Diagnostic and Interventional Radiology最新文献

Purpose: In this study, we assessed the performance of apparent diffusion coefficient (ADC) and diffusion-weighted imaging (DWI) metrics and their ratios across different magnetic resonance imaging (MRI) acquisition settings, with or without an endorectal coil (ERC), for the evaluation of prostate cancer (PCa) aggressiveness using whole-mount specimens as a reference.

Methods: We retrospectively reviewed the data of prostate carcinoma patients with a Gleason score (GS) of 3+4 or higher who underwent prostate MRI using a 3T unit at our institution. They were divided into two groups based on the use of ERC for MRI acquisition, and patients who underwent prostate MRI with an ERC constituted the ERC (n = 55) data set, while the remaining patients accounted for the non-ERC data set (n = 41). DWI was performed with b-values of 50, 500, 1000, and 1,400 s/mm2, and ADC maps were automatically calculated. Additionally, computed DWI (cDWI) was performed with a b-value of 2000 s/mm2. Six ADC and two cDWI parameters were evaluated. In the ERC data set, receiver operating characteristic (ROC) curves were plotted for each metric to determine the best cutoff threshold values for differentiating GS 3+4 PCa from that with a higher GS. The performance of these cutoff values was assessed in non-ERC dataset. The diagnostic accuracies and area under the curves (AUCs) of the metrics were compared using Fisher's exact test and De Long's method, respectively.

Results: Among all metrics, the ADCmean-ratio yielded the highest AUC, 0.84, for differing GS 3+4 PCa from that with a higher GS. The best threshold cutoff values of ADCmean-ratio (£0.51) for discriminating GS 3+4 PCa from that with a higher GS classified 48 patients out of 55 with an accuracy of 87.27%. However, there was no significant difference between each metric in terms of accuracy and AUC (p = 0.163 and 0.214). Similarly, in the non-ERC data set, the ADCmean-ratio provided the highest diagnostic accuracy (82.92%) by classifying 34 patients out of 41. However, Fisher's exact test yielded no significant difference between DWI and ADC metrics in terms of diagnostic accuracy in non-ERC data (p = 0.561).

Conclusion: The mean ADC ratio of the tumor to the normal prostate showed the highest accuracy and AUC in differentiating GS 3+4 PCa and PCa with a higher GS across different MRI acquisition settings; however, the performance of different ADC and DWI metrics did not differ significantly.

PURPOSE We aimed to investigate the safety and tumor seeding rate of a coaxial implantation technique combined with injection of a gelfoam pellet in establishing a VX2 liver tumor model in rabbits. METHODS A VX2 liver tumor model was established in 60 male New Zealand white rabbits, which were randomly divided into 3 groups (20 in each group) based on implantation technique (all performed under ultrasound guidance): group A, single needle only; group B, single needle with injection of a gelfoam pellet; or group C, coaxial technique with injection of a gelfoam pellet. The rates of liver tumor formation and tumor seeding to extrahepatic tissues were compared 2 weeks after implantation. Data were also collected regarding procedure time, number of punctures, occurrence of complications, and mortality rate. RESULTS A VX2 liver tumor model was established in all 60 rabbits (100%, 60/60). Ectopic implantation rate was 70% (14/20) in group A, 35% (7/20) in group B, and 5% (1/20) in group C, with significant difference among the groups (p < 0.001). Post hoc analysis showed significant difference between group A and group C (p < 0.001). However, there were no significant differences between group B and group A or group C (p = 0.027, p = 0.048, respectively). There were no significant differences among the groups in terms of procedure time (p = 0.405) or number of punctures (p = 0.612). No complications or deaths occurred. CONCLUSION A coaxial technique with injection of a gelfoam pellet is an effective and safe method for VX2 liver tumor implantation in rabbits, and this technique can reduce the risk of tumor seeding to the abdominal wall and omentum.

Adrenal vein sampling (AVS) failure is often attributed to difficulty sampling the right adrenal vein (RAV). Normally, the RAV is caudally oriented, however, cranial orientation of the RAV is not uncommon. In such cases, use of a multipurpose (MPA) catheter shape may facilitate sampling. Between 2014 and 2019, 351 patients underwent AVS and RAV sampling with an MPA catheter occurred in 23 patients (7%, 10M:13F). Data regarding pre-AVS imaging, procedural details, and AVS results were collected, the RAV vertical angle was measured on venography using the IVC right lateral wall as the craniocaudal axis (0° defined as caudal, 180° cranial), and correlation of the number of catheters used until successful sampling with the MPA catheter and various procedural measures was assessed. Twenty-four technically successfully AVS were performed in 23 patients, all of whom had cranially oriented RAVs on intra-procedural venography. An MPA catheter was the first choice in 2 patients with previously known cranially oriented RAVs. In the remaining patients, the MPA catheter was 2nd choice in 21% (n = 5), 3rd choice in 50% (n = 12), and up to 8th choice (n=1). Early utilization of the MPA catheter correlated with lower fluoroscopic time (R = 0.71, P = 0.0001) and lower contrast volume (R = 0.77, P < 0.0001). These results support the use of the MPA catheter when sampling cranially oriented RAVs. MPA catheters should be readily considered when cranially oriented RAVs are present and when caudally-oriented catheters fail to identify the RAV.

Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) is an emerging quantitative imaging biomarker that accurately measures the fat fraction of tissue by correcting factors influencing magnetic resonance signal intensity. Beyond fat quantification, it also measures R2* which is a direct measure of iron concentration. The utilization of MRI-PDFF in liver diseases is well established. In the present review, we focused on applications of MRI-PDFF in different body areas including pancreas, bone, muscle, spleen, testis, visceral, and subcutaneous adipose tissue. Future studies can enable tracking of quantitative fat fraction changes in different organs simultaneously, which can be critical in understanding fat metabolism.

Purpose: To compare the inter-center cranial computed tomography (CT) acquisition rates, CT findings, CT related radiation dose, and variability of CT acquisition parameters for neurologic events among patients with implantable cardioverter-defibrillator (ICD) or left ventricular assist device (LVAD).

Methods: A total of 224 patients [ICD group (n = 155) and LVAD group (n = 69)] who had at least one cranial CT scan were enrolled from three medical centers. The variability and effect of the number, indication, and findings of cranial CT scans as well as CT acquisition parameters including tube potential, tube current, tube rotation time (TI), slice collimation (cSL), and spiral or sequential scanning techniques on CT dose index volume (CTDIvol), total dose length product (DLP) were analyzed.

Results: The mean DLP value of Center A and mean CTDIvol values of Center A and C were significantly lower than Center B (p < 0.001). The mean CTDIvol and DLP values in the ICD group were substantially lower than the LVAD group (p<0.001). The most potent parameters causing the changes in CTDIvol and DLP were kV, mAs values, and CT scanning technique as sequential or spiral according to multivariate linear regression analysis.

Conclusion: Cranial CT acquisition parameters and radiation doses vary significantly between centers, which necessitates optimization of cranial CT protocols to overcome the cumulative radiation dose burden in patients with neurologic events.

Purpose: To evaluate the embolic effect of fish-derived gelatin microparticles (GMPs) and compare the degradation periods and biocompatibilities of different molecular weight (MW) GMPs in a rabbit model.

Methods: GMPs were designed to degrade within 21 days (high MW GMP, 15-30 kDa) and 2 days (low MW GMP, 5-15 kDa) in vivo. Renal arteries of 24 rabbits were embolized using both high and low MW GMPs (155-350 µm). Rabbits were sacrificed either immediately after embolization, or after follow-up (F/U) angiogram on days 2 and 21 of embolization, respectively (4 rabbits in each of the 6 subgroups). Pathological changes of recanalized vessels were evaluated using the Banff classification. For the in vitro study, each type of GMP was mixed with normal saline and morphological changes were compared for 14 days.

Results: Fish-derived GMPs showed effective embolization. On 2-day F/U angiography, occluded vessels were more recanalized to the peripheral branches in low MW group. On day 21, a parenchymal perfusion defect recovered to a greater extent in low MW group than that in high MW group. Mean Banff scores for intimal arteritis on 2-day F/U and interstitial fibrosis on 21-day F/U were higher in high MW group (1.75 ± 0.58 vs. 0.19 ± 0.4 and 2.56 ± 0.63 vs. 0.88 ± 0.89; P < .001). On in vitro assessment, low MW GMP lost the spherical shape and degraded, and was invisible on microscopy on day 6, whereas high MW GMP was only partially degraded after 2 weeks.

Conclusion: Fish-derived GMPs showed effective embolization in a rabbit model. Low MW GMPs degraded within 2 days with a low inflammatory response.

PURPOSE The increasing interest of endplate and Modic changes as potential pain generators in low back pain (LBP), along with advancement of functional quantitative magnetic resonance imaging (MRI) techniques, makes it important to characterize the vertebral dynamic behavior in detail. This study aims to perform characterization of the dynamic behavior of the vertebral bodies (VB) by investigating the VB diurnal variation in T2-relaxation time in a cross-sectional asymptomatic group of individuals. METHODS T2-mapping of 30 VBs (L1-L5) in six healthy volunteers (mean age, 40 years; range, 29-65 years) was performed with a 1.5 Tesla MRI at three time points over the day (7 am, 12 am, 5 pm). Volumetric regions of interest were segmented manually to determine VB T2-relaxation time, which was compared between the three time points. RESULTS On a group level only small and not significant diurnal VB variation was detected (all P >.10), with median T2 (ms) (quartiles; Q1, Q3) at the three time points 88.7 (84.1, 99.1), 87.3 (85.0, 96.1) and 87.8 (84.4, 99.2). However, in some VBs up to 7% increase respectively 9% decrease in T2-relaxation time was found during the day. Further, there was a relatively large variation between the individuals in absolute VB T2-relaxation times (range 73.2-108.3 ms), but small differences between the VBs within an individual. CONCLUSION This first T2-mapping study of the VB signal dynamics, in repeated investigations during one day, display variation in T2-relaxation time in specific individual VBs but were negligible on a group level. The result may be of importance when evaluating patients with spinal pathologies and suggest further examinations of dynamic changes not only of the disc but also vertebrae.

Purpose: We aimed to assess the feasibility of radiomics analysis based on non-contrast-enhanced thoracic CT images in predicting synchronous brain metastasis (SBM) in lung cancer patients at initial diagnosis.

Methods: This retrospective study enrolled 371 lung cancer patients (with SBM n=147, without SBM n=224) confirmed by histopathology. Patients were allocated to the training set (n=258) and testing set (n=113). The optimal radiomics features were selected by using the least absolute shrinkage and selection operator (LASSO) algorithm. The radiomics, clinicoradiologic, and combined models were developed to predict SBM using multivariable logistic regression. Then the discrimination ability of the models was assessed. Furthermore, the prediction performance of the abovementioned three models for oligometastatic (1-3 lesions) or multiple (>3 lesions) brain metastases in SBM, metachronous brain metastasis (MBM), and total (SBM and MBM) groups were investigated.

Results: Six radiomics features and two clinicoradiologic characteristics were chosen for predicting SBM. Both the radiomics model (area under the receiver operating characteristic curve [AUC] = 0.870 and 0.824 in the training and testing sets, respectively) and the combined model (AUC = 0.912 and 0.859, respectively) presented better predictive ability for SBM than the clinicoradiologic model (AUC = 0.712 and 0.692, respectively). The decision curve analysis (DCA) demonstrated the clinical usefulness of the radiomics-based models. The radiomics model can also be used to predict oligometastatic or multiple brain metastases in SBM, MBM, and total groups (P = .045, P = .022, and P = .030, respectively).

Conclusion: The radiomics model and the combined model we presented can be used as valuable imaging markers for predicting patients at high risk of SBM at the initial diagnosis of lung cancer. Furthermore, the radiomics model can also be utilized as an indicator for identifying oligometastatic or multiple brain metastases.

Purpose: Percutaneous biopsy has demonstrated high accuracy in diagnosis of lung nodules, but the technique is not innocuous and a yield decrease in lesions smaller than 20 mm has been reported. We carried out a prospective study to evaluate and compare the complications and efficacy of percutaneous core needle biopsy (CNB) of solitary solid lung nodules, which were performed with two types of automatic guns.

Methods: 330 consecutive CT-guided CNB were included. Tru-cut or end-cut 18G devices were used alternatively. Nodules were categorized by their size: ≤10 mm, 11-20 mm and >20 mm. Incidence of complications such as pneumothorax or hemoptysis and factors influencing them (nodule size and depth within lung parenchyma) were evaluated. Diagnostic accuracy of CNB achieved in the three groups of nodules regarding the two different needles were calculated and statistically evaluated and compared.

Results: We performed 68 CNB in nodules ≤10 mm, 130 in 11-20 mm and 132 in >20 mm. Pneumothorax appeared in 24.2% of them, but only 5.7% required drainage. Hemoptysis was developed in 9.4% and abundant hemoptysis with hypoxemia was observed in only 4.2% of patients. Regarding appearance of complications between the two needle types, no significant differences were found. A higher risk of hemoptysis was observed in nodules ≤10 mm (OR = 3.87; 95% CI = 1.24-12.06, P = 0.019) and in those located deeper in pulmonary parenchyma (OR = 2.21; 95% CI = 1.04-4.69, P = 0.038). End-cut needles reached a diagnostic accuracy of 93.7%, 92.1% and 98.3%, in nodules sized ≤10 mm, 11-20 mm and >20 mm, respectively. Corresponding results for tru-cut were 84.7%, 88.5% and 92.1%. In spite of differences reaching up to 9% in smaller nodules, intra-group results were not significant.

Conclusion: Both needles have similar complications rate. Despite not having observed statistically significant differences between the two types of needles, end-cut devices have demonstrated a higher diagnostic yield in the three groups of nodules and could be a more suitable option especially for CNB of nodules ≤10 mm.