Journal of Computer Assisted Tomography最新文献

Objective: In recent years, experience has been accumulated in microwave ablation (MWA) of ground-glass nodules (GGNs). The goal of this retrospective study was to explore the feasibility, safety, and efficacy of synchronized computed tomography (CT)-guided MWA combined with intraoperative percutaneous biopsy (PB) for the treatment of highly suspected malignant GGNs.

Methods: From January 2021 to February 2025, 93 patients with highly suspected malignant GGNs underwent MWA and PB. Forty-one patients in group A were treated with sequential low power MWA-PB-radical MWA in one session. Fifty-two patients in group B were treated with staged procedures. The pathologic diagnostic results and pathology positive diagnosis rate were evaluated. The technical success, complete ablation rate, and complications were analyzed. The total operative time, irradiation dose, hospitalization time, and hospitalization expenses were compared between the 2 groups.

Results: The technical success rate of both groups was 100%. The complete ablation rates of group A and group B were 100% and 98.1%, respectively ( P >0.05). The positive pathologic diagnosis rate of group A was 90.2% (37/41). The incidence of pneumothorax and intrapulmonary hemorrhage was lower in group A than in group B (29.3% vs. 50.0%, P =0.04; 17.1% vs. 61.5%, P <0.001). The total operative time, irradiation dose, hospitalization time, and hospitalization expenses were lower in group A than in group B (all P <0.001).

Conclusion: Synchronized MWA and intraoperative PB is a safe and effective strategy with satisfactory technical success, complete ablation rates, and acceptable rates of positive pathologic diagnosis, which is an alternative treatment for GGNs with high suspicion of malignancy.

Objective: Adoption of abdominal photon counting detector CT (PCD-CT) into clinical pediatric CT practice requires evidence that it provides diagnostic images at acceptable radiation doses. Thus, this study aimed to compare radiation dose and image quality of PCD-CT and conventional energy-integrating detector CT (EID-CT) in pediatric abdominopelvic CT.

Materials and methods: This institutional review board-approved retrospective study included 147 children (median age 8.5 y; 80 boys, 67 girls) who underwent clinically indicated contrast-enhanced abdominopelvic PCD-CT between October 1, 2022 and April 30, 2023 and 147 children (median age 8.5 y; 74 boys, 73 girls) who underwent EID-CT between July 1, 2021 and January 1, 2022. Patients in the 2 groups were matched by age and effective diameter. Radiation dose parameters (CT dose index volume, CTDI vol ; dose length product, DLP; size-specific dose estimate, SSDE) were recorded. In a subset of 25 matched pairs, subjective image quality was assessed on a scale of 1 to 4 (1=highest quality), and liver attenuation, dose-normalized noise, and contrast-to-noise ratio (CNR) were measured. Groups were compared using parametric and/or nonparametric testing.

Results: Among the 147 matched pairs, there were no significant differences in sex ( P =0.576), age ( P =0.084), or diameter ( P =0.668). PCD-CT showed significantly lower median CTDI vol , DLP, and SSDE (1.6 mGy, 63.8 mGy-cm, 3.1 mGy) compared with EID-CT (3.7 mGy, 155.3 mGy-cm, 6.0 mGy) ( P< 0.001). In the subset of 25 patients, PCD-CT and EID-CT showed no significant difference in overall image quality for reader 1 (1.0 vs. 1.0, P =0.781) or reader 2 (1.0 vs. 1.0, P =0.817), or artifacts for reader 1 (1.0 vs. 1.0, P =0.688) or reader 2 (1.0 vs. 1.0, P =0.219). After normalizing for radiation dose, image noise was significantly lower with PCD-CT ( P <0.001), while CNR in the liver ( P =0.244) and portal vein ( P =0.079) were comparable to EID-CT.

Conclusion: Abdominopelvic PCD-CT in children significantly reduces radiation dose while maintaining subjective image quality, and accounting for dose levels, has the potential to lower image noise and achieve comparable CNR to EID-CT. These data expand understanding of the capabilities of PCD-CT and support its routine use in children.

Objective: To analyze symptoms, imaging features, management, and outcomes of musculoskeletal myeloid sarcoma in adult leukemic patients.

Materials and methods: This is a retrospective analysis of clinical symptoms, imaging features, management, and outcomes in 41 adult leukemic patients with biopsy-proven myeloid sarcomas of bones and muscles.

Results: Nineteen patients had acute, and 15 had chronic myeloid leukemia. Additional 5 previously treated leukemia patients included 1 with chronic myeloid leukemia, 3 with myelofibrosis, and 1 with myelodysplastic syndrome. The remaining 2 patients had isolated myeloid sarcoma with normal marrow without a history of hematologic disorder. Twenty-nine patients had bone tumors only, 3 muscle tumors only, 8 both bone and soft tissue tumors, and 1 intraarticular synovial tumor of an ankle. Of the 71 focal bone tumors, 68 were lytic and 3 were sclerotic. In addition, diffuse sclerotic bone lesions were present in 1 patient, and diffuse mixed lytic/sclerotic bone lesions in 2 patients. Most tumors were asymptomatic and were discovered incidentally on imaging. Local pain, mass, and pathologic fractures were the most common complaints when present. Vertebral bone and paravertebral soft tissue tumors caused neurological symptoms. Muscle tumors became symptomatic when they involved adjoining bone, nerve, or spinal cord. Only 3 among 13 muscle tumors presented as palpable masses. The imaging features of these musculoskeletal tumors were nonspecific. On MRI, both muscle and lytic bone MSs were hypo-to-iso-intense on T1WI, hyperintense on fat-suppressed T2WI, and enhanced on post-contrast fat-suppressed T1WI. A synovial myeloid sarcoma of the ankle showed diffusely thickened synovium on MRI. F-18 FDG PET-CT was helpful in the detection, monitoring of treatment response, and post-treatment surveillance in 5 patients. All patients were treated with cytarabine-based systemic anti-leukemic treatment and optional radiation, surgical resection, bone marrow transplant, and/or a combination of these. The known mean survival time of 35 dead patients after the appearance of musculoskeletal MS was 12.1 months.

Conclusions: Musculoskeletal myeloid sarcoma, which can occasionally precede it, is a rare complication of AML. Most tumors are asymptomatic. Imaging, particularly MRI and 18-F FDG PET-CT, plays a crucial role in detecting and monitoring treatment response, as well as post-treatment surveillance. The disease has poor clinical outcomes and short-term survival.

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.