Journal of Computer Assisted Tomography最新文献

Purpose: Early diagnosis of cauda equina syndrome is essential to prevent irreversible neurological damage, but MRI can be unavailable or contraindicated. This study aimed to evaluate whether photon-counting CT (PCCT) can be a reliable alternative to reference standard MRI for diagnosing cauda equina syndrome.

Methods: In this prospective study, participants with different conditions, including degenerative spinal canal stenosis, disk herniation, vertebral compression fracture, and intraspinal extradural tumor underwent PCCT and MRI between November 2022 and March 2024 at a university hospital. Three radiologists independently evaluated images for compression of cauda equina and/or spinal cord, level and cause of compression, and spinal cord visibility. Intrarater sensitivity and specificity in diagnosing compression of cauda equina and/or spinal cord on PCCT versus MRI were calculated. Pearson correlation between PCCT and MRI was assessed for dural sac areas at all lumbar disk levels. Point-biserial correlation was calculated for body mass index (BMI) versus spinal cord visibility.

Results: A total of 14 participants [mean age 76±6 y (SD); 8 women] were examined. PCCT demonstrated 100% sensitivity and 60% to 83% specificity for diagnosing compression of cauda equina and/or spinal cord across 3 raters, compared with MRI. Axial area measurements showed an almost perfect correlation between modalities (r >0.9), with PCCT slightly underestimating areas in 70% of measurements. PCCT visualized the spinal cord in all participants, but in 19% of the assessments it was barely visible. No correlation was found between BMI and spinal cord visibility ( P >.05).

Conclusions: Photon-counting CT demonstrated its usefulness as a rapid alternative in selected patients with suspected cauda equina syndrome (excluding spinal hematomas and spondylodiscitis), when MRI is unavailable or contraindicated. There were strong correlations in spinal canal stenosis measurements with MRI, showing its potential as an alternative to MRI in nonacute conditions of the lumbar spine, such as degenerative disk disease.

Purpose: To conduct an intraindividual comparative analysis of ophthalmic artery imaging quality between photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT), evaluating both objective and subjective assessments.

Materials and methods: This retrospective study analyzed patients undergoing carotid artery imaging with both PCD-CT and EID-CT systems. Quantitative analysis involved objective measurements of vascular attenuation (Hounsfield units, HU), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) using standardized region-of-interest (ROI) placements. For qualitative assessment, 2 blinded radiologists independently evaluated subjective image quality through 5-point Likert scales.

Results: The cohort [n=26; mean age 65.6±12.6 y; 16 males (61.5%)] demonstrated significantly enhanced performance with PCD-CT. Compared with EID-CT, SNR, CNR, and attenuation values from the PCD-CT system were all significantly higher than values from EID-CT (all P <0.05). Qualitative assessments revealed superior PCD-CT scores across all parameters (all P <0.0001).

Conclusions: PCD-CT provides significant improvements in both objective and subjective measurements of ophthalmic artery imaging compared with EID-CT, suggesting its potential as the preferred modality for vascular visualization.

Objective: To determine the optimal iodine concentration (IC) to differentiate enhancing from nonenhancing renal lesions at venous phase photon-counting CT (PCCT).

Materials and methods: Sixty-seven patients [41 males, mean (SD) age: 68 (13) y] who underwent contrast-enhanced venous phase abdominal PCCT and contrast-enhanced MRI were retrospectively identified. MRI characterization of renal lesions as simple cysts, hemorrhagic/proteinaceous cysts or masses was the reference standard. Two radiologists, blinded to MRI characterization, independently drew region-of-interests (ROI) within each renal lesion and the aorta to determine IC, iodine concentration normalized to aortic enhancement (NIC), postcontrast and virtual noncontrast attenuation. These variables were compared using nonparametric tests, and intraclass correlation coefficient was assessed. ROC analysis for IC, NIC, and attenuation difference was performed using mean measurements.

Results: Median (IQR) IC was 0.015 (0.00 to 0.20) mg/mL for cysts (n = 41) and 3.00 (1.59 to 4.10) mg/mL for masses (n = 26; P < 0.001). NIC was 2 (-1 to 4)% for cysts and 58 (33 to 81)% for masses ( P < 0.001). For differentiating cysts from masses, 0.6 mg/mL IC had 100% sensitivity and 95% specificity [AUC = 1.00 (0.99, 1.00)] and 14.1%. NIC had 100% sensitivity and 98% specificity [AUC = 1.00 (0.99, 1.00)]. For differentiating cysts from enhancing masses, a 20 HU attenuation change from VNC to postcontrast images demonstrated a sensitivity of 96% and specificity of 95% [AUC = 1.00 (0.99, 1.00)]. IC was 0.13 (-0.11 to 0.20) mg/mL for hemorrhagic cysts (n = 16) and 1.63 (1.31 to 1.89) mg/mL for papillary neoplasms (n = 8; P < 0.001). NIC was 2 (-1 to 5)% and 32 (22 to 40)%, respectively ( P < 0.001). For differentiating hemorrhagic cysts from papillary neoplasms, 0.53 mg/mL IC had 100% sensitivity and 88% specificity [AUC = 0.98 (0.93, 1.00)] and 14.1% NIC had 100% sensitivity and 94% specificity [AUC = 0.98 (0.95, 1.00)]. A 20 HU change had 88% sensitivity and specificity. For differentiating hemorrhagic cysts from papillary neoplasms, a 20 HU attenuation change had 88% sensitivity and 88% specificity [AUC = 0.98 (0.93, 1.00)].

Conclusions: PCCT iodine concentration showed outstanding diagnostic performance to differentiate renal cysts from neoplasms. A 20 HU change in attenuation from VNC to postcontrast imaging on PCCT remains a reliable threshold for enhancing lesion, similar to conventional CT. Iodine concentration demonstrated superior sensitivity and specificity compared with 20 HU change when identifying renal cysts versus masses.

Photon-counting detector computed tomography (PCD-CT) is an emerging imaging modality that offers substantial benefits in pediatric imaging, including improved spatial and contrast resolution, reduced radiation exposure, and advanced spectral imaging capabilities. This review summarizes current evidence across key pediatric body systems. In neurological imaging, PCD-CT has demonstrated superior image quality in evaluating fine temporal bone structures and reduced radiation dose, particularly in children under 6. Cardiovascular applications benefit from high-pitch dual-source acquisition and spectral imaging, improving delineation of congenital heart defects with reduced radiation and, potentially, contrast dose. Thoracic studies highlight significant radiation dose reduction while preserving diagnostic image quality in diseases such as cystic fibrosis. In abdominal imaging, PCD-CT allows consistent, high-quality imaging with simplified protocols and reduced iodinated contrast requirements, especially in challenging tasks like biliary structure visualization. Despite promising phantom and retrospective studies, research in musculoskeletal imaging remains sparse, with only limited pediatric data available. Nonetheless, PCD-CT shows potential for quantitative bone assessment, a critical application for children with chronic disease or at risk for osteoporosis. While early data are promising, significant gaps remain regarding protocol optimization, age-stratified performance, and the full utility of spectral reconstructions in pediatric imaging. Continued investigation is necessary to establish evidence-based guidelines and unlock the full clinical potential of PCD-CT in pediatric radiology.

Objective: We hypothesize that contrast warming, which reduces the viscosity of iodinated contrast media, is associated with fewer pressure-limited injections and greater arterial enhancement in the left ventricle, aortic root, left coronary artery, and right coronary artery, which would reflect improved image quality.

Methods: We conducted a retrospective review of cardiac CTA studies performed with iohexol 350 mg/mL solution either prewarmed to body temperature (37 °C, N=591) or at room temperature (24 °C, N=59). χ 2 test was used to compare the rate of pressure-limited injections (pressure limit 325 psi) between prewarmed and nonwarmed studies. Hounsfield unit (HU) attenuation was measured from regions of interest in the left ventricle, aortic root, left coronary artery, and right coronary artery. The Mann-Whitney U test was used to compare enhancement between prewarmed and nonwarmed exams. Linear regression was used to further examine the enhancement between contrast groups.

Results: Cardiac CTA studies using prewarmed contrast had a significantly lower rate of pressure-limited injections (22/591 vs. 42/59, χ 21 =275.1; P <0.001). Prewarmed contrast resulted in significantly greater enhancement on cardiac CTA in the left ventricle (488 vs. 400 HU; P <0.001), aortic root (494 vs. 400 HU; P <0.001), left coronary artery (467 vs. 387 HU; P <0.001), and right coronary artery (449 vs. 377 HU; P <0.001). With linear regression, prewarmed contrast use was associated with greater enhancement in the left ventricle ( R2 =0.220, F7, 602 =24.211, P <0.001), aortic root ( R2 =0.228, F7, 602 =25.467, P <0.001), left coronary artery ( R2 =0.216, F8, 587 =20.274, P <0.001), and right coronary artery ( R2 =0.221, F8, 571 =20.302, P <0.001).

Conclusions: The results support our hypothesis that prewarming of iodinated contrast media to body temperature results in fewer pressure-limited injections and improved vascular enhancement.

Background: Hypertriglyceridemic acute pancreatitis (HTG-AP) is a distinct subtype of acute pancreatitis with a wide spectrum of clinical severity, ranging from mild to moderately severe or severe disease. Timely identification of patients at higher risk is essential for informing early clinical decisions and improving outcomes. However, reliable tools specifically designed to stratify HTG-AP severity remain limited.

Objective: To develop and validate a predictive model for distinguishing mild from moderately severe/severe hypertriglyceridemic acute pancreatitis (HTG-AP) using routine clinical and imaging parameters.

Methods: This retrospective study included 106 patients diagnosed with HTG-AP at Guangzhou First People's Hospital from January 2018 to April 2023. Patients were categorized into mild (HTG-MAP) and moderately severe/severe (HTG-MSAP/SAP) groups based on the revised Atlanta classification. Clinical data, laboratory results, and imaging findings, including peak C-reactive protein (CRP), serum calcium levels, and Modified CT Severity Index (MCTSI) scores, were analyzed. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of disease severity. Model performance was assessed through 10-fold cross-validation and bootstrap calibration.

Results: Among the 106 patients (median age: 38 y; 82.1% male), 46 had HTG-MAP and 60 had HTG-MSAP/SAP. Multivariate analysis identified peak CRP (OR: 1.0082, P =0.011), serum calcium (OR: 0.05, P =0.014), and MCTSI score ≥6 (OR: 4.91, P =0.008) as independent predictors of severe disease. The final logistic regression model demonstrated excellent discrimination, with an AUC of 0.900 in the overall cohort and a mean cross-validated AUC of 0.87. Calibration was satisfactory (Hosmer-Lemeshow P =0.774), and overall diagnostic accuracy reached 84.91%.

Conclusions: The proposed model, incorporating peak CRP, serum calcium, and MCTSI score, effectively distinguishes between HTG-MAP and HTG-MSAP/SAP. Compared with conventional scoring systems such as Bedside Index for Severity in Acute Pancreatitis (BISAP), it demonstrates superior specificity and overall diagnostic accuracy, providing clinicians with a practical tool for risk stratification and clinical decision-making in HTG-AP.

Objective: To prospectively estimate the ability of photon-counting detector (PCD) CT to improve radiologist confidence for peritoneal disease compared with conventional energy-integrating detector (EID) CT.

Methods: Patients with suspected abdominopelvic peritoneal disease underwent clinically indicated EID-CT followed by a same-day research PCD-CT after informed consent. Both scans used IV contrast (up to 200 mL total across both scans). In separate evaluation sessions, 4 radiologists independently reviewed each subject's images once per session, randomly evaluating EID-CT images (1 or 2 mm) or PCD-CT images (120 kV threshold low 1 mm or 50 keV 2 mm). Readers evaluated right versus left supracolic, and inframesocolic spaces, rating confidence in peritoneal malignancy (0 to 100). Overall tumor burden in these regions and on serosal surfaces of the liver, spleen, small bowel, and anterior peritoneal reflection was also graded (0 to 3 scale). In side-by-side comparisons (blinded to CT modality and reconstruction configuration), radiologists ranked preference for each modality/configuration from greatest to least, with ties permitted and with differences ≥ of 2 indicating increased confidence in diagnosis, with separate comparisons for the upper abdomen, mid-abdomen, and pelvis. Linear regression with mixed effects was used to compare confidence and tumor burden scores for each modality/configuration while logistic regression with mixed effects was used for side-by-side comparisons.

Results: Twenty-one patients underwent same-day EID-CT and PCD-CT (mean CTDI vol EID-CT-11.6 versus PCD-CT-11.2 mGy). Despite significantly less iodinated contrast used at PCD-CT (63.8±11.7 versus 136.2±11.7 mL, P <0.0001), confidence scores were similar between modalities. Tumor burden was estimated to be greater for serosal metastases to the liver ( P =0.043) when using 1 mm PCD-CT images. In blinded side-by-side comparisons, the odds of 120 kV 1-mm or 50 keV 2-mm PCD-CT images having a preference rank reflecting increased confidence compared with EID-CT 1 mm in the mid-abdomen was significant [odds ratios (OR): 5.19 and 8.54, respectively, P <0.001] with similar findings in the pelvis (OR for 50 keV PCD-CT: 5.26, P =0.007).

Conclusion: Despite using substantially less IV contrast, radiologist confidence in malignancy was similar at PCD-CT performed after EID-CT. In side-by-side comparisons, PCD-CT images had a significantly increased odds of increasing radiologist confidence compared with EID-CT in the mid-abdomen and pelvis.

Purpose: To describe the clinical manifestations of coral reef aorta (CRA), determine the common locations of CRA on CT, and assess the relationship between lesion location and clinical symptoms.

Materials and methods: Keyword detection in CT reports at a single institution between 2008 and 2021 revealed 27 patients with CRA. Aortic segments were grouped by relation to the aortic branches. Patient's characteristics, cardiovascular risk factors, treatments, and outcomes were collected from the medical record.

Results: Median age was 63.7 (IQR: 58.1-70.6). Of the total, 77.8% (21/27) were females. The most common risk factors were hypertension (23/27) and smoking (24/27). Diabetes was present in 4/27, 14.8%. All CRAs were at the level of the celiac trunk or distal. The most common symptom was claudication (9/27), but 8/27 were asymptomatic. Approximately 74% of the CRAs were superior to the inferior mesenteric artery (20/27).Claudication was significantly more common in patients with CRA inferior to the inferior renal artery (iRA, 8/13, 61.5%) than those with the CRA superior to the iRA (including iRA) (2/14, 14.3%; P = 0.018). Pulmonary edema was seen in 2/5 patients with CRA between the superior renal artery and iRA compared with none when the CRA was located in other segments ( P = 0.043).

Conclusion: Nearly all patients with CRA had a history of hypertension and smoking, and the majority were female. The most common CRA segment was distal to the iRA, which was associated with claudication. The CRA involving the renal arteries was associated with recurring pulmonary edema.

Objective: Anatomic image-defined risk factors (IDRFs) and metabolic metrics from PET/CT imaging can evaluate tumor biology and guide clinical decision-making in neuroblastoma. This study explored the association between IDRFs and 18 F-FDG PET/CT metabolic metrics in neuroblastoma and compared their prognostic value.

Methods: A retrospective analysis was conducted on 24 neuroblastoma patients who underwent pretreatment CECT and 18 F-FDG PET/CT imaging. IDRF counts were determined from CECT, while PET/CT metabolic metrics, including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were measured. The Spearman correlation analysis assessed associations between IDRF counts and PET/CT metabolic metrics. Survival analysis evaluated the prognostic significance of IDRF counts and PET/CT metabolic metrics.

Results: IDRF counts were positively correlated with SUVmean ( r =0.431, P =0.036), MTV ( r =0.679, P <0.001), and TLG ( r =0.771, P <0.001), but no significant correlation was observed with SUVmax ( r =0.325, P =0.121). Subgroup analysis revealed IDRF counts correlated with MTV ( r =0.718, P =0.001) and TLG ( r =0.683, P =0.002) in abdominopelvic lesions, and with SUVmax ( r =0.808, P =0.028), SUVmean ( r =0.875, P =0.010), and TLG ( r =0.788, P =0.035) in cervicothoracic lesions. Neither IDRF counts nor PET/CT metabolic metrics were significantly associated with overall survival ( P >0.05).

Conclusion: IDRF counts are significantly associated with 18 F-FDG PET/CT metabolic metrics in neuroblastoma, with distinct correlation patterns based on lesion location.

Objective: The purpose of this study was to evaluate the potential clinical value of spectral CT for image guidance during percutaneous thermal ablation, particularly investigating high monoenergetic (MonoE) for metal artifact reduction.

Materials and methods: A phantom experiment was performed in which an ablation probe was scanned in "continuous CT" (CCT) mode on a spectral CT scanner. ROI measurements quantified metal artifacts for conventional and MonoE CCT images. Subsequently, a retrospective reader study was conducted with 10 patient cases. Three radiologists reviewed cases to select the optimal MonoE setting and perform a Likert score rating (+2: MonoE preferred, -2: conventional preferred).

Results: Phantom measurements indicated a reduction in metal artifact for high MonoE (150 keV: -46 HU) relative to conventional CCT (-122 HU). The MonoE setting preference was 151±21 keV. The mean Likert score was 1.2±0.7. Radiologists indicated a perceived benefit of high MonoE CCT when probe placement was near a critical structure.

Conclusions: This study indicates a clinical preference for high MonoE CCT compared with conventional CCT. Insofar as spectral CCT can be offered at a clinically feasible time frame, our results support the assessment of 150 keV image to reduce metal artifact while maintaining satisfactory soft tissue contrast.