Computed Tomography Densitometry Research Articles

Association of clinical outcome and imaging endpoints in extensive ischemic stroke—comparing measures of cerebral edema

Abstract Objectives Ischemic edema is associated with worse clinical outcomes, especially in large infarcts. Computed tomography (CT)–based densitometry allows direct quantification of absolute edema volume (EV), which challenges indirect biomarkers like midline shift (MLS). We compared EV and MLS as imaging biomarkers of ischemic edema and predictors of malignant infarction (MI) and very poor clinical outcome (VPCO) in early follow-up CT of patients with large infarcts. Materials and methods Patients with anterior circulation stroke, large vessel occlusion, and Alberta Stroke Program Early CT Score (ASPECTS) ≤ 5 were included. VPCO was defined as modified Rankin scale (mRS) ≥ 5 at discharge. MLS and EV were quantified at admission and in follow-up CT 24 h after admission. Correlation was analyzed between MLS, EV, and total infarct volume (TIV). Multivariable logistic regression and receiver operating characteristics curve analyses were performed to compare MLS and EV as predictors of MI and VPCO. Results Seventy patients (median TIV 110 mL) were analyzed. EV showed strong correlation to TIV (r = 0.91, p < 0.001) and good diagnostic accuracy to classify MI (EV AUC 0.74 [95%CI 0.61–0.88] vs. MLS AUC 0.82 [95%CI 0.71–0.94]; p = 0.48) and VPCO (EV AUC 0.72 [95%CI 0.60–0.84] vs. MLS AUC 0.69 [95%CI 0.57–0.81]; p = 0.5) with no significant difference compared to MLS, which did not correlate with TIV < 110 mL (r = 0.17, p = 0.33). Conclusion EV might serve as an imaging biomarker of ischemic edema in future studies, as it is applicable to infarcts of all volumes and predicts MI and VPCO in patients with large infarcts with the same accuracy as MLS. Clinical relevance statement Utilization of edema volume instead of midline shift as an edema parameter would allow differentiation of patients with large and small infarcts based on the extent of edema, with possible advantages in the prediction of treatment effects, complications, and outcome. Key Points • CT densitometry–based absolute edema volume challenges midline shift as current gold standard measure of ischemic edema. • Edema volume predicts malignant infarction and poor clinical outcome in patients with large infarcts with similar accuracy compared to MLS irrespective of the lesion extent. • Edema volume might serve as a reliable quantitative imaging biomarker of ischemic edema in acute stroke triage independent of lesion size.

Diagnostic Efficacy of High-Resolution Computed Tomography Densitometry for Diagnosing Otosclerosis.

The purpose of this study is to evaluate the reliability of temporal bone density measurements for diagnosing otosclerosis. A retrospective case-control study is presented. Bone density was measured in Hounsfield units (HUs) by using high-resolution computed tomography in eight regions of interest (ROI) where otosclerotic foci are usually localized. The density of 113 otosclerotic ears was compared with that of 33 nonotosclerotic ears to determine sensitivity and specificity. Furthermore, the binormal receiver operating characteristic curve of each ROI's density was calculated to estimate the diagnostic value for osteosclerosis. In addition, the radiological density of seven cases-where radiological visual examination exhibited no findings but surgery confirmed stapes fixation-was compared with nonotosclerotic controls. ROI densities were significantly lower in otosclerotic patients compared with nonotosclerotic controls. The area under the curve of the fissula ante fenestram (FAF) presented the highest diagnostic performance: 1,871 HU cut-off value (area under the curve = 0.986), 96.64% sensitivity, and 100% specificity. Significantly lower densities in the FAF area were observed in the seven cases with negative radiology but intraoperatively confirmed otosclerosis. The high-resolution computed tomography density of the FAF is a reliable measurement for diagnosing otosclerosis. A value less than 1,871 HU exhibited the highest sensitivity and specificity in a European Caucasian population.

Study of bone density according to СT data before and in the remote period after unicondylar knee arthroplasty

Background. Unicondylar knee arthroplasty has become popular among orthopedists in recent years. The main complication of this technology is the instability of the tibial component of the endoprosthesis due to the development of local osteoporosis in the area of arthroplasty. Patients with decreased bone density are at high risk of developing instability of the tibial component of the endoprosthesis. Therefore, determining the levels of bone mineral density in patients with osteopenia before arthroplasty make it possible to calculate the risk of complications in the long term. Objective: to evaluate the bone mineral density according to the computed tomography (CT) of the tibial plateau resection zone for unicondylar arthroplasty in patients at risk. Materials and methods. The state of three cortical layer zones was assessed: anterior, middle, posterior and 4 zones of the plateau cut plane. The optical density of bone tissue was measured on CT images of the tibial plateau of the knee joint using the Hounsfield scale. Changes in bone structures in the area of placing tibial component of the endoprosthesis were studied in 2 groups of patients: group I — ten individuals who had undergone unicondylar knee arthroplasty 3–6 years ago and complained of negative phenomena in the prosthetic knee, group II — ten patients who had undergone unicondylar arthroplasty 1.2–2 years ago. These patients underwent CT densitometry at the follow-up examination. Results. Before arthroplasty, the maximum optical density of bone tissue was statistically the same. The density of the cortical layer was maximal in the anterior part of the bone (~ 720 HU), minimal — in the posterior part (580 HU). For the spongy bone zone, the maximum optical density was observed in the anterior part (~ 470 HU), and in the posterior part, it was lower. In 3–6 years, patients of group I showed a significant decrease in the optical density of the bone, both in its cortical layer and in the cancellous tissue. The greatest losses were detected in the medial zones of the cancellous bone. Patients had areas of cortical layer resorption, and in some individuals, its complete absence. At the same time, the absorption index of the cortical layer in the areas of destruction did not exceed 100 HU. The maximum optical density of the cortical layer in the zones also decreased. In patients of group II, 1.5–2 years after arthroplasty, there were no noticeable changes in the bone structures in the surgery area. Changes occurred in the medial zones of the cancellous bone of the tibial plateau. Patients with osteopenia reported changes in bone optical density already in the first years after arthroplasty, although they do not lead to instability of the tibial component of the endoprosthesis. Conclusions. Patients with decreased bone density (osteopenia) during joint arthroplasty are at risk of developing local osteoporosis in the area of bone resection. The first signs of resorption of the cancellous bone can be observed 1.5–2 years after arthroplasty. Timely treatment measures can slow down the further progression of osteoporosis.

Imaging Recommendations for Diagnosis, Staging, and Management of Adrenal Tumors

AbstractAdrenal glands are affected by a wide variety of tumors apart from infective and inflammatory lesions and their noninvasive characterization on imaging is important for the management of these patients. Incidentalomas form the major bulk of adrenal tumors and differentiation of benign adenomas from other malignant lesions, especially in patients with a known malignancy, guide further management. Imaging is an integral part of management along with clinical and biochemical features. The cornerstone of clinical and biochemical evaluation of adrenal tumors is to determine whether the lesion is functional or nonfunctional. Computed tomography (CT) is considered as the workhorse for imaging evaluation of adrenal lesions. CT densitometry and CT contrast washout characteristics are quite reliable in differentiating adenomas from malignant lesions. CT is also the modality of choice for the evaluation of resectability and staging of primary adrenal tumors. Magnetic resonance imaging (MRI) has superior contrast resolution compared to other morphological imaging modalities and is generally used as a problem-solving tool. MRI chemical shift imaging can also be used to reliably detect adrenal adenomas. Ultrasonography (USG) is used as a screening tool that is usually followed by either CT or MRI to better characterize the tumor and it is not routinely used for assessing the resectability, staging, and characterization of adrenal tumors. Another important role of USG is in image-guided sampling of tumors. Fluorodeoxyglucose positron emission tomography-computed tomography and other nuclear medicine modalities are a valuable addition to morphological imaging modalities. Image-guided interventions also play an important role in obtaining tissue samples where diagnostic imaging is not able to characterize adrenal tumors. In the functioning of adrenal tumors, adrenal venous sampling is widely used to accurately lateralize the secreting tumor.

Does the Bone Mineral Density of the Lumbar Spine Correlate With Dual-Energy X-ray Absorptiometry T Score? A Cadaveric-Based Analysis of Computed Tomography Densitometry.

Pedicle screw loosening is a complication of spinal instrumentation in osteoporotic patients. Dual-energy x-ray absorptiometry scans are not able to detect variations in bone mineral density (BMD) within specific regions of vertebrae. The purpose of this study was to investigate whether spine T scores correlate with cortical and cancellous BMD of pedicles and other 6 anatomical regions of lumbar spine. Eleven cadaveric spines with a mean age of 73 years were digitally isolated by applying filters for cortical and cancellous bone on computed tomography images. Eleven L5 vertebrae were separated into 7 anatomical regions of interest using 3-dimensional software modeling. Hounsfield units (HU) were determined for each region and converted to cortical and cancellous BMD with calibration phantoms of known BMD. Correlations between T scores and HU values were calculated using Pearson correlation coefficient. Mean vertebral T score was 0.15. Cortical BMD of pedicles was strongly correlated with T score (R 2 = 0.74). There was moderate correlation between T score and cortical BMD of lamina, inferior articular process (IAP), superior articular process (SAP), spinous process, and vertebral body. There was weak correlation between T score and cortical BMD of transverse process (R 2 = 0.16). Cancellous BMD of vertebral body was strongly correlated with T score (R 2 = 0.82). There was moderate correlation between T score and cancellous BMD of pedicles, spinous process, and transverse process. There was weak correlation between T scores and cancellous BMD of lamina, IAP, and SAP. There is a strong correlation between T scores and cortical BMD of lumbar pedicle. There is strong correlation between T scores and cancellous BMD of vertebral body. Cortical and cancellous BMD of transverse process and lamina were weakly correlated with T score and less affected by osteoporosis. Patients with osteoporosis may especially benefit from the development of extrapedicular fusion strategies due to the relatively higher bone density of these fixation sites.

CТ densitometry as an additional method in the diagnosis of pulmonary hypertension: a prospective study

INTRODUCTION: This article presents the results of application of CT densitometry in the computed tomography (CT) of the chest to diagnose various forms of pulmonary hypertension.OBJECTIVES: To determine the diagnostic value of CT densitometry using comparative analysis of lung tissue density in patients with various forms of pulmonary hypertension.MATERIALS AND METHODS: The study included 528 patients diagnosed with pulmonary hypertension by means of right heart catheterization (RHC) of the National Research Cardiac Surgery Center, Republic of Kazakhstan. All patients were divided into 4 groups according to the classification of pulmonary hypertension of the World Health Organization (ESC/ERS Guidelines) from 2015. The first group included 254 patients with pulmonary hypertension pulmonary hypertension due to left heart disease (PHLHD). The second group included 210 patients with pulmonary arterial hypertension (PAH). The third group included 49 patients with chronic thromboembolic pulmonary hypertension (CTEPH). The fourth group — 15 patients with pulmonary hypertension due to respiratory disease (PHDRD). The mean age of the patients was 52.15±16.75 years. Contrast-enhanced chest CT imaging performed with a 64-slice multislice computed tomography system (Somatom Definition AS, Siemens) with post-processing to assess the lung tissue densitometric parameters, analyse the diameters of the pulmonary trunk and its main branches. The CT examination was carried in accordance with an «Embolism» protocol with intravenous administration of a contrast agent according to indications. Statistics: analysis was conducted using the Statistica 10 software. To quantitatively compare the two groups nonparametric Mann-Whitney test and the Kruskal-Wallace test were applied. Mean value and standard deviation in the format of «M±S» were used for quantitative parameters. Correlation analysis was carried out using Spearman’s nonparametric rank correlation.RESULTS: In patients with severe pulmonary hypertension a tendency for fibrotic changes was most clearly observed in cases of pulmonary hypertension due to left heart disease (–809.92±26.52), and emphysematous changes in the pulmonary arterial hypertension group (–843.27±43.88).CONCLUSION: CT lung densitometry should be performed in all patients with suspected pulmonary hypertension as an additional method of examination.

Quantitative CT lung densitometry as an obstructive marker for the diagnosis of bronchiolitis obliterans in children.

The purpose of this study is to evaluate the quantitative diagnostic performance of computed tomography (CT) densitometry in pediatric patients with bronchiolitis obliterans (BO). We measured the mean lung density (MLD) and represented the difference of MLD in inspiratory and expiratory phases (MLDD), the ratio of the MLD (E/I MLD), and the relative volume percentage of lung density at 50-Hounsfield unit (HU) interval threshold (E600 to E950). We calculated the sensitivity, specificity, and diagnostic accuracy of the lung density indices for the diagnosis of BO. A total of 81 patients, including 51 patients with BO and 30 controls, were included in this study. In the BO patients, expiratory (EXP) MLD and MLDD were significantly lower, and E/I MLD and expiratory low attenuation areas below the threshold of −850 HU to −950 HU (E850, E900, and E950) were statistically significantly higher than controls. Multivariate logistic regression analysis showed that MLDD (odds ratio [OR] = 0.98, p < .001), E/I MLD (OR = 1.39, p < .001), and E850 to E950 were significant densitometry parameters for BO diagnosis. In a receiver-operating characteristic analysis, E900 (cutoff, 1.4%; AUC = 0.920), E/I MLD (cutoff, 0.87; AUC = 0.887), and MLDD (cutoff, 109 HU; AUC = 0.867) showed high accuracy for the diagnosis of BO. In conclusion, the lung CT densitometry can serve as a quantitative marker providing additional indications of expiratory airflow limitation in pediatric patients with BO.

Clinical CT densitometry for wooden cultural heritage analysis validated by FTIR and Raman spectroscopies

The identification and characterization of wood material represent an ongoing challenge for artefacts of interest in cultural heritage. Fourier transforms infrared spectroscopy (FTIR) and micro-Raman (MRS) spectroscopies and more recently Surface-Enhanced Raman Scattering (SERS), being non-destructive techniques, have been largely used for the analysis of painted wood. In this work, for the first time, the X-ray Computed Tomography (CT), using a CT medical scanner, was adopted to discriminate three types of wood, usually used in the construction of heritage objects. Wood interior features have been identified in CT images processed through the volumetric rendering technique (VRT), without the need to destructively “take out” a piece of the sample. The information at the macroscopic level collected by CT (density, volumes, morphology, etc.) was enriched by the evidence, at the microscopic level, obtained by the Raman and FTIR spectroscopic techniques. So, the samples have been classified in softwood and hardwood, with the advantage with respect to the conventional analytical methods to be able to distinguish specific structures within the cell walls only through the CT diagnostic technique. Ultimately, a new non-destructive approach is proposed to analyze wood-based heritage objects, but which can be also extended to other materials (i.e., pigments, glues, consolidants).

Designing Clinical Trials in "Regular" COPD Versus Alpha-1 Antitrypsin Deficiency-Associated COPD: "More Alike Than Unalike?"

Alpha-1 antitrypsin deficiency (AATD) predisposes to emphysema, liver disease, and panniculitis. This emphysema risk naturally invites a comparison between "regular" chronic obstructive pulmonary disease (COPD) (i.e., unrelated to AATD) and AATD-associated emphysema. Several features characterize both conditions. Both can be life-limiting and highly debilitating. Both are highly under-recognized. An important corollary of this comparison between "regular" COPD and AATD-associated COPD is whether both should be treated similarly and whether clinical trials to assess new therapies can be conducted similarly in both. Here, the distinctions between "regular" COPD and AATD-associated COPD are quite pronounced. Therapeutically, sparse available data suggest that lung volume reduction surgery confers less improvement in forced expiratory volume in 1 second (FEV1) in AATD and that such benefits are shorter-lived. Perhaps the most striking contrast between the 2 conditions is that clinical trial designs and conduct are necessarily very different. The relative scarcity of diagnosed individuals with AATD hampers recruitment to trials. Furthermore, primary outcome measures in trials of "regular" COPD must differ markedly from those of AATD-associated emphysema. Specifically, power calculations show that FEV1 and exacerbation frequency, which are amply represented as endpoints in large COPD trials, are infeasible in studies of AATD-associated emphysema. Rather, in the 3 available randomized controlled trials of intravenous augmentation therapy, the rate of emphysema progression based on serial computed tomography densitometry measurements has been the only feasible primary outcome measure. These considerations underscore the distinctive challenges and needs of conducting treatment trials in AATD-associated emphysema and emphasize that, with regard to clinical study design, the 2 conditions are "more unalike than alike."

Stability of computed tomography densitometry in patients with otosclerosis:a two-year follow-up

ObjectivesTo quantify the progression of otosclerosis in the unoperated ear between two stapedotomy procedures for patients with bilateral otosclerosis which can help to determine whether a HRCT scan should be re-performed before the second surgery for patients who already received HRCT imaging before the initial surgery. Methods35 patients who underwent bilateral stapedotomy were included. Two rounds of HRCT examination and audiometry were performed at the time of the first surgery and second surgery on the ear that was not operated on during the initial surgery. The relationship between the changes in HRCT densitometry and audiometry over time was analyzed. ResultsThe second round of HRCT did not add significant information about the changes to the otosclerosis lesions in either the imaging diagnosis or the HRCT density values except for small changes in the HRCT densitometry readings at the area anterior to the inner auditory (P = 0.01). While the changes in HRCT manifestation are small, changes near the fissula ante fenestram (FAF) were still positively correlated with the air bone gap (ABG) of patients (p = 0.031, r = 0.388). ConclusionsThe progression of lesions in otosclerosis is slow resulting in small and insignificant changes to the HRCT features. Therefore, a repeat HRCT evaluations prior to surgery is not necessary for patients who have had a previous HRCT evaluation within 2 years of the operation. The small changes in HRCT manifestation near the FAF were still correlated with negative effects on the ABG which could cause worsened hearing thresholds over this timeframe.

Imaging in alpha-1 antitrypsin deficiency: a window into the disease.

Imaging modalities such as plain chest radiograph and computed tomography (CT) are important tools in the assessment of patients with chronic obstructive pulmonary disease (COPD) of any etiology. These methods facilitate differential diagnoses and the assessment of individual lung pathologies, such as the presence of emphysema, bullae, or fibrosis. However, as emphysema is the core pathological consequence in the lungs of patients with alpha-1 antitrypsin deficiency (AATD), and because AATD is associated with the development of other lung pathologies such as bronchiectasis, there is a greater need for patients with AATD than those with non-AATD-related COPD to undergo more detailed assessment using CT. In the field of AATD, CT provides essential information regarding the presence, distribution, and morphology of emphysema. In addition, it offers the option to quantify the extent of emphysema. These data have implications for treatment decisions such as initiation of alpha-1 antitrypsin (AAT) therapy, or suitability for surgical or endoscopic interventions for reducing lung volume. Furthermore, CT has provided vital insight regarding the natural history of emphysema progression in AATD, and CT densitometry has underpinned research into the efficacy of AAT therapy. Moving forward, hyperpolarized xenon gas (129Xe) lung magnetic resonance imaging (MRI) is emerging as a promising complement to CT by adding comprehensive measures of regional lung function. It also avoids the main disadvantage of CT: the associated radiation. This chapter provides an overview of technological aspects of imaging in AATD, as well as its role in the management of patients and clinical research. In addition, perspectives on the future potential role of lung MRI in AATD are outlined.

Association of Computed Tomography Densitometry with Disease Severity, Functional Decline, and Survival in Systemic Sclerosis-associated Interstitial Lung Disease.

Rationale: Measuring disease extent and progression of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is challenging, with recent studies suggesting potential utility of quantitative measurements from computed tomography (CT) scans.Objectives: To determine the associations of quantitative computed tomography (qCT) density-based measures with physiological parameters, visual CT scores, and survival in patients with SSc-ILD.Methods: Patients with SSc-ILD and volumetric high-resolution CT images with ≤1.25-mm slice thickness were retrospectively identified. Cardiothoracic radiologists produced visual CT scores of ground glass, reticulation, and honeycombing, with visual fibrosis score equaling the sum of reticulation and honeycombing. qCT measurements included high-attenuation areas (HAA), skewness, kurtosis, and mean lung attenuation (MLA). Associations of qCT measures with pulmonary physiology, visual CT scores, and mortality were analyzed using Spearman's rank correlation and Cox regression.Results: A total of 503 CT scans from 170 patients with SSc-ILD were included. qCT HAA, skewness, kurtosis, and MLA were associated with lung function and visual fibrosis scores, independent of age, sex, and pack-years, using both baseline and change data. Baseline and changes in qCT measures (except ∆skewness) were associated with mortality on unadjusted analysis. Changes in all qCT variables remained associated with survival after adjustment for baseline age, sex, pack-years, and lung function, but not when adjusting for changes in lung function. ∆HAA and ∆MLA were associated with survival after adjustment for age, sex, pack-years, and change in visual CT scores.Conclusions: CT density measurements correlate with physiologic impairment and visual CT scores in patients with SSc-ILD; however, they were not associated with survival independent of changes in pulmonary physiology. The clinical utility of more sophisticated qCT measures should be explored.

CT Densitometry and Morphology of Radiofrequency-Ablated Stage IA Non–Small Cell Lung Cancer: Results from the American College of Surgeons Oncology Group Z4033 (Alliance) Trial

To evaluate tumor and ablation zone morphology and densitometry related to tumor recurrence in participants with Stage IA non-small cell lung cancer undergoing radiofrequency ablation in a prospective, multicenter trial. Forty-five participants (median 76 years old; 25 women; 20 men) from 16 sites were followed for 2 years (December 2006 to November 2010) with computed tomography (CT) densitometry. Imaging findings before and after ablation were recorded, including maximum CT attenuation (in Hounsfield units) at precontrast and 45-, 90-, 180-, and 300-s postcontrast. Every 1-cm increase in the largest axial diameter of the ablation zone at 3-months' follow-up compared to the index tumor reduced the odds of 2-year recurrence by 52% (P= .02). A 1-cm difference performed the best (sensitivity, 0.56; specificity, 0.93; positive likelihood ratio of 8). CT densitometry precontrast and at 45 seconds showed significantly different enhancement patterns in a comparison among pretreated lung cancer (delta=+61.2 HU), tumor recurrence (delta=+57 HU), and treated tumor/ablation zone (delta[change in attenuation] =+16.9 HU), (P < .0001). Densitometry from 45 to 300 s was also different among pretreated tumor (delta=-6.8 HU), recurrence (delta=-11.2 HU), and treated tumor (delta=+12.1 HU; P= .01). Untreated and residual tumor demonstrated washout, whereas treated tumor demonstrated increased attenuation. An ablation zone ≥1 cm larger than the initial tumor, based on 3-month follow-up imaging, is recommended to decrease odds of recurrence. CT densitometry can delineate tumor versus treatment zones.

The comparison of computed tomography densitometry and DEXA for diagnosis of osteoporosis

The comparison of computed tomography densitometry and DEXA for diagnosis of osteoporosis

Analyses of size and computed tomography densitometry parameters for prediction of keloid recurrence after postoperative electron beam radiation therapy.

The lesion size is a risk factor for keloid recurrence after postoperative radiotherapy. However, it remains unclear whether the major axis diameter is the most appropriate parameter to evaluate lesion size, because keloids are often irregular in shape. Additionally, no previous study has investigated computed tomography (CT) densitometry parameters of keloids as potential predictors for recurrence after postoperative radiotherapy. The size and CT densitometry parameters were measured for 74 lesions with CT images of sufficient quality for evaluation. The association between recurrence and size or CT densitometry parameters was analyzed for 64 lesions that could be followed up for 6months or more. The major axis diameter×minor axis diameter×thickness showed the strongest correlation with volume (ρ=0.96, P<.0001). The median follow-up period was 71months, and 17 lesions recurred. The major axis diameter×minor axis diameter×thickness ≥2.5cm3 (hazard ratio=5.9, P=.0052) and volume ≥1.2ml (hazard ratio=4.3, P=.029) were significantly associated with keloid recurrence under multivariate analyses, while the major axis diameter alone were not. The mean and maximum CT values, and the kurtosis and skewness of density histogram were not significantly different between recurrent and non-recurrent lesions. The major axis diameter×minor axis diameter×thickness may be a better parameter than the major axis diameter alone. CT densitometry analyses may not help to predict keloid recurrence after postoperative electron beam radiotherapy.

Efficacy of Thrombus Density on Noninvasive Computed Tomography Neuroimaging for Predicting Thrombus Pathology and Patient Outcome after Mechanical Thrombectomy in Acute Ischemic Stroke.

Background and Purpose:The aim of this study was to investigate the efficacy of thrombus density on noninvasive computed tomography (CT) neuroimaging for predicting thrombus pathology and patient outcome after mechanical thrombectomy in acute ischemic stroke.Materials and Methods:This retrospective chart and imaging review included patients that were treated by mechanical thrombectomy at Siriraj Hospital according to the American Heart Association/American Stroke Association guidelines for the early management of patients with acute ischemic stroke from March 2010 to February 2015 study period. Preintervention noncontrast CT (NCCT), CT angiography (CTA), and/or contrast-enhanced CT (CECT) images were interpreted using CT densitometry. Pathology results were classified as white, red, or mixed thrombi. The result of treatment was evaluated by the modified Rankin Scale at 90 days after treatment.Results:From 97 included patients – 97 NCCT images, 48 CTA images, 48 CECT images, and 54 pathologic results of cerebral thrombi were included in the final analysis. Mean clot Hounsfield unit values on NCCT, CTA, and CECT were significantly different between red and white thrombus (P = 0.001 on NCCT, P = 0.03 on CTA, and P = 0.001 on CECT), and between red and mixed thrombus (P = 0.043 on NCCT and P = 0.002 on CTA). However, no significant difference was observed between white thrombus and mixed thrombus (P = 0.09 on NCCT, P = 1.00 on CTA, and P = 0.054 on CECT). There was no significant correlation between type of cerebral thrombus or clot density and the result of treatment.Conclusion:Thrombus density on CT was found to be a significant predictor of thrombus pathology; however, no significant association was observed between thrombus type or clot density and patient outcome after mechanical thrombectomy.

Noninvasive Imaging Biomarker Identifies Small Airway Damage in Severe Chronic Obstructive Pulmonary Disease.

Rationale: Evidence suggests damage to small airways is a key pathologic lesion in chronic obstructive pulmonary disease (COPD). Computed tomography densitometry has been demonstrated to identify emphysema, but no such studies have been performed linking an imaging metric to small airway abnormality.Objectives: To correlate ex vivo parametric response mapping (PRM) analysis to in vivo lung tissue measurements of patients with severe COPD treated by lung transplantation and control subjects.Methods: Resected lungs were inflated, frozen, and systematically sampled, generating 33 COPD (n = 11 subjects) and 22 control tissue samples (n = 3 subjects) for micro-computed tomography analysis of terminal bronchioles (TBs; last generation of conducting airways) and emphysema.Measurements and Main Results: PRM analysis was conducted to differentiate functional small airways disease (PRMfSAD) from emphysema (PRMEmph). In COPD lungs, TB numbers were reduced (P = 0.01); surviving TBs had increased wall area percentage (P < 0.001), decreased circularity (P < 0.001), reduced cross-sectional luminal area (P < 0.001), and greater airway obstruction (P = 0.008). COPD lungs had increased airspace size (P < 0.001) and decreased alveolar surface area (P < 0.001). Regression analyses demonstrated unique correlations between PRMfSAD and TBs, with decreased circularity (P < 0.001), decreased luminal area (P < 0.001), and complete obstruction (P = 0.008). PRMEmph correlated with increased airspace size (P < 0.001), decreased alveolar surface area (P = 0.003), and fewer alveolar attachments per TB (P = 0.01).Conclusions: PRMfSAD identifies areas of lung tissue with TB loss, luminal narrowing, and obstruction. This is the first confirmation that an imaging biomarker can identify terminal bronchial pathology in established COPD and provides a noninvasive imaging methodology to identify small airway damage in COPD.

Densitometric density of urinary stones as a predictive factor demonstrating their efficiency of disintegration in treatment of urolithiasis

Urolithiasis is one of the most common urological diseases, occurring in at least 3% of the human population and 34.2% of the Russian population. Data from the Ministry of Health of the Russian Federation show that in the past 4 years, the incidence of urolithiasis has increased from 405.2 to 460.3 patients per 100,000 population. The purpose of this study was to assess the significance of determining the density of urinary stones via computed tomography, as well as the chemical composition of urinary stones, in order to choose an optimal treatment strategy for patients with urolithiasis. The results of treatment of 108 patients with stones of different localization and sizes were investigated. The patients were subjected to laboratory examination to determine the urinary salt environment; moreover, the levels of electrolytes were examined in blood samples from the patients, and computed tomography densitometry was performed to determine the density of the detected stones. The qualitative chemical compositions of urinary stones in patients with urolithiasis were determined. The density of urinary stones was evaluated by computed tomography densitometry in these patients. The relationship was determined between the chemical compositions of stones and their corresponding densitometric densities. The densitometric density of urinary stones, as determined by computed tomography, can serve as a predictor of the effectiveness of stone disintegration, because it allows selection of the best method to destroy stones for treatment of urolithiasis.

Association of respiratory integer and fractional-order models with structural abnormalities in silicosis

Background and objectiveInteger and fractional-order models have emerged as powerful methods for obtaining information regarding the anatomical or pathophysiological changes that occur during respiratory diseases. However, the precise interpretation of the model parameters in light of the lung structural changes is not known. This study analyzed the associations of the integer and fractional-order models with structural changes obtained using multidetector computed tomography densitometry (MDCT) and pulmonary function analysis. MethodsInteger and fractional-order models were adjusted to data obtained using the forced oscillation technique (FOT). The results obtained in controls (n = 20) were compared with those obtained in patients with silicosis (n = 32), who were submitted to spirometry, body plethysmograph, FOT, diffusing capacity of the lungs for carbon monoxide (DLCO), and MDCT. The diagnostic accuracy was also investigated using ROC analysis. ResultsThe observed changes in the integer and fractional-order models were consistent with the pathophysiology of silicosis. The integer-order model showed association only between inertance and the non-aerated compartment (R = −0.69). This parameter also presented the highest associations with spirometry (R = 0.81), plethysmography (−0.61) and pulmonary diffusion (R = 0.53). Considering the fractional-order model, the increase in the poorly aerated and non-aerated regions presented direct correlations with the fractional inertance (R = 0.48), respiratory damping (R = 0.37) and hysteresivity (R = 0.54) and inverse associations with its fractional exponent (R = −0.62) and elastance (−0.35). Significant associations were also observed with spirometry (R = 0.63), plethysmography (0.37) and pulmonary diffusion (R = 0.51). Receiver operator characteristic analysis showed a higher accuracy in the FrOr model (0.908) than the eRIC model (0.789). ConclusionsOur study has shown clear associations of the integer and fractional-order parameters with anatomical changes obtained via MDCT and pulmonary function measurements. These findings help to elucidate the physiological interpretation of the integer and fractional-order parameters and provide evidence that these parameters are reflective of the abnormal changes in silicosis. We also observed that the fractional-order model showed smaller curve-fitting errors, which resulted in a higher diagnostic accuracy than that of the eRIC model. Taken together, these results provide strong motivation for further studies exploring the clinical and scientific use of these models in respiratory medicine.

Lung function and CT lung densitometry in 37- to 39-year-old individuals with alpha-1-antitrypsin deficiency.

BackgroundAlpha-1-antitrypsin (AAT) deficiency is a hereditary disorder that predisposes to emphysema. A cohort of severe (PiZZ) and moderate (PiSZ) AAT-deficient newborn infants was identified by the Swedish national neonatal AAT screening program in 1972–1974 and has been followed-up since birth. Our aim was to study whether the cohort has signs of emphysema in pulmonary function tests (PFTs) and computed tomography (CT) densitometry at 38 years of age in comparison with an age-matched control group, randomly selected from the population registry.MethodsForty-one PiZZ, 18 PiSZ, and 61 control subjects (PiMM) underwent complete PFTs, measurement of resistance and reactance in the respiratory system by impulse oscillometry (IOS)/forced oscillation technique (FOT), and CT densitometry. The results were related to self-reported smoking habits.ResultsThe total lung capacity (TLC) % of the predicted value was significantly higher in the PiZZ ever-smokers than in the PiZZ never-smokers (P<0.05), PiSZ never-smokers (P=0.01) and the PiMM never-smokers (P=0.01). The residual volume (RV) % of the predicted value was significantly higher in the PiZZ ever-smokers compared to the PiMM never-smokers (P<0.01). The PiZZ ever-smokers had a significantly lower carbon monoxide transfer coefficient (Kco) than the PiSZ never-smokers (P<0.01) and PiMM never-smokers (P<0.01). Respiratory system resistance at 5 Hz (P<0.01), at 20 Hz (P<0.01), and the area of low reactance (Alx; P<0.05) were significantly lower and respiratory system reactance at 5 Hz (P<0.05) was significantly higher in PiZZ subjects compared to the PiMM subjects. No statistically significant differences in the CT densitometry parameters were found between the Pi subgroups.ConclusionThe physiological parameters in the PiZZ ever-smokers showed evidence of hyperinflation and emphysema before the age of 40 years.