Computed Tomography Research Articles

Utility of computed tomography (CT) –based staging of mismatch repair deficient (dMMR) colon cancer.

45 Background: dMMR tumors are characterized by rapid primary tumor growth with reduced likelihood for nodal and distant metastases compared to MMR proficient (pMMR) tumors. Neoadjuvant immune checkpoint inhibitors (ICIs) have demonstrated promising efficacy for localized colon cancer with high pathologic complete response rates and low relapse rates. This raises the question if surgical treatment could be avoided with accurate radiographic staging while avoiding overtreatment of early stage tumors. This study assesses the utility of radiographic staging by CT for dMMR tumors compared to pathologic staging. Methods: Patients with stage I-III colon cancer treated with upfront surgical resection were retrospectively reviewed from a single institution from 2012 to 2023 in two cohorts: 1) dMMR colon cancer and 2) pMMR colon cancer limited to similar sample size as matched controls. Clinical stage was determined based on CT scans prior to surgical resection by 2 independent radiologists blinded to pathologic stage, and the results were correlated to pathologic stage. Clinical characteristics were extracted from the electronic medical record. Statistical analysis was performed using SPSS. Results: We identified 80 patients with dMMR colon cancer and 66 with pMMR tumors. CT clinical tumor staging was discordant from pathologic staging for 68% of dMMR tumors and 61% for pMMR tumors. For T4 dMMR tumors, CT had a 74% sensitivity and 44% specificity. T4 tumors were understaged by radiology to less than T4 for 56% of cases. For dMMR nodal staging, CT had 89% sensitivity and 50% specificity (Table 1). For pathologic node positive tumors, 14% were understaged by radiologist CT read to node negative. For pathologic node negative tumors, 50% of tumors were overstaged to node positive by radiologist CT read. There was poor inter-rater reliability for both T stage and N stage for dMMR and pMMR tumors. The weakest agreement between radiologists was for T stage (dMMR kappa = 0.246, mMMR kappa = 0.145). Conclusions: Radiologic clinical staging of dMMR and pMMR colon cancer does not correlate well with pathologic staging. There were high rates of understaging by CT evaluation for patients who may be candidates for neoadjuvant treatment (T4, N+). Furthermore, there was poor inter-rater reliability between radiologists, indicating that CT staging alone may not be sufficient. Additional diagnostic modalities for nodal detection may be necessary to accurately clinically stage patients before neoadjuvant ICIs in patients with locally advanced disease. Comparing utility of pMMR versus dMMR tumors for T4 and node positive disease. pMMR (n = 66) dMMR (n = 80) T4 versus T3 or less Sensitivity (%) 92 74 Specificity (%) 51 47 PPV (%) 80 77 NPV (%) 82 63 Node positive versus node negative Sensitivity (%) 60 50 Specificity (%) 75 89 PPV (%) 81 89 NPV (%) 53 50 Abbreviations: PPV = positive predictive value; NPV = negative predictive value.

EORTC1527/JCOG1609INT/ESSO02: Diffusion-weighted magnetic resonance imaging (DW-MRI) assessment of initially unresectable liver metastasis to improve surgical planning (DREAM)—Primary analysis.

257 Background: Disappearing liver metastases (DLMs) diagnosed on post-chemotherapy (Cx) computed tomography (CT) is a favorable prognostic factor in patients (pts) with colorectal liver metastases (CRLM). However, the optimal treatment of DLMs - whether they should be resected or left behind - is controversial. This is a prospective, multi-centred, international study examining the added value of MRI (DWI, T1/T2 and contrast-enhanced) to that of CT alone in accurate assessment of the viability of DLMs. Methods: Pts with initially unresectable CRLM downstaged to a planned liver resection after Cx were enrolled, based on the obligatory decision of a multidisciplinary team. Pts were imaged by both CT and MRI at baseline and presurgical timepoints. DLMs were defined as disappeared lesions diagnosed by CT alone, while confirmed DLMs (cDLMs) were defined as lesions that disappeared on both CT and MRI. cDLMs were either resected or followed-up for 2 years if not resected. All imaging scans were collected centrally for quality assurance. The primary endpoint was the negative predictive value (NPV) of MRI and CT in confirming the status of cDLMs using either pathological complete response or the absence of a local recurrence at the site of cDLMs during the 2 year follow up. The study was aimed at excluding a NPV ≤0.85 with a 1-sided alfa of 5% and power of 90% under the alternative that the NPV ≥0.95. The planned sample size was 92 evaluable (resected or left behind) cDLMs, assuming a within-patient correlation between cDLMs of 0.2 and an average number of 2 cDLMs per pt. Results: 233 pts were registered at 22 participating centres, and 112 were enrolled for analysis. A median of 8 cycles of Cx was delivered, and pts had a median of 7 CRLMs at baseline. A total of 203 cDLMs were identified while the number of DLMs diagnosed by CT was 296. Of these, 152 cDLMs and 227 DLMs, respectively, were evaluable according to the imaging protocol. Intraoperative ultrasound was performed for 195 cDLMs and, of these, 59 (30.2%) were still detected. The rate of R0/R1 resection was 95.5%. The NPV of evaluable cDLMs either resected or left behind was 62.5 % (95/152, 95% CI:50.8-74.2), which was lower than the prespecified threshold. The NPV of DLMs was 52.9% (119/227, 95% CI:42.7, 63.0). The NPV of resected cDLMs, and those left behind were 56.8% (50/88, 95% CI: 44.2, 69.5) and 70.3% (45/64, 95% CI: 48.6 -92.0), respectively. For DLMs, the NPV of resected DLMs and those left behind were 45.6% (72/158, 95% CI: 35.4-55.7) and 69.6% (48/69, 95% CI: 47.7-91.5), respectively. Conclusions: For pts with initially unresectable CRLM, cDLMs diagnosed by both CT and MRI do not correspond to tumor viability, even after highly effective chemotherapy. Ongoing survival analysis (to be presented at the annual meeting) may impact the treatment strategy of pts with DLMs. Clinical trial information: NCT02781935 .

Impact of intravenous CT contrast agents on internal calibration techniques to determine trabecular BMD of the lumbar spine.

Contrast agents are frequently administered in computed tomography (CT) scans used for opportunistic screening of osteoporosis. The objective of this study is to compare the impact of contrast-related bone mineral density (BMD) increase between phantom-based and internal CT calibration techniques. Phantom-based and internal CT calibration techniques were used to determine trabecular BMD in 93 existing clinical CT scans of the lumbar spine of 34 subjects, scanned before and after administration of contrast agents. BMD differences between native (Nat) and contrast-enhanced scans in arterial (Art) and portal venous (PV) phases were compared among calibration methods. Three pairs of internal reference materials were investigated: blood/air, subcutaneous adipose tissue (SAT)/air and muscle tissue/air. Contrast agents increased CT values of blood in the aorta and the inferior vena cava in the Art phase by 210±99HU and 47±35HU, respectively and in the PV phase by 110±49HU and 73±28HU, respectively. Effects on CT values of muscle and SAT were<5HU in the Art phase and<10HU in the PV phase. BMD obtained with phantom calibration increased significantly (p<0.01) in Art and PV phases by 8.6±14.7mg/cm3 and 14.4±16.3mg/cm3, respectively. If SAT/air or muscle/air were used as internal reference materials, increases in internally calibrated BMD (<12mg/cm3 in AT phase and<17mg/cm3 in PV phase) did not significantly differ (p>0.1 for Art and PV phases) from increases of phantom-calibrated BMD. Although CT values of internal reference materials increased following the administration of contrast, internal calibration was unable to mitigate the contrast-related BMD increases observed in phantom-based calibration.

Impact of Vaccination Status on Chest CT Findings and Disease Outcomes in COVID-19 Era: A Retrospective Study

Background: Computerized Tomography (CT) was extensively used in the COVID-19 era to confirm the diagnosis and follow the patient's response. The vaccine was rapidly introduced to break the disease chain of infection. The current study primarily aimed to examine the relationship between vaccination status and pulmonary CT findings. Moreover, it also aimed to validate the role of CT scan along with other patient criteria in predicting disease outcomes. Methods: A retrospective cohort study was conducted at the radiology department of two Iraqi hospitals in Baghdad. The study enrolled all hospitalized patients with a confirmed COVID-19 diagnosis older than 18 years old. Their data regarding demographic criteria, vaccination criteria (the status and types), and radiological CT-scan parameters (including CT finding and severity score index) were collected Results: It was found that 23 percent of COVID-19 patients were immunized. Most of the unvaccinated cases were older than 45 years and were females. There was a significant correlation between the degree and severity of lung involvement and the vaccination status (p &lt; 0.001). The worst radiological sign for severity was the ground glass appearance. The vaccine type showed significant changes in chest CT. Pfizer had the worst severity score, followed by Sinopharm in vaccinated cases. The overall mortality was 4.5%. Moreover, the vaccine significantly reduced mortality among vaccinated vs. non-vaccinated cases (p = 0.03). By logistic regression, the CT score reliably predicted mortality with an odds ratio of 1.31 (1.18 to 1.45; p &lt; 0.001). Conclusion: Vaccines were found to be significantly effective in protecting vaccinated people against severe infection and limiting lung injury, as evidenced by CT scores. Vaccines had a trend effect on reducing mortality. Moreover, CT scores were reliable in predicting the disease outcome.

Generating synthetic CT images from unpaired head and neck CBCT images and validating the importance of detailed nasal cavity acquisition through simulations.

Computed tomography (CT) of the head and neck is crucial for diagnosing internal structures. The demand for substituting traditional CT with cone beam CT (CBCT) exists because of its cost-effectiveness and reduced radiation exposure. However, CBCT cannot accurately depict airway shapes owing to image noise. This study proposes a strategy utilizing a cycle-consistent generative adversarial network (cycleGAN) for denoising CBCT images with various loss functions and augmentation strategies, resulting in the generation of denoised synthetic CT (sCT) images. Furthermore, through a rule-based approach, we were able to automatically segment the upper airway in sCT images with high accuracy. Additionally, we conducted an analysis of the impact of finely segmented nasal cavities on airflow using computational fluid dynamics (CFD). We trained the cycleGAN model using various loss functions and compared the quality of the sCT images generated by each model. We improved the artifact removal performance by incorporating CT images with added Gaussian noise augmentation into the training dataset. We developed a rule-based automatic segmentation methodology using threshold and watershed algorithms to compare the accuracy of airway segmentation for noise-reduced sCT and original CBCT. Furthermore, we validated the significance of the nasal cavity by conducting CFD based on automatically segmented shapes obtained from sCT. The generated sCT images exhibited improved quality, with the mean absolute error decreasing from 161.60 to 100.54, peak signal-to-noise ratio increasing from 22.33 to 28.65, and structural similarity index map increasing from 0.617 to 0.865. Furthermore, by comparing the airway segmentation performances of CBCT and sCT using our proposed automatic rule-based algorithm, the Dice score improved from 0.849 to 0.960. Airway segmentation performance is closely associated with the accuracy of fluid dynamics simulations. Detailed airway segmentation is crucial for altering flow dynamics and contributes significantly to diagnostics. Our deep learning methodology enhances the image quality of CBCT to provide anatomical information to medical professionals and enables precise and accurate biomechanical analysis. This allows clinicians to obtain precise quantitative metrics and facilitates accurate assessment.

Habitat radiomics based on CT images to predict survival and immune status in hepatocellular carcinoma, a multi-cohort validation study.

Though several clinicopathological features are identified as prognostic indicators, potentially prognostic radiomic models are expected to preoperatively and noninvasively predict survival for HCC. Traditional radiomic models are lacking in a consideration for intratumoral regional heterogeneity. The study aimed to establish and validate the predictive power of multiple habitat radiomic models in predicting prognosis of hepatocellular carcinoma (HCC). A total of 232 HCC patients were retrospectively included, including a training/validation cohort and two external testing cohorts from 4 centers. For habitat radiomics, intratumoral habitat partitioning based on CT images was first performed by using Otsu thresholding method. Second, a total of 350 habitat radiomic models were constructed to select the optimal model. Then, both ROC curve analyses and Kaplan-Meier survival curve analyses were applied to assess the predictive performances. Ultimately, an immune status profiling was conducted based on bioinformatic analyses and multiplex immunohistochemistry (mIHC) assays to reveal the potential mechanisms. A total of 4 habitats were segmented, and the corresponding habitat radiomic models were constructed based on each habitat and an integration of all the four habitats. Generally, habitat radiomic models outperformed traditional radiomic models in stratifying prognosis for HCC. The habitat radiomic model based on the segmented habitat 4 involving decision tree (DT) screening and random forest (RF) classifier was identified as the optimal model with an AUCmean of 0.806. Distinct resting natural killer (NK) cell infiltrations significantly contributed to the prognosis stratification of HCC by the optimal habitat radiomic model. The habitat radiomic model based on CT images was potentially predictive of overall survival for HCC, with a superiority over the traditional radiomic model. The prognostic power of the habitat radiomic model was partly attributed to the distinct immune status captured in the CT images.

A phase 2, multicenter, open-label study of AlloStim combined with anti-PD-L1immunotherapy as 4L therapy in patients with MSS/pMMR metastatic colorectal cancer.

TPS318 Background: Microsatellite stable (MSS)/mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC) are immunologically 'cold' tumors that do not respond to immunotherapy. Cold tumors represent a formidable hurdle for checkpoint blockade immunotherapy approaches. Therefore, there is a need for novel strategies that could reprogram mCRC cold tumors to become inflamed hot tumors in a manner that might potentially convert low tumor mutational burden (TMB) tumors into checkpoint blockade responsive tumors. AlloStim is an experimental allogeneic, non-genetically manipulated, Th1-like activated living cell immunotherapy derived from healthy unrelated blood donors. The mechanism of action is designed to convert immunologically cold tumors into inflamed hot tumors. A case study of a single 3L MSS/pMMR mCRC patient primed with AlloStim followed by combination anti-PD-1/anti-CTLA4 checkpoint blockade resulted in a rare objective tumor response (Hirschfeld, et al, Translational Medicine Communications (2024) 9:15). The AlloStim priming results in an abundance of infiltrating interferon-gamma producing Th1 cells. Interferon-gamma has been shown to increase expression of PD-L1 in the TME. Therefore, it is hypothesized that the combination of AlloStim with an anti-PD-L1 checkpoint inhibitor might optimally evoke anti-tumor immune responses in this immunotherapy-refractory MSS/pMMR mCRC population. Methods: The study is a phase 2, multicenter, single-arm clinical trial of MSS/pMMR mCRC subjects in 4L that have been previously treated with an oxaliplatin-containing and irinotecan-containing chemotherapy regimen, anti-EGFR (RAS wt and left-sided), anti-VEGF and have progressed on 3L TAS-102 +/- bevacizumab or regorafenib or fruquinitinib. The study is evaluating weekly AlloStim priming from day 0 to day 49 followed by combination of AlloStim IV infusion (q2w) followed a week later by anti-PD-L1 (avelumab 800mg/q2w) from days 63 to day 98. Objective tumor response and disease control rate are the primary end-points. Overall survival is the secondary end-point. Clinically stable patients at day 112 can continue in an expansion phase with another round of combination AlloStim and avelumab from day 119 to day 154. CT scans are conducted at baseline, day 56 after AlloStim priming, day 112 after combination of alternating q2w infusions of AlloStim and avelumab and day 168 in all patients. CT scans will be analyzed by independent central readers using RECIST 1.1. Up to 50 patients will be enrolled with an interim analysis performed to assess efficacy after 20 patients become evaluable. The study is open and has not yet enrolled any patients at time of submission. Clinical trial information: NCT06557278 .

The Oncopig hepatocellular carcinoma model: An innovative large animal platform for evaluating treatment effects.

619 Background: Hepatocellular carcinoma (HCC) is an aggressive disease associated with poor prognosis and limited treatment options. Systemic therapies for advanced HCC include sorafenib, lenvatinib, and atezolizumab plus bevacizumab. However, given the limited efficacy of systemic treatment options, novel treatment approaches including combination of systemic and locoregional therapies (LRTs) is required to improve patient outcomes. These approaches require advanced large animal models to prove effectiveness. Pigs represent an ideal platform that provide both regulatory acceptable and clinically relevant large animal cancer models due to their similar physiology, size, genetics, immunity, and metabolism in relation to humans. The Oncopig HCC model is an ideal tool for testing LRT and other oncolytic based treatments. Methods: The Oncopig cancer model develops tumors following induced expression of KRAS G12D and TP53 R167H driver mutations utilizing an adenoviral vector encoding Cre recombinase (AdCre). Oncopig HCC cell lines were developed by isolating hepatocytes from Oncopig liver biopsies and transformed in vitro via exposure to AdCre. Transgene expression and hepatocyte cell origin were validated by RT-PCR and arginase-1 staining, respectively. Comparison of in vitro Oncopig, human, and murine HCC cell line phenotypes (proliferation, migration, and chemotherapeutic response) was performed. Oncopig HCC tumor formation was performed via autologous intrahepatic injection of Oncopig HCC cells. Tumor formation was evaluated using ultrasound and CT imaging. Results: Oncopig and human HCC cell lines displayed similar cell cycle lengths and migration rates. Oncopig HCC cells were consistently more predictive of human HCC responses than murine cells when treated with standard chemotherapeutic agents (doxorubicin, cisplatin, mitomycin C, and sorafenib). Importantly, consistent with human HCC, Oncopig HCC cells were non-responsive to 5-fluorouracil, while murine HCC cells were responsive. Intrahepatic injection of Oncopig HCC cells resulted in tumors visible on ultrasound and CT scan within 2-4 weeks. Resulting tumors were consistent with human tumors on imaging. Histological analysis of tumor biopsies confirmed the identity of the resulting masses as HCC tumors based on positive arginase-1 and KRAS G12D staining. Conclusions: The Oncopig HCC model may be more predictive of human HCC chemotherapeutic responses than currently employed murine models. Tumors develop rapidly (within 2-4 weeks) and are readily identified on ultrasound and CT imaging, making this an ideal model for evaluation of novel therapeutic approaches. Further exploration and development of additional tumor models including further translational characterization will be important for broader utility.

Tumor vascularity as a predictor of FGFR inhibitor response in FGFR2-fused intrahepatic cholangiocarcinoma.

638 Background: Fibroblast growth factor receptor 2 (FGFR2) fusion is a well-established mutation in intrahepatic cholangiocarcinoma (iCCA), accounting for approximately 10% of cases. Current treatments, including pemigatinib, infigratinib, and futibatinib, have shown promising results with response rates of less than 40%. Most patients experience progression within 6-8 months, and reliable biomarkers to predict treatment response are still lacking. This study aimed to assess the clinical outcomes of FGFR inhibitors in patients (pts) with FGFR2-fused iCCA, while investigating tumor vascularity as a potential predictor of treatment efficacy. Methods: We retrospectively analyzed data from 134 pts treated at MD Anderson Cancer Center between 2009 and 2024, focusing on 73 pts with comprehensive clinical data. The cohort included pts treated with futibatinib (n=16), infigratinib (n=16), pemigatinib (n=36), and derazantinib (n=5). Tumor vascularity was assessed via Hounsfield units (HU) from CT images, including a mathematical parameter to calculate a ratio of hypervascular tumor rim thickness to tumor diameter. Transcriptomic analysis of 11 pts was performed to explore mRNA expression related to tumor vasculature. Kaplan-Meier analysis for progression-free survival (PFS) and ANOVA for statistical comparisons were applied. Results: The median age was 60 years, and 41 pts were female. For FGFR2-fused iCCA, median PFS for first-line gemcitabine-based chemotherapy with or without immunotherapy was 4.07 months [3.0-5.1]. Among FGFR inhibitors, mPFS was 7.07 months [95% CI: 5.10-8.16], with no significant difference in outcomes between FGFR inhibitors. 59 pts had comparable CT images and were grouped into 3 groups based on K-means clustering: Group 1 (n=30) had mPFS of 3.07 months [2.03-4.10]; Group 2 (n=22), mPFS of 9.10 months [8.2-11.2]; Group 3 (n=7), mPFS of 34.03 months [18.2-37.6]. Group 1 had the most hypovascular tumors (the lowest HU in the periphery of tumors), while Group 3 had the most hypervascular tumors (p=0.017). The HU ratio of the hypervascular tumor rim thickness to tumor diameter showed a trend, with the highest ratio in Group 3 and the lowest in Group 1 (p=0.09). Transcriptomic analysis revealed a trend toward higher VEGF/VEGFR gene expression in hypervascular tumors. Eight pts received second-line FGFR inhibitors, with mPFS of 5.0 months [2.1-8.3]. Conclusions: Pts with FGFR2-fused iCCA have a shorter PFS on first-line chemotherapy, and PFS outcomes for FGFR inhibitors were consistent with existing data. Tumor vascularity, as assessed by CT imaging, may be a valuable predictor of response to FGFR inhibitors. This study suggests that hypervascular tumors may have better outcomes, warranting further investigation in a larger cohort to confirm these findings and establish tumor vascularity as a predictive biomarker for FGFR inhibitor therapy.

Prediction of stroke in patients with severe aortic stenosis by left atrial appendage filling defect patterns on early and late-phase computed tomography.

Stroke is a feared complication after TAVI. The objective was to assess whether left atrial appendage (LAA) filling-defect (FD) patterns from early and late-phase computed tomography (CT), predict stroke/TIA in patients with severe aortic stenosis. 124 patients with severe aortic stenosis (79.5y, 46.8% females) who underwent CT-Angiography for TAVI-planning were included (66.1% underwent TAVI, 18.6% surgical, 15.3% conservative treatment).CT-image-analysis included: CT-density (HU) from LAA tip-to-base and HU-gradients (I-III), the HU-ratio LAA/aorta, left-atrial-wall-thickness (LAWT) and the periatrial fat attenuation index (FAI). Stroke/TIA rate was 9.6%. LAA-HU-gradient was slightly higher in non-stroke patients (p=0.087). Persisting FDs during the late-phase were associated with stroke (p=0.047) but not early-phase FDs. Early-phase FDs with HU<245 (n=15) were correlated with stroke (p=0.05). A LAA-HU-gradient>10HU had 91% sensitivity and 68% specificity for prediction of stroke. LAA-HU gradient I had a moderate accuracy (c=0.592; 95%CI:0.472-0.711; p=0.317) for discrimination of stroke during the early phase, which enhanced during the late phase (c=0.686;95%CI:0.503-0.868; p=0.046). Patients with stroke had a higher rate of FDs with HU-progression from early to late phase (>10HU)(p=0.013), while the ratios LAA/aorta, LAWT, and periatrial-FAI were not different. Among clinical parameters, only age predicted stroke but not CHA2DS2-VASc-score. In multivariate analysis, late-phase FDs (p=0.059)(OR 5.66: 95%CI:0.936-34.28) but not early-phase FD were associated with stroke, and none of the major conventional risk factors. Persisting LAA-filling defects on CT during the late-phase, and early-phase FD with <245HU predict stroke, and a CT-density progression >10HU from early-to-late phase. LAA-FD may improve stroke risk stratification.

An organ-preserving strategy in patients with esophageal squamous cell carcinoma treated with immunochemotherapy.

424 Background: This study evaluated the strategy of dose-dense chemotherapy plus a PD-1 inhibitor with selective organ-preservation in patients with advanced esophageal squamous cell carcinoma (ESCC). Methods: Patients with locally advanced or metastatic (confined to the supraclavicular lymph nodes) ESCC were enrolled to receive treatment with a PD-1 inhibitor plus albumin bound-paclitaxel, cisplatin and 5-FU every two weeks. After six cycles of treatment, patients with clinical complete response (cCR) confirmed by computed tomography (CT), endoscopy and biopsy underwent an organ-preserving strategy with continuation of immunochemotherapy. The primary endpoint was cCR rate in the intention-to-treat population. A post hoc analysis was also conducted in patients with advanced ESCC who had a best response of CR after immunochemotherapy from three prospective studies we previously reported. Consecutive patients who had not received esophagectomy prior to immunochemotherapy, and had durable CR as confirmed by imaging, endoscopy with or without biopsy were identified to provide supporting evidence for the organ-preserving strategy. Results: A total of twenty patients were enrolled. At data cut-off (September 12, 2024), eight patients fulfilled the criteria of cCR (40%), while six patients actually adopted the organ-preserving strategy. 75% of the patients experienced ≥ grade 3 treatment-related adverse events (TRAEs), most commonly neutropenia and leukopenia. All TRAEs were managed with appropriate medical care. In the post hoc analysis, out of 71 patients who had a best response of CR to immunochemotherapy in three previous trials, sixteen consecutive patients who had not received esophagectomy before immunochemotherapy, and remained CR assessed with CT at data cut-off were identified. Although endoscopy was not mandatory during follow-up, twelve patients underwent endoscopic exams, and none of them had suspected tumor with endoscopic visualization. Biopsies were taken for eight patients, and were all negative for tumor. The median follow-up for these twelve patients reached 42.7 months, suggesting a long-term disease-free survival after immunochemotherapy. Conclusions: Dose-dense nab-paclitaxel, cisplatin and 5-FU combined with a PD-1 inhibitor showed encouraging cCR rate and manageable safety, making organ-preservation a possible subsequent approach in patients with advanced ESCC. Clinical trial information: ChiCTR2300072992.

Quantitative assessment of transmural remission in Crohn's disease using low dose computed tomography (CT) enterography perfusion imaging: a single-centre study based on intestinal microcirculation.

To assess transmural remission in patients with Crohn's disease using low-dose small bowel computed tomography (CT) perfusion scans. Forty six patients were divided into active and remission phases based on Crohn's Disease Activity Index (CDAI) and C-reactive protein (CRP). Dual-source CT enterography with low-dose perfusion scans was conducted to generate perfusion parameter maps, including blood flow (BF), blood volume (BV), time to peak (TTP), mean transit time (MTT), and permeability of surface (PS). We compared differences in perfusion parameter values of intestinal walls, mesenteric fat, and lymph nodes between two groups. Receiver operating characteristic (ROC) curves were plotted, and area under the curve (AUC), sensitivity, specificity, and cutoff values were calculated. The BF, BV, TTP, MTT, and PS values of the intestinal wall were significantly higher in the active phase (P0.05). Additionally, lymph node BF and TTP displayed significant differences (P<0.01). Dual-source CT enterography with low-dose perfusion scans enables quantitative assessment of Crohn's disease microcirculation in intestinal walls, mesenteric fat, and lymph nodes. These quantitative indicators provide strong diagnostic efficacy and offer insights into whether the disease is in transmural remission.

Noise-matched total-likelihood-based bilateral filter: Experimental feasibility in a benchtop photon-counting CBCT system.

Material decomposition induces substantial noise in basis images and their synthesized computed tomography (CT) images. A likelihood-based bilateral filter was previously developed as a neighborhood filter that effectively reduces noise. However, this method is sensitive to image contrast, and the noise texture needs improvement. It is also necessary to address how to optimally combine filtered basis images to synthesize CT images. This study addressed these issues by introducing total likelihood and a noise-matched condition. The experimental feasibility of the proposed method was demonstrated in a benchtop photon-counting CT (PCCT) system using the following steps: (1) A calibration process for forward modeling, (2) maximum likelihood (ML)-based material decomposition, which is accurate but suffers from substantial noise, (3) noise reduction by applying a total-likelihood-based filter, and (4) CT image synthesis using the noise-matched condition. The proposed method was compared with conventional neighborhood filters and statistical iterative reconstruction with edge-preserving regularization. The local noise and task-based modulation transfer function (TTF) were analyzed using a test phantom, and the proposed method was found to preserve the spatial resolution better than the other methods, especially in low-contrast regions. In the chicken leg experiment, the proposed method improved the fine structures and background textures in the denoised images and exhibited superior properties in analyzing the noise power spectrum. The proposed method is effective and computationally efficient for noise reduction in PCCT and can potentially replace conventional iterative edge-preserved regularization approaches.

Nodular-bronchiectatic pattern in pulmonary nocardiosis: Immune status and treatment outcomes in a multicenter retrospective study.

Pulmonary nocardiosis is a rare opportunistic infection, with approximately 15% of patients being immunocompetent. The isolation rate of Nocardia spp. has recently increased, indicating rising clinical concern. This study aimed to summarize computed tomography (CT) findings, evaluate treatment outcomes, and improve disease recognition. We retrospectively analyzed 12 pulmonary nocardiosis cases recorded over 10 years in three hospitals, excluding two unclear cases. All pathogens were detected on smears and isolated from respiratory specimens. The mean age was 73.0±12.9 years, with 9 men and 6 smokers. Among the included patients, 8 had underlying pulmonary diseases, 4 had non-pulmonary diseases, and 3 were on steroids. The most common species were N. cyriacigeorgica and N. nova. CT findings included cavitary, consolidation/infiltrative, and nodular-bronchiectatic (NB) patterns. The NB pattern, particularly common in immunocompetent patients, was associated with significantly better treatment outcomes than non-NB patterns (Fisher's exact test, p=0.0476). All isolates were susceptible to trimethoprim/sulfamethoxazole. Eight patients recovered with appropriate antimicrobial therapy, while two patients died. Pulmonary nocardiosis presented three CT patterns, with the NB pattern being the most frequent and showing favorable treatment outcomes, especially in immunocompetent patients. While Nocardia spp. can develop in patients with preexisting bronchiectasis, it may also independently cause bronchiectasis. Nocardia infection should be considered as a differential diagnosis in patients exhibiting the NB pattern, resembling that of nontuberculous mycobacterial pulmonary diseases.

CT and MRI features of adrenal hemangioma: A study of 21 cases from two centers

PurposeTo retrospectively analyze the CT and MR imaging presentations of adrenal hemangioma (AH) and to strengthen the recognition for such tumors. Materials and methodsThis retrospective study enrolled 21 patients with 22 lesions histologically proven AH from two centers between October 2010 and November 2023. The clinical presentation and preoperative diagnosis were recorded. Two radiologists reviewed the CT and MR imaging features in consensus, including number, size, shape, boundary, attenuation, signal intensity, and dynamic enhancement pattern. ResultsThe study included nine men and twelve women (mean age 55.6 ± 12.5 years, range, 35–77 years) without hormone production. AH was unilateral in 19 cases, bilateral in 2 cases. The maximum diameter was more than 3 cm in 19/22(86 %). AHs had oval (10/22,45 %), round (5/22, 23 %), or (7/22, 32 %) multilocular shape, and well-defined boundary (18/22,82 %). On unenhanced CT, 11/20 (55 %) displayed peripheral iso-density and central hypo-intensity, 3/20 (15 %) heterogeneously hyper-density, 6/20 (30 %) hypodensity, and 14/20 (70 %) contained speckled calcification. On T2-weighted images, 7/12 (58 %) exhibited nodular hyper-intensity peripherally, markedly hyper-intensity centrally, and hypo-intense fibrotic scar in between, 5/12 (42 %) hyperintensity. On T1-weighted images, 6/12 (50 %) displayed center hyper-intensity surrounded by peripheral hypo-intensity,5/12 hypo-intensity, 1/11 (9 %) hyperintensity. On DWI, 7/12 (58 %) demonstrated peripheral hyper-intensity and central hypo-intensity, 5/12 (42 %) hyper-intensity. CT and MR imaging findings were suggestive of cystic change and necrosis (19/22,86 %, 4 cystic tumors), hemorrhage (15/22,68 %), fat (7/22, 33 %) within the tumors. CT and MR enhanced images showed peripheral nodular enhancement with (3/22,14 %) or without (13/22, 59 %) delayed central filling, nodular peripheral and center enhancement with progressive partial fill-in (2/22,9%), capsular and/or septal mild enhancement (4/22, 18 %), and capsule (16/22,73 %). The solid part was significantly enhanced, similar to the abdominal aorta (AA) with no statistical difference between the two (P > 0.05). ConclusionsSmall AHs (<3cm) have the typical imaging features of hemangioma. The imaging findings of large AHs were various, the combination of T2-hyperintense signal with inner hypo-intense fibrotic scar, speckled calcification, central extensive necrosis and hemorrhage, and nodular peripheral enhancement with persistently slight further contrast accumulation may contribute to suggest the possibility. Cystic AH should be considered as a differential diagnosis for cystic adrenal masses.

Imaging Findings, Complications, and Mimics after Common and Advanced Dental Procedures.

Various new dental treatment methods have been introduced in dental clinics, and many new materials have been used in recent years for dental treatments. Dentistry is divided into several specialties, each offering unique treatments, such as endodontics, implantology, oral surgery, and orthodontics. CT and MR images after dental treatment reveal a variety of hard- and soft-tissue changes and dental materials, which often cause image artifacts. Familiarity with posttreatment changes and dental materials is crucial to avoid misinterpretation of image artifacts as true pathologic features, identify complications, and evaluate for recurrent disease. It also is necessary to be aware of conditions that mimic posttreatment changes and know how to differentiate them at imaging. The authors focus on the imaging of expected and unexpected post-dental treatment changes and characteristics of dental materials on CT and MR images in the head and neck region. The article is divided into five sections: (a) imaging after dental implant treatment, (b) imaging after oral surgery, (c) imaging after endodontic treatment, (d) imaging after orthodontic treatment, and (e) imaging effects of dental treatments. Strategies are provided for distinguishing true pathologic features from posttreatment changes, and the importance of understanding dental procedures, the materials used, and their appearances at radiologic imaging is highlighted. Ultimately, this knowledge can enhance radiologists' ability to interpret complex posttreatment imaging findings, improve diagnostic accuracy, and facilitate effective treatment planning for patients with a history of dental procedures. ©RSNA, 2025 Supplemental material is available for this article.

Analysis of Prognostic Factors and Treatment Outcomes in Indirect Traumatic Optic Neuropathy: A Retrospective Review of 105 Patients

Purpose To identify risk factors for vision recovery in indirect traumatic optic neuropathy (TON) and to analyze the outcomes associated with surgical treatment for TON. Methods Between 2020 and 2023, a total of 105 patients diagnosed with traumatic optic neuropathy (TON) at Shanghai Ninth People’s Hospital and Shanghai Minhang Hospital were included in a retrospective study. These individuals underwent optic nerve decompression surgery as part of their treatment. To collect comprehensive data, both preoperative and postoperative information was gathered. For analytical purposes, only those patients who had a minimum of one month follow-up post-treatment were considered. The statistical analysis incorporated the use of median values, odds ratios (OR), and 95% confidence intervals (CI) to interpret the data. Any p-values less than 0.05 were deemed to indicate statistical significance, underlining the rigorous criteria set for this study. Results A total of 105 patients, with a mean age of 31.8 ± 14.9 years, met the inclusion criteria; 89.5% (94) were men, and 10.5% (11) were women. The median time to seek medical attention after injury was 4 days (range: 1 to 15 days). Prognostic factors associated with visual acuity (VA) improvement included a gradual VA loss pattern (OR: 2.22, 95% CI: 0.91–5.67, p = 0.045), while canal fractures (OR: 0.31, 95% CI: 0.095–0.933, p = 0.019) significantly correlated with poor VA outcomes. Conclusions This study suggested that surgical interventions benefit TON patients with low vision. Gradual VA loss, rather than sudden loss after injury, may be a potential prognostic factor for favorable VA outcomes, while canal fractures, as detected on computed tomography (CT) imaging—especially complex canal fractures, are associated with poor VA outcomes. In the future, more definitive prospective treatment trials are required to identify optimal treatment strategies for TON.

An Endpoint Adjudication Committee for the Assessment of Computed Tomography Scans in Fracture Healing

IntroductionEndpoint Adjudication Committees (EACs) benefit the quality of randomized control trials (RCTs) where outcomes depend on subjective interpretations. However, assembling a committee to adjudicate large datasets is cumbersome. In a recent RCT, the primary outcome was time to union following operative fixation of scaphoid non-union, with real or placebo adjunctive ultrasound treatment. Union status was determined with computed tomography (CT) scans interpreted by treating surgeons and radiologists. An EAC was established to deliberate discrepancies between radiologists’ and surgeons’ interpretations of union status. MethodsThree hundred sixty-four CT scans from 142 participants were collected in the RCT. The treating surgeon and an MSK radiologist categorized images by percent-union (0%, 1-24%, 25-49%, 50-74%, 75-99%, 100%). Union was defined as at least 50% trabecular bridging. The EAC adjudicated those images that were deemed major discrepancies. The committee was composed of three members assembled by the committee chair, an MSK radiologist. A charter was established to guide the adjudication process. Ten minutes were allotted to each scan, including 2-3 minutes of an independent adjudicator's review, followed by 5-7 minutes of committee discussion to reach a diagnosis. ResultsAdjudicators spent an average of seven minutes on each scan. The EAC assessed 101 CT scans from 69 patients collected across five study sites: four scans from the agreed upon group as practice interpretations, 75 major discrepancies, and 22 missing interpretations from either the initial MSK radiologist, the treating orthopaedic surgeon, or both. These were adjudicated for final union status. Twenty-eight of the images with major discrepancies were adjudicated to union, and 47 to non-union. Adjudication changed the primary outcome of time to union in 40/142 (28%) of study participants. ConclusionThis adjudication process provides a valuable research tool for reference by other clinical investigators whose RCTs’ outcomes are dependent on interpretation of radiographic images.

Massive pneumocephalus after Valsalva maneuver in sphenoidal meningocele.

Pneumocephalus, defined as the presence of gas within the intracranial space, typically results from head trauma, surgery, or diagnostic/therapeutic procedures that disrupt the dura. However, spontaneous or non-traumatic pneumocephalus is rare. This video article presents a case report of a 64-year-old woman referred to the Department of Otolaryngology with a severe frontal headache and clear nasal discharge (rhinorrhea) after performing the Valsalva maneuver to relieve ear fullness. The patient had previously been diagnosed with sphenoidal meningocele and was awaiting skull base reconstruction surgery. A computed tomography (CT) scan of the brain and paranasal sinuses revealed significant pneumocephalus, with a defect in the sellar floor and cerebrospinal fluid (CSF) pooling in the sphenoid sinus. An endoscopic trans-sphenoidal repair of the CSF leak was promptly performed, and a post-operative CT scan showed complete resolution of the pneumocephalus. At the 2-month follow-up, the defect had healed optimally, with no intracranial complications observed. Pneumocephalus is a rare clinical condition, and prompt, accurate diagnosis, along with early intervention, is crucial to prevent neurological complications.

The impact of maximum cross-sectional area of lesion on predicting the early therapeutic response of multidrug-resistant tuberculosis.

Early evaluation of culture conversion after 6-month treatment of multidrug-resistant tuberculosis (MDR-TB) is vital for outcome prediction. This study aims to merge the maximum lesion cross-sectional area observed via computed tomography (CT) imaging during treatment to predict therapeutic response. We retrospectively involved MDR-TB patients who completed 6 months of treatment from two hospitals. Patients were categorized into culture conversation and no culture conversation groups based on sputum culture results. The data from the two hospitals were used as internal training and external testing cohorts, respectively. Logistic regression and random forest models were developed using the maximum lesion cross-sectional area and most important predictive features. The model performance was evaluated using the area under the curve (AUC), accuracy, sensitivity, specificity, and F1 score. In the model without the maximum lesion cross-sectional area to predict culture conversion for MDR-TB after 6 months of treatment, logistic regression and random forest models achieved AUC values of 0.796 and 0.958, sensitivities of 0.725 and 0.993, and F1 scores of 0.803 and 0.957 in the training cohort, respectively. In the testing cohort, logistic regression and random forest models achieved AUC values of 0.889 and 0.855, respectively. Evaluating the maximum lesion cross-sectional area at baseline, 2 months, and 6 months, logistic regression and random forest models in the training cohort yielded AUC values of 0.819 and 0.998, sensitivities of 0.674 and 1.000, and F1 scores of 0.772 and 0.986. In the testing cohort, the AUC values were 0.869 and 0.920, sensitivities were 0.933 and 1.000, and F1 scores were 0.848 and 0.841, respectively. The integration of maximum lesion cross-sectional area during treatment can improve the prediction of early treatment response in MDR-TB. When applied in a clinical setting, the random forest model is more suitable for guiding appropriate treatment plans quickly.