Acta radiologica最新文献

Background: Bone marrow lesions (BMLs) in knee osteoarthritis (OA) have been assessed histopathologically and by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI); however, a direct comparison of the results has not been reported.

Purpose: To evaluate and compare the findings by DCE-MRI and histopathology of subchondral BMLs in knee OA.

Material and methods: In total, 19 patients with medial tibiofemoral knee OA undergoing total knee arthroplasty were analyzed. Preoperative MRI, including a DCE sequence, was performed, and bone biopsies were obtained from the resected specimens corresponding to BML areas. The contrast enhancement by DCE-MRI was analyzed using semi-quantitative (area under the curve [AUC]), peak enhancement [PE]), and quantitative (Ktrans, Kep) methods. Enhancement in the medial OA compartment was compared with similar areas in a normal lateral compartment, and the DCE characteristics of BMLs were correlated with semi-quantitatively graded histopathological features.

Results: AUC and PE were significantly higher in medial tibial and femoral BMLs compared with the values in the lateral condyles; Ktrans and Kep were only significantly higher in the tibial plateau. In the tibia, AUC and PE were significantly correlated with the grade of vascular proliferation, and PE also with the degree of marrow fibrosis. There was no significant correlation between AUC/PE and histopathological findings in the femur and no correlation between quantitative DCE parameters and histopathological findings.

Conclusion: BML characteristics by semi-quantitative DCE in the form of AUC and PE may be used as parameters for the degree of histopathological vascularization in the bone marrow whereas quantitative DCE data were less conclusive.

Background: Post-treatment evaluation of patients with rectal cancer (RC) using magnetic resonance imaging (MRI) burdens medical resources, necessitating an exploration of abbreviated protocols.

Purpose: To evaluate the diagnostic performance of abbreviated MRI (A-MRI) for the post-treatment evaluation of RC patients.

Material and methods: This retrospective study included RC patients who underwent non-contrast rectal MRI and standard liver MRI, as well as abdominal contrast-enhanced computed tomography (CECT) for post-treatment evaluation. A-MRI comprised diffusion-weighted imaging (DWI) and T2-weighted imaging of the upper abdomen and the pelvic cavity. Three radiologists independently reviewed A-MRI, CECT, and standard liver MRI in the detection of viable disease. The diagnostic performances were compared using a reference standard considering all available information, including pathology, FDG-PET, endoscopic results, and clinical follow-up.

Results: We included 78 patients (50 men, 28 women; mean age=60.9 ± 10.2 years) and observed viable disease in 34 (43.6%). On a per-patient-basis analysis, A-MRI showed significantly higher sensitivity (95% vs. 81%, P = 0.04) and higher accuracy (93% vs. 82%, P < 0.01), compared to those of CECT, while A-MRI showed comparable sensitivity (91% vs. 91%, P = 0.42) and accuracy (97% vs. 98%, P = 0.06) to that of standard liver MRI. On a per-lesion-based analysis, A-MRI exhibited significantly superior lesion detectability than that of CECT (figure of merit 0.91 vs. 0.77, P < 0.01) and comparable to that of standard liver MRI (figure of merit 0.91 vs. 0.92, P = 0.75).

Conclusion: A-MRI exhibited higher sensitivity and diagnostic accuracy than those of CECT in the post-treatment evaluation of RC, while it showed comparable performances with standard liver MRI. A-MRI provides diagnostic added value in the follow-up of RC patients.

Background: Focal liver lesions (FLLs) are a common form of liver disease, and identifying accurate pathological types is required to guide treatment and evaluate prognosis.

Purpose: To compare and analyze the application effect of contrast-enhanced ultrasound (CEUS) and conventional ultrasound (US) in the clinical diagnosis of focal liver lesions.

Material and methods: A retrospective analysis was performed on 682 patients with space-occupying liver lesions admitted to our hospital between December 2015 and August 2021. Of these, 280 underwent CEUS-guided biopsies and 402 underwent conventional US biopsies, with the results of each biopsy subsequently compared between the two groups. The success rate and accuracy of the biopsies and their relationship with different pathological features were also analyzed.

Results: The success rate, sensitivity, diagnostic accuracy, positive predictive value, and negative predictive value of the CEUS group were significantly higher than those of the US group (P < 0.05). Lesion size accuracy in the CEUS group was significantly higher than that in the US group (89.29% vs. 40.55%; P < 0.05). Lesion type accuracy in the CEUS group was significantly higher than that in the US group (86.49% vs. 43.59%), and the difference between the two groups was statistically significant (P < 0.05). The logistic regression analysis indicated that malignant lesions, lesions ≥5 cm, and lesions ≤1 cm were independent factors affecting the success rate of the puncture procedure (P < 0.05).

Conclusion: The sensitivity, specificity, and diagnostic accuracy of lesion size and type in the CEUS group were higher than those in the US group.

Background: Hypertension and cerebral amyloid angiopathy are the most common causes of spontaneous intracerebral hemorrhage (ICH); however, these conditions do not imply macrovascular pathology. Still, computed tomography (CT) angiography (CTA) is often performed in the acute phase in patients with ICH.

Purpose: To assess the diagnostic yield of CTA in the detection of secondary etiology in consecutive patients with spontaneous ICH.

Material and methods: We performed a retrospective analysis of data from a prospective single-center cohort study of 203 patients presenting with spontaneous ICH admitted to a comprehensive stroke center over a two-year period (15 October 2016 to 15 October 2018). The underlying vascular pathology was assessed using CTA.

Results: CTA was performed in addition to non-contrast CT and/or magnetic resonance imaging (MRI). Vascular pathology was found in 11 of 203 (5.4%) patients and included arteriovenous malformations (n=4), aneurysms (n=4), vasospasms (n=1), cerebral venous thrombosis (n=1), and other vascular malformations (n=1). In eight cases, the finding was deemed symptomatic. Patients with vascular pathology on CTA more often had lobar located hemorrhages (63.6% vs. 36.4%, P = 0.049). Numerically, patients with vascular pathology were younger, had smaller hematoma volumes, and lower mortality.

Conclusion: Underlying macrovascular pathology was detected on CTA in only approximately 1 of 20 consecutive patients with ICH. The patients with vascular pathology more often had a hemorrhage with a lobar location and young age and the present study is supportive of a risk-based stratification approach in performing CTA.

Background: Parameters from diffusion-weighted imaging (DWI) have been increasingly used as imaging biomarkers for the diagnosis and monitoring of treatment responses in cancer. The consistency of DWI measurements across different centers remains uncertain, which limits the widespread use of quantitative DWI in clinical settings.

Purpose: To investigate the consistency of quantitative metrics derived from DWI between different scanners in a multicenter clinical setting.

Material and methods: A total of 193 patients with cervical cancer from four scanners (MRI1, MRI2, MRI3, and MRI4) at three centers were included in this retrospective study. DWI data were processed using the mono-exponential and intravoxel incoherent motion (IVIM) model, yielding the following parameters: apparent diffusion coefficient (ADC); true diffusion coefficient (D); pseudo-diffusion coefficient (D*); perfusion fraction (f); and the product of f and D* (fD*). Various parameters of cervical cancer obtained from different scanners were compared.

Results: The parameters D and ADC derived from MRI1 and MRI2 were significantly different from those derived from MRI3 or MRI4 (P <0.01 for all comparisons). However, there was no significant difference in cervical cancer perfusion parameters (D* and fD*) between the different scanners (P >0.05). The P values of comparisons of all DWI parameters (D, D*, fD*, and ADC) between MRI3 and MRI4 (same vendor in different centers) for cervical cancer were all >0.05, except for f (P = 0.05).

Conclusion: Scanners of the same model by the same vendor can yield close measurements of the ADC and IVIM parameters. The perfusion parameters showed higher consistency among the different scanners.

Background: Preoperative effective assessment of cervical lymph node metastasis in thyroid cancer plays an important role in formulating the surgical plan.

Purpose: To investigate the significance of synthetic magnetic resonance imaging (MRI) for quantitatively analyzing cervical lymph node metastasis in thyroid cancer.

Material and methods: A retrospective analysis was conducted on 30 patients with thyroid cancer, consisting of 19 thyroid cancer nodules, 45 metastatic lymph nodes, and 47 non-metastatic lymph nodes. Regions of interest (ROIs) for each type of nodule were manually delineated using a workstation. Quantitative parameters, such as T1, T2, and proton density (PD) values, were automatically extracted from synthetic MRI scans. Statistical tests and regression analysis were performed to assess differences and correlations among the quantitative parameters.

Results: There were no significant differences in the quantitative parameter values between the primary tumor and metastatic lymph node tissues (P > 0.05). However, significant differences were observed in the quantitative parameters between the primary tumor and non-metastatic lymph node tissues and between the metastatic and non-metastatic lymph node tissues (P < 0.05). The diagnostic accuracy for cervical lymph node metastasis in thyroid cancer was 94.4% for the T1 and T2 combined index, 91.9% for T₂, 86.8% for T1, and 71.7% for PD values.

Conclusion: The application of quantitative parameters from synthetic MRI can assist clinicians in accurately planning surgical interventions for thyroid cancer patients before surgery.

Background: The use of dual-energy X-ray absorptiometry (DEXA) and quantitative computed tomography (QCT) methods are important for the diagnosis and follow-up of osteoporosis, and are used especially in cases to determine the degree of osteoporosis and the risk of fracture, monitoring the effectiveness of the treatment applied.

Purpose: To compare the parameters measured using the DEXA method from the lumbar (L1-L4) vertebrae and the Hounsfield unit (HU) values measured with QCT at the same levels among young adults and the elderly.

Material and methods: The study included 155 patients (age range = 26-93 years). A total of 57 (36.8%) patients (age range = 26-64 years) were defined as the first group, and 98 (63.2%) patients (aged ≥65 years) were defined as the second group. T-test and correlation analysis were performed to compare bone mineral density (BMD), T score, and HU values measured using DEXA and QCT.

Results: A statistically significant difference was found between T score, lumbar total BMD, and HU values according to age and sex (P < 0.05). When the values measured from lumbar vertebrae were compared using both DEXA and CT, a high correlation was found between them.

Conclusion: In the study, it was observed that QCT attenuation measurements of the lumbar spine measured between different age groups provided reliable results in terms of BMD scanning, as in DEXA. It should be noted that QCT has a longer imaging time and higher radiation dose compared to DEXA, and unnecessary scans should be avoided.

Background: Ovarian thecoma-fibroma and solid ovarian cancer have similar clinical and imaging features, and it is difficult for radiologists to differentiate them. Since the treatment and prognosis of them are different, accurate characterization is crucial.

Purpose: To non-invasively differentiate ovarian thecoma-fibroma and solid ovarian cancer by convolutional neural network based on magnetic resonance imaging (MRI), and to provide the interpretability of the model.

Material and methods: A total of 156 tumors, including 86 ovarian thecoma-fibroma and 70 solid ovarian cancer, were split into the training set, the validation set, and the test set according to the ratio of 8:1:1 by stratified random sampling. In this study, we used four different networks, two different weight modes, two different optimizers, and four different sizes of regions of interest (ROI) to test the model performance. This process was repeated 10 times to calculate the average performance of the test set. The gradient weighted class activation mapping (Grad-CAM) was used to explain how the model makes classification decisions by visual location map.

Results: ResNet18, which had pre-trained weight, using Adam and one multiple ROI circumscribed rectangle, achieved best performance. The average accuracy, precision, recall, and AUC were 0.852, 0.828, 0.848, and 0.919 (P < 0.01), respectively. Grad-CAM showed areas associated with classification appeared on the edge or interior of ovarian thecoma-fibroma and the interior of solid ovarian cancer.

Conclusion: This study shows that convolution neural network based on MRI can be helpful for radiologists in differentiating ovarian thecoma-fibroma and solid ovarian cancer.