American Journal of Roentgenology最新文献

Background: A Society of Abdominal Radiology (SAR) Pancreatic Ductal Adenocarcinoma (PDAC) Disease-Focused Panel (DFP) consensus statement described findings suspicious for local recurrence (LR) on surveillance imaging after PDAC resection. Objective: To evaluate the interreader agreement and predictive utility of potential imaging findings of LR on serial surveillance CT examinations after Whipple procedure for PDAC, using the SAR PDAC DFP consensus statement. Methods: This retrospective study included 126 patients (mean age, 68.5±10.3 years; 72 men, 54 women) who underwent Whipple surgery for PDAC between January 2009 and December 2014. Three radiologists independently reviewed baseline and subsequent postoperative contrast-enhanced abdominopelvic CT examinations performed within 2 years postoperatively, evaluating features in the SAR PDAC DFP consensus statement relating to surgical bed stranding, surgical bed soft tissue, vessel encasement, main pancreatic duct dilatation, and ascites. Interreader agreement was calculated. The reference standard for LR development within 2 years postoperatively incorporated all available information. Imaging features' frequencies were calculated for recurrence examinations (i.e., first surveillance examinations indicating LR). For baseline postoperative examinations, features associations' with eventual LR development were assessed by multivariable logistic regression analysis. Results: LR developed within 2 years postoperatively in 81/126 patients. For both baseline and subsequent examinations, agreement for stranding and soft tissue morphology were poor, for vessel encasement was fair, for soft tissue and ascites were moderate, and for main pancreatic duct dilatation was substantial. On recurrence examinations, across readers, new or increased stranding was present in 27-77%; new or increased soft tissue, 80-86%; soft tissue with vessel encasement and luminal narrowing, 36-59%; new or increased main pancreatic duct dilatation, 25-26%; and new or increased ascites, 20-23%. On baseline postoperative examinations, independent predictors of eventual LR were soft tissue for all three readers (OR=2.78-6.85) and stranding for reader 1 (OR=3.59); main pancreatic duct dilatation and ascites were not independent predictors of LR for any reader. Conclusion: This study highlights the role of soft tissue, particularly when associated with vessel encasement and luminal narrowing, in raising suspicion for LR after PDAC resection. Clinical Impact: This study supports the SAR PDAC DFP consensus statement, while highlighting opportunities for continued optimization.

Background: Pericoronary adipose tissue (PCAT) attenuation and fat attenuation index (FAI) may serve as markers of inflammation and risk of adverse cardiac events. However, standardization of relevant CT acquisition and reconstruction parameters is lacking. Objective: To investigate the influence of vessel attenuation, virtual monoenergetic image (VMI) level, and reconstruction kernel on PCAT attenuation and FAI using energy-integrating detector (EID) and photon-counting detector (PCD) CT systems in an ex-vivo porcine heart model. Methods: A porcine heart's right coronary artery (RCA) was injected with saline or varying contrast media dilutions to achieve vessel attenuations ranging from 0 to 1000 HU. After each injection, the heart was scanned with EID CT at 120 kVp and PCD CT at 140 kVp, at constant CTDIvol (10 mGy). For EID CT, polychromatic images were reconstructed with Qr40 kernel. For PCD CT, VMI (40-80 keV at 10-keV increments) were reconstructed with Qr40, Bv40, and Bv56 kernels. ROIs were placed to measure RCA and PCAT attenuation. FAI was determined using software; histogram analysis was performed of voxel attenuations in the volumes of interest for FAI calculation. Results: Correlations were observed between attenuation in the RCA and adjacent PCAT (r=0.3-1.0), and between vessel attenuation and FAI (r=-0.9-1.0). For PCAT attenuation and FAI, these associations became progressively weaker for progressively sharper kernels. For increasing vessel attenuation for EID CT and for increasing VMI level for PCD CT, FAI histograms showed right shifts of the peak attenuation; the percentage of histogram voxels meeting the threshold range for inclusion in FAI calculation for EID CT was 8-29% and for PCD CT at VMI levels of 70-80 keV was 5-42%. For PCD CT, sharper kernels were associated with left shifts in peak attenuations and greater percentages of voxels within the threshold range for inclusion in FAI calculations. Conclusion: PCAT attenuation and FAI are influenced by vessel lumen attenuation, VMI level, and reconstruction kernel. A minority of pericoronary voxels contribute to FAI measurements for polychromatic EID CT and for PCD CT at high VMI levels. Clinical Impact: These findings may help standardize acquisition and reconstruction parameters for PCAT attenuation and FAI measurements.

Background: Advanced MRI-based neuroimaging techniques, such as perfusion and spectroscopy, have been increasingly incorporated into routine follow-up protocols in patients treated for high-grade glioma (HGG), to help differentiate tumor progression from treatment effect. However, these techniques' influence on clinical management remains poorly understood. Objective: To evaluate the impact of MRI-based advanced neuroimaging on clinical decision-making in patients with HGG in the posttreatment setting. Methods: This prospective study, performed at a comprehensive cancer center from March 1, 2017, to October 31, 2020, included adult patients treated by chemoradiation for WHO grade 4 diffuse glioma who underwent MRIbased advanced neuroimaging (comprising multiple perfusion imaging sequences and spectroscopy) to further evaluate findings on conventional MRI equivocal for tumor progression versus treatment effect. The ordering neuro-oncologists completed surveys before and after each advanced neuroimaging session. The percent of care episodes with a change between the intended and actual management plan on the surveys conducted before and after advanced neuroimaging, respectively, was computed and compared with a previously published percent using the Wald test for independent samples proportions. Results: The study included 63 patients (mean age, 55±13 years; 36 women, 27 men) who underwent 70 advanced neuroimaging sessions. Ordering neuro-oncologists' intended and actual management plans on the surveys completed before and after advanced neuroimaging, respectively, differed in 44% (31/70, [95% CI: 33-56%]) of episodes, which differed from the previously published frequency of 8.5% (5/59) (p<.001). These management plan changes included selection of a different plan for 6/8 episodes with an intended plan to enroll patients in a clinical trial, 12/19 episodes with an intended plan to change chemotherapeutic agents, 4/8 episodes with an intended plan of surgical intervention, and 1/2 episodes with an intended plan of re-irradiation. The ordering neuro-oncologists found advanced neuroimaging to be helpful in 93% (95% CI: 87%-99%) (65/70) of episodes. Conclusion: Neuro-oncologists' management plans changed in a substantial fraction of adult patients with HGG who underwent advanced neuroimaging to further evaluate conventional MRI findings equivocal for tumor progression versus treatment effect. Clinical Impact: The findings support incorporation of advanced neuroimaging into HGG posttreatment monitoring protocols.