Journal of Computer Assisted Tomography最新文献

Purpose: Magnetic resonance cholangiopancreatography (MRCP) may assist in the workup of infantile cholestasis as nonvisualization of the biliary tree is seen with biliary atresia (BA). However, this finding can also be seen with other causes of infantile cholestasis. The purpose of this study is to differentiate BA from other causes of infantile cholestasis using a classification tool integrating MRCP-based radiomics and clinical signatures in patients with nonvisualization of the extrahepatic biliary tree on MRCP.

Methods: Data from infants with cholestasis due to BA, cytomegalovirus infection, or idiopathic neonatal hepatitis (INH) from 2 sites was collected. Radiomics features from MRCP images were selected using Spearman and LASSO methods, followed by applying the optimal machine learning model to develop a radiomics signature. Clinical factors showing significant differences between BA and non-BA groups in training cohort were used to develop a clinical signature using the model. A nomogram model incorporating the signatures was developed. The nomogram model and signatures' performance were assessed using the area under the curve (AUC), accuracy, sensitivity, specificity, precision, and F1 score. The DeLong test, decision curve analysis (DCA), calibration curves, and the Hosmer-Lemeshow test were utilized to evaluate the nomogram model.

Results: The training cohort consisted of 112 cases (62 BA and 50 non-BA) from site 1, while the external validation cohort included 35 cases (20 BA and 15 non-BA) from site 2. After screening, 2 clinical factors and 8 radiomics features were included. The signatures were fitted using the K-Nearest Neighbors model. The nomogram model showed an AUC of 0.981 in the training cohort and 0.913 in the external validation cohort, significantly outperforming both the signatures in the training cohort and the clinical signature in the external validation cohort, as confirmed by the DeLong test. The DCA indicated the clinical utility of the model. The Calibration curves and the Hosmer-Lemeshow test confirmed the model's adequate fit.

Conclusion: The nomogram model may hold clinical utility. In our cohorts, it was effective for identifying BA among cases with infantile cholestasis attributed to BA, cytomegalovirus infection, or INH in scenarios where the extrahepatic biliary system is not visualized on MRCP.

Objective: To assess agreement between abdominal ultrasound and MRI for the detection of focal liver lesions and manifestations of portal hypertension in patients with Fontan circulation.

Materials and methods: To perform this single-center, retrospective study, we identified patients with Fontan circulation who underwent clinical abdominal ultrasound and MRI examinations within ±12 months between January 1, 2018 and June 30, 2023. Imaging reports were reviewed for the presence of liver lesions (specifically noting lesions >1 cm and radiologist-indicated suspicious lesions), features of portal hypertension (ie, presence of ascites and spleen length), abnormal liver contour, and liver stiffness. Intermodality agreement, sensitivity and specificity of ultrasound relative to MRI, and Spearman correlation were used to compare ultrasound and MRI measurements. Follow-up of detected lesions was also performed using electronic health records.

Results: There were 58 patients included. Agreement between MRI and ultrasound for the findings of Fontan-associated liver disease (FALD) was as follows: presence of a liver lesion of any size [k = 0.20 (95% CI: 0.08 to 0.32)], presence of a liver lesion >1 cm [k = 0.43 (95% CI: 0.18 to 0.68)], radiologist-indicated suspicious liver lesion(s) [k = 0.07 (95% CI: -0.13 to 0.27)], presence of ascites [k = 0.57 (95% CI: 0.32 to 0.81)], abnormal liver contour [k = 0.31 (95% CI: 0.03 to 0.59)], and spleen length [intraclass correlation coefficient = 0.81 (95% CI: 0.58 to 0.92)]. Sensitivity and specificity of ultrasound using MRI as the reference standard were as follows: 34% (95% CI: 20% to 50%) and 100% (95% CI: 77% to 100%) for the presence of a liver lesion of any size, and 39% (95% CI: 17% to 64%) and 98% (95% CI: 87% to 100%) for the presence of a liver lesion >1 cm. There was a poor correlation between ultrasound and MRI liver stiffness measurements [rho = 0.22 (95% CI: -0.14 to 0.53); P = 0.23]. Of 44 patients with liver lesions, 3 (6.8%) had biopsy-confirmed hepatocellular neoplasms, including 2 adenomas and 1 hepatocellular carcinoma. All 3 lesions were detected by both MRI and ultrasound.

Conclusions: There is poor to fair agreement between ultrasound and MRI for detecting manifestations of FALD, with ultrasound having poor sensitivity compared with MRI. While ultrasound detected all 3 clinically important liver lesions in our study, our results raise questions about whether ultrasound is an appropriate screening tool for FALD in patients post-Fontan.

Objective: Portable computed tomography (CT) scanners allow bedside brain imaging in critically ill patients without the risks of transport, but historically these scanners have demonstrated image quality inferior to that of fixed scanners. In this study, the quality of head CT examinations using a newer-generation portable scanner, the On.site, was compared with that of an older-generation portable scanner, the CereTom, as well as to that of fixed CT scanners.

Methods: Head CT examinations performed on the On.site scanner were retrospectively compared with those conducted on the same patient within 24 hours using the CereTom scanner or fixed scanners. A similar analysis was also carried out between the CereTom and fixed scanners. Three neuroradiologists rated the images qualitatively. Quantitative assessment included signal difference to noise ratio (SdNR) and noise magnitude in the cerebrospinal fluid, bone, and pons.

Results: The On.site scanner had higher image quality scores than the CereTom scanner ( P <0.001) and was 10 to 20 times less likely to produce subpar images. Mean noise in the pons was slightly higher with On.site than with CereTom ( P =0.014). Fixed scanners had higher qualitative scores than the On.site scanner, but there was no significant difference between the scanners in the probability of producing subpar images. The CereTom scanner had significantly lower qualitative scores than fixed scanners, and significantly increased probability of producing subpar and nondiagnostic images ( P <0.001). The SdNR was lower with the On.site scanner than with the fixed scanners ( P <0.001). Noise magnitude measures were higher with On.site than with fixed scanners ( P <0.001 for all).

Conclusions: The On.site scanner had significantly better qualitative image quality than the CereTom scanner and had a much lower probability of producing subpar or nondiagnostic images. Although the On.site scanner had inferior qualitative and quantitative image quality compared with the fixed scanners, there was no significant difference in the probability of producing subpar or nondiagnostic images. This may indicate a decreased need to transport sick patients out of the neurological intensive care unit for imaging in the future.

Objective: This study aims to investigate the diagnostic value of dual-energy computed tomography (DECT)-derived quantitative imaging parameters, including arterial iodine fraction (AIF), extracellular volume fraction (fECV), and iodine washout rate (IWR), in the assessment of liver function grading in patients with cirrhosis, to identify the optimal diagnostic parameters.

Methods: We collected DECT data from 68 patients with cirrhosis and 25 healthy controls at our institution and used the albumin-bilirubin (ALBI) scoring system for liver function grading. DECT images were processed for iodine quantification, and AIF, fECV, and IWR parameters were calculated. The correlation between DECT iodine parameters and ALBI grading was analyzed using the Spearman correlation coefficient; independent-sample t tests or nonparametric Mann-Whitney U tests were used to compare the differences in parameters between the cirrhosis group and the normal control group. The nonparametric Kruskal-Wallis H test was used to compare DECT iodine parameters across different ALBI groups within the cirrhosis cohort. The diagnostic efficacy of the iodine parameters in discriminating different ALBI grades was analyzed using the receiver operating characteristic (ROC) curve.

Results: Significant correlations were observed between AIF, fECV, and IWR with ALBI grades (r=0.873, 0.908, and -0.846, respectively; all P<0.001). In the cirrhosis group, AIF, fECV, and IWR exhibited statistically significant differences across ALBI grades (all P<0.001). The AUC values of fECV for distinguishing Control versus ALBI1+2+3, ALBI1 versus ALBI2+3, and ALBI1+2 versus ALBI3 were 0.955 (0.918 to 0.993), 0.945 (0.900 to 0.994), and 0.974 (0.942 to 1.000), respectively, with corresponding optimal cutoff values of 27.41%, 29.34%, and 35.40%, the diagnostic effect was better than AIF and IWR.

Conclusion: DECT-derived AIF, fECV, and IWR effectively assess liver function in cirrhosis through ALBI grading, with fECV showing superior standalone performance; multiparametric integration enhances diagnostic accuracy.

Objectives: This study aimed to simultaneously evaluate 4D cardiac magnetic resonance (MR)-derived kinetic energy (KE) of intra-left ventricular (LV) blood flow, wall kinetics, and myocardial perfusion under pharmacological stress in patients with coronary artery disease (CAD) using a hybrid PET/MR system.

Methods: Sixty-five patients (mean 68±12 y; male, 53) with CAD who underwent rest-stress 13N-ammonia PET/MR were included. MR acquisition was performed simultaneously during the PET scan to obtain rest-stress 4D flow, and followed by cine MR to measure LV ejection fraction (LVEF) and myocardial strain, including global longitudinal strain (GLS). The maximum KE during the cardiac cycle was calculated and indexed to the end-diastolic LV volume (maxKEi, μJ/mL) at rest and during stress. Perfusion defect, myocardial flow (MBF), and flow reserve (MFR) were assessed through rest-stress PET.

Results: MaxKEi showed a significant correlation with LVEF and GLS for both rest and stress (r=0.3, P=0.01, r=-0.4, P=0.04 for rest LVEF and GLS; r=0.4, P=0.0009, r=-0.4, P=0.003, for stress LVEF and GLS, respectively). Stress maxKEi showed a significant correlation with stress MBF and MFR (r=0.3, P=0.006, and r=0.3, P=0.03, for stress MBF and MFR, respectively).

Conclusion: Noninvasive assessment of 4D flow MR-derived intra-LV KE demonstrated a significant association with wall kinetics and endothelial function under pharmacological stress.

Objective: This study aims to identify factors associated with the detectability of the right adrenal vein (RAV) on preoperative contrast-enhanced CT scans of adrenal venous sampling (AVS) in the era of high-resolution CT (HRCT).

Materials and methods: In this retrospective study, 36 patients (15 men and 21 women; mean age, 56 y) who underwent preoperative contrast-enhanced CT [11 patients in HRCT with 0.25 mm detector matrix (Cannon Medical Systems) and 25 patients in conventional multidetector CT with 0.5 mm matrix] were included. A contrast agent dose of 600 mgI/kg was injected, and CT images were acquired at a fixed scan delay of 50 and 80 seconds. Adrenal venography and venous sampling were performed for the diagnosis of suspected primary hyperaldosteronism. The qualitative detectability of RAV on preoperative CT was assessed with adrenal venography as a reference. Clinical and imaging factors associated with a good detectability of RAV were analyzed via regression analysis. Optimal acquisition timing was assessed by analyzing the time-intensity curve and contrast enhancement pattern of the inferior vena cava using CT data from a separate cohort (n=5).

Results: The qualitative detectability of RAV was deemed good in 15 patients and poor in 21 patients. Regression analysis revealed that only heterogeneous enhancement of inferior vena cava with bolus high attenuation, corresponding to an optimal acquisition timing from time-intensity curve analysis, was associated with a good detectability of RAV (odds ratio, 5.06). The use of HRCT was not statistically significant.

Conclusions: Optimal acquisition timing is a crucial factor for the detectability of RAV in preprocedural CT for AVS, while high-resolution 0.25 detector CT appears to have limited significance.

Objective: To assess image quality between single-energy CT (SECT) and dual-energy CT (DECT) scans compared with a novel deep learning (DL) reconstruction for SECT used to improve contrast enhancement.

Methods: The raw data from a prior prospective HIPAA-compliant study (March through August 2022) was used to create a novel reconstruction in patients with biopsy-proven colorectal adenocarcinoma and liver metastases. Patients underwent 120 kVp SECT and DECT (50 keV reconstruction) abdominal scans in the portal venous phase in the same breath hold. Two readers independently assessed the scans.

Results: The final study group was 13 men and 2 women with a mean age of 60 years ± 10, a mean height of 171 cm ± 8, a mean weight of 87 kg ± 23, and a mean body mass index of 30 kg/m 2 ± 6. Liver, pancreas, spleen, psoas muscle, and aorta HUs were all significantly higher with the virtual DL reconstruction compared with the 120 kVp series, but significantly lower than the 50 keV series ( P <0.05). Readers scored the DL reconstruction to have better contrast enhancement than the standard 120 kVp series and improved artifacts, noise texture, and resolution compared with the 50 keV series ( P <0.05).

Conclusions: Contrast enhancement with the new reconstruction is superior compared with the standard 120 kVp series approaching that of 50 keV DECT, but with improved perception of artifacts, noise texture, and resolution.

Multidisciplinary case conferences have been shown to improve patient outcomes. However, such case conferences may be unavailable in some settings. This multidisciplinary discussion of 4 challenging hepatobiliary cases was presented at the 2023 Society of Advanced Body Imaging Annual Meeting in Dallas, TX. The cases include an "imaging occult" pancreatic tumor, a large pancreatic mass, an intraductal biliary mass, and a polypoid intraluminal gallbladder mass.

Objective: To evaluate the impact of deep learning image reconstruction on image quality in CCTA compared with adaptive statistical iterative reconstruction (ASIR).

Materials and methods: CCTA data sets from 100 consecutive patients with suspected CAD were acquired with a Revolution Apex 256-row CT scanner, reconstructed with ASIR-V and DLIR-H, and subsequently analyzed. Image noise, SNR, and CNR in five regions of interest (25 mm) were calculated and t tested. The normality of quantitative variables was assessed using the Shapiro-Wilk test. For non-normally distributed data, the Mann-Whitney U test was applied. The concordance of HU values within specific ROIs was analyzed with Bland-Altman plots. Correlation between ASIR-V and DLIR-H was conducted using the Spearman rank correlation test.Subjective image analysis was conducted using a 5-point scale to evaluate noise level, vascular enhancement smoothness, artifact reduction, and diagnostic confidence. Intraclass correlation (ICC) was used to assess the reliability and consistency of subjective ratings among the reader.

Results: DLIR-H significantly reduced image noise across all ROIs (from 15% to 41%, all P <0.05), compared with ASIR-V. Mean SNR (ASIR-V vs. DLIR-H) were septum=4.3±1.7 versus 6.4±2.2; cavity of the left ventricle=24.3±8.3 versus 36.6±11.7; CNR: septum=8.2±2.5 versus 12.4±3.5; cavity of left ventricle= 28.2±9.1 versus 42.5±13.0. Spearman rank correlation ranged from 0.64 to 0.79 ( P <0.05). Bland-Altman analysis showed good agreement between ASIR-V and DLIR-H, with no discernible patterns. Subjectively, DLIR-H significantly outperformed ASIR-V across all evaluated criteria (all P <0.05). ICC values indicated strong agreement among readers, demonstrating excellent reliability for most criteria and good reliability for vascular enhancement smoothness.

Conclusions: DLIR-H significantly improved CCTA image quality compared with ASIR-V, which contributes to a more accurate diagnosis in patients with suspected CAD.

Background: Ovarian cancer is one of the most common malignant tumors of the female reproductive system, characterized by high malignancy and poor prognosis. Epithelial ovarian cancer (EOC) accounts for 90% to 95% of all cases. This study aims to investigate the diagnostic value of delta apparent diffusion coefficient (dADC) values in distinguishing between type I and type II EOC and to explore its correlation with Ki-67 expression.

Methods: A retrospective analysis included 95 patients (mean age: 51.6 ± 12.5 y; range: 17 to 73 y) diagnosed with EOC at our hospital from September 2021 to August 2023. Of these, 51 patients had type I EOC (low-grade serous carcinoma, clear cell carcinoma, endometrioid carcinoma, mucinous carcinoma, or borderline tumors), and 44 had type II EOC (high-grade serous carcinoma or high-grade endometrioid carcinoma). Bilateral lesions were observed in 16.8% of patients. Preoperative MRI, including diffusion-weighted imaging (DWI), serum CA125 levels, and postoperative immunohistochemical Ki-67 expression, were analyzed. Tumor staging was based on the 2021 FIGO criteria. Minimum ADC (minADC), maximum ADC (maxADC), and dADC values were calculated from the solid tumor components. Receiver operating characteristic (ROC) curves assessed diagnostic performance, and the correlation between dADC and Ki-67 expression was examined.

Results: The maxADC and minADC of type II EOC were lower than those of type I, while dADC was higher than type I ( P <0.05). ROC curve analysis showed that the efficacy of dADC in distinguishing between type I and type II EOC was higher than that of minADC and maxADC ( P <0.05). When the dADC threshold was 0.31×10 -3  mm 2 /s, the area under the curve (AUC) was 0.982, with a sensitivity of 95.3% and specificity of 97.3%. Pearson correlation analysis showed a positive correlation between dADC and Ki-67 expression.

Conclusion: dADC has a certain value in accurately distinguishing between type I and type II EOC preoperatively, and it can reflect the proliferative activity of tumor cells.