scholarly journals Estimation of nephron number in living humans by combining unenhanced computed tomography with biopsy-based stereology

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Takaya Sasaki ◽  
Nobuo Tsuboi ◽  
Yusuke Okabayashi ◽  
Kotaro Haruhara ◽  
Go Kanzaki ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Arterial Phase ◽  
Nephron Number ◽  
Living Kidney Donors ◽  
Explanatory Variables ◽  
Cortical Volume ◽  
Unenhanced Ct ◽  
Enhanced Ct ◽  
Phase Images ◽  
Unenhanced Computed Tomography

Abstract Methods for estimating nephron number in a clinical setting may be useful for predicting renal outcomes. This study aimed to establish such a method using unenhanced computed tomography (CT) and biopsy-based stereology. Patients or living kidney donors simultaneously subjected to enhanced and unenhanced CT examinations were randomly assigned to development and validation groups. The enhanced CT-measured arterial phase and the venous phase images of kidneys were regarded as the true values for cortical volume and parenchymal volume, respectively. Linear multiple regression analysis was used to create models for estimating cortical volume using explanatory variables including unenhanced CT-measured parenchymal volume. Nephron number was determined as the product of cortical volume and the glomerular density in biopsies of donors. Five equations for estimating cortical volume were created and verified. In donors, estimated nephron number by unenhanced CT was consistent with that by enhanced CT, with minimal errors in all models (636–655 ± 210–219 vs. 648 ± 224 × 103/kidney). Clinical characteristics combined with parenchymal volume did not improve the equation over parenchymal volume alone. These results support the feasibility of estimating nephron number by a combination of unenhanced CT and biopsy-based stereology, with a possible application for renal disease patients who are often not suitable for contrast media.

scholarly journals Contrast-Enhanced Computed Tomography Does Not Provide More Information about Sarcopenia than Unenhanced Computed Tomography in Patients with Pancreatic Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yan Zhang ◽  
Jiabin Liu ◽  
Fei Li ◽  
Feng Cao ◽  
Ang Li
Keyword(s):  
Computed Tomography ◽  
Pancreatic Cancer ◽  
Contrast Agent ◽  
Fixed Dose ◽  
Arterial Phase ◽  
Cross Sectional ◽  
Unenhanced Ct ◽  
Psoas Muscles ◽  
Enhanced Ct ◽  
The Difference

Objective. The aim of this study was to understand whether enhanced CT can provide more information than unenhanced CT on diagnosis of sarcopenia. Materials and Methods. We reviewed the enhanced CT data of 45 patients of pancreatic cancer. Manual tracing of the psoas muscles was used for measuring the cross-sectional muscle areas and attenuation at umbilicus level; afterwards, PMI, PMD, and Δ PMD were calculated. Results. In the unenhanced scanning, arterial, venous, and parenchymal phases of enhanced CT, PMI values were 6.905 ± 2.170, 6.886 ± 2.195, 6.923 ± 2.239, and 6.866 ± 2.218, respectively, and the difference was not statistically significant. The PMD values at different phases were 34.311 ± 7.535, 37.487 ± 7.118, 40.689 ± 7.116, and 42.989 ± 7.745, respectively, which were gradually increased, and the difference was statistically significant. Meanwhile, the PMD of arterial phase, venous phase, and parenchyma phase showed a linear correlation with PMD of unenhanced scanning phase. 31 patients had low PMD and 14 had normal PMD during the unenhanced scanning phase. With the addition of contrast agent, ΔPMD values increased faster in the low PMD group than in the normal PMD group during the venous and parenchymal phases (7.048 ± 3.067 vs 4.893 ± 2.558; 9.581 ± 3.033 vs 6.679 ± 2.621; p < 0.05 ), which made the gap between PMD after contrast-enhancement vs. unenhanced scanning smaller. Conclusion. The use of contrast agent has no effect on the manually measured PMI values but can change the results of PMD. This change makes the difference of PMD in different enhancement phases smaller than that in plain scan phase and furthermore increases the examination cost; therefore, it is not recommended to use enhanced CT routinely with fixed dose administration of contrast agent for patients’ assessment of PMI and PMD.

scholarly journals Additional Diagnostic Value of Unenhanced Computed Tomography plus Diffusion-Weighted Imaging Combined with Routine Magnetic Resonance Imaging Findings of Early-Stage Gliblastoma

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Hexiang Wang ◽  
Zhenyou Liu ◽  
Yong Zhang ◽  
Feng Hou ◽  
Weiwei Fu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Diffusion Weighted Imaging ◽  
Early Stage ◽  
Diagnostic Value ◽  
Imaging Findings ◽  
Hyperintense Lesion ◽  
Unenhanced Ct ◽  
Unenhanced Computed Tomography

Purpose. This study was performed to determine whether diffusion-weighted imaging (DWI) plus unenhanced computed tomography (CT) of the brain increases the diagnostic value of routine magnetic resonance (MR) imaging findings of early-stage glioblastoma. Methods. Postcontrast MR images of eight unenhanced lesions that had been pathologically diagnosed as glioblastoma were retrospectively examined. The location, margin, signal intensity, and attenuation on MR imaging and CT were assessed. Results. On MR imaging, all lesions were ill-defined, small, and isointense to hypointense on T1-weighted images and hyperintense on T2-weighted images. Four patients had perilesional edema. In seven patients, DWI showed an inhomogeneous hyperintense lesion (n = 1) or isointense lesion with a hyperintense region (n = 6). On unenhanced CT, all masses presented as a hypoattenuated lesion with a hyperattenuated region (n = 7) or isoattenuated region (n = 1). The hyperattenuated region (n = 6) or isoattenuated region (n = 1) on CT appeared on DWI as an inhomogeneous hyperintense lesion (n = 1), isointense lesion with a hyperintense region (n = 3), or ring-like peritumoral hyperintensity (n = 3). Conclusions. MR imaging was the most sensitive imaging method for depicting early-stage glioblastoma. The CT finding of a hyperattenuated or isoattenuated region combined with the DWI finding of the same region containing an inhomogeneous hyperintense lesion or isointense lesion with a hyperintense region may be a specific diagnostic sign for early-stage glioblastoma. DWI plus unenhanced CT added diagnostic value to the routine MR imaging findings of early-stage glioblastoma.

scholarly journals Unenhanced computed tomography as a diagnostic tool in suspected pulmonary hypertension: a retrospective cross-sectional pilot study

2021 ◽  
Vol 6 ◽  
pp. 249
Author(s):  
Ze Ming Goh ◽  
Christopher S. Johns ◽  
Tarik Julius ◽  
Samual Barnes ◽  
Krit Dwivedi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Hypertension ◽  
Characteristic Curve ◽  
Right Atrial ◽  
Heart Catheterization ◽  
Great Vessel ◽  
Cross Sectional ◽  
Specialist Registrar ◽  
Unenhanced Ct ◽  
Unenhanced Computed Tomography

Background: Computed tomography pulmonary angiography (CTPA) has been proposed to be diagnostic for pulmonary hypertension (PH) in multiple studies. However, the utility of the unenhanced CT measurements diagnosing PH has not been fully assessed.  This study aimed to assess the diagnostic utility and reproducibility of cardiac and great vessel parameters on unenhanced computed tomography (CT) in suspected pulmonary hypertension (PH). Methods: In total, 42 patients with suspected PH who underwent unenhanced CT thorax and right heart catheterization (RHC) were included in the study. Three observers (a consultant radiologist, a specialist registrar in radiology, and a medical student) measured the parameters by using unenhanced CT. Diagnostic accuracy of the parameters was assessed by area under the receiver operating characteristic curve (AUC). Inter-observer variability between the consultant radiologist (primary observer) and the two secondary observers was determined by intra-class correlation analysis (ICC). Results: Overall, 35 patients were diagnosed with PH by RHC while 7 patients were not. Main pulmonary arterial (MPA) diameter was the strongest (AUC 0.79 to 0.87) and the most reproducible great vessel parameter. ICC comparing the MPA diameter measurement of the consultant radiologist to the specialist registrar’s and the medical student’s were 0.96 and 0.92, respectively. Right atrial area was the cardiac measurement with highest accuracy and reproducibility (AUC 0.76 to 0.79; ICC 0.980, 0.950) followed by tricuspid annulus diameter (AUC 0.76 to 0.79; ICC 0.790, 0.800). Conclusions: MPA diameter and right atrial areas showed high reproducibility. Diagnostic accuracies of these were within the range of acceptable to excellent, and might have clinical value. Tricuspid annular diameter was less reliable and less diagnostic and was therefore not a recommended diagnostic measurement.

The Value of “Liver Windows” Settings in the Detection of Small Renal Cell Carcinomas on Unenhanced Computed Tomography

2014 ◽  
Vol 65 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Kamal Sahi ◽  
Stuart Jackson ◽  
Edward Wiebe ◽  
Gavin Armstrong ◽  
Sean Winters ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Renal Cell ◽  
Roc Analysis ◽  
Ct Images ◽  
Operating Characteristics ◽  
Renal Cell Carcinomas ◽  
Unenhanced Ct ◽  
Single Slice ◽  
Unenhanced Computed Tomography

Objective To assess if “liver window” settings improve the conspicuity of small renal cell carcinomas (RCC). Methods Patients were analysed from our institution's pathology-confirmed RCC database that included the following: (1) stage T1a RCCs, (2) an unenhanced computed tomography (CT) abdomen performed ≤ 6 months before histologic diagnosis, and (3) age ≥ 17 years. Patients with multiple tumours, prior nephrectomy, von Hippel-Lindau disease, and polycystic kidney disease were excluded. The unenhanced CT was analysed, and the tumour locations were confirmed by using corresponding contrast-enhanced CT or magnetic resonance imaging studies. Representative single-slice axial, coronal, and sagittal unenhanced CT images were acquired in “soft tissue windows” (width, 400 Hounsfield unit (HU); level, 40 HU) and liver windows (width, 150 HU; level, 88 HU). In addition, single-slice axial, coronal, and sagittal unenhanced CT images of nontumourous renal tissue (obtained from the same cases) were acquired in soft tissue windows and liver windows. These data sets were randomized, unpaired, and were presented independently to 3 blinded radiologists for analysis. The presence or absence of suspicious findings for tumour was scored on a 5-point confidence scale. Results Eighty-three of 415 patients met the study criteria. Receiver operating characteristics (ROC) analysis, t test analysis, and kappa analysis were used. ROC analysis showed statistically superior diagnostic performance for liver windows compared with soft tissue windows (area under the curve of 0.923 vs 0.879; P = .0002). Kappa statistics showed “good” vs “moderate” agreement between readers for liver windows compared with soft tissue windows. Conclusion Use of liver windows settings improves the detection of small RCCs on the unenhanced CT.

scholarly journals Computed tomography criteria for discrimination of adrenal adenomas and adrenocortical carcinomas: analysis of the German ACC registry

2015 ◽  
Vol 172 (4) ◽  
pp. 415-422 ◽  
Author(s):  
Stephan Petersenn ◽  
Paul-Ajoy Richter ◽  
Thomas Broemel ◽  
Christian O Ritter ◽  
Timo Deutschbein ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Roc Analysis ◽  
Ct Scans ◽  
Adrenal Tumors ◽  
Hounsfield Units ◽  
Unenhanced Ct ◽  
Median Tumor Size ◽  
Lower Specificity ◽  
Unenhanced Computed Tomography ◽  
Adrenocortical Carcinomas

ObjectiveThresholds of 2–20 hounsfield units (HU) in unenhanced computed tomography (CT) are suggested to discriminate benign adrenal tumors (BATs) from malignant adrenal tumors. However, these studies included only low numbers of adrenocortical carcinomas (ACCs). This study defines a HU threshold by inclusion of a large cohort of ACCs.DesignRetrospective, blinded, comparative analysis of CT scans from 51 patients with ACCs (30 females, median age 49 years) and 25 patients with BATs (12 females, median age 64 years) diagnosed during the period of 2005–2010 was performed.MethodsTumor density was evaluated in unenhanced CT by two blinded investigators.ResultsMedian tumor size was 9 cm (range 2.0–20) for ACCs vs 4 cm (2.0–7.5) for BATs (P<0.0001). In ACCs, the median unenhanced HU value was 34 (range 14–74) in comparison with 5 (−13 to 40) in BATs (P<0.0001). ROC analysis revealed a HU of 21 as threshold with the best diagnostic accuracy (sensitivity 96%, specificity 80%, and AUC 0.89). However, two ACCs that were 5 and 6 cm in size would have been missed. Setting the threshold to 13.9 allowed for 100% sensitivity, but a lower specificity of 68%.ConclusionsThis first large study on ACCs confirmed that the vast majority of ACCs have unenhanced HU >21. However, to avoid misdiagnosing an ACC as benign, a threshold of 13 should be used.

scholarly journals SUN-243 ESTIMATION OF THE TOTAL NEPHRON NUMBER IN HUMANS COMBINING UNENHANCED COMPUTED TOMOGRAPHY AND A BIOPSY-BASED METHOD

2019 ◽  
Vol 4 (7) ◽  
pp. S260
Author(s):  
T. SASAKI ◽  
N. Tsuboi ◽  
Y. Okabayashi ◽  
K. Haruhara ◽  
G. Kanazaki ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Nephron Number ◽  
Unenhanced Computed Tomography

scholarly journals Can Enhancement Pattern and Enhancement Level on Biphasic Enhanced CT Distinguish Homogeneous Pheochromocytomas From Adenomas Without Lipid

2020 ◽  
Author(s):  
Yongyu An ◽  
Fengjuan Tian ◽  
Bin Lin ◽  
Meihua Shao ◽  
Fangmei Zhu ◽  
...  
Keyword(s):  
Arterial Phase ◽  
Inclusion Criteria ◽  
Enhancement Pattern ◽  
Unenhanced Ct ◽  
Peak Enhancement ◽  
Enhanced Ct ◽  
Cystic Changes ◽  
Venous Phase ◽  
The Mean ◽  
Attenuation Values

Abstract Objective The purpose of our study was to evaluate whether enhancement pattern and enhancement level on biphasic enhanced CT can distinguish homogeneous pheochromocytomas from adenomas without lipid and explore the value of percentage of peak enhancement (PPE) in differentiating the two entities.Methods We retrospectively analysed pathologically proven 17 pheochromocytomas and 34 adenomas. Both tumors were homogeneous without necro-cystic changes and hemorrhage. The inclusion criteria for adenomas without lipid in our study was that the mean attenuation values were greater than 10 HU and the minimum values were greater than 0 HU on unenhanced CT. Biphasic CT scan protocol consisted of unenhanced phase, arterial phase (25-35 seconds) and venous phase (60-80 seconds). The enhancement pattern, attenuation values on unenhanced and enhanced phases and PPE were compared between the two groups.Results Enhancement pattern was similar between the two groups (p>0.99), persistent enhancement pattern on venous phase was the most common in both tumors. The precontrast CT values of pheochromocytomas were significantly higher than that of adenomas without lipid (41 HU vs 37 HU, p=0.006). The enhancement level on arterial and venous phase of pheochromocytomas was greater than that of adenomas without lipid, but no significant differences were found (100 HU vs 85 HU, p=0.223; 103 HU vs 96 HU, p=0.905, respectively). The distribution of PPE of two entities was different. A range of 100%-240% of PPE can discriminate adenomas without lipid from pheochromocytomas, with sensitivity of 88.2%, specificity of 47.1%. Conclusion The enhancement pattern and enhancement level on biphasic enhanced CT could not distinguish homogeneous pheochromocytomas from adenomas without lipid. Further studies are needed to prove the potential value of PPE due to its low specificity.

scholarly journals Effects of Interobserver Variability on 2D and 3D CT- and MRI-Based Texture Feature Reproducibility of Cartilaginous Bone Tumors

2021 ◽  
Author(s):  
Salvatore Gitto ◽  
Renato Cuocolo ◽  
Ilaria Emili ◽  
Laura Tofanelli ◽  
Vito Chianca ◽  
...  
Keyword(s):  
Bone Tumors ◽  
Intraclass Correlation ◽  
Texture Feature ◽  
Region Of Interest ◽  
Unenhanced Ct ◽  
Unenhanced Computed Tomography ◽  
2D And 3D ◽  
Feature Stability ◽  
Ct And Mri ◽  
T2 Weighted Images

AbstractThis study aims to investigate the influence of interobserver manual segmentation variability on the reproducibility of 2D and 3D unenhanced computed tomography (CT)- and magnetic resonance imaging (MRI)-based texture analysis. Thirty patients with cartilaginous bone tumors (10 enchondromas, 10 atypical cartilaginous tumors, 10 chondrosarcomas) were retrospectively included. Three radiologists independently performed manual contour-focused segmentation on unenhanced CT and T1-weighted and T2-weighted MRI by drawing both a 2D region of interest (ROI) on the slice showing the largest tumor area and a 3D ROI including the whole tumor volume. Additionally, a marginal erosion was applied to both 2D and 3D segmentations to evaluate the influence of segmentation margins. A total of 783 and 1132 features were extracted from original and filtered 2D and 3D images, respectively. Intraclass correlation coefficient ≥ 0.75 defined feature stability. In 2D vs. 3D contour-focused segmentation, the rates of stable features were 74.71% vs. 86.57% (p < 0.001), 77.14% vs. 80.04% (p = 0.142), and 95.66% vs. 94.97% (p = 0.554) for CT and T1-weighted and T2-weighted images, respectively. Margin shrinkage did not improve 2D (p = 0.343) and performed worse than 3D (p < 0.001) contour-focused segmentation in terms of feature stability. In 2D vs. 3D contour-focused segmentation, matching stable features derived from CT and MRI were 65.8% vs. 68.7% (p = 0.191), and those derived from T1-weighted and T2-weighted images were 76.0% vs. 78.2% (p = 0.285). 2D and 3D radiomic features of cartilaginous bone tumors extracted from unenhanced CT and MRI are reproducible, although some degree of interobserver segmentation variability highlights the need for reliability analysis in future studies.

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