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Journal of Computer Assisted Tomography - Current Issue

Journal of Computer Assisted Tomography - Current Issue
  1. A Comparison of the Image Quality and Radiation Dose With Routine Computed Tomography and the Latest Gemstone Spectral Imaging Combination of Different Scanning Protocols in Computed Tomography Angiography of the Kidney
    imageObjective: The objective of our study was to compare the image quality and radiation dose of computed tomography angiography (CTA) of the kidney in patients with different body mass indexes using routine CT and the latest gemstone spectral imaging (GSI) combination of different scanning protocols with the adaptive statistical iterative reconstruction 2.0 algorithm. Methods: A total of 90 patients who had undergone a CTA of the kidney were divided into 3 groups (A, B, and C), with 30 patients in each group. Group A underwent a routine CT examination, whereas groups B and C underwent GSI with different scanning protocols. All images were restructured using the adaptive statistical iterative reconstruction 2.0. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of all images were calculated when the kidney CTA was completed. Each subjective image evaluation used a 5-point scoring method and was conducted by 2 independent radiologists. The CT dose index of volume and the dose-length product were recorded, and the mean value was calculated. The dose-length product was converted to the effective dose. All data were compared with a 1-way analysis of variance. Results: The SNR, CNR, and subjective image quality in group A were significantly lower than those in groups B and C (P < 0.01). There were no significant differences in SNR, CNR, and subjective image quality between groups B and C. The effective dose of group C decreased by 46.05% and 15.03% relative to those of groups A and B, respectively (P < 0.01). Conclusions: The latest GSI with different scanning protocols can more effectively reduce the radiation dose than can the routine CT scan mode for a kidney CTA while still maintaining diagnostic image quality.



  2. Aortic and Hepatic Contrast Enhancement During Hepatic-Arterial and Portal Venous Phase Computed Tomography Scanning: Multivariate Linear Regression Analysis Using Age, Sex, Total Body Weight, Height, and Cardiac Output
    imageObjective: We evaluated the effect of the age, sex, total body weight (TBW), height (HT) and cardiac output (CO) of patients on aortic and hepatic contrast enhancement during hepatic-arterial phase (HAP) and portal venous phase (PVP) computed tomography (CT) scanning. Methods: This prospective study received institutional review board approval; prior informed consent to participate was obtained from all 168 patients. All were examined using our routine protocol; the contrast material was 600 mg/kg iodine. Cardiac output was measured with a portable electrical velocimeter within 5 minutes of starting the CT scan. We calculated contrast enhancement (per gram of iodine: [INCREMENT]HU/gI) of the abdominal aorta during the HAP and of the liver parenchyma during the PVP. We performed univariate and multivariate linear regression analysis between all patient characteristics and the [INCREMENT]HU/gI of aortic- and liver parenchymal enhancement. Results: Univariate linear regression analysis demonstrated statistically significant correlations between the [INCREMENT]HU/gI and the age, sex, TBW, HT, and CO (all P < 0.001). However, multivariate linear regression analysis showed that only the TBW and CO were of independent predictive value (P < 0.001). Also, only the CO was independently and negatively related to aortic enhancement during HAP and to liver parenchymal enhancement when the contrast material injection protocol was adjusted for the TBW (P < 0.001). Conclusion: By multivariate linear regression analysis only the TBW and CO were significantly correlated with aortic and liver parenchymal enhancement; the age, sex, and HT were not. The CO was the only independent factor affecting aortic and liver parenchymal enhancement at hepatic CT when the protocol was adjusted for the TBW.



  3. Non-Gaussian Diffusion Imaging Shows Brain Myelin and Axonal Changes in Obstructive Sleep Apnea
    imageObjective: Obstructive sleep apnea (OSA) is accompanied by brain changes in areas that regulate autonomic, cognitive, and mood functions, which were initially examined by Gaussian-based diffusion tensor imaging measures, but can be better assessed with non-Gaussian measures. We aimed to evaluate axonal and myelin changes in OSA using axial (AK) and radial kurtosis (RK) measures. Materials and Methods: We acquired diffusion kurtosis imaging data from 22 OSA and 26 controls; AK and RK maps were calculated, normalized, smoothed, and compared between groups using analysis of covariance. Results: Increased AK, indicating axonal changes, emerged in the insula, hippocampus, amygdala, dorsolateral pons, and cerebellar peduncles and showed more axonal injury over previously identified damage. Higher RK, showing myelin changes, appeared in the hippocampus, amygdala, temporal and frontal lobes, insula, midline pons, and cerebellar peduncles and showed more widespread myelin damage over previously identified injury. Conclusions: Axial kurtosis and RK measures showed widespread changes over Gaussian-based techniques, suggesting a more sensitive nature of kurtoses to injury.



  4. Tumor Enhancement and Heterogeneity Are Associated With Treatment Response to Drug-Eluting Bead Chemoembolization for Hepatocellular Carcinoma
    imagePurpose: Treatment response to drug-eluting bead chemoembolization (DEB-TACE) is well established for patients with hepatocellular carcinoma (HCC); however, few studies have evaluated tumor imaging characteristics associated with treatment responses. The aim of our study was to identify imaging characteristics associated with treatment responses and overall survival after DEB-TACE of HCC. Methods: This is a retrospective cohort study of 33 tumors in 32 patients who underwent DEB-TACE for inoperable HCC in a single, large academic medical center. Arterial phase computed tomography data were reviewed to assess tumor size, edge characteristics, tumor enhancement on pixel density histogram, and heterogeneity using coefficient of variation. We assessed correlation between these markers of tumor morphology and response to DEB-TACE using mRECIST criteria, progression-free survival, and overall survival. Results: Tumor heterogeneity (P = 0.01) and tumor enhancement greater than 50% (P = 0.05) were significantly associated with complete response to DEB-TACE in patients with HCC; however, neither was associated with overall or progression-free survival. Tumor size and edge characteristics were not associated with complete response to DEB-TACE, although tumor size greater than 6 cm was associated with worse overall survival (hazard ratio, 3.349; P = 0.02). Conclusions: Tumor heterogeneity and enhancement on arterial phase imaging may be predictive markers of treatment response to DEB-TACE among patients with HCC.



  5. Magnetic Resonance Imaging Features of Solitary Hypothalamitis
    imageObjective: The study aimed to characterize magnetic resonance imaging (MRI) findings of solitary hypothalamitis and evaluate their clinical value in diagnosis. Methods: Magnetic resonance imaging scans, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and contrast-enhanced T1-weighted sequences, of 8 biopsy-proven hypothalamitis lesions were retrospectively analyzed along with MRI features including size, shape, signal intensity, enhancement pattern, correlation with adjacent tissues, and changes in infundibular stalk and sella turcica. Results: Of 8 patients, 5 were diagnosed with lymphoplasmacytic proliferative inflammation, 2 with Langerhans cell histocytosis, and 1 with Rosai-Dorfman disease. Solitary hypothalamitis predominantly demonstrated mild hypointensity/isointensity in T1WI and mild hyperintensity in T2-weighted imaging. In contrast-enhanced T1WI, all lesions showed heterogeneous but primarily peripheral enhancement patterns. Seven cases showed the polygon sign. In T1WI, the normal high signal intensity of neurohypophysis was absent from all patients, with no infundibular stalk thickening. Seven patients presented with optic chiasma edema, and 5 with edema-like changes along the optic tract (OTE), but most showed no visual impairment (n = 7). Conclusions: Magnetic resonance imaging, particularly postcontrast MRI, is the optimal modality for assessment of hypothalamic lesions. Peripheral enhancement with polygon sign and optic tract or chiasm edema without visual impairment are highly suggestive of hypothalamitis.


  6. Absent Vascular Signal on Time-of-Flight Magnetic Resonance Angiography Due to Recent Ferumoxytol Infusion
    imageAbstract: Time-of-flight magnetic resonance angiography is used for craniocervical arterial evaluation. Absent flow-related signal may be the result of slow flow, complex flow, or focal susceptibility effects. We report a case with complete absence of flow-related signal in the intracranial and cervical vessels due to ferumoxytol infusion given 5 days before magnetic resonance angiography. Ferumoxytol is a newly approved parenteral therapy for iron-deficiency anemia in patients with renal failure and awareness of this drug–magnetic resonance imaging interaction is needed.



  7. Characterization of Thyroid Nodules by 4-Dimensional Computed Tomography: Initial Experience
    imageObjective: We aimed to evaluate the use of 4-dimensional computed tomography (4DCT) for characterization of thyroid nodules. Methods: Our study drew from 100 consecutive patients with primary hyperparathyroidism who underwent 4D parathyroid CT imaging for adenoma localization. Included subjects had tissue sampling of a thyroid nodule within 3 months of 4DCT. Results: Twenty subjects (18 women and 2 men) had thyroid nodules that were pathologically confirmed. Precontrast nodule attenuation was significantly lower in malignant nodules when compared with benign nodules (36 vs 61 HU, P = 0.05). Arterial phase and delayed phase nodule attenuations were not significantly different in malignant and benign nodules (128 vs 144 HU, P = 0.7; 74 vs 98 HU, P = 0.3). Conclusions: Our initial experience with a small group of patients was unable to support the use of 4DCT for characterizing thyroid nodules; however, precontrast nodule attenuation was significantly lower in malignant nodules when compared with benign nodules.



  8. Computed Tomography–Guided Tumor Ablation: Analysis and Optimization of Computed Tomography Technique With Various Ablation Devices
    imagePurpose: Ablation device-associated computed tomography beam hardening artifacts can make tumor margin visualization and its relationship to the ablation applicator tip challenging. Determine optimal scanning conditions for currently-used applicators. Materials and Methods: Eleven applicators were placed in ex vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various computed tomography scans were performed at 440 mA with 5 mm thickness changing kVp (80, 100, 120, 140), scan time (0.5, 0.7, 1.0, 2.0 seconds), adaptive statistical iterative reconstruction (ASiR) (30, 60, 90), scan type (helical, axial), pitch (0.5, 0.94, 1.37, 1.75), and reconstruction algorithm (soft, standard, lung). Two radiologists blindly scored the images for image quality and artifact quantitatively. Results: Cool-tip single (CTS) RF electrode (Covidien) performed significantly better than all other devices in both perceived image quality and artifact while Boston Scientific 4.0 RF electrode (Boston Scientific) underperformed (all P < 0.001), when not controlling for any other factors. An effect for artifact (P < 0.001) was found for kVp and device: for most conditions, 80 kVp was rated significantly lower than all other levels, whereas 120 and 140 performed significantly better than 100 and 80. No significant effect with ASiR level and device was found for the artifact. There was an effect observed for artifact (P < 0.001) between scan time and probe: for most devices, 0.5 seconds was rated significantly lower than all other scan times, but CTS was resilient—showing no difference from other scan times. Algorithm did not show any significant effects. Taking into account ASiR, kVp, and time, CTS outperformed all other devices. Conclusions: Higher kVp and scan times reduce device artifacts. It appears that CTS performs the best, even when considering ASiR, kVp, pitch, scan type, and scan time.



  9. High-Resolution Diffusion-Weighted Imaging Improves the Diagnostic Accuracy of Dynamic Contrast-Enhanced Sinonasal Magnetic Resonance Imaging
    imageObject: The aim of the study was to evaluate the incremental value of high-resolution diffusion-weighted imaging and apparent diffusion coefficient (ADC) mapping compared with that of dynamic contrast-enhanced (DCE) sinonasal magnetic resonance imaging (MRI) in the characterization of benign versus malignant sinonasal tumors at 3.0T. Materials and Methods: Ninety-eight patients (61 females, 37 males; mean age, 48 years) with sinonasal lesions who underwent high-resolution DW-MRI and DCE-MRI were included in this study. The lesions were divided into malignant and benign groups on the basis of pathological examination. In total, 58 malignant tumors and 40 benign tumors were evaluated. Apparent diffusion coefficients were acquired with 0 and 1000 s/mm2b values. Semiquantitative parameters (time–signal intensity curve [TIC] type, time of peak enhancement within the first 2 minutes [Tpeak], peak percentage enhancement within the first 2 minutes [PEpeak], the last time point percentage enhancement [PElast], and the washout percentage-enhancement difference [PEwashout]) were derived from DCE-MRI. The DCE-MRI parameters and ADCs were included in multivariate models to predict a diagnosis of a benign versus malignant lesion. Results: The accuracy using semiquantitative DCE-MRI parameters alone was 70.4% (0.693 area under the ROC curve, 57.5% sensitivity, 79.3% specificity). Adding absolute ADCs to dynamic contrast-enhanced MR data showed the higher diagnostic accuracy of 85.7% (0.873 area under the ROC curve, 85.0% sensitivity, 86.2% specificity). Moreover, the absolute ADCs differed significantly between the benign (mean [SD] ADC, 1.211 [0.32] × 10−3 mm2/s) and malignant (mean [SD] ADC, 0.702 [0.28] × 10−3 mm2/s) sinonasal tumors (P < 0.001). In addition, a significant difference was found between the ADC values of malignant and benign lesions in washout enhancement TICs (t = 7.039, P < 0.001). Conclusions: High-resolution DWI with ADC mapping significantly improved the diagnostic accuracy of dynamic contrast-enhanced sinonasal MRI at 3.0T. In addition, ADC values could distinguish benign lesions from malignant tumors in washout enhancement TICs.



  10. Obesity, Hepatic Steatosis, and Their Impact on Fat Infiltration of the Trunk Musculature Using Unenhanced Computed Tomography
    imageObjectives: The aim of the study was to assess whether hepatic steatosis predicts muscle fat content independent of body mass index (BMI). Methods: Regions of interest were drawn over several trunk muscles and over the right lobe of the liver to obtain the computed tomography (CT) density in 100 subjects with unenhanced CT studies of the abdomen and pelvis. Univariate and multivariate linear regression were used to examine the associations between BMI and hepatic steatosis and between BMI and trunk muscle density. Results: Body mass index was associated with trunk muscle fat (P < 0.05) and hepatic steatosis (P < 0.05). Computed tomography density of the liver correlated with that of each trunk muscle (P < 0.05). After adjusting for age, sex, and BMI, hepatic steatosis was associated with increased trunk muscle fat content in the psoas only. Conclusions: The association between muscle fat in most trunk muscles and hepatic steatosis is due to underlying BMI. However, hepatic steatosis predicted psoas muscle fat content independent of BMI (P < 0.05).


  11. Influence of Age on Healing Capacity of Acute Tears of the Anterior Cruciate Ligament Based on Magnetic Resonance Imaging Assessment
    imageObjective: The purpose of this study was to evaluate the influence of patient age on the effects of conservative treatment of the anterior cruciate ligament (ACL). Methods: A total of 102 consecutive patients with acute ACL injury were allowed to heal without surgery. Final magnetic resonance imaging images of the ACL were classified from grade I, indicating good morphological recovery, to grade IV, indicating poor recovery. Chi-square analysis was used to determine significant differences in the incidence of grades I and II among those less than 20 versus those 20 years or more of age. Results: The mean follow-up to final magnetic resonance imaging was 9 months. A significant difference in the frequency of grades I and II was observed between age groups (<20 years, 13.0%; ≥20 years, 69.6%; P < 0.0001). Conclusion: ACL injury was more severe, and morphological recovery with conservative treatment was poorer among younger patients than among adults.



  12. Is Carotid Plaque Contrast Enhancement on MRI Predictive for Cerebral or Cardiovascular Events? A Prospective Cohort Study
    imageObjective: The aim of this study was to correlate carotid plaque contrast enhancement (CPCE) to onset of cerebral/cardiovascular events (CCVE) in patients with atherosclerotic carotid disease. Methods: The ethics committee approved this prospective study. Patients with carotid artery stenosis underwent magnetic resonance angiography before/after injection of 0.1 mmol/kg of gadobenate dimeglumine. Carotid plaque contrast enhancement was graded as follows: 0, no CPCE; 1, 1 single enhancement focus; 2, 2 or more foci. Results: Seventy-seven patients (71 ± 9 years) had a stenosis degree: 34 mild, 16 moderate, 27 severe at the right side, and 36, 15, and 25 at the left side. Carotid plaque contrast enhancement was 0 in 30 patients, 1 in 26, 2 in 11 at the right, and 37, 19, and 13 at the left. Forty-seven CCVE occurred after magnetic resonance imaging, correlated to both stenosis degree (P = 0.006) and CPCE (P = 0.032). Excluding surgery/stenting, the correlation held only for CPCE (P = 0.017). Of 49 patients showing CPCE, 5 (10%) reported CCVE; of 21 patients without CPCE, none reported CCVE (P = 0.129). Conclusions: The absence of CPCE seems to be a negative predictor for CCVE.



  13. Magnetic Resonance Imaging Findings of Ischiofemoral Impingement in Patients With Inflammatory Myositis: An Observational Study
    imageObjective: To determine the frequency of magnetic resonance imaging (MRI) findings of ischiofemoral impingement (IFI) in patients with inflammatory myositis (IM) and associated factors. Methods: Pelvis and thigh MRI studies of 314 consecutive patients (57% women; mean age, 55.5 years; range, 18–85) with suspected muscle disease were reviewed. Results: Ischiofemoral impingement at MRI was present in 11% of patients with a final diagnosis of IM and in 2% of patients with an alternative diagnosis (P = 0.008). In multiple logistic regression analysis, IM, but not age or sex, was independently associated with IFI at MRI (odds ratio, 5.18; 95% confidence interval, 1.19–22.6; P = 0.028). Fatty atrophy of hip stabilizing muscles was independently associated with IFI at MRI (odds ratio per unit increase of fatty atrophy score, 1.03; 95% confidence interval, 1.01–1.05; P = 0.0007). Conclusions: Magnetic resonance imaging findings of IFI are present in 11% of IM patients and are independently associated with fatty atrophy of hip stabilizing muscles.



  14. Shortened Mean Transit Time in CT Perfusion With Singular Value Decomposition Analysis in Acute Cerebral Infarction: Quantitative Evaluation and Comparison With Various CT Perfusion Parameters
    imageObjective: We aimed to clarify the cause of shortened mean transit time (MTT) in acute ischemic cerebrovascular disease and examined its relationship with reperfusion. Methods: Twenty-three patients with acute ischemic cerebrovascular disease underwent whole-brain computed tomography perfusion (CTP). The maximum MTT (MTTmax), minimum MTT (MTTmin), ratio of maximum and minimum MTT (MTTmin/max), and minimum cerebral blood volume (CBV) (CBVmin) were measured by automatic region of interest analysis. Diffusion weighted image was performed to calculate infarction volume. We compared these CTP parameters between reperfusion and nonreperfusion groups and calculated correlation coefficients between the infarction core volume and CTP parameters. Results: Significant differences were observed between reperfusion and nonreperfusion groups (MTTmin/max: P = 0.014; CBVmin ratio: P = 0.038). Regression analysis of CTP and high-intensity volume on diffusion weighted image showed negative correlation (CBVmin ratio: r = −0.41; MTTmin/max: r = −0.30; MTTmin ratio: r = −0.27). Conclusions: A region of shortened MTT indicated obstructed blood flow, which was attributed to the singular value decomposition method error.



  15. Bone Mineral Density Estimations From Routine Multidetector Computed Tomography: A Comparative Study of Contrast and Calibration Effects
    imageIntroduction: Phantom-based (synchronous and asynchronous) and phantomless (internal tissue calibration based) assessment of bone mineral density (BMD) in routine MDCT (multidetector computed tomography) examinations potentially allows for diagnosis of osteoporosis. Although recent studies investigated the effects of contrast-medium application on phantom-calibrated BMD measurements, it remains uncertain to what extent internal tissue-calibrated BMD measurements are also susceptible to contrast-medium associated density variation. The present study is the first to systemically evaluate BMD variations related to contrast application comparing different calibration techniques. Purpose: To compare predicative performance of different calibration techniques for BMD measurements obtained from triphasic contrast-enhanced MDCT. Materials and Methods: Bone mineral density was measured on nonenhanced (NE), arterial (AR) and portal-venous (PV) contrast phase MDCT images of 46 patients using synchronous (SYNC) and asynchronous (ASYNC) phantom calibration as well as internal calibration (IC). Quantitative computed tomography (QCT) served as criterion standard. Density variations were analyzed for each contrast phase and calibration technique, and respective linear fitting was performed. Results: Both asynchronous calibration-derived BMD values (NE-ASYNC) and values estimated using IC (NE-IC) on NE MDCT images did reasonably well in predicting QCT BMD (root-mean-square deviation, 8.0% and 7.8%, respectively). Average NE-IC BMD was 2.7% lower when compared with QCT (P = 0.017), whereas no difference could be found for NE-ASYNC (P = 0.957). All average BMD estimates derived from contrast-enhanced scans differed significantly from QCT BMD (all P < 0.005) and led to notable systemic BMD biases (mean difference at least > 6.0 mg/mL). All regression fits revealed a consistent linear dependency (R2 range, 0.861–0.963). Overall accuracy and goodness of fit tended to decrease from AR to PV contrast phase. Highest precision and best linear fit could be reached using a synchronously scanned phantom (root-mean-square deviation, 9.4% for AR and 14.4% for PV). Both ASYNC and IC estimations performed comparably accurate and precise. Conclusions: Our data suggest that internal calibration driven BMD measurements derived from contrast-enhanced MDCT need the same amount of post hoc contrast-effect adjustment as measurements using phantom calibration. Adjustment using linear correction equations can correct for systematic bias of bone density variations related to contrast application, irrespective of the calibration technique used.


  16. Evaluation of the Relationships Between Computed Tomography Features, Pathological Findings, and Prognostic Risk Assessment in Gastrointestinal Stromal Tumors
    imageObjectives: The aim of this study was to correlate computed tomography (CT) findings with pathology in gastrointestinal stromal tumors (GISTs). Methods: A retrospective evaluation of CT images of 44 patients with GISTs was performed. Computed tomography findings analyzed were location, size, margins, degree and pattern of contrast enhancement, angiogenesis, necrosis, signs of invasion, peritoneal effusion, peritoneal implants, surface ulceration, and calcifications. Associations between CT features and mitotic rate, Miettinen classes of risk, lesions size, and among CT features were investigated. χ2 Test and Fisher test were performed. Results: Mitotic rate was associated with margins (P = 0.016) and with adjacent organ invasion (P = 0.043). Pattern of contrast enhancement (P = 0.002), angiogenesis (P = 0.006), necrosis (P = 0.006), invasion of adjacent organs (P = 0.011), and margins (P = 0.006) were associated with classes of risk. Several associations (P < 0.05) between lesion size and CT features and among all the investigated CT features were found. Conclusions: Computed tomography features could reflect GIST biology being associated with the mitotic rate and with classes of risk.



  17. Computed Tomography and Magnetic Resonance Imaging Characteristics of Peripheral Primitive Neuroectodermal Tumor: A Retrospective Analysis of 16 Cases
    imagePurpose: The aim of this study was to analyze the radiological features of peripheral primitive neuroectodermal tumor (pPNET). Materials and Methods: The radiological and clinical findings for 16 patients with pPNETs were retrospectively reviewed. The 16 tumors were classified into 4 groups (meninges group, n = 4; spine group, n = 3; bone group, n = 5; soft-tissue group, n = 4), and clinical data, size, and common and unique CT/MRI characteristics were assessed. Results: Peripheral primitive neuroectodermal tumors presented as large solid masses with aggressive extension into the neighboring tissue. Most tumors (11/16) presented with necrosis, and 5 of the 16 cases showed signs of hemorrhage. The “dural tail sign” was observed in the meninges and spine groups. The pPNETs of bone demonstrated bony destruction with spiculated periosteal reaction, and small nourishing vessels were found in tumors in the soft-tissue group. Conclusions: Peripheral primitive neuroectodermal tumor should be suggested as an important differential diagnosis when the tumor presents as a large, ill-defined solid mass with aggressive extension and significant enhancement.



  18. Multislice Spiral Perfusion Computed Tomography to Assess Pancreatic Vascularity in Mild Acute Pancreatitis
    imageObjective: This study aims to use perfusion computed tomography to compare pancreatic perfusion in mild acute pancreatitis (MAP) versus normal pancreas. Methods: This observational study included 39 patients with MAP and 18 patients with normal pancreatic function. Perfusion computed tomography parameters, including blood flow (BF), blood volume (BV), mean transit time, and permeability surface area product, were compared. Results: Both serum and urinary amylase levels were significantly higher in patients with MAP than in controls (all Ps < 0.05). Patients with MAP showed significantly lower BF and BV and higher mean transit time and permeability surface area product than the controls (all Ps < 0.05). Correlation analysis on the 39 patients with MAP revealed negative coefficients between serum amylase level and BF and BV values. Conclusions: Pancreatic perfusion seems to be poorer, and pancreatic vascular leakage may increase in MAP compared with normally functioned pancreas.



  19. Proton Magnetic Resonance Spectroscopy–Detected Changes of Marrow Fat Content in a Rabbit Model of Osteoporosis Treated With Epigallocatechin-3-Gallate
    imageObjective: The aim of this study was to longitudinally evaluate the changes in marrow fat content of ovariectomized (OVX) rabbits treated with epigallocatechin-3-gallate (EGCG) using proton magnetic resonance spectroscopy (1H-MRS). Methods: Thirty-six female New Zealand rabbits were equally divided into sham operation, OVX controls, and OVX treated with EGCG (intraperitoneally, 1.8 mg/kg) for 5 months. Marrow fat fraction by 1H-MRS and bone density by peripheral quantitative computed tomography were determined at 0, 3, and 5 months. Serum biomarkers and marrow adipocytes were determined at the end of experiment. Results: Estrogen deficiency increased marrow fat content in a time-dependent manner, with a variation of marrow fat fraction (FF) (+25.3%) at month 3 from baseline, and it was maintained until month 5 (+66.6%, all P < 0.001). In comparison with the sham-operated controls, adipocytes density, size, and percentage of adipocytes area in the OVX controls increased by 62.9%, 44.4%, and 178%, respectively (all P < 0.05). These OVX-induced pathological changes were partly reversed by EGCG treatment. In addition, EGCG treatment reduced bone turnover and increased bone density of OVX rabbits. Conclusions: Epigallocatechin-3-gallate exhibits an anabolic effect on osteoporotic bone by concomitantly rescuing bone mass and mitigating marrow adiposity. 1H-MRS appears to be a useful tool for monitoring osteoporosis-related treatments.



  20. Incidental Findings in Abdominal Dual-Energy Computed Tomography: Correlation Between True Noncontrast and Virtual Noncontrast Images Considering Renal and Liver Cysts and Adrenal Masses
    imagePurpose: To assess correlation between attenuation measurements of incidental findings in abdominal second generation dual-energy computed tomography (CT) on true noncontrast (TNC) and virtual noncontrast (VNC) images. Materials and Methods: Sixty-three patients underwent arterial dual-energy CT (Somatom Definition Flash, Siemens; pitch factor, 0.75–1.0; gantry rotation time, 0.28 seconds) after endovascular aneurysm repair, consisting of a TNC single energy CT scan (collimation, 128 × 0.6 mm; 120 kVp) and a dual-energy arterial phase scan (collimation, 32 × 0.6 mm, 140 and 100 kVp; blended, 120 kVp data set). Attenuation measurements in Hounsfield units (HU) of liver parenchyma and incidental findings like renal and hepatic cysts and adrenal masses on TNC and VNC images were done by drawing regions of interest. Statistical analysis was performed by paired t test and Pearson correlation. Results: Incidental findings were detected in 56 (89%) patients. There was excellent correlation for both renal (n = 40) and hepatic cysts (n = 12) as well as adrenal masses (n = 6) with a Pearson correlation of 0.896, 0.800, and 0.945, respectively, and mean attenuation values on TNC and VNC images of 10.6 HU ± 12.8 versus 5.1 HU ± 17.5 (attenuation value range from −8.8 to 59.1 HU vs −11.8 to 73.4 HU), 6.4 HU ± 5.8 versus 6.3 HU ± 4.6 (attenuation value range from 2.0 to 16.2 HU vs −3.0 to 15.9 HU), and 12.8 HU ± 11.2 versus 12.4 HU ± 10.2 (attenuation value range from −2.3 to 27.5 HU vs −2.2 to 23.6 HU), respectively. As proof of principle, liver parenchyma measurements also showed excellent correlation between TNC and VNC (n = 40) images with a Pearson correlation of 0.839 and mean attenuation values on TNC and VNC images of 47.2 HU ± 10.5 versus 43.8 HU ± 8.7 (attenuation value range from 21.9 to 60.2 HU vs 4.5 to 65.3 HU). Conclusions: In conclusion, attenuation measurements of incidental findings like renal cysts or adrenal masses on TNC and VNC images derived from second generation dual-energy CT scans show excellent correlation providing considerable dose savings, favorable for future application in clinical routine.


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