CT Density Research Articles

Computed Tomography Density and β-Amyloid Deposition of Intraorbital Optic Nerve May Assist in Diagnosing Mild Cognitive Impairment and Alzheimer's Disease: A 18F-Flutemetamol Positron Emission Tomography/Computed Tomography Study.

ObjectiveThe aim was to study whether the computed tomography (CT) density and β-amyloid (Aβ) level of intraorbital optic nerve could assist in diagnosing mild cognitive impairment (MCI) and Alzheimer’s disease (AD).MethodsA total of sixty subjects were recruited in our study, including nine normal control (NC) subjects (i.e., 4 men and 5 women), twenty four MCI subjects (i.e., 11 men and 13 women), and twenty seven AD subjects (i.e., 14 men and 13 women). All subjects conducted 18F-flutemetamol amyloid positron emission tomography (PET)/CT imaging. Blinded to the clinical information of the subjects, two physicians independently measured and calculated the standardized uptake value ratio (SUVR) of the bilateral occipital cortex, SUVR of the bilateral intraorbital optic nerve, and CT density of the bilateral intraorbital optic nerve by using GE AW 4.5 Workstation.ResultsBetween AD and NC groups, the differences of the bilateral intraorbital optic nerve SUVR were statistically significant; between AD and MCI groups, the differences of the left intraorbital optic nerve SUVR were statistically significant. Between any two of the three groups, the differences in the bilateral intraorbital optic nerve density were statistically significant. The bilateral occipital SUVR was positively correlated with the bilateral intraorbital optic nerve SUVR and negatively correlated with the bilateral intraorbital optic nerve density. Bilateral intraorbital optic nerve SUVR was negatively correlated with the bilateral intraorbital optic nerve density. The area under the receiver operating characteristic (ROC) curve of multiple logistic regression was 0.9167 (for MCI vs. NC) and 0.8951 (for AD vs. MCI). The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores were positively associated with the intraorbital optic nerve density and were negatively associated with the intraorbital optic nerve SUVR. The regression equation of MoCA was y = 16.37-0.9734 × x1 + 0.5642 × x2-3.127 × x3 + 0.0275 × x4; the R2 was 0.848. The regression equation of MMSE was y = 19.57-1.633 × x1 + 0.4397 × x2-1.713 × x3 + 0.0424 × x4; the R2 was 0.827.ConclusionThe CT density and Aβ deposition of the intraorbital optic nerve were associated with Aβ deposition of the occipital cortex and the severity of cognitive impairment. The intraorbital optic nerve CT density and intraorbital optic nerve Aβ deposition could assist in diagnosing MCI and AD.

Normal Lung Tissue CT Density Changes after Volumetric-Arc Radiotherapy (VMAT) for Lung Cancer.

Radiation-induced lung injury remains a significant toxicity in thoracic radiotherapy. Because a precise diagnosis is difficult and commonly used assessment scales are unclear and subjective, there is a need to establish quantitative and sensitive grading methods. The lung tissue density change expressed in Hounsfield units (HUs) derived from CT scans seems a useful numeric surrogate. The study aimed to confirm a dose-response effect on HU value changes (ΔHU), their evolution in time, and the impact of selected clinical and demographic factors. We used dedicated, self-developed software to register and analyze 120 pairs of initial and follow-up CT scans of 47 lung cancer patients treated with dynamic arc radiotherapy. The differences in HU values between CT scans were calculated within discretized dose-bins limited by isodose lines. We have proved the dose-effect relationship, which is well described with a sigmoid model. We found the time evolution of HU changes to suit a typical clinical presentation of radiation-induced toxicity. Some clinical factors were found to correlate with ΔHU degree: planning target volume (PTV), V35 in the lung, patient’s age and a history of arterial hypertension, and initial lung ventilation intensity. Lung density change assessment turned out to be a sensitive and valuable method of grading post-RT lung toxicity.

Impact of pixel value truncation on image quality of low dose chest CT.

In some noisy low dose CT lung cancer screening images, we noticed that the CT density values of air were increased and the visibility of emphysema was distinctly decreased. By examining histograms of these images, we found that the CT density values were truncated at -1024 HU. The purpose of this study was to investigate the effect of pixel value truncation on the visibility of emphysema using mathematical models. Assuming CT noise follows a normal distribution, we derived the relationship between the mean CT density value and the standard deviation (SD) when the pixel values below -1024 HU are truncated and replaced by -1024 HU. To validate our mathematical model, 20 untruncated phantom CT images were truncated by simulation, and the mean CT density values and SD of air in the images were measured and compared with the theoretical values. In addition, the mean CT density values and SD of air were measured in 100 cases of real clinical images obtained by GE, Siemens, and Philips scanners, respectively, and the agreement with the theoretical values was examined. Next, the contrast-to-noise ratio (CNR) between air (-1000 HU) and lung parenchyma (-850 HU) was derived from the mathematical model in the presence and absence of truncation as a measure of the visibility of emphysema. In addition, the radiation dose ratios required to obtain the same CNR in the case with and without truncation were also calculated. The mathematical model revealed that when the pixel values are truncated, the mean CT density values are proportional to the noise magnitude when the magnitude exceeds a certain level. The mean CT density values and SD measured in the images with pixel values truncated by simulation and in the real clinical images acquired by GE and Philips scanners agreed well with the theoretical values from our mathematical model. In the Siemens images, the measured and theoretical values agreed well when a portion of the truncated values were replaced by random values instead of simply replacing by -1024 HU. The CNR of air and lung parenchyma was lowered by truncating CT density values compared to that of no truncation. Furthermore, it was found that higher radiation dose was required to obtain the same CNR with truncation as without. As an example, when the noise SD was 60 HU, the radiation dose required for the GE and Philips truncation method was about 1.2 times higher than that without truncation, and that for the Siemens truncation method was about 1.4 times higher. It was demonstrated mathematically that pixel value truncation causes a brightening of the mean CT density value and decreases the CNR of emphysema. Our results indicate that it is advisable to turn off truncation at -1024 HU, especially when scanning at low and ultra-low radiation doses in the thorax.

Dual energy computed tomography in differentiation of iodine contrast agent staining from secondary brain haemorrhage in patients with ischaemic stroke treated with thrombectomy

The aim of this study was to assess the value of dual energy computed tomography (DECT) in the differentiation of iodine contrast agent staining from secondary brain haemorrhage in patients with acute ischaemic stroke treated with mechanical thrombectomy. The group analysed consisted of 66 hyperdense areas in 64 patients with acute ischaemic stroke treated with mechanical thrombectomy and controlled in DECT performed within the first 24 hours after thrombectomy. In every area both qualitative and quantitative analysis of iodine and water material density (MD) maps was performed for the differentiation of iodine and blood, as well as CT density analysis. 66.7% of hyperdense areas were classified as iodine, 18.2% as iodine + blood, and 15.1% as blood. The density of iodine was significantly higher in the iodine (median 9.64 100ug/cm3) group compared to the blood (median 3.97 100ug/cm3) and iodine + blood (median 7.57 100ug/cm3) groups. The density of water was significantly higher in the blood (median 1,051.50 mg/cm3) and iodine + blood (median 1,038.00 mg/cm3) groups compared to the iodine (median 1,021.00 mg/cm3) group. DECT with iodine-water material decomposition maps is a valuable tool in the differentiation of prolonged staining of iodine contrast agent from secondary brain haemorrhage in patients with acute ischaemic stroke treated with mechanical thrombectomy. The value of 6 100ug/cm3 (0.6 mg/cm3) seems a good threshold in quantitative differentiation of iodine from blood on iodine (water) MD maps. The value of 1,030 mg/cm3 seems a good threshold in quantitative differentiation of iodine from blood on water (iodine) MD maps.

Body fat composition as biomarker for clinical outcomes and treatment tolerance in high-risk prostate cancer.

159 Background: Androgen deprivation therapy (ADT) is a standard of care for high-risk prostate cancer, but treatment tolerance is variable. Prior work has demonstrated the correlation between body composition (BC) and clinical outcomes in prostate cancer. Specifically, high visceral fat density has been associated with fat depletion phenomenon and poor prognosis in prostate cancer. However, the interaction of long-term ADT tolerance and body fat composition is less studied. We investigated if BC could predict for outcomes and treatment tolerance in patients with high-risk prostate cancer with planned ADT. Methods: An IRB-approved retrospective review was conducted at a tertiary care center of patients with high-risk (T3a or prostate-specific antigen [PSA] > 20 ng/mL or Gleason score 8-10 or N/M+) prostate cancer who received definitive external beam radiation therapy (RT) from 2006 to 2013. A previously validated, fully automated deep learning BC analysis pipeline was performed on RT simulation scans to compute BC at the top of L3 slice, including total skeletal muscle (SM), subcutaneous fat (SF), and visceral fat (VF) surface area (cm2) and average CT density (Hounsfield Units (HU)); results were manually validated by experts. BC was stratified by median value. Adult Comorbidity Evaluation-27 (ACE) was used to measure co-morbidity. Long-term ADT was defined as > 2 years, tolerance was defined as unplanned discontinuation > 3-month difference in intended/actual duration of ADT. The association between BC markers, oncologic outcomes, and treatment tolerance was analyzed using univariable Cox regression and chi-square test. Results: A total of 207 men were analyzed with a median follow up time of 10.8 years (range 0.7-17.3y). Median age was 65 (range 42-83), with 61 (29.4%) patients classified as high-risk, 134 (64.7%) very-high-risk, and 12 (5.8%) N+/M+ at diagnosis. High VF density was associated with worse overall survival (OS) (HR 1.71, 95%CI 1.09-2.68, p = 0.0204) but not cancer-specific survival (CSS) (p = 0.08) or biochemical-relapse free survival (bRFS) (p = 0.97). SM and SF density, as well as area of SM, VF, SF, and total fat were not associated with outcomes. N/M stage was associated with bRFS (p = 0.0139), and N/M stage (p = 0.0101) and higher ACE score (p = 0.0218) were associated with OS. Among 88 (42.5%) patients planned for long-term ADT use, 24 (27%) patients discontinued ADT prior to duration, of which 15 (17%) patients discontinued due to toxicity. BC markers did not correlate with tolerance to long-term ADT (p = 0.17). Tolerance to long-term ADT was not associated with bRFS or OS. Conclusions: High VF density is associated with worse OS but not bRFS or CSS in high-risk prostate cancer patients, and not associated with adipose area or ADT tolerance. VF density may be a biomarker of underlying metabolic health in prostate cancer patients independent of disease, and a potential area of intervention.

Pixel-based analysis of pulmonary changes on CT lung images due to COVID-19 pneumonia.

Objectives: Computed tomography (CT) plays a complementary role in the diagnosis of the pneumonia-burden of COVID-19 disease. However, the low contrast of areas of inflammation on CT images, areas of infection are difficult to identify. The purpose of this study is to develop a post-image-processing method for quantitative analysis of COVID-19 pneumonia-related changes in CT attenuation values using a pixel-based analysis rather than more commonly used clustered focal pneumonia volumes. The COVID-19 pneumonia burden is determined by experienced radiologists in the clinic. Previous AI software was developed for the measurement of COVID-19 lesions based on the extraction of local pneumonia features. In this respect, changes in the pixel levels beyond the clusters may be overlooked by deep learning algorithms. The proposed technique focuses on the quantitative measurement of COVID-19 related pneumonia over the entire lung in pixel-by-pixel fashion rather than only clustered focal pneumonia volumes.Material and Methods: Fifty COVID-19 and 50 age-matched negative control patients were analyzed using the proposed technique and commercially available artificial intelligence (AI) software. The %pneumonia was calculated using the relative volume of parenchymal pixels within an empirically defined CT density range, excluding pulmonary airways, vessels, and fissures. One-way ANOVA analysis was used to investigate the statistical difference between lobar and whole lung %pneumonia in the negative control and COVID-19 cohorts.Results: The threshold of high-and-low CT attenuation values related to pneumonia caused by COVID-19 were found to be between ₋642.4 HU and 143 HU. The %pneumonia of the whole lung, left upper, and lower lobes were 8.1 ± 4.4%, 6.1 ± 4.5, and 11.3 ± 7.3% for the COVID-19 cohort, respectively, and statistically different (P < 0.01). Additionally, the pixel-based methods correlate well with existing AI methods and are approximately four times more sensitive to pneumonia particularly at the upper lobes compared with commercial software in COVID-19 patients (P < 0.01).Conclusion: Pixel-by-pixel analysis can accurately assess pneumonia in COVID-19 patients with CT. Pixel-based techniques produce more sensitive results than AI techniques. Using the proposed novel technique, %pneumonia could be quantitatively calculated not only in the clusters but also in the whole lung with an improved sensitivity by a factor of four compared to AI-based analysis. More significantly, pixel-by-pixel analysis was more sensitive to the upper lobe pneumonia, while AI-based analysis overlooked the upper lung pneumonia region. In the future, this technique can be used to investigate the efficiency of vaccines and drugs and post COVID-19 effects.

The CT and PET/CT findings in primary pulmonary lymphoepithelioma-like carcinoma with pathological correlation: a study of 215 cases

To investigate the computed tomography (CT) and integrated positron-emission tomography (PET)/CT findings of primary pulmonary lymphoepithelioma-like carcinoma (PLELC). The imaging and histopathological data of 215 patients with PLELC confirmed at histopathology were analysed retrospectively. All patients underwent CT, and 70 underwent PET/CT. None of the cohort had nasopharyngeal lymphoepithelioma-like carcinoma. The PLELC was demonstrated as a solitary nodule/mass in 188 cases (188/215, 87%), multiple nodules/masses in 12 cases (12/215, 6%), lobar or segmental consolidation in 15 cases (15/215, 7%). The tumour showed a well-defined margin in 171 cases (171/215, 80%), lobular sign in 177 cases (177/215, 82%), and spicule sign in 91 cases (91/215, 42%). Most of the cases showed homogeneous density in unenhanced CT (128/215, 60%), and vascular shadows inside the tumour in the arterial stage were found in 105 cases (105/158, 66%). Involvement of the bronchus was found in 154 cases (154/215, 72%). Hilar or mediastinal lymph nodes were enlarged in 160 patients (160/215, 74%). Seventy cases demonstrated avid 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) uptake on PET/CT. The range of maximum standardised uptake values (SUVmax) was 2.1-28.5 (14±5.93). Microscopic pathological classification of 124 resected specimens included 87 cases of the Regaud type and 37 cases of the Schmincke type. Epstein-Barr virus (EBV)-encoded small RNAs (EBERs) was positive in all 215 cases. PLELC should be suspected when a large, lobulate, well-defined lung tumour with homogeneous density, vascular encasement, and high 18F-FDG uptake is found. Moreover, EBERs are helpful in patients with suspected PLELC.

Accuracy of a CT density threshold enhancement to identify pancreatic parenchyma necrosis in acute pancreatitis during the first week

PurposeThe purpose of this study was to identify attenuation threshold value on computed tomography (CT) that allowed discriminating between interstitial edematous pancreatitis (IEP) and necrotizing pancreatitis (NP) in patients with acute pancreatitis during the first week of the disease and evaluate interobserver reproducibility for the diagnosis of acute pancreatitis category. Materials and methodsPatients with acute pancreatitis who underwent CT examination of the abdomen between March 2015 and December 2019 were retrospectively included. Actual diagnosis of IEP or NP was based on final clinical report, follow-up evaluation, and complications. Six regions of interest were manually placed in the pancreatic gland and peripancreatic fat, and differences in CT attenuation values before contrast injection and during the portal venous phase of enhancement were computed. Performance in the diagnosis of AP category was evaluated using receiver operating characteristic analysis. Interobserver agreement was estimated by the intraclass correlation coefficient (ICC) and Bland Altman analysis was used to estimate reproducibility between pairs of observers. ResultsSixty-six patients with NP (46 men, 20 women; mean age, 55 ± 17 [SD] years; age range: 20-89 years) and 70 patients with IEP (39 men, 31 women; mean age, 54 ± 18 [SD] years; age range: 21–87 years) were included. An enhancement value less than 30 Hounsfield units (HU) in the pancreatic gland during the portal phase compared to non-contrast phase, yielded 90.9% sensitivity (60/66; 95% CI: 81.3–96.6), 94.3% specificity (66/70; 95% CI: 86.0–98.4) and an area under curve of 0.958 (95% CI: 0.919–0.996) for the diagnosis of NP versus IEP. Interobserver reproducibility for pancreas enhancement was good using Bland Altman plot and ICC was excellent for pancreatic gland analysis (ICC 0.978; 95% CI: 0.961–0.988) but poor or moderate (ICC ≤0.634) regarding peripancreatic fat necrosis. ConclusionBy using a pancreas enhancement threshold value of 30 HU, CT is accurate and reproducible for the diagnosis of NP during the first week of the disease.

Timing of brain computed tomography for predicting neurological prognosis in comatose cardiac arrest survivors: a retrospective observational study.

To assess the association between relevant brain computed tomography (CT) parameters at different time and neurological prognosis in adult comatose survivors after cardiac arrest (CA). A total of 94 CA patients who underwent early and late CT scans (within 24 h and 24 h to 7 d respectively after CA) between January 2018 and April 2020 were enrolled in this retrospective study. According to the Cerebral Performance Category (CPC) score at hospital discharge, the patients were divided into either a good outcome (CPC 1-2) group or a poor-outcome group (CPC 3-5). The grey-to-white matter ratio (GWR) and the proportion of cerebrospinal fluid volume (pCSFV) were measured. In predicting poor outcomes, the prognostic performance of relevant CT parameters was evaluated, and the comparison analysis (expressed as the ratio of parameters in late CT to those in the early CT) of different CT time was conducted. Totally 26 patients were in the good-outcome group, while 68 patients were in the poor-outcome group. The putamen density, GWR, and pCSFV in late CT were significantly lower in the poor-outcome group (P<0.05). The ratios of GWR and pCSFV in the poor-outcome group were significantly decreased according to comparison analysis of different CT time (P<0.05), while there was no significant difference in the ratio of putamen density. GWR-basal ganglia <1.18 in late CT showed the best predictive value. The ratio of pCSFV <0.98 predicted unfavorable neurological outcomes with a sensitivity of 65.9% and a specificity of 93.8% (P=0.001). Brain CT performed >24 h after CA may be a good choice as a neuroimaging approach to evaluating prognosis. To predict neurological prognosis, comparison analysis of different CT time can be used as another promising tool in comatose CA survivors.

Muscle Density Analysis in COVID-19

Objective: Coronavirus-2019 (COVID-19) was declared a pandemic by the World Health Organization, continues to spread globally, and patients may not exhibit specific musculoskeletal involvement symptoms. Materials and Methods: Clinical data and images of 389 consecutive patients, who applied to the pandemic outpatient clinic with a COVID-19 pre-diagnosis with musculoskeletal complaints, and 203 consecutive control patients who underwent thoracic computed tomography (CT) for an unrelated reason and diagnosed as normal were included in the study. Bilateral sternocleidomastoid and trapezius muscle CT density and blood creatine kinase (CK) levels of all participants were obtained. Results: In COVID-19 patients, a significant decrease in sternocleidomastoid muscle density was observed when compared to radiological grade; however, a significant increase in the density of the trapezius muscle was identified. In CK values, there was a significant increase in trapezius density. Conclusion: Although the cause or effect was controversial, respiratory muscles were affected due to forced breathing and muscle damages were determined. This study demonstrated the need for multicenter studies with detailed neurological and electrophysiological tests and pathological correlations with an adequate number of patients.

Epikardiyal yağ dokusu ve hepatosteatoz ile koroner ateroskleroz arasındaki ilişkinin çok kesitli bilgisayarlı tomografi ile değerlendirilmesi

Background: In this study, the relationship of CAD (coronary artery disease) with EAT (epicardial adipose tissue) volume and hepatosteatosis were investigated by using multidetector computed tomography (MDCT).&#x0D; Material and Method: EAT (Epicardial Adipose Tissue) volume, CCS (coronary calcium score) and CT density of liver (CTDL) were measured by using 64-detector computed tomography in 96 patients who were clinically referred for the evaluation of CAD. The relationship between EAT volume, CCS, CTDL and their effectiveness in detecting coronary heart disease were investigated. Data analysis was done with MedCalc (Version 9.6.2.0) package program. &#x0D; Results: CCS (AUC=0.866) and EAT volume (AUC=0.672) were significantly effective in determination of CAD. The diagnostic accuracy of CCS in detecting CAD was higher than of EAT volume. EAT volume was higher in patients with CAD (85.81±34.51 cm³), compared to patients without CAD (68.38±29.23 cm³) (P=0.0119). CTDL in patients with CAD (58.74±12.22 HU) was significantly lower than in patients without CAD (63.02±8.93) (P=0.0553). There was no statistically significant relationship between EAT volume and CCS (r=0.1620, P=0.1148), EAT volume and CTDL (r=0.0046, P=0.9648), and CCS and CTDL (r=0.0109, P=0.9162).&#x0D; Conclusion: There was no relationship between EAT volume, CTDL and CCS. EAT volume is higher in patients with CAD than in patients without CAD. EAT volume had moderate but lower diagnostic power than CCS, to determine CAD.

Association of ct skeletal muscle area and density with age: a prospective study in 200 non-critically ill patients

Rationale: The CT skeletal muscle area (SMA) at L3 highly correlates with whole-body muscle mass. The CT skeletal muscle density (SMD) is a measure of muscle quality. The higher the SMD is, the less myosteatosis there is. The goal was to study the variations of SMA and SMD with age in 200 non-critically ill patients.

Assessing the representative elementary volume of rock types by X-ray computed tomography (CT) – a simple approach to demonstrate the heterogeneity of the Boda Claystone Formation in Hungary

Abstract X-ray computed tomography (CT) can reveal internal, three-dimensional details of objects in a non-destructive way and provide high-resolution, quantitative data in the form of CT numbers. The sensitivity of the CT number to changes in material density means that it may be used to identify lithology changes within cores of sedimentary rocks. The present pilot study confirms the use of Representative Elementary Volume (REV) to quantify inhomogeneity of CT densities of rock constituents of the Boda Claystone Formation. Thirty-two layers, 2 m core length, of this formation were studied. Based on the dominant rock-forming constituent, two rock types could be defined, i.e., clayey siltstone (20 layers) and fine siltstone (12 layers). Eleven of these layers (clayey siltstone and fine siltstone) showed sedimentary features such as, convolute laminations, desiccation cracks, cross-laminations and cracks. The application of the Autoregressive Integrated Moving Averages, Statistical Process Control (ARIMA SPC) method to define Representative Elementary Volume (REV) of CT densities (Hounsfield unit values) affirmed the following results: i) the highest REV values corresponded to the presence of sedimentary structures or high ratios of siltstone constituents (&gt; 60%). ii) the REV average of the clayey siltstone was (5.86 cm3) and (6.54 cm3) of the fine siltstone. iii) normalised REV percentages of the clayey siltstone and fine siltstone, on the scale of the core volume studied were 19.88% and 22.84%; respectively. iv) whenever the corresponding layer did not reveal any sedimentary structure, the normalised REV values would be below 10%. The internal void space in layers with sedimentary features might explain the marked textural heterogeneity and elevated REV values. The drying process of the core sample might also have played a significant role in increasing erroneous pore proportions by volume reducation of clay minerals, particularly within sedimentary structures, where authigenic clay and carbonate cement were presumed to be dominant.

CT pectoralis muscle area is associated with DXA lean mass and correlates with emphysema progression in a tobacco-exposed cohort

IntroductionMuscle loss is an important extrapulmonary manifestation of COPD. Dual energy X-ray absorptiometry (DXA) is the method of choice for body composition measurement but is not widely used for muscle...

Are the washout values currently accepted for lesion characterization in dedicated adrenal CT adequate for diagnosis?

We aimed to investigate the accuracy of density characteristics and washout values of lesions detected on computed tomography (CT) at the cutoff values obtained from the literature by taking the pathological results of adrenalectomy specimens as reference and to determine the cutoff values of parameters evaluated on CT for the differentiation of adenoma and nonadenoma lesions in the study group. Hospital records and standard CT imaging data (noncontrast early phase [65 s] and late phase [15 min] ) of 84 patients with 87 lesions who underwent adrenalectomy between January 2012 and December 2018 were retrospectively reevaluated by two radiologists in consensus. The patients were categorized as having adenoma and nonadenoma lesions according to the pathology results. The sensitivity, specificity and diagnostic accuracy of CT parameters (density values and washout percentages) were evaluated. Differences in the CT parameters (size, noncontrast and early-late enhancement density and absolute and relative washout values) were investigated. The optimal cutoff values of CT parameters were determined by ROC analysis. Noncontrast CT had a specificity of 87.75% and 95.9%, sensitivity of 60% and 48.6%, diagnostic accuracy of 77.7% and 89.47% for adenomas, at the cutoff values of ≤10 HU and ≤0 HU, respectively. For absolute washout value ≥ 60%, the sensitivity, specificity and accuracy were 64.7%, 52.38% and 56.75%, respectively; while these rates were 76.47%, 56.52% and 62.16%, respectively, for relative washout value ≥40%. Adenomas and nonadenomas showed significant difference in terms of size (p < 0.0001), unenhanced attenuation (p < 0.0001), relative washout (p = 0.020) and delay enhancement (p < 0.001). But there were no differences in terms of absolute washout (p = 0.230) and early enhancement (p = 0.264). The cutoff values for the differentiation of adenomas and nonadenomas were as follows: size ≤44 mm, noncontrast density <20 HU, early-phase density ≥45 HU, delayed-phase density ≤44 HU, absolute washout 74.83% and relative washout 57.76%. The current washout criteria used in the differentiation of adenoma and nonadenoma lesions in dynamic CT imaging can give false negative and positive results. According to the existing criteria, the most reliable parameter in adenoma-nonadenoma differentiation is ≤ 0 HU noncontrast CT density value.

Multi-slice spiral CT findings of tubulovillous adenoma of the duodenum

ObjectivesTo analyze the appearance of duodenal tubulovillous adenoma on multi-slice spiral CT images to facilitate early diagnosis and treatment to potentially improve prognosis. MethodsWe retrospectively analyzed clinical data and CT imaging findings of 11 cases of duodenal tubulovillous adenomas, all confirmed by pathology. The location, size, shape, CT density, relationship with surrounding structures, accompanying bile duct obstruction, and enhancement pattern of each lesion were documented. ResultsAll 11 lesions occurred in the descending part of the duodenum. Ten cases occurred in the duodenal papilla area. Nine cases had a low-density ring sign or semicircle sign between the lesion and the adjacent normal intestinal wall on axial images. Eight cases had differing degrees of bile duct dilatation, five of which had concomitant pancreatic duct dilatation. Noncontrast images revealed uniform soft tissue density; contrast enhanced images showed moderate, mostly uniform enhancement, with the most enhancement in the venous phase. In the arterial phase, two lesions showed linear enhancing vessels. ConclusionsOn multi-slice spiral CT imaging, duodenal tubulovillous adenomas have certain characteristics that could be used for clinical diagnosis and treatment. PrecisOn multi-slice spiral CT imaging of duodenal tubulovillous adenoma, findings of nodular or cauliflower-like shape, uniform density, uniform moderate enhancement, and a peripheral low-density ring sign could improve diagnostic accuracy.

Age-related Changes in Computed Tomography Density of Thyroid Gland in Children: A Single-Center Retrospective Study in Northern China.

The thyroid gland normally presents as a hyperdense organ on noncontrast computed tomography (CT) in adults. The correlation between thyroid gland CT density and its functional status has been studied; however, little is known regarding its density in children with normal thyroid functions. We aimed to assess the correlation between thyroid gland CT density and age in children with normal thyroid functions. From April 2017 to March 2021, we enrolled 74 patients who had normal thyroid functions within 1 month before or after undergoing neck or cervical spine CT for trauma, neck masses, congenital diseases, and airway stenosis. Their CT images were retrospectively analyzed by 2 independent radiologists. Based on age, patients were divided into 4 groups: infant, preschool-aged, school-aged, and adolescence groups. Patients with thyroid gland hypodensity in the infant group (70%, 14 of 20) were significantly more numerous than those in preschool-aged (25%, 4 of 16), school-aged (20%, 5 of 25), and adolescence (15.4%, 2 of 13) groups (P = 0.007, 0.001, and 0.002, respectively, Fisher exact test). The mean CT density of the thyroid gland was also lower in the infant group compared with the densities in other age groups. There was a weak positive correlation between thyroid CT density and age (r = 0.264, P = 0.023, linear regression analysis). Thyroid CT density is related to age in children. The thyroid gland normally has a low density on noncontrast CT in most infants with normal thyroid function.

Utility of multidetector computed tomography quantitative measurements in identifying sarcopenia: a propensity score matched study.

To evaluate the utility of multidetector computed tomography MDCT quantitative measurements in identifying sarcopenia. The clinical data and MDCT images of 64 patients of sarcopenia and 184 non-sarcopenic participants between October 2020 and January 2021were retrospectively analyzed. Propensity score matching was used to match the sarcopenic patients with the non-sarcopenic participants. Two radiologists independently measured the cross-sectional area (CSA) of skeletal muscle and intramuscular fat tissue and CT density of skeletal muscle at the middle L3 vertebral level on CT images of all participants. Intra-observer agreement was evaluated via intraclass correlation coefficients (ICC). A receiver operating characteristic (ROC) curve was built for each variable. Correlations between CT parameters and clinical data were assessed via Pearson or Spearman correlation coefficient. A total of 74 participants (mean age 72 ± 4years, range 66-85years; 38 men and 36 women) were included, comprising 37 sarcopenic patients and 37 non-sarcopenic participants. There were no significant intergroup differences regarding age, sex ratio, and body mass index (BMI) (P < 0.05). The CSA and density of skeletal muscle measured by two radiologists were reliable (ICC ≥ 0.75, P < 0.001). Compared with the sarcopenic group, the non-sarcopenic group had a significantly greater CSA and CT density of the total skeletal muscle (TSM) and paraspinal skeletal muscle (PSM) and skeletal muscle index at L3 level (L3 SMI) (P < 0.05). The fat infiltration ratio (FIR) of TSM, PSM, and psoas muscle was significantly higher in the sarcopenic group than that in non-sarcopenic participants (P < 0.05). ROC curve analysis showed the PSM FIR + PSM CT density (PSM D) had the best predictive value for sarcopenia (AUC = 0.836). The PSM FIR and age were moderately positively correlated (r = 0.410, P < 0.001). Fat infiltration of skeletal muscle had better predictive value than L3 SMI in the diagnosis of sarcopenic. The PSM FIR + PSMD had the best predictive value for sarcopenia, which was moderately positively correlated with age.

The relationship between CRP at admission and thorax CT findings in patients diagnosed with COVID-19.

IntroductionThe current study aims to evaluate the relationship between C‐reactive protein (CRP) levels, thorax CT findings and CT‐SS in patients presenting to the emergency department with COVID‐19.MethodsPatients diagnosed with COVID‐19 by nasopharyngeal rt‐PCR (+) in the emergency department were included in the study. In addition to the CRP, ferritin and D‐dimer examinations of patients at admission, thorax CT involvement findings and CT‐SS results were recorded. The relationship of CRP value with CT‐SS and clinical outcome was evaluated.ResultsA total of 974 COVID‐19 patients, 572 males (58.7%) and 402 females (41.3%), with a mean age of 59.64 ± 17.34 years, were included in the study. The CRP values of the patients who needed intensive care and needed respiratory support were also significantly higher at admission (95.1 mg/dL vs 31.05 mg/dL) (P < .001). The CRP values of the patients who developed any complications during the treatment of COVID‐19 were higher (79.9 mg/dL vs 41.85 mg/dL) (P < .001).In the case of CRP >124.5, a thorax CT density score 7.35 times higher was determined to be severe. In addition, it was determined that there was a 9.09‐fold increase in the incidence of negative imaging findings in terms of COVID‐19 in cases where the CRP value was <12.5 mg/dL.ConclusionThe CRP levels of COVID‐19 patients measured upon admission to the emergency room are correlated with the severity of lung involvement and are an important predictor of clinical outcomes.

The improvement of cardiac multispiral computed tomography protocol for planning interventional arrhythmia management

Purpose. The study aimed at the comparison of computed tomography (СT) contrast enhancement (CE) protocols for optimal visualization of cardiac chambers, evaluation of their impact on results of non-invasive superficial cardiac mapping.Methods. The study included 93 patients with heart rhythm disorders in whom catheter ablation of arrhythmia was planned. Noninvasive cardiac mapping for arrhythmia localization was performed and included multichannel ECG-registration and CT with intravenous СE (1st group - monophasic (50 patients), 2nd group - split-bolus (18 patients), 3rd group - with pre-bolus (25 patients). Qualitative and quantitative (measurement of mean blood attenuation in four chambers, calculation of ventricular-myocardial [VM] contrast-to-noise ratio VM-LV и VM-RV for the left ventricle [LV] and right ventricle [RV], respectively) parameters were compared between the groups. Fusion of ECG and CT data was carried out a semi-automatic mode with a non-invasive imaging complex.Results. Regardless of CE technique, sufficient and homogeneous contrast attenuation was obtained for the left atrium (LA) and LV (mean blood attenuation in LA more than 278 HU, LV 250 HU, VM-LV 0,582). In most cases, the enhancement of the right heart was insufficient with the monophasic protocol; the average CT density was lower than 200 HU, VM-RV 0,256. The split-bolus protocol improved visualization of the right atrium (RA) and RV (blood density in RA 258HU, RV 227HU, VMRV 0,541); however, there was a heterogeneity of the RA cavity due to artifacts from the superior vena cava (VC) and unenhanced blood from the inferior VC. Pre-bolus administration increased the contrast ratio between RA myocardium and blood due to the improvement of blood CT density in the inferior VC (blood density 294 HU). The quality of RV CE was similar to 2nd group (blood density 264 HU, VM-RV 0,565).Conclusion. The split-bolus and with pre-bolus CE protocols improve visualization of the RV, supporting the high-level enhancement of the left heart. The protocol with a pre-bolus is preferable for exact differentiation of the right atrial endocardial contour.