT/MR in LNM of CC. Further studies are needed for evaluating primary and metastatic lesions of 68Ga-FAPI PET CT/MR in different GC.

Acta Radiologica, Ahead of Print. <br/>BackgroundRadiofrequency ablation (RFA) of subphrenic hepatocellular carcinomas (HCCs) using ultrasound (US) guidance presents a challenge.PurposeTo 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 MethodsWe 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.ResultsA 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).ConclusionUS-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.

Acta Radiologica, Ahead of Print. <br/>BackgroundIndividually tailored contrast medium (CM) may improve vascular image quality in chest computed tomography (CT).PurposeTo 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 MethodsPatients 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).ResultsOf 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).ConclusionFixed-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.

Acta Radiologica, Ahead of Print. <br/>BackgroundThis study utilized quantitative susceptibility mapping (QSM) to evaluate magnetic susceptibility of brain nuclei in Parkinson's disease (PD).PurposeTo explore iron deposition patterns in PD and ascertain if these patterns can distinguish between motor subtypes.Material and MethodsThis 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.ResultsNotable 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.ConclusionPathologic 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.

Acta Radiologica, Ahead of Print. <br/>BackgroundThe association of Mini-Mental State Examination (MMSE) with microstructure of individual regions across the entire brain remains unexplored.PurposeTo 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 MethodsDKI 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.ResultsThe 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.ConclusionOlder 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.

Acta Radiologica, Ahead of Print. <br/>BackgroundThe depth of myometrial invasion determines whether International Federation of Gynecology and Obstetrics stage I endometrioid endometrial carcinoma (EEC) patients undergo lymph node dissection. However, subjective evaluation results relying on magnetic resonance imaging (MRI) are not always satisfactory.PurposeTo develop a nomogram based on whole-volume tumor MRI histogram parameters to preoperatively predict deep myometrial invasion (DMI) in patients with stage I EEC.Material and MethodsThis retrospective analysis included 131 EEC patients and a training/validation cohort of 92/39 patients at a 7:3 ratio. The histogram parameters were obtained from multiple sequences (ADC mapping and T2-weighted imaging) within volumes of interest. Univariate analysis, least absolute shrinkage and selection operator (LASSO) regression, and multivariate logistic regression were used for feature selection. The performance of clinical model, histogram model, and histogram nomogram was evaluated by calculating the area under the receiver operating characteristic curve (AUC).ResultsAge and two morphological features (maximum anteroposterior tumor diameter on sagittal T2-weighted images [APsag] and the tumor area ratio [TAR]) were selected to construct the clinical model. Five histogram parameters were selected for the creation of the histogram model. The nomogram, which combines the histogram parameters, age, APsag, and TAR, achieved the highest AUCs in both the training and validation cohorts (nomogram vs. histogram vs. clinical model: 0.973 vs. 0.871 vs. 0.934 [training] and 0.972 vs. 0.870 vs. 0.928 [validation]).ConclusionThe MR histogram nomogram can help predict the DMI of patients with stage I EEC preoperatively, assisting physicians in the development of personalized treatment strategies.

Acta Radiologica, Ahead of Print. <br/>BackgroundIntravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), which indicates biological tissue attributes, may be applied to accurately assess breast tumors.PurposeTo analyze the IVIM parameters of different molecular prognostic factors and subtypes to find out whether there are any connections.Material and MethodsA total of 181 patients enrolled in this retrospective study had preoperative magnetic resonance imaging (MRI) examinations, and pathologies were verified as breast cancers. Regions of interest were placed at all slices of the parameter maps (D, tissue diffusivity; ADC, apparent diffusion coefficient; f, perfusion fraction; and D*, pseudo-diffusivity maps) of IVIM and generated parameter values to be used for comparative analysis among molecular prognostic factors and subtypes.ResultsD and ADC were greater in estrogen receptor (ER)-negative, human epidermal growth factor receptor 2 (HER2)-positive, and Ki67-low expression groups (all P values < 0.05). The progesterone receptor (PR)-negative group had a higher D value (P < 0.05). f was larger in the lymph node metastasis-negative group and the PR-positive group (P = 0.012 and 0.046, respectively). Among breast cancer subtypes, D and ADC were different between the HER2-overexpression and the Luminal B (HER2-negative) subtypes (P = 0.019 and 0.028, respectively). The difference in D between the luminal and non-luminal subtypes was statistically significant (P = 0.008). The triple-negative subtype significantly differs from the other subtypes in D* and f (P = 0.012 and 0.016, respectively).ConclusionIVIM-related metrics exhibited relationships with breast cancer molecular prognosis factors and subtypes.

Acta Radiologica, Ahead of Print. <br/>BackgroundPercutaneous ultrasound-guided thrombin injection has become the gold standard treatment for pseudoaneurysms caused by cardiac catheterization. However, failure can occur in up to 25% of the procedures and little is known about its causes.PurposeTo study the efficacy and safety of the technique and to determine possible risk factors responsible for the unsuccess.Material and MethodsA cohort study was carried out based on data from medical records collected between December 2012 and June 2020 of 110 patients with the diagnosis of pseudoaneurysm, femoral or radial, secondary to cardiac catheterization. Clinical data, pseudoaneurysm morphological parameters, and technical factors related to catheterization were reviewed.ResultsPrimary and global technical success rates were 85.5% and 100%, respectively. Age, neck, and anteroposterior diameter variables were predictors of primary failure on multivariate analysis. The odds ratio (OR) for age was 0.960 (95% confidence interval [CI]=0.927–0.995; P = 0.025), for anteroposterior diameter, OR was 2.023 (95% CI=1.144–3.578; P = 0.015), and for neck diameter, it was 4.625 (95% CI=1.023–20.904; P = 0.047). The receiver operating characteristic (ROC) curve was performed for the multivariate analysis model and the three predictors of failure. The area under the curve for the multivariate analysis model was 0.695, for age it was 0.675, for anteroposterior diameter it was 0.679, and for neck diameter it was 0.676. No complications were observed.ConclusionsPercutaneous ultrasound-guided thrombin injection is safe and effective for the treatment of pseudoaneurysms after cardiac catheterization. Largest anteroposterior diameter, largest neck diameter, and a younger age were independent predictors of primary failure with the technique.