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Biomedical subjects

Michael Weber

Publications and source records attributed to Michael Weber.

At least 37 records · Page 2Linked to original sources
PubMed2006

Contrast-enhanced, high-resolution, susceptibility-weighted magnetic resonance imaging of the brain: dose-dependent optimization at 3 tesla and 1.5 tesla in healthy volunteers.

OBJECTIVES: We sought to determine the optimal dose of a contrast agent with known high relaxivity on 1.5 and 3 Tesla scanners that would achieve the best compromise between image quality and scan time for the clinical application of contrast-enhanced susceptibility-weighted imaging (CE-SWI). METHODS: Pre- and postcontrast SWI was performed with different contrast agent doses (0.05, 0.1, and 0.2 mmol/kg gadobenate dimeglumine) at both 1.5 and 3 T in 6 healthy volunteers, resulting in 72 examinations. Venograms were created from minimum intensity projection reconstructions over specified deep white matter volumes to enhance the visual appearance of connected venous structures. Three independent radiologists blindly rated the visibility of the veins on a continuous scale of 1 to 10. A general linear model was used for statistical evaluation, with fixed effects of the contrast agent dose, the field strength, the rater and the patients as a random effect. RESULTS: With CE-SWI, we found significant differences in the visibility of the deep veins dependent on the contrast media dose (P=0.02). At 3 T, the visibility of deep venous vessels, with regard to susceptibility effect, image quality, and scan time reduction after a standard contrast agent dose 0.1 mmol/kg was significantly better than that achieved with 0.05 mmol/kg. The visibility was considered equal with 0.1 mmol/kg of the contrast agent to the precontrast images and a dose of 0.2 mmol/kg. At 1.5 T, no significant difference was found between the 4 contrast agent doses. We found no difference in the visibility of the veins with the shorter sequences at 3 T compared with the sequences at 1.5 T. CONCLUSIONS: Only a standard dose (0.1 mmol/kg) of gadobenate dimeglumine is required to achieve the optimum susceptibility effect and image quality at 3 T, together with a reduced scan time. This result can be attributed to the higher relaxivity of gadobenate dimeglumine, compared with conventional gadolinium chelates.

Adult↗
PubMed2006

Comparative transcriptome analysis of toxic metal responses in Arabidopsis thaliana and the Cd(2+)-hypertolerant facultative metallophyte Arabidopsis halleri.

Toxic effects of both essential and non-essential heavy metals are well documented in plants. Very little is known, however, about their modes of toxicity, about tolerance mechanisms and the signalling cascades involved in mediating transcriptional responses to toxic metal excess. We analysed transcriptome changes upon Cd2+ and Cu2+ exposure in roots of Arabidopsis thaliana and the Cd(2+)-hypertolerant metallophyte Arabidopsis halleri. Particularly, three categories of genes were identified with the help of this comparative approach: (1) common responses, which might indicate stable and functionally relevant changes conserved across plant species; (2) metallophyte-specific responses as well as transcripts differentially regulated between the two species, representing candidate genes for Cd2+ hypertolerance; and (3) those specifically responsive to Cd2+ and therefore indicative of toxicity mechanisms or potentially involved in signalling cascades. Our data define, for instance, Arabidopsis core responses to Cd2+ and Cu2+. In addition, they suggest that Cd2+ exposure very rapidly results in apparent Zn deficiency, and they show the existence of highly specific Cd2+ responses and distinct signalling cascades. Array results were independently confirmed by real-time quantitative PCR, thereby further validating cross-species transcriptome analysis with oligonucleotide microarrays.

Adaptation, Physiological↗
PubMed2006

Occult scaphoid fractures: comparison of multidetector CT and MR imaging--initial experience.

PURPOSE: To compare the diagnostic performance of multidetector computed tomography (CT) and magnetic resonance (MR) imaging in patients clinically suspected of having a scaphoid fracture and who had normal initial radiographs, with radiographs obtained 6 weeks after trauma as the reference standard. MATERIALS AND METHODS: The ethics committee approved the study, and all patients gave written informed consent. Twenty-nine patients (17 male, 12 female; age range, 17-62 years; mean age, 34 years +/- 13) underwent multidetector CT and MR imaging within 6 days after trauma. CT data were obtained with 0.5-mm collimation. For image review, 0.7-mm-thick multiplanar reformations were performed in transverse, coronal, and sagittal planes relative to the wrist. The 1.0-T MR examination consisted of coronal and transverse short inversion time inversion-recovery, coronal and transverse T1-weighted spin-echo, and coronal volume-rendered T2-weighted gradient-echo sequences. Two radiologists analyzed the CT and MR images. A binomial test was used to evaluate the significance of the differences between MR imaging and CT in detection of scaphoid fractures and cortical involvement (P < .05). RESULTS: The 6-week follow-up radiographs depicted a scaphoid fracture in 11 (38%) patients. Eight patients had a cortical fracture, while three patients had only a bandlike lucency within the trabecular portion of the scaphoid. MR imaging depicted all 11 fractures but only three [corrected] cortical fractures. Multidetector CT depicted all eight cortical fractures but failed to depict trabecular fractures. No false-positive fractures were seen on MR or CT images. Differences between MR imaging and CT were not significant for the detection of scaphoid fractures (P = .25) but were significant for cortical involvement (P = .03). CONCLUSION: Multidetector CT is highly accurate in depicting occult cortical scaphoid fractures but appears inferior to MR imaging in depicting solely trabecular injury. MR imaging is inferior to multidetector CT in depicting cortical involvement.

Adolescent↗
PubMed2006

CT angiography of pulmonary arteries to detect pulmonary embolism: improvement of vascular enhancement with low kilovoltage settings.

PURPOSE: To retrospectively compare a low kilovoltage scanning protocol with a reduced radiation dose with a standard high kilovoltage, moderate-dose protocol for the depiction of central and peripheral pulmonary arteries at single-detector spiral computed tomography (CT). MATERIALS AND METHODS: This retrospective study had institutional review board approval; informed consent was waived. A 100-kVp protocol (volume CT dose index [CTDI(vol)], 3.4 mGy) was compared with a standard 140-kVp protocol (CTDI(vol), 10.4 mGy) in two groups that were each composed of 35 consecutive patients who were suspected of having pulmonary embolism (PE) and scanned with otherwise identical acquisition parameters and contrast material injection protocols. Mean main pulmonary artery enhancement and maximum enhancement in peripheral pulmonary arteries were compared. In a blinded evaluation, the percentages of segmental and subsegmental arteries that were considered analyzable for assessment of PE were determined. Overall image quality and delineation of various anatomic areas were subjectively assessed. Comparison of percentages of analyzable segmental and subsegmental arteries and subjective grading of image quality between the two different protocols were performed with the Mann-Whitney U test. RESULTS: There were 38 male and 24 female patients (mean age, 61 years; range, 17-86 years) in the final evaluation. There was a significantly higher average CT number in the main pulmonary artery (379 HU +/- 95) for the 100-kVp protocol than for the 140-kVp protocol (268 HU +/- 63, P < .001, two-sided t test). Maximum CT numbers in peripheral pulmonary arteries at the level of the aortic arch and lung bases, respectively, were 290 HU +/- 91 and 279 HU +/- 100 for 100 kVp and 185 HU +/- 65 and 144 HU +/- 63 for 140 kVp (P < .001). Mean percentage of subsegmental arteries considered analyzable per patient was higher for 100 kVp than for 140 kVp (segmental arteries, 92% vs 88%, P = .13; subsegmental arteries, 71% vs 55%, P < .001). Subjective grading of overall image quality and of the delineation of structures in the lungs, mediastinum, and upper abdomen did not significantly differ between protocols. CONCLUSION: At reduced radiation exposure, low kilovoltage scanning increases the percentage of central and peripheral pulmonary arteries that can be evaluated with CT angiography without a substantial decrease in image quality.

Adolescent↗
PubMed2006

MDCT versus digital radiography in the evaluation of bone healing in orthopedic patients.

OBJECTIVE: Assessment of bone healing in orthopedic patients is usually monitored by radiographs in two views. The purpose of our study was to compare multiplanar reconstructions from MDCT data sets with digital radiographs for assessing the extent of bone healing. MATERIALS AND METHODS: Forty-three orthopedic patients (19 women, 24 men) who underwent MDCT and radiography after arthrodesis, fractures, or spinal fusions were included in our study. MDCT was performed on an MX 8000IDT scanner and served as the gold standard. The technical parameters were adapted to the anatomic region. A bone algorithm for reconstruction was used (3,500/600 H). Multiplanar reconstructions were calculated in two orthogonal planes. All patients underwent digital radiography on a Multix FD system in two views according to standard procedures. Multiplanar reconstructions and radiographs were analyzed by two musculoskeletal radiologists in a consensus interpretation to determine bone healing using a semiquantitative approach. RESULTS: In 27 patients (63%), MDCT and digital radiography were concordant with regard to the extent of bone healing, whereas in 16 patients (37%) the results were not concordant. In eight patients (19%) digital radiographs underestimated the extent of bone healing, whereas in another eight patients (19%) they overestimated the degree of fusion. CONCLUSION: MDCT using high-quality 2D reformatting is recommended as the primary imaging technique for the evaluation of bone healing.

Female↗
PubMed2006

[Evaluation of a modular out-patient education program for adult asthmatics with office-based specialists--results of a controlled, randomized multicenter trial].

The efficacy of a modular education program for adult asthmatics was evaluated in a controlled, randomized multicenter trial under outpatient conditions for six months. The education was performed with material (patient handout and PowerPoint slides) of the MASA Program (i.e. a modular outpatient education program for adult asthmatics) according to the contents list of the NASA Program (i.e. a national education program for adult asthmatics). In total, 75 patients of seven asthma specialists were included. The complete data of 53 patients were obtained and evaluated. All patients had been diagnosed with asthma in the year before, most of them (54%) with moderately severe asthma. The patients in the intervention group attended a two-hour teaching program for three times; the control group once received a short introduction to the use of a peak-flow meter, an asthma diary and asthma emergency instructions. Compared to the control group, the intervention group patients showed significantly less mild asthma attacks. The mean requirement for inhalation of short-acting beta-agonists was 0.18 times vs. 1.5 times per week for the intervention and the control group, respectively (p = 0.0062). Another primary outcome was the number of unscheduled asthma-related visits to the doctor within six months. There was a trend to lower numbers in the intervention group, but due to the small number of patients the results did not reach significance. The same applies to the patients' estimation of their quality of life, measured by the SF-36 questionnaire. Patients in the intervention group had a significantly better knowledge about their disease (improvement in the number of correctly answered questions: 6.7 times in the intervention and 5.5 times in the control group; p = 0.0062) and showed a better adherence to their regular medication. In conclusion, this trial proves the quality of the MASA education program and its feasibility in the outpatient setting of a chest physician's practice, and it demonstrates the efficacy of outpatient education programs for asthmatics.

Adult↗
PubMed2006

[PVD-layering for increased retention of glass fibre reinforced endodontic posts].

For esthetical and biomechanical reasons root canal posts made of fibre-reinforced composite (FRC) have gained an important role in clinical application. Additionally, in contrast to metal or ceramic posts, FRC-posts offer the option of removal. Prior to adhesive placement of FRC-posts the root canal dentin of the non vital tooth and the post surface have to be preconditioned. Up to now the post preconditioning has to be proceeded in the chair side technique. This leads to an additional time expense in the clinical treatment schedule. Also a certain risk of errors in application during chair side conditioning procedure is of concern. Modern PVD-technologies can help to make the treatment by the manufacturer well in advance of the clinical use more efficient and reliable, as well as saving clinicians valuable chair-time. For this reason the apical surfaces of the posts were intensively cleaned and activated, PVD-layered and coated by a conserving transparent layer. This coating has the meaning to protect the surface against environmental contamination and allows the try-in of the posts without any risk of damage of the preconditioned surface. To prove the stability of the layer system under simulated clinical conditions pull out tests after 180 days'storage in physiological saline solution have been performed.

Cementation↗
PubMed2005

Light microscopic, immunohistochemical, and ultrastructural findings in congenital fibular aplasia or hypoplasia (FAH).

Congenital aplasia or hypoplasia of the fibula (FAH) is a rare malformation that is defined by a partial or complete absence of the fibular bone. Etiology and pathogenesis are unknown and the precise morphology of the tissue cord replacing the malformed fibula has not been well described. Therefore, tissue cord was examined in 8 patients with FAH. Light microscopic, immunohistochemical, and electron microscopic investigations showed a core of embryonic cartilage with collagen II and VI expressions surrounded by connective tissue. Although collagen II expression is typical for chondroid differentiation, collagen VI reactivity is normally seen in articular cartilage and tendon-like fibrocartilaginous tissue but is absent in hyaline cartilage. Further ultrastructural analyses by electron microscopy supported these findings. The histomorphologic changes correspond to the histologic findings of Papenbrock et al. (2000, Mech Dev 92:113-123) who produced a congenital malformation in transgenic mice that resembled FAH by overexpression of Hox c11.

Abnormalities, Multiple↗
PubMed2005

Diagnostic utility of new immunoassays for the cardiac markers cTnI, myoglobin and CK-MB mass.

OBJECTIVES: We investigated the diagnostic value of a new system, the Innotrac Aio! immunoassays for troponin, myoglobin and CK-MB, in 270 samples from patients with ACS, after bypass surgery (CABG) or with stable heart failure in comparison to the respective Roche assays. RESULTS: The values of the cardiac markers assessed by the respective assays correlated (cTnT/cTnI Rho = 0.94, myoglobin Rho = 0.87, CK-MB Rho = 0.84). If values were dichotomised, we found a high concordance of test positive and negative classified patients by troponins with the respective assays. CONCLUSION: There is strong evidence that the Innotrac Aio! system for cTnI measurement can be used reliably.

Acute Disease↗
PubMed2005

Chromosome-wide and promoter-specific analyses identify sites of differential DNA methylation in normal and transformed human cells.

Cytosine methylation is required for mammalian development and is often perturbed in human cancer. To determine how this epigenetic modification is distributed in the genomes of primary and transformed cells, we used an immunocapturing approach followed by DNA microarray analysis to generate methylation profiles of all human chromosomes at 80-kb resolution and for a large set of CpG islands. In primary cells we identified broad genomic regions of differential methylation with higher levels in gene-rich neighborhoods. Female and male cells had indistinguishable profiles for autosomes but differences on the X chromosome. The inactive X chromosome (Xi) was hypermethylated at only a subset of gene-rich regions and, unexpectedly, overall hypomethylated relative to its active counterpart. The chromosomal methylation profile of transformed cells was similar to that of primary cells. Nevertheless, we detected large genomic segments with hypomethylation in the transformed cell residing in gene-poor areas. Furthermore, analysis of 6,000 CpG islands showed that only a small set of promoters was methylated differentially, suggesting that aberrant methylation of CpG island promoters in malignancy might be less frequent than previously hypothesized.

Cell Line, Transformed↗
PubMed2005

Symptomatic relief precedes improvement of myocardial blood flow in patients under spinal cord stimulation.

BACKGROUND: Spinal cord electrical stimulation (SCS) has shown to be a treatment option for patients suffering from angina pectoris CCS III-IV although being on optimal medication and not suitable for conventional treatment strategies, e.g. CABG or PTCA. Although many studies demonstrated a clear symptomatic relief under SCS therapy, there are only a few short-term studies that investigated alterations in cardiac ischemia. Therefore doubts remain whether SCS has a direct effect on myocardial perfusion. METHODS: A prospective study to investigate the short- and long-term effect of spinal cord stimulation (SCS) on myocardial ischemia in patients with refractory angina pectoris and coronary multivessel disease was designed. Myocardial ischemia was measured by MIBI-SPECT scintigraphy 3 months and 12 months after the beginning of neurostimulation. To further examine the relation between cardiac perfusion and functional status of the patients we measured exercise capacity (bicycle ergometry and 6-minute walk test), symptoms and quality of life (Seattle Angina Questionnaire [SAQ]), as well. RESULTS: 31 patients (65 +/- 11 SEM years; 25 male, 6 female) were included into the study. The average consumption of short acting nitrates (SAN) decreased rapidly from 12 +/- 1.6 times to 3 +/- 1 times per week. The walking distance and the maximum workload increased from 143 +/- 22 to 225 +/- 24 meters and 68 +/- 7 to 96 +/- 12 watt after 3 months. Quality of life increased (SAQ) significantly after 3 month compared to baseline, as well. No further improvement was observed after one year of treatment. Despite the symptomatic relief and the improvement in maximal workload computer based analysis (Emory Cardiac Toolbox) of the MIBI-SPECT studies after 3 months of treatment did not show significant alterations of myocardial ischemia compared to baseline (16 patients idem, 7 with increase and 6 with decrease of ischemia, 2 patients dropped out during initial test phase). Interestingly, in the long-term follow up after one year 16 patients (of 27 who completed the one year follow up) showed a clear decrease of myocardial ischemia and only one patient still had an increase of ischemia compared to baseline. CONCLUSION: Thus, spinal cord stimulation not only relieves symptoms, but reduces myocardial ischemia as well. However, since improvement in symptoms and exercise capacity starts much earlier, decreased myocardial ischemia might not be a direct effect of neurostimulation but rather be due to a better coronary collateralisation because of an enhanced physical activity of the patients.

Journal Article↗
PubMed2005

Relation of N-terminal pro B-type natriuretic peptide to progression of aortic valve disease.

AIMS: Recently an elevation of B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP) in patients with aortic stenosis (AS) and aortic regurgitation (AR) has been described. The objective of this study was to evaluate the relation of NT-proBNP values to the progression of aortic valve disease. METHODS AND RESULTS: One hundred and sixty-eight patients were included. NT-proBNP was elevated in patients with AS (n=109) and AR (n=37) linked to disease severity. Values for NT-proBNP, pressure gradient, and left ventricular mass were identical in patients (n=22) after previous valve replacement and in those patients with mild AS. NT-proBNP levels decreased in 86 patients after valve replacement (2292+/-353 vs. 785+/-101 pg/ml; P<0.01) but increased in 82 patients who were treated conservatively (616+/-120 vs. 1155+/-432 pg/mL; P=0.029), related to the progression of disease. CONCLUSION: NT-proBNP is elevated in patients with aortic valve disease linked to disease severity and decreases after successful surgical therapy but increases in conservatively treated patients. These data underline the consistent relation of NT-proBNP to severity of aortic valve disease. Therefore, NT-proBNP should be considered as a biomarker for the monitoring of disease during follow-up, but further studies are warranted.

Aged↗
PubMed2005

Endurance exercise training in orthostatic intolerance: a randomized, controlled trial.

Orthostatic intolerance is a syndrome characterized by chronic orthostatic symptoms of light-headedness, fatigue, nausea, orthostatic tachycardia, and aggravated norepinephrine levels while standing. The aim of this study was to assess the protective effect of exercise endurance training on orthostatic symptoms and to examine its usefulness in the treatment of orthostatic intolerance. 2768 military recruits were screened for orthostatic intolerance by questionnaire. Tilt-table testing identified 36 cases of orthostatic intolerance out of the 2768 soldiers. Subsequently, 31 of these subjects with orthostatic intolerance entered a randomized, controlled trial. The patients were allocated randomly to either a "training" (3 months jogging) or a "control" group. The influence of exercise training on orthostatic intolerance was assessed by determination of questionnaire scores and tilt-table testing before and after intervention. After training, only 6 individuals of 16 still had orthostatic intolerance compared with 10 of 11 in the control group. The Fisher exact test showed a highly significant difference in diagnosis between the 2 groups (P=0.008) at the end of the study. Analysis of the questionnaire-score showed significant interaction between time and group (P=0.001). The trained subjects showed an improvement in the average symptom score from 1.79+/-0.4 to 1.04+/-0.4, whereas the control subjects showed no significant change in average symptom score (2.09+/-0.6 and 2.14+/-0.5, respectively). Our data demonstrate that endurance exercise training leads to an improvement of symptoms in the majority of patients with orthostatic intolerance. Therefore, we suggest that endurance training should be considered in the treatment of orthostatic intolerance patients.

Adult↗
PubMed2005

Contrast-enhanced high-resolution magnetic resonance imaging of autologous cartilage implants of the knee joint.

Over the past decade, a number of interventions for durable cartilage repair have emerged. Magnetic resonance (MR) tomography is an excellent noninvasive method for monitoring cartilage repair tissues throughout the postsurgical period. However, evaluating cartilage morphology after matrix-based autologous cartilage implantation (ACI) with MR imaging (MRI) still remains a challenge. In this study, we combined a high-resolution cartilage-sensitive fast-spin echo (FSE) sequence with intravenous application of a contrast agent for enhancing synovial fluid. Two independent musculoskeletal radiologists interpreted the pictures for the thickness, length and surface of the cartilage implants. A multivariate two-way analysis of variance with two repeated measures was performed and showed that evaluation of cartilage implant morphology was significantly improved after the application of gadodiamide on proton density FSE images. Contrast-enhanced MRI of articular cartilages is a promising technique in the postoperative follow-up of patients after ACI.

Adult↗
PubMed2005

Vascular changes in the periosteum of congenital pseudarthrosis of the tibia.

The etiology and the pathogenesis of congenital pseudarthrosis of the tibia (CPT) are still unknown. The affected tibia exhibits insufficient mechanical strength and osteogenetic capability. CPT is frequently associated with neurofibromatosis type 1 (NF1; von Recklinghausen's disease); however, both diseases have not yet been linked pathogenetically. This study presents the pathomorphologic findings of CPT under special consideration of NF1. Therefore, samples from patients operated on for CPT (n = 4) with (n = 3) and without (n = 1) neurofibromatosis were investigated by light microscopy, immunohistochemistry, and electron microscopy. The most striking finding in all patients was thickened periosteum with accumulation of nerval cells surrounding small arteries, causing subtotal or complete obliteration. In conclusion, impaired vascularization can result in decreased osteogenic capabilities. The similarity of ultrastructural findings in the abnormal periosteum and in skin neurofibromas of neurofibromatosis patients may indicate a pathogenetic association of both diseases.

Adolescent↗
PubMed2005

Application of division arrest technology to cell-based HTS: comparison with frozen and fresh cells.

Cell-based functional assays are becoming popular in many HTS laboratories because of recent advances in detection and automation technologies. However, the supply of large amounts of live cells with consistent cellular response for day-to-day screening operations over several days/weeks is a tremendous challenge. The high cost of cell culture, labor-intensive nature of the work, and inherent variability in cellular responses from time to time tend to be prohibitive for extensive applications of cell-based assays in HTS. We therefore tested division-arrested cells that were prepared in a single batch and frozen at -80 degrees C before use in several cell-based assays and in a robotic screening campaign. Chinese hamster ovary cells expressing a Gq-coupled receptor were analyzed for the agonist-induced intracellular Ca2+ response measured on a fluorescent imaging plate reader. In this case, the division-arrested cells showed consistent agonist-induced intracellular Ca2+ concentration response as reflected by signal-to-basal ratio and EC50 even 48 h after cell plating. In comparison, the responses from untreated frozen cells and fresh cells declined significantly approximately 30 h after cell plating. In other cell-based assays tested (cyclic AMP assay, reporter gene beta-lactamase assay, and ion-channel assay), the division-arrested cells performed as well as frozen, or fresh cells. We thus conclude that the use of alternate strategies such as frozen cells or division-arrested cells may alleviate the need for several batches of cell plating each day during HTS while maintaining the desired robotic throughput and assay quality.

Animals↗
PubMed2005

Computed radiography and direct radiography: influence of acquisition dose on the detection of simulated lung lesions.

PURPOSE: We sought to evaluate the performance of dual-readout and single-readout computed radiography compared with direct radiography for detecting subtle lung abnormalities with a standard and a low-dose technique. MATERIALS AND METHODS: Posteroanterior radiographs of an anthropomorphic chest phantom were obtained with a single-readout storage phosphor radiography system (CRS, pixel size 200 microm), a dual-readout storage phosphor radiography system (CRD, pixel size 100 microm), and a direct detector (DR, pixel size 143 microm) at dose levels of 400 and 800 speed. Ten templates were superimposed to project 4 types of lesions over low- and high-attenuation areas, simulating nodules, micronodules, lines, and patchy opacities. Six radiologists evaluated 60 hard-copy images for the presence or absence of lesions. Statistical significance of differences was evaluated using receiver operating characteristic analysis and analysis of variance. RESULTS: For both low- and high-attenuation areas, CRD (Az = 0.85 and 0.66) was superior to CRS (Az = 0.75 and 0.58) for overall performance and all lesion subtypes (P < 0.05). DR (Az = 0.87 and 0.67) performed slightly better than CRD, being significant only for the detection of micronodules. Acquisition dose significantly affected only the detection of lines and micronodules, whereas the detection of nodules and patchy opacities was not significantly different with reduced exposure, regardless of the system used. CONCLUSION: The dual-readout CR system significantly outperformed the single-readout CR and almost equaled the performance of DR. Dose reduction was more critical for small-sized lesions (micronodules, lines) than for nodular or patchy opacifications and affected mainly the lesions in high attenuation areas.

Humans↗