Multidetector row CT for imaging the paediatric tracheobronchial tree.
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ABSTRACT:
SUBMITTER: Papaioannou G
PROVIDER: S-EPMC1891645 | biostudies-other | 2007 Jun
REPOSITORIES: biostudies-other
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Project description:Background and purposeThe ability to perform neuroimaging on the angiography suite is important in making decisions during neurointerventions. Our aim was the evaluation of ACT as a fast available diagnostic tool during and after neuroendovascular procedures and the comparison of ACT with postinterventional MDCT.Materials and methodsEighty-four peri-interventional ACT acquisitions were obtained and evaluated: 38 after coil embolization of cerebral aneurysms, 16 after intracranial angioplasty with stent placement, and 30 after endovascular mechanical thrombectomy and lysis. Interventions and ACTs were performed on a biplane angiography system equipped with flat panel detectors. Postprocessing was performed on a dedicated workstation, and multiplanar reformations were generated. Reference studies were performed on a 16- or 128-section MDCT scanner. All studies were independently evaluated by 3 blinded neuroradiologists. The Wilcoxon test was applied for the statistical analysis.ResultsACT and MDCT images were of equal diagnostic quality in most cases related to the supratentorial ventricular system and the detection of hemorrhages (subarachnoidal, intraparenchymal, and intraventricular). Regarding the supratentorial ventricular system, an adequate diagnostic quality was assigned to 94% of the ACT acquisitions. For the detection of hemorrhage, no statistically significant difference was noted between ACT and MDCT. However, for the infratentorial region, ACT performed relatively poorly compared with MDCT. The diagnostic evaluation of gray matter (basal ganglia, insular cortex, and central cortex) by ACT is not sufficient, with <20% of the acquisitions scoring a diagnostic value.ConclusionsAfter neuroendovascular procedures and within the angiography suite, ACT enables an immediate detection of peri-interventional hemorrhage or hydrocephalus. However, for the detection of cerebral infarction, ACT is not yet reliable.
| S-EPMC7965444 | biostudies-literature
Project description:OBJECTIVE: To compare diagnostic performances of two reduced z-axis coverages to full coverage of the abdomen and pelvis for the diagnosis of acute appendicitis and alternative diseases at unenhanced CT. METHODS: This study included 152 adults suspected of appendicitis who were enrolled in two ethical committee-approved previous prospective trials. Based on scans covering the entire abdomen and pelvis (set L), two additional sets of images were generated, each with reduced z-axis coverages: (1) from the top of the iliac crests to the pubis (set S) and (2) from the diaphragmatic crus to the pubis (set M). Two readers independently coded the visualisation of the appendix, measured its diameter and proposed a diagnosis (appendicitis or alternative). Final diagnosis was based on surgical findings or clinical follow-up. Fisher exact and McNemar tests and logistic regression were used. RESULTS: 46 patients had a definite diagnosis of appendicitis and 53 of alternative diseases. The frequency of appendix visualisation was lower for set S than set L for both readers (89% and 84% vs 95% and 91% by Readers A and B, respectively; p=0.021 and 0.022). The probability of giving a correct diagnosis was lower for set S (68%) than set L (78%; odds ratio, 0.611; p=0.008) for both readers, without significant difference between sets L and M (77%, p=0.771); z-axis coverage being reduced by 25% for set M. CONCLUSION: Coverage from diaphragmatic crus to pubis, but not focused on pelvis only, can be recommended in adults suspected of appendicitis. ADVANCES IN KNOWLEDGE: In suspected appendicitis, CT-coverage can be reduced from diaphragmatic crus to pubis.
| S-EPMC3745057 | biostudies-other
Project description:To assess the optimal method for grading carotid artery stenosis with computed tomographic angiography (CTA), we compared visual estimation to caliper measurements, and determined inter-observer variability and agreement relative to digital subtraction angiography (DSA). We included 46 patients with symptomatic carotid stenosis for whom CTA and DSA of 55 carotids was available. Stenosis quantification by CTA using visual estimation (CTA(VE)) (method 1) was compared with caliper measurements using subjectively optimized wide window settings (method 2) or predefined contrast-dependent narrow window settings (method 3). Measurements were independently performed by two radiologists and two residents. To determine accuracy and inter-observer variability, we calculated linear weighted kappa, performed a Bland-Altman analysis and calculated mean difference (bias) and standard deviation of differences (SDD). For inter-observer variability, kappa analysis was "very good" (0.85) for expert observers using CTA(VE) compared with "good" (0.61) for experts using DSA. Compared with DSA, method 1 led to overestimation (bias 5.8-8.0%, SDD 10.6-14.4), method 3 led to underestimation (bias -6.3 to -3.0%, SDD 13.0-18.1). Measurement variability between DSA and visual estimation on CTA (SDD 11.5) is close to the inter-observer variability of repeated measurements on DSA that we found in this study (SDD 11.6). For CTA of carotids, stenosis grading based on visual estimation provides better agreement to grading by DSA compared with stenosis grading based on caliper measurements.
| S-EPMC2778777 | biostudies-other
Project description:The purpose of this study was to identify the normal variance of emphysema index (EI) measured in examinations acquired with 64 multidetector-row computed tomography (64-MDCT). A longitudinal, noninterventional study was performed retrieving all patients in our institution who are currently registered in our lung nodule protocol. All patients with clinical, functional, or significant radiological changes were excluded. We assumed that EI should remain unchanged within a short period of time. We reviewed 475 MDCTs in order to select 50 clinically stable patients who had two sequential chest MDCTs performed within a time interval of less than three months, and who presented at least one lung free of abnormalities but emphysema. CT densitovolumetry was used to calculate EI with thresholds set at -950 Hounsfield units (HUs) (EI-950) and -970 HUs (EI-970); on both studies from each patient. We observed the variation of total lung volume (TLV), mean lung density (MDL), and EI for measurements at the baseline and at follow-up scans. Differences observed between baseline and follow-up measurements were: TLV μ= 149 ml; IC = μ +1.96 (133); EI-950 μ = 0.02%; p 95 = 0.89%; EI-970 μ = 0.04%; p 95 = 0.23% and MLD μ = 15 HU; IC = μ +1.96 (18). The correlations obtained were the following: TLV r = 0.96, EI-950 r = 0.79, EI-970 r = 0.85. Accepting that emphysema would remain unchanged within three months on stable patients, differences of less than 0.89% for EI-950 and of less than 0.23% for EI-970 are within the variance of the method.
| S-EPMC5714530 | biostudies-literature
Project description:ObjectiveTo investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection.MethodsForty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared.ResultsThe BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044).ConclusionsThis study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values.
| S-EPMC5300209 | biostudies-literature
Project description:Background: Reconstruction with the use of perforator flaps makes it possible to make the skin surface resistant to the influence of mechanical factors and as similar to the lost skin cover as possible. However, while planning any flap, along with the design of the required shape and size, its blood supply should be taken into account to ensure optimal viability. Therefore, the task to precisely determine the topographic-anatomical relationships suitable for the formation of a pedicle of perforators is still relevant. The aim of this study was to increase the efficiency of surgical reconstruction of wound defects by transposition of locoregional perforator flaps. Methods: The authors conducted a retrospective analysis of 72 cases of reconstruction by means of locoregional perforator flaps with vascular pedicle detachment to determine the efficiency of preoperative diagnostic preparation with the help of multidetector-row computed tomographic angiography (MDCT) in the process of reconstruction. Thirty-seven individual cases of surgical interventions were chosen using a case-controlled study from the study group when MDCT with angiography was used for preoperative planning of perforator flaps, as well as 35 control cases similar in terms of important predictive peculiarities with the reconstruction at the same level of difficulty. The patient groups were precisely matched by gender (P = .950), age (P = .804), flap area (P = .192), and type of reconstruction that was performed. Results: In all cases, the location of the perforator with a diameter greater than 1.0 mm was marked. All perforators determined during MDCT scanning were faultlessly localized intraoperatively. The distance between the intraoperative position of the perforator and the position obtained in the result of the examination did not exceed 1 cm. There was no need to change the planned design of the flap intraoperatively. In all cases where MDCT was performed, the duration of the surgical procedure varied from 60 to 150 minutes (average: 120.77 [18.90] minutes) and was reduced by 49.40 minutes (95% CI: 39.17-59.63) compared with the patients who did not undergo preoperative visualization of perforators where the average duration of the operation was 170.17 (19.19) minutes (from 140 to 220 minutes). Among the patients examined by MDCT, surgical complications were noted in 5 cases (13.51%) compared to 14 cases (40.00%) in the control group. Conclusions: The preoperative MDCT for the locoregional perforator flap reconstruction makes it possible to increase the efficiency of patient treatment given the reduction in surgery duration by 49.40 minutes (95% CI: 39.17-59.63) on average and the reduction in the level of postsurgery complications from 40% to 13.5% compared with the group of patients in whom presurgical visualization was not performed (P = .031).
| S-EPMC9900034 | biostudies-literature
Project description:The mechanisms responsible for thromboembolic events in children with congenital heart disease have not yet been fully elucidated. Furthermore, establishment of long-term anticoagulation therapy in Fontan patients remains controversial. Here, we report the case of a 9-year-old boy who presented with hemiparesis due to a thromboembolic stroke; the boy had previously undergone staged pulmonary artery banding and Fontan procedure. Cardiac multidetector-row computed tomography (MDCT) clearly showed the supravalvular thrombus at the roofed (blind) pulmonary valve and circulatory stasis, which could be considered a possible source of the thrombus. Follow-up CT examination showed that the thrombus disappeared, but the circulatory stasis remained. Therefore, because the risk of thrombus formation was not eliminated, anticoagulation therapy was continued for the patient. Our case indicates the possible application of cardiac MDCT for providing insight into the hemodynamic mechanisms responsible for the thromboembolic events in children with congenital heart disease.
| S-EPMC6265222 | biostudies-literature
Project description:BackgroundTo perform laparoscopic gastrectomy safely, we aimed to comprehensively re-evaluate perigastric vessel anatomies using a three-dimensional angiography reconstructed from enhanced multidetector-row computed tomography data.MethodsPerigastric vessel anatomy was preoperatively analyzed using a multidetector-row computed tomography-based three-dimensional angiography reconstructed in 127 patients undergoing gastric surgery.ResultsOf the 67 left gastric veins that ran along the dorsal side of the arteries, 59 (88.1%) ran along the dorsal side of the common hepatic artery and flowed into the portal vein. In 18 cases, a common trunk of one to three left gastric arteries and the replaced left hepatic artery was observed. The left inferior phrenic artery ramified from the left gastric artery in 5.5% of the cases. The right gastric artery was classified into distal (73.2%), caudal (18.1%), and proximal (8.7%) types. The infra-pyloric artery was also classified into distal (64.6%), caudal (26.0%), and proximal (9.4%) types. The posterior gastric artery branched as a common trunk with the superior polar artery in the proximal (37.9%) and distal (18.4%) regions of the splenic artery. The left gastroepiploic artery ramified from the splenic (18.1%) and inferior terminal arteries (81.9%). No, one, and two gastric branches of the left gastroepiploic artery, which ramified between the roots of the left gastroepiploic artery and its omental branch, were found in 36.5%, 49.2%, and 14.3% of the cases, respectively.ConclusionsPreoperative 3D angiography is useful for the precise evaluation of perigastric vessel anatomies, and may help us to perform laparoscopic gastrectomy and robotic surgery safely.
| S-EPMC9677658 | biostudies-literature
Project description:PurposeTo investigate the possibility of reducing the injected activity for whole-body [18F]FDG-PET/CT studies of paediatric oncology patients and to assess the usefulness of time-of-flight (TOF) acquisition on PET image quality at reduced count levels.ProceduresTwenty-nine paediatric oncology patients (12F/17M, 3-18 years old (median age 13y), weight 45±20 kg, BMI 19±4 kg/m2), who underwent routine whole-body PET/CT examinations on a Siemens Biograph mCT TrueV system with TOF capability (555ps) were included in this study. The mean injected activity was 156 ± 45 MBq (3.8 ± 0.8 kg/MBq) and scaled to patient weight. The raw data was collected in listmode (LM) format and pre-processed to simulate reduced levels of [18F]FDG activity (75, 50, 35, 20 and 10% of the original counts) by randomly removing events from the original LM data. All data were reconstructed using the vendor-specific e7-tools with standard OSEM only, with OSEM plus resolution recovery (PSF). The reconstructions were repeated with added TOF (TOF) and PSF+TOF. The benefit of TOF together with the reduced count levels was evaluated by calculating the gains in signal-to-noise ratio (SNR) in the liver and contrast-to-noise ratio (CNR) in all PET-positive lesions before and after TOF employed at every simulated reduced count level. Finally, the PSF+TOF images at 50, 75 and 100% of counts were evaluated clinically on a 5-point scale by three nuclear medicine physicians.ResultsThe visual inspection of the reconstructed images did not reveal significant differences in image quality between 75 and 100% count levels for PSF+TOF. The improvements in SNR and CNR were the greatest for TOF reconstruction and PSF combined. Both SNR and CNR gains did increase linearly with the patients BMI for both OSEM only and PSF reconstruction. These benefits were observed until reducing the counts to 50 and 35% for SNR and CNR, respectively.ConclusionsThe benefit of using TOF was noticeable when using 50% or greater of the counts when evaluating the CNR and SNR. For [18F]FDG-PET/CT, whole-body paediatric imaging the injected activity can be reduced to 75% of the original dose without compromising PET image quality.
| S-EPMC8410733 | biostudies-literature
Project description:Determining the branching pattern of the popliteal artery (PA) is an important step in planning some radiological and surgical procedures. The aim of this study was to investigate the course and morphology of the terminal branches of the popliteal artery using multidetector computed tomography (MDCT) angiography, and also to determine possible role gender in branching pattern. Three-hundred forty lower extremity MDCT angiography images for 170 patients (118?M, 52?F), who were between 20-80 years old, were examined. Popliteal artery branching types were grouped as percentage incidences. TPT diameters and lengths in Type IA extremities were compared based on gender and right or left side. Anterior tibial artery (ATA), posterior tibial artery (PTA) and peroneal artery dominance rates were calculated. 5000 times measurement data was mixed so that the cascade mean filter values were calculated for the right and left TPT length each time. It was observed that Type IA was the most common branching pattern (89.4%). The variational pattern incidence was 10.6% and the most common category was Type III (4.1%). The most common pattern was Type IB (3.2%). Variational pattern was 2 times more prevalent in females when compared to the males. The mean TPT diameter was 4.5?mm (2.7-7.3?mm) and there was no difference based on gender and the right-left side. The most common dominant artery for the right and left legs was PTA in both genders. The cut-off values calculated for the right and left TPT independent of gender were 31.30?±?2.40 and 28.36?±?2.58, respectively. Three new subtypes were identified as short (S???2?cm), standard (N?=?2-4?cm) and long (L???4?cm) in Type IA, since it is in a wide variational range although it is a typical PA branching pattern.
| S-EPMC7235002 | biostudies-literature