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Background Although many hair disorders can be readily diagnosed based on their clinical appearance, their progression and response to treatment are often difficult to monitor, particularly in quantitative terms. We introduce an innovative technique utilizing a smartphone and computerized image analysis to expeditiously and automatically measure and compute hair density and diameter in patients in real time. Methods A smartphone equipped with a dermatoscope lens wirelessly transmits trichoscopy images to a computer for image processing. A black-and-white binary mask image representing hair and skin is produced, and the hairs are thinned into single-pixel-thick fiber skeletons. Further analysis based on these fibers allows morphometric characteristics such as hair shaft number and diameters to be computed rapidly. The hair-bearing scalps of fifty participants were imaged to assess the precision of our automated smartphone-based device in comparison with a specialized trichometry device for hair shaft density and diameter measurement. The precision and operation time of our technique relative to manual trichometry, which is commonly used by hair disorder specialists, is determined. Results An equivalence test, based on two 1-sided t tests, demonstrates statistical equivalence in hair density and diameter values between this automated technique and manual trichometry within a 20% margin. On average, this technique actively required 24 seconds of the clinician's time whereas manual trichometry necessitated 9.2 minutes. Conclusion Automated smartphone-based trichometry is a rapid, precise, and clinically feasible technique which can significantly facilitate the assessment and monitoring of hair loss. Its use could be easily integrated into clinical practice to improve standard trichoscopy.

Objective To evaluate and compare the diagnostic feasibility of measuring the optic nerve sheath diameter (ONSD), via brain computed tomography (CT) and ocular ultrasonography (US) for prediction of raised intracranial pressure (ICP) in severe traumatic brain injury (TBI) patients. Methods The PubMed and EMBASE databases were searched for studies assessing the diagnostic accuracy of brain CT or ocular US for predicting raised ICP. Bivariate and hierarchical summary receiver operating characteristic modeling were performed to evaluate and compare the diagnostic feasibility of measuring the ONSD in adult patients with severe TBI according to modality (ocular US vs. brain CT). Results Five studies (four with ocular US and one with brain CT) were included. The ONSD had a pooled sensitivity of 0.91, pooled specificity of 0.77, and area under the HSROC curve of 0.92 for predicting raised ICP. More importantly, studies using ocular US found an almost equal sensitivity (0.91 vs. 0.90; p = .35) and higher specificity (0.82 vs. 0.58; p = .01) than those using brain CT. Conclusions Measurement of the ONSD may be a useful method for predicting raised ICP in adult patients with severe TBI.

Cardiovascular disease is a severe threat to human health. The assessment of the degree of cardiovascular stenosis is very important for the diagnosis of cardiovascular disease. The segmentation of coronary angiographic images is the basis of analyzing the degree of stenosis. In this paper, a method that evaluates explicitly the degree of stenosis of blood vessels of interest is proposed. This method first extracts the vessels of interest by interactive segmentation, then thins it, and then calculates the diameter by edge intersection method. The average Dice Similarity Coefficient (DSC) value of the proposed segmentation method exceeds 92%, and the average Jaccard Similarity (JAC) value is over 86%. The area under the ROC curve value of the method is larger than the u-net method and the multiscale Hessian method. The results indicate that the interactive method can have good segmentation results and meet the general segmentation requirements. The qualitative and quantitative evaluation of the diameter measurement effect also shows that the effect of the corresponding diameter measurement method can reflect the change of the thickness of the blood vessel and basically meet the needs of clinical use.

In order to provide an alternative for fresh frozen specimens to map the lymphatic system, the possibility of using Thiel embalmed specimens for this purpose was explored. The thoracic duct was used to investigate if retrograde injection of contrast agent was possible in Thiel embalmed specimens and to verify up to which diameter lymphatic vessels could be reconstructed and rendered in 3D, after CT scanning. 3D renderings were used for digital diameter measurement, to determine the smallest lymphatic diameter that could still be visualized on CT. Finally, the contrast agent concentration was adapted based on the findings during image reconstruction and 3D rendering. All Thiel embalmed specimens proved suitable for retrograde injection of contrast agent into the thoracic duct and all 3D renderings perfectly overlapped with the dissection pictures. The smallest diameter of contrast filled lymphatics that could be reconstructed and rendered in 3D was 0.23 mm. Increasing the concentration of barium sulphate from 10% to 50% reduced the post-processing time needed to render a ‘clean’ 3D structure, following automatic segmentation based on grey values, by 95%. The authors would recommend the use of Thiel embalmed specimens for mapping the lymphatic system, as these specimens do not show the rapid putrefaction that occurs in fresh frozen specimens, thus greatly facilitating experimental planning.

Investigation of association of ONSD with hyponatremia in symptomatic patients.89 patients who were diagnosed to have hyponatremia (Na + 135 mmol/L) were prospectively analyzed and compared with 72 patients who have normal serum sodium levels presented to ED at the same time interval. Subjects' demographic properties including age and sex were recorded, as were admission symptoms, serum Na + level, and pre-treatment and post-treatment optic nerve sheath diameter (ONSD).The mean age of the study population was 62.3 ± 17.6 years, and the control group 55.1 ± 20.0 years (p 0.05). There was a significant difference between the patient group's pre-treatment and post-treatment OSNDs compared to the controls (p 0.05). There was a significant negative correlation between the admission sodium level and ONSD in the patient group (p 0.05). In the pre-treatment period, patients with symptoms had a significantly greater mean ONSD than those without symptoms (0.546 ± 0.068 mm vs 0.448 ± 0.081 mm; p 0.05). The area under the curve was 0.870; the cut-off level calculated for hyponatremia was 0.49 mm, which had a sensitivity of 81% and a specificity of 81.9%.Ultrasonic imaging of ONSD measurement in the emergency department appears to reflect changes consistent with ICP changes in hyponatremia and change in serum sodium.

Pseudotumor cerebri (PTC) occurs when the pressure inside the skull increases for no obvious reason. The aim of this study was to investigate three different methods: the optic nerve sheath diameter (ONSD) method, ONSD/eyeball transverse diameter (ETD) index, and ONSD/orbital transverse diameter (OTD) index for the initial detection of elevated intracranial pressure in patients with PTC.A retrospective study of magnetic resonance data from adult PTC patients (n = 42) and control group (n = 40) was performed. ONSD and OTD measurements were made 3 mm and 10 mm posterior to the globe, after intracranial pressure was measured with lumbar puncture. The sensitivity, specificity, and overall accuracy of the findings on magnetic resonance imaging were calculated.The optic nerve sheath was enlarged in the PTC group compared with the control group. It showed 97% sensitivity and 100% specificity and 79% sensitivity and 87.5% specificity for 3 mm and 10 mm, respectively. The ONSD/ETD and ONSD/OTD indices were increased in the PTC group compared with the control group. For 3 mm posterior to the globe, the ONSD/ETD index had 90.5% sensitivity and 92% specificity, and the ONSD/OTD index had 86% sensitivity and 95% specificity. For 10 mm posterior to the globe, the sensitivity and specificity of the ONSD/ETD and ONSD/OTD indices were 86% and 80% and 74% and 82.5%, respectively.According to our study, the ONSD method and the ONSD/ETD and ONSD/OTD indices are reliable diagnostic markers for PTC. These noninvasive techniques may be useful in monitoring the invasive intracranial catheter and have wide potential clinical applications in district hospitals, emergency departments and intensive care units.

In the August 2020 issue of the JEVT, Shammas et al1 highlighted a crucial point regarding the value of imaging in the treatment of infrapopliteal arterial occlusive disease. The authors compared angiography to intravascular ultrasound (IVUS) imaging in the evaluation of infrapopliteal vessel diameter and the presence and severity of dissections after balloon dilation alone or atherectomy followed by balloon dilation. The findings of their study are of outmost importance since technical details are crucial to success in a challenging vascular district. It is clear that angiography, as a diagnostic tool, is largely inadequate to provide all the necessary information for evaluating both preoperative conditions and treatment outcome. Too many aspects cannot be evaluated by simple contrast imaging, that is, hemodynamic pattern, 3-dimensional distribution of the lesion, and the condition of the arterial wall. Moreover, to characterize any lesion, angiography should be performed in a variety of projections, which has a series of drawbacks. First of all, the amount of contrast medium would increase significantly, with consequences on renal function, which is typically already impaired in atherosclerotic patients. Also, in some projections the target arterial segment may be hidden by bone margin or other arteries. Finally, the hemodynamic aspect cannot be evaluated.2 Up to now, no clear benefit of endovascular techniques has been demonstrated over surgical revascularization in infrainguinal disease.3,4 Plain balloon angioplasty, primary stenting, subintimal angioplasty, atherectomy, bailout stenting, drug-coated balloon (DCB) angioplasty, and so on, have been advocated as the method of choice in treating lower limb occlusive disease without reaching a consensus.5,6 The Shammas study1 focused on infrapopliteal treatment, which is still a particularly challenging field in peripheral revascularization and is associated with poor results.

Transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI) have yielded excellent results in aortic root diameter measurement in patients with tricuspid aortic valve. However, accuracy in bicuspid aortic valve (BAV), often associated with aortic root asymmetry, is not fully defined. The aim of this study was to determine the agreement between TTE and MRI in proximal ascending aortic diameters in patients with BAVs.Seventy-six consecutive patients with BAVs (mean age, 53 ± 15 years; 65% men) who underwent both TTE and MRI for ascending aortic assessment in a follow-up protocol were included in the study. Maximum aortic root and ascending aortic diameters were compared.For the whole population, TTE slightly underestimated aortic root diameter (difference, -0.8 ± 2.9 mm; P = .02). However, agreement was significantly better in BAV with fusion of the left and right coronary cusps than with fusion of the right coronary and noncoronary cusps, both with (type 1) and without (type 0) raphe (mean difference, 0.1 ± 2.5 vs -2.8 ± 2.8 mm, P .001, respectively). In raphe BAV, mean absolute differences of maximum diameters between both techniques were significantly greater in asymmetric versus symmetric aortic roots (3.3 ± 2.2 vs 1.6 ± 1.9 mm, P = .002). BAV type and root asymmetry were independent related to measurement disagreement between both modalities.Although TTE is the technique of choice in the follow-up of patients with BAVs, aortic root diameter measurements may be inaccurate in the presence of root asymmetry and in BAV with fusion of the right coronary and noncoronary cusps. In these cases, cross-sectional imaging, with MRI or computed tomography, to confirm aortic diameters may be advisable.

Purpose: Abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR) is still unpredictable. The issue of optimal frequency of computed tomography angiography for surveillance and its measurement method accuracy remain unclear. We aimed to assess the value of abdominal aneurysm sac volume measurement for detecting expansions and the association of preprocedural intraluminal thrombus (ILT) volume with aneurysm sac growth following EVAR. Material and methods: A total of 107 patients underwent elective EVAR. Inclusion criteria provided a cohort of 39 patients. Changes of postoperative maximum aneurysm sac diameter and AAA volume were calculated. Volumetric AAA changes and demographic data of the cases with clinically irrelevant AAA diameter enlargement were evaluated. Preoperative ILT volumes were collected. ILT and AAA sac volume ratio was calculated. Statistical data analysis was performed using standard methods. Results: The mean changes of maximum AAA diameter and volume in percentage after EVAR were -5.08 ± 8.20 mm and -13.39 ± 23.32%, respectively. A moderate positive linear correlation between those changes was found (R2 = 0.731; p < 0.0001). The mean relative AAA volume increase in cases without clinically relevant diameter enlargement was 11.50 ± 8.27%. The means of ILT and AAA sac ratios were 0.59 ± 0.17 and 0.52 ± 1.8 in growing AAA sac and in stable or shrinking AAA sac groups, respectively (p = 0.308). Conclusions: Volumetric AAA measurement may be useful as an additional method to diameter measurement after EVAR to identify clinically relevant sac growth. Preoperative volume of ILT may not significantly affect the growth rate of AAA after EVAR.

Objective: To determine the accuracy of fetal transverse cerebellar diametermeasurement in the prediction of gestational age in growth restricted fetuses. Material andmethods: This controlled was conducted at Sobhraj Maternity Hospital, Karachi from July 2012to June 2013. A total of 100 pregnant women in the third trimester of pregnancy satisfying theeligibility criteria were included. Among these 50 were fetuses with normal fetal growth and50 growth restricted fetuses. Results: The mean transverse cerebellar diameter in the fetusesshowing normal growth was not statistically different from the mean transverse cerebellardiameter in the growth restricted fetuses (p-value = 0.219). Conclusions: Transverse cerebellardiameter measurement can be used reliably for accurate estimation of gestational age in growthrestricted fetuses.

This chapter presents the approach to optic nerve sheath diameter measurement via ocular ultrasound, and its correlation with intracranial pressure. The technique for accurately obtaining this measurement will be outlined. The utility of optic nerve sheath diameter measurement in the prehospital setting will be discussed.

The study investigated ultrasound (US) transducer push, tantamount to applied transducer pressure, during abdominal aortic aneurysm (AAA) US scanning in a simulated non-clinical setup. During an assessment of maximal AAA diameter on a three-dimensional print-based AAA phantom, US transducer push varied as much as 2000% (range: 0.52–12.45 kPa) amongst 16 experienced sonographers. The mean transducer push was 5.54 ± 3.91 kPa (CV = 0.71). Deformation of a standardized gel-pad allowed for transducer push calculation based on US images; Young’s modulus of the gel-pad was estimated to 44,26 N/m2. The method is theoretically validated in a safe and non-clinical environment. Future investigations with the aim of clinical validation of the gel-pad principle on AAA patients are suggested, including the objectification of the magnitude of an eventual transducer push-related error during US AAA diameter measurement.

Objective The aim of this study was to evaluate an automatic, deep learning based method (Augmented Radiology for Vascular Aneurysm [ARVA]), to detect and assess maximum aortic diameter, providing cross sectional outer to outer aortic wall measurements. Methods Accurate external aortic wall diameter measurement is performed along the entire aorta, from the ascending aorta to the iliac bifurcations, on both pre- and post-operative contrast enhanced computed tomography angiography (CTA) scans. A training database of 489 CTAs was used to train a pipeline of neural networks for automatic external aortic wall measurements. Another database of 62 CTAs, including controls, aneurysmal aortas, and aortic dissections scanned before and/or after endovascular or open repair, was used for validation. The measurements of maximum external aortic wall diameter made by ARVA were compared with those of seven clinicians on this validation dataset. Results The median absolute difference with respect to expert’s measurements ranged from 1 mm to 2 mm among all annotators, while ARVA reported a median absolute difference of 1.2 mm. Conclusion The performance of the automatic maximum aortic diameter method falls within the interannotator variability, making it a potentially reliable solution for assisting clinical practice.

OBJECTIVE As aneurysm-related events and rupture is not eliminated, postoperative lifelong surveillance is mandatory after endovascular aneurysm repair (EVAR). For surveillance colored Doppler ultrasound (CDUS) is a standard method of noninvasive evaluation having the advantages of availability, cost-effectiveness, and lack of nephrotoxicity and radiation. We evaluated CDUS for primary surveillance tool after elective EVAR by comparing with computerized tomography. METHODS Between January 2018 and March 2020, 84 consecutive post-EVAR patients were evaluated. First, CDUS was performed by two Doppler operators from the Radiology Department and then computed tomographic angiography (CTA) was performed. The operators were blind to CTA reports. A reporting protocol was organized for endoleak detection and largest aneurysm diameter. RESULTS Among 84 patients, there were 11 detected endoleaks (13.1%) with CTA and seven of them was detected with CDUS (r = .884, p

BACKGROUND: To investigate the accuracy of size estimation and potential diagnosis efficacy of native T1-mapping in focal pulmonary lesion, compared to T1-star 3D-volumetric interpolated breath-hold sequence (VIBE), T2-fBLADE turbo-spin echo (TSE), and computed tomography (CT). METHODS: Thirty-nine patients with CT-detected focal pulmonary lesions underwent thoracic 3.0-T magnetic resonance imaging (MRI) using axial free-breathing 3D T1-star VIBE, respiratory triggered T2-fBLADE TSE, breath-hold T1-Turbo fast low angle shot (FLASH) and T1-FLASH 3D. Native T1-mapping images were generated by T1-FLASH 3D with B1-filed correction by T1-Turbo FLASH. The intraclass correlation coefficient (ICC) and Bland-Altman plots were used to evaluate intra-observer agreement and inter-method reliability of diameter measurements. Native T1-values were measured and compared among the malignancy, tuberculosis, non-tuberculosis benign groups using Mann-Whitney U tests. RESULTS: Forty-five focal pulmonary lesions were displayed by CT, native T1-mapping, T1-star VIBE, and T2-fBLADE TSE. T1-mapping-based diameter measurements yielded an intra-observer ICC of 0.995. Additionally, inter-method measurements were highly consistent (T1-mapping & T1-star VIBE: ICC 0.982, T1-mapping & T2-fBLADE TSE: ICC 0.978, T1-mapping & CT: ICC 0.972). For lesions

We aimed to evaluate whether optic nerve sheath diameter (ONSD) measurement by computed tomography (CT) can be a diagnostic criteria for the detection of ventriculoperitoneal shunt dysfunction among children whose fontanels are still open.Patients with a ventriculoperitoneal shunt who were currently showing clinical and radiological signs of acute hydrocephalus depending on the shunt dysfunction were included in this study. The study was designed to compare the preoperative and postoperative ONSDs of three groups of patients divided according to their ages: group 1, patients aged4 months; group 2, patients aged 4-18 months; and group 3, patients aged18 months.We included 138 patients (mean age, 35.18 ± 51.01 months). Among the patients, 46.4% were females and 53.6% were males. ONSD measurements in the preoperative period were2.86 ± 0.59 in group 1, 3.93 ± 0.82 in group 2, and 5.40 ± 0.81 in group 3 and those in the postoperative period were 2.02 ± 0.38 in group 1, 2.72 ± 0.62 in group 2, and 3.64 ± 0.81 in group 3. Right, left, and mean ONSDs increased significantly in the three groups and were found to be statistically significant.ONSD measurement in CT has been evaluated as an appropriate finding that can be used especially in acute hydrocephalus, when clinical and radiological findings are not diagnostic.

Flow mediated dilation (FMD) is a clinically accepted non-invasive tool for assessing endothelial dysfunction. FMD is conventionally performed with B-mode ultrasound systems that involve recording of the image sequences as DICOM files or video-graphic files and processing them offline. Sometimes the examinations may have to be rejected due to poor or unstable image sequences resulting non-reliable diameter estimates. We had earlier developed and extensively validated an image-free ultrasound technology, ARTSENS®, for the measurement of carotid artery wall dynamics and arterial stiffness metrics. In this work, we evaluate the feasibility of using the technology for continuous real-time diameter measurement of the brachial artery and thereby FMD. To investigate the performance of the ARTSENS® device an in-vivo study was conducted on 5 subjects as pilot. As a reference the measurements were also performed by a B-mode imaging system with a help of a commercially available clinically validated offline FMD analysis tool. The brachial artery diameter and FMD measurements performed by the ARTSENS® device were consistent with the earlier reported literature. The beat-to-beat repeatability of the baseline diameter measurements was acceptable with a CoV < 4% for all the subjects. The diameter measurements performed by the two devices exhibited a significant correlation (r-square = 0.81, p < 0.05). The RMSE for the diameter and FMD% measurements was 0.32 mm and 0.63% respectively, illustrating the measurement accuracy. The study demonstrated that the ARTSENS® can be reliably employed for performing FMD measurements and assessing endothelial dysfunction. This would help realize a field deployable solution for real-time automated FMD measurement and consequently for the acceleration of large population studies in this research area.

Aims Vascular complications are among the most commonly observed complications after TAVI. Iliofemoral vascular outcome has been described extensively. Little is known about vascular complications in transaxillary TAVI. The aim of the current study was to describe the incidence and predictors of axillary artery complications incorporating computed tomography angiography (CTA) measurements. Methods and results CT analysis was performed in two hundred patients treated with transaxillary TAVI in our centre between January 2014 and December 2017. Vascular complications occurred in 37 (18.5%) patients. Patient characteristics predicting this outcome were female gender (aOR 3.88 [1.48-10.14], p=0.006) and age (aOR 1.08 [1.01-1.16], p=0.034). The CTA measurement predicting vascular complications was a sheath to artery area ratio (SAAR) equal to or larger than 1.63 (OR 3.95 [1.29-12.12], p=0.016). Conclusions The present study describes the incidence of axillary artery complications and identifies patient characteristics associated with this outcome. CTA analysis was shown to be an important screening tool in the assessment of patient (access) eligibility. Axillary artery dimensional screening should be based on vascular luminal area assessment rather than diameter measurement alone.

Lung cancer is the leading cause of cancer-related mortality worldwide. National Lung Screening Trial (NLST) demonstrated reduced lung cancer mortality of 20% for whom underwent annual low-dose CT screening (1). For the screening-detected nodules, size measurement is mandatory as the nodule size is directly proportional to the lung cancer risk (2). For the size estimation, unidimensional or bi-dimensional diameter measurement have been the standard in practice.

© 2019 IEEE. Studying dynamic characteristics of retinal vessels, as opposed to static measures, may provide additional insight into pathophysiological changes associated with local and systemic abnormalities such as glaucoma and hypertension. Various approaches have been developed to derive static biomarkers from retinal still images, but not many for dynamic analysis of video sequences. This study presents a novel method for the assessment of time-dependent diameter changes in high-speed videos (125 fps) from the rat retina. The proposed method is composed of a vessel segmentation and a diameter measurement module. The specificity and sensitivity of the segmentation method over 25 images were 95.1% and 97.3% respectively. The mean and standard deviation of the diameter measurement errors were -0.147±0.41 pixels over 100 measurements.

Tracheal collapse is a progressive airway disease that can ultimately result in complete airway obstruction. Intraluminal tracheal stents are a minimally invasive and viable treatment for tracheal collapse once the disease becomes refractory to medical management. Intraluminal stent size is chosen based on the maximum measured tracheal diameter during maximum inflation. The purpose of this prospective, cross-sectional study was to compare tracheal lumen diameter measurements and subsequent selected stent size using both fluoroscopy and CT and to evaluate inter- and intraobserver variability of the measurements. Seventeen healthy Beagles were anesthetized and imaged with fluoroscopy and CT with positive pressure ventilation to 20 cm H2 O. Fluoroscopic and CT maximum tracheal diameters were measured by three readers. Three individual measurements were made at eight predetermined tracheal sites for dorsoventral (height) and laterolateral (width) dimensions. Tracheal diameters and stent sizes (based on the maximum tracheal diameter + 10%) were analyzed using a linear mixed model. CT tracheal lumen diameters were larger compared to fluoroscopy at all locations (P-value < 0.0001). When comparing modalities, fluoroscopic and CT stent sizes were statistically different. Greater overall variation in tracheal diameter measurement (height or width) existed for fluoroscopy compared to CT, both within and among observers. The greater tracheal diameter measured with CT and lower measurement variability has clinical significance, as this may be the imaging modality of choice for appropriate stent selection to minimize complications in veterinary patients.

Summary: Objective: Compared to the diameter measurement, volume measurement of the aneurysm can be an alternative option for accurate evaluation. This study was undertaken to analyze the relationship between the diameter and the volume measurement of the aorta after EVAR. Methods: From January 2012 to December 2016, 82 patients underwent EVAR in our institution. The infrarenal aorta after EVAR was evaluated with regard to maximal aortic diameter (DMAX) and aortic volume. The relationship between the DMAX and the aortic volume measurement after EVAR were analyzed. Results: The rate of enlargement of aortic volume with endoleak over time was 0.02 cm3/month. The rate of enlargement of DMAX with endoleak over time was 0.007 mm/month. The mean rate of enlargement of aortic volume was significantly different from the mean enlargement rate of DMAX (p = 0.02). A ≥12% of increase rate of aortic volume was equivalent to an increase of ≥5 mm in the DMAX after EVAR.Significantly more endoleak occurred in the DMAX-enlargement group than no-enlargement group (100% vs. 26.76%, p

Background: Assessment of fetal gestational age (GA) is an essential part of obstetric USG. Accurate knowledge of fetal GA is important to facilitate the best possible prenatal care and successful pregnancy outcome. For the estimation of GA the commonly used parameters in third trimester are:- BPD, HC, AC and FL. As all these parameters are affected by fetal growth disorders and fetal position. TCD can be used as another parameter for the estimation of GA in growth restricted fetuses.Methods: This study was conducted at Mahila Chikitsalaya Sanganeri Gate; SMS Medical College Jaipur from July 2005 to September 2006. A total of 80 pregnant women in third trimester with singleton pregnancy including 40 pregnant women with known cases of IUGR and 40 AGA fetuses were studied for TCD measure.Results: Correlation coefficient between TCD and gestational age was highly significant and no significant difference was found in TCD of AGA and IUGR fetuses.Conclusions: TCD measurement can be used as more reliable parameter for accurate estimation of gestational age in IUGR fetuses in third trimester.

Objective: Predicting which abdominal aortic aneurysms (AAA) will require surgery and which may remain stable remains a challenge. We set out to evaluate whether semi-automatic diameter measurements and finite element analysis (FEA) might predict the four-year prognosis of AAAs more precisely than standard diameter measurements. Methods: From a retrospective dataset of 97 patients with aneurysm baseline diameter of 40-50 mm, 39 AAAs remained below 55 mm in diameter for four years whilst 58 expanded beyond 54 mm within four years, or were treated surgically. Standard diameters, measured by radiologists or vascular surgeons, were recorded at baseline and at follow-up. Maximal external and luminal diameters as well as total and luminal volume were semi-automatically re-measured from 3D models based on CT images. FEA, estimating the peak wall rupture index (PWRI), was subsequently performed. Further, in 94 patients from the dataset, standard diameter growth rates between baseline and follow-up were calculated. Results: Aneurysms that would require surgery within four years were identified with 100% specificity by semi-automatic diameter, n=13 (22%), luminal diameter, n=14 (24%), PWRI, n=7 (12%), and luminal volume, n=5 (8.6%). Neither standard diameter nor total volume could reach 100% specificity. AAA diameter growth rate correlated with baseline semi-automatic diameter (r=0.39, p=9.2e-5), luminal diameter (r=0.29, p=0.005) and luminal volume (r=0.23, p=0.027) but not with PWRI (r=0.17, p=0.094), total volume (r=0.16, p=0.13), nor standard diameter (r=0.14, p=0.17). Conclusion: In AAAs with small diameters, precise, semiautomatic measurement of the maximal external and luminal diameter is able to specifically identify aneurysms requiring surgery within four years.

Background: Computed tomography angiography (CTA) is the reference technique for the measurement of native maximum abdominal aortic aneurysm (AAA) diameter when surgery is being considered. However, there is a wide choice available for the methodology of maximum AAA diameter measurement on CTA, and to date, no consensus has been reached on which method is best. We analyzed clinical decisions based on these various measures of native maximum AAA diameter with CTA, then analyzed their reproducibility and identified the method of measurement yielding the highest agreement in terms of patient management. Materials and Methods: Three sets of measures in 46 native AAA were obtained, double-blind by three radiologists (J, S, V) on orthogonal planes, curved multiplanar reconstructions, and semi-automated-software, based on the AAA-lumen centerline. From each set, the clinical decision was recorded as follows: "Follow-up" (if all diameters Results: Clinical decisions varied according to the measurement sets used by each observer, and according to intra and interobserver (lecture#1) reproducibility. Based on the first reading of each observer, the number of AAA proposed for surgery ranged from 11 to 24 for J, 5 to 20 for S, and 15 to 23 for V. The rate of AAAs classified as "ambiguous" varied from 11% (5/46) to 37% (17/46).The semi-automated method yielded very good intraand interobserver agreements in clinical decisions in all comparisons (Kappa range 0.83–1.00). Conclusion: The semi-automated method seems to be appropriate for native AAA maximum diameter measurement on CTA. In the absence of AAA outer-wallbased software more robust for complex AAA, clinical decisions might best be made with diameter values obtained using this technique.

Purpose The goal of this study was to compare agreement between computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of the major Liver Imaging Reporting and Data System (LI-RADS) features used in assessment of hepatocellular carcinoma: arterial phase hyperenhancement (APHE), portal venous phase washout (WO), capsule appearance (capsule), and largest diameter (diameter). Methods Patients with liver protocol CT and gadoxetate-enhanced MRI within 1 month of each other and at least 1 discrete untreated liver lesion were included. Two readers independently reviewed hepatic arterial phase and portal venous phase of each lesion on both CT and MRI, presented at random. The APHE, WO, capsule, and diameter were assessed for each lesion on CT and MRI. The LI-RADS category was assigned based on the recorded major features. Interobserver agreements between the readers for both imaging modalities and for each of the major features were assessed using κ statistics. Agreement between CT and MRI for each reader and for each feature was assessed using κ statistics. Agreement was interpreted based on κ as follows: 0.20 or less, slight agreement; 0.21 to 0.40, fair agreement; 0.41 to 0.60, moderate agreement; 0.61 to 0.80, substantial agreement; and 0.81 to 1.00, almost perfect agreement. Intraclass correlation coefficient was used to assess concordance of diameter measurements. Results There were 42 patients (mean age, 62.2 ± 7.0 years; 33 men [78.6%]) with 50 lesions. On CT, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.85), WO (κ = 0.83), and capsule (κ = 0.86). On MRI, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.86) and WO (κ = 0.83) and moderate for capsule (κ = 0.59). Intraclass correlation coefficient for diameter measurement was 0.99 for CT and 0.98 for MRI. For reader 1, the agreement between CT and MRI was fair for APHE (κ = 0.39) and capsule (κ = 0.26) and moderate for WO (κ = 0.49). For reader 2, the agreement between CT and MRI was moderate for APHE (κ = 0.43) and capsule (κ = 0.43) and fair (κ = 0.38) for WO. Agreement between readers for final LI-RADS category was substantial for CT (κ = 0.79) and moderate for MRI (κ = 0.60). Agreement for final LI-RADS categories between MRI and CT was fair for both reader 1 (κ = 0.33) and reader 2 (κ = 0.39). Conclusions Interobserver agreement for the major LI-RADS features varies from moderate to almost perfect, for both CT and MRI. However, the agreement between CT and MRI for each of the major LI-RADS features is poor, ranging from fair to moderate. This poor agreement contributes to substantial differences between final LI-RADS category assigned on CT versus MRI.

The usefulness of placentome diameter measurement for the determination of gestational age in Nigerian breed of sheep and goats was investigated in two experiments. In the first experiment, cross-sectional design was used and placentome diameters were measured in 18 Yankasa/Uda crossbred ewes and 20 Sahel does using trans-abdominal probe. A tentative estimate of gestation age was made using placentome diameter and gestation age correlates from a previous study. Subsequently, the date of parturition was recorded for each animal and the actual conception date was calculated retrospectively using a previously described 148-day gestation table for ewes and does. In the second experiment, a prospective cohort design was used on 6 goats, from end of second trimester until parturition. The date of conception was then retrospectively calculated. It was found that the estimated and actual gestation ages in both sheep and goats were not significantly different (P>0.05). The correlation coefficient (r²) between the placentome diameter and gestation age was 0.84 (P= 0.0001), for sheep and 0.90 (P= 0.0001) for goats suggesting a significant high positive correlation between placentome diameter and gestational age. The regression equation was y + 2.809 x + 7.555 and y = 2.930 x + 9.611 for sheep and goats, respectively. However, the placentome diameters monitored until parturition were not significantly different (P>0.05) between the weeks and not significantly correlated with gestational age. It was concluded that placentome diameter is useful to estimate gestational age at mid gestation and not within the last third of pregnancy. Keywords: Gestational age, Goat, Placentome diameter, Sheep, Ultrasonography

ObjectivesManagement of abdominal aortic aneurysms (AAAs) is based on diameter. CT angiography (CTA) is commonly used, but requires radiation and iodinated contrast. Non-contrast MRI is an appealing alternative that may allow better characterization of intraluminal thrombus (ILT). This study aims to 1) validate non-contrast MRI for measuring AAA diameter, and 2) to assess ILT with CTA and MRI.Method28 patients with AAAs (diameter 50.7 ± 12.3mm) underwent CTA and non-contrast MRI. MRI was acquired at 3T using 1) a conventional 3D gradient echo (GRE) sequence and 2) a 3D T1-weighted black blood fast-spin-echo sequence. Two radiologists independently measured the AAA diameter. The ratio of signal of ILT and adjacent psoas muscle (ILTr = signalILT/signalMuscle) was quantified.ResultsStrong agreement between CTA and non-contrast MRI was shown for AAA diameter (intra-class coefficient > 0.99). Both approaches had excellent inter-observer reproducibility (ICC > 0.99). ILT appeared homogenous on CTA, whereas MRI revealed compositional variations. Patients with AAAs ≥5.5cm and

Lung cancer screening by low-dose computed tomography (LDCT) is recommended for high-risk individuals by US guidelines, while lung cancer programs in Europe and Asia are being prepared. This review will mainly focus on two most recent concepts and discusses the latest developments. First, while a pulmonary nodule has an infinite number of diameters, it possesses only one volume. Traditionally, nodule size has been determined by diameter measurement, however semi-automated measurement of nodule volume is becoming increasingly available. Secondly, nodules that develop newly after baseline should distinguished from nodules already present at baseline. Until recently, new nodule management was mostly based on expert-opinion or data derived from baseline nodules.

Inferior vena cava (IVC) measurements correlate modestly with right atrial pressure (RAP). Part of this inaccuracy is due to the high compliance of the venous system where a large change in blood volume may result in only a small change in pressure. This uncoupling of pressure and volume is

Introduction Following recommendations from the National Abdominal Aortic Aneurysm Screening Programme (NAAASP), an audit was performed to assess the impact of measuring inner rather than outer aortic wall diameters during scans for abdominal aortic aneurysm. Methods Inner and outer aortic wall diameters were taken from a prospective series of 302 patients attending the Vascular Studies Unit at the Leicester Royal Infirmary for routine ultrasound screening or surveillance of their abdominal aorta. Absolute differences, as well as the potential impact on patient management, were assessed. Results The mean difference between measuring techniques was found to be 1.6 mm (95% CI 1.59–1.61 mm). Aortas close to the threshold for surgery were referred on average 8.7 months later than if their outer wall dimensions had been used. Additionally, 1.6% of aortas were considered normal using inner wall measurements, but aneurysmal when measured using the outer aortic walls. Conclusion Mean differences between the two measurement techniques are small and well within acceptable levels of observer agreement. There is currently no evidence to suggest that a delay in aneurysm surgery of around nine months has a detrimental effect to either mortality or morbidity rates. Those patients falling just below the threshold for aneurysm (2.5–3.0 cm) remain a subject of review.

Purpose: To analyze the literature comparing ultrasound [duplex (DUS) or contrast-enhanced (CEUS)] or magnetic resonance imaging (MRI) with computed tomography angiography (CTA) for endoleak detection and aneurysm diameter measurement after endovascular aneurysm repair (EVAR). Methods: A systematic review identified 31 studies that included 3853 EVAR patients who had paired scans (DUS or CEUS vs CTA or MRI vs CTA) within a 1-month interval for identification of endoleaks during EVAR surveillance. The primary outcome was the number of patients with an endoleak detected by one test but undetected by another test. Results are presented for all endoleaks and for types I and III endoleaks only. Aneurysm diameter measurements between CTA and ultrasound were examined using meta-analysis. Results: Endoleaks were seen in 25.6% (985/3853) of patients after EVAR. Fifteen studies compared DUS with CTA for the detection of all endoleak types. CTA had a significantly higher proportion of additional endoleaks detected (214/2346 vs 77/2346 for DUS). Of 19 studies comparing CEUS with CTA for the detection of all endoleak types, CEUS was more sensitive (138/1694) vs CTA (51/1694). MRI detected 42 additional endoleaks that were undetected by CTA during the paired scans, whereas CTA detected 2 additional endoleaks that MRI did not show. CTA had a similar proportion of additional types I and III endoleaks undetected by CEUS or MRI. Of 9 studies comparing ultrasound vs CTA for post-EVAR aneurysm diameter measurement, the aneurysm diameter measured by CTA was greater than ultrasound (mean difference −1.70 mm, 95% confidence interval −2.45 to −0.96, p

The aim of this feasibility study was to assess the impact that image processing of abdominal aortic ultrasound (US) images had on the intra-observer reliability of the diameter measurement. The study compared variability between inner-to-inner (ITI), outer-to-outer (OTO) and outer-to-inner (OTI) wall diameter measurements and their resilience to image processing. Three US images of transverse abdominal aortas were manipulated in 13 different ways using functions from Image J software (National Institutes of Health, Bethesda, MD, USA). Blinded measurements were performed of the aortic diameters from each image; this was repeated for ITI, OTO and OTI. Profiles of each image were produced and sets of rules developed to provide detailed instructions as to where, on the profile, the callipers should be placed to correspond with the actual image. The reliability of the diameter measurements compared to the original diameter measurement was least affected by adjusting the brightness and contrast of the US images (better than ± 1.5 mm). Using the functions ‘Sharpen’ and ‘Find Edges’ created the largest difference (up to −5 mm). The ITI measurements had the widest spread of variability, whereas the OTI measurements proved to be the most repeatable and resilient to image processing. This study suggests the precision of the measurements can be kept within satisfactory levels even after image manipulation. It also showed the most reliable measuring guideline was OTI, in contrast to the guideline currently used by the NHS Abdominal Aortic Aneurysm Screening Programme. Further research is needed to transfer the findings into the clinical setting of the National Screening Programme to increase its reliability.

Rationale and Objectives The aim of this study was to evaluate a new formula for the rapid assessment of pericardial effusion (PE) volume by computed tomography. Materials and Methods Twenty computed tomographic scans positive for PE were reviewed by two observers. Diameters of PE were measured at four locations. Additionally, PE volume was assessed by volumetry. The correlation between PE diameters and volume was evaluated, and a linear equation was derived for each diameter location. To test validity and reliability of the measurements, intraclass correlation and Bland-Altman analysis were performed. Results Good validity was expressed by strong correlations between diameter measurements at all four locations and PE volume (all R values >0.80 and P values 0.75) and Bland-Altman analysis revealed good interobserver and intraobserver reliability of diameter measurements. The best values were observed for apical diameter measurements. The following linear equation was derived for apical diameter measurements: PE volume = 296 (mL/cm) × apical diameter (cm) − 32 mL. Conclusions PE volume can rapidly be assessed by apical PE diameter measurement using the simplified formula PE volume = 0.3 (L/cm) × apical diameter (cm).

Purpose The purpose of this study was to clarify the most suitable method to measure the aortic annulus diameter. Patients and methods Fifty-five patients, who had undergone aortic valve replacement at Miyazaki University Hospital between April 2008 and May 2011, were included in this study. The maximum diameter of the sizing tool that could be inserted into the left ventricle through the annulus had been predicted, based on the diameter measured by each modality. Agreement with surgery and each imaging modality, namely transthoracic echocardiography, multidetector computed tomography and contrast angiography, were compared using Bland-Altman analysis. Results The predicted aortic annulus diameter, based on the diameter measured by transthoracic echocardiography, multidetector computed tomography and contrast angiography, was 20.3 ± 2.50, 23.9 ± 3.19, and 23.5 ± 3.55 mm, respectively, whereas, the diameter measured at surgery was 23.7 ± 2.99 mm. Predicted aortic annulus diameter measured by multidetector computed tomography best agreed with that measured at surgery. Conclusion We conclude that the aortic annulus diameter, measured by multidetector computed tomography, is the best modality to measure the aortic annulus diameter.

Amac: Renal arteriyel stenozun (RAS) tespiti ve derecelendirmesinde cok kesitli bilgisayarli tomografik anjiyografinin (CKBTA) tanisal degeri belirlendi. Ca­lis­ma­ pla­ni:­Hipertansiyonu olan ve CKBTA’da RAS saptanan veya CKBTA’da abdominal aort anevrizmasi nedeni ile abdominal aort anevrizmasinin endovaskuler tedavisi uygun bulunan 78 hastaya (53 erkek, 25 kadin; ort. yas 60.8±14.9 yil; dagilim 18-86 yil) dijital subtraksiyon anjiyografisi (DSA) incelemeleri yapildi. Cok kesitli bilgisayarli tomografik anjiyografi bulgulari DSA bulgulari ile karsilastirildi. Istatistiksel degerlendirmeler renal arter stenozunun saptanmasi ve renal arter stenoz derecesinin capa gore degerlendirilmesi icin yapildi. Calisma prospektif olarak gerceklestirildi, hastane kurumsal inceleme kurulu tarafindan onaylandi. Tum hastalardan bilgilendirilmis onam formlari alindi. Bul gu lar: Yuz elli alti renal arterin 79’unda stenoz, altisinda okluzyon saptanir iken 71’i CKBTA’da normal idi. Dijital subtraksiyon anjiyografide 156 renal arterden 70’inde stenoz, altisinda okluzyon saptanir iken 80’i normal idi. Genel duyarlilik, ozgulluk, pozitif kestirim degeri (PKD), negatif kestirim degeri (NKD) ve dogruluk orani sirasiyla %97.4, %86.3, %87.1, %97.2 ve %91.7 olarak hesaplandi. Stenoz derecesinin saptanmasinda duyarlilik %74.1-100 araliginda, ozgulluk %93.7-100 araliginda, PKD %55-100 araliginda, NKD %94.5-100 ve dogruluk orani %90.4-100 araligindaydi. So­nuc:­Cokkesitli bilgisayarli tomografik anjiyografi RAS degerlendirmesinde yuksek duyarlilik, ozgulluk ve tanisal dogruluk oranlarina sahip noninvazif ve guvenilir bir yontem olarak kabul edilebilir. Anah tar soz cuk ler: Anjiyografi; dijital subtraksiyon anjiyografi; cokkesitli bilgisayarli tomografi; renal arter stenozu. Background:­ We determined the diagnostic value of multidetector computed tomography angiography (MDCTA) for detection and gradation of renal arterial stenosis (RAS). Methods: Seventy-eight patients (53 males, 25 females; mean age 60.8±14.9 years; range 18 to 86 years) who suffered from hypertension and were found to have RAS on MDCTA or who were found suitable for endovascular treatment of an abdominal aortic aneurysm during the evaluation with MDCTA underwent digital subtraction angiographic (DSA) examinations. The MDCTA findings were compared with the DSA findings. Statistical analysis of data was performed to detect renal arterial stenosis and the degree of stenosis based on diameter measurement. The study was carried out prospectively and approved by the hospital institutional review board. Informed consent was obtained from all patients. Results:­ Seventy-nine of 156 renal arteries were found to have stenosis and six were found to have occlusion while 71 were normal on MDCTA. Seventy of 156 renal arteries were found to have stenosis and six to have occlusion while 80 were normal on DSA. Overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy rate were found to be 97.4%, 86.3%, 87.1%, 97.2% and 91.7%, respectively. For determination of the degree of stenosis, the sensitivity was in the range of 74.1-100%, the specificity was in the range of 93.7-100%, the PPV was in the range of 55-100%, the NPV was in the range of 94.5-100%, and the accuracy rate was in the range of 90.4-100%. Conclusion:­ Multidetector computed tomography angiography can be accepted as a noninvasive and reliable modality for the evaluation of RAS with high sensitivity, specificity, and diagnostic accuracy rates.

Purpose. It was to quantify the intraobserver and interobserver variability of the sonographic measurements of renal pelvis and classify hydronephrosis severity.Methods. Two ultrasonographers evaluated 17 fetuses from 23 to 39 weeks of gestation. Renal pelvis APD were taken in 50 renal units. For intraobserver error, one of them performed three sequential measurements. The mean and standard deviation from the absolute and percentage differences between measurements were calculated. Bland-Altman plots were used to visually assess the relationship between the precision of repeated measurements. Hydronephrosis was classified as mild (5.0 to 9.9 mm), moderate (10.0 to 14.9 mm), or severe (≥15.0 mm). Interrater agreement were obtained using the Kappa index.Results. Absolute intraobserver variation in APD measurements was %. Interobserver variation of ultrasonographers was %. Neither intraobserver or interobserver error increased with increasing APD size. The overall percentage of agreement with the antenatal hydronephrosis diagnosis was 64%. Cohen's Kappa to hydronephrosis severity was 0.51 (95% CI, 0.33 to 0.69).Conclusion. Inter and intraobserver APD measurement errors were low in these group, but the agreement to hydronephrosis diagnosis and classification was fair. We suggest that standard and serial APD measurement can better define and evaluate fetal hydronephrosis.

Background: Perinatal mortality a concern in the developing countries and intrauterine growth restriction (IUGR) is an important cause. Therefore early diagnosis of IUGR babies is the key to prevent complications as well as mortality. Multiple biometric parameters including trans-cerebellar diameter can be used to predict the gestational age. Thus, the present study was designed to measure and compare the trans-cerebellar diameter and evaluates the usefulness of transverse cerebellar diameter as against the conventional parameters and to find out the usefulness of transverse cerebellar diameter in antenatal diagnosis of intrauterine growth retardation. Methods: A cross-sectional study was conducted on normal antenatal women of 15-40 weeks gestational age referred for antenatal ultrasonography between January to December 2015. Total 250 patients were examined. Data collected was compared with the conventional parameters. Results: Good correlation was found between transverse cerebellar diameter (TCD) and other parameters. Also TCD showed a linear relationship between the cerebellar growth and the gestational age. It was found to be better than BPD in circumstances like excessive molding and dolicocephaly. Also TCD measurement was not fraught with problems as encountered in FL measurement. The mean TCD/AC ratio was 13.866%. So it was found that TCD can be used as a reliable parameter for determination of gestational age in mass studies. Conclusion: There is good correlation between TCD and other parameters in normal pregnancies at 15 to 40 weeks of gestation. This implies that, TCD is a better parameter for gestational age assessment compared to BPD and FL.

BACKGROUND AND PURPOSE Diameter measurement of the third ventricle with magnetic resonance imaging (MRI) and recently also with transcranial sonography (TCS) has emerged as a surrogate marker for brain atrophy and disease progression in multiple sclerosis (MS). This study aims to evaluate TCS measurements of the third ventricle diameter in a clinical routine setting against MRI. METHODS Transverse diameters of the third ventricle were determined in 27 MS patients using both, TCS and MRI. In TCS, the distance between the leading edges of the brain-ventricle interfaces was assessed in axial image planes. In MRI, the transverse diameter of the mid-portion of the third ventricle was measured on axial T1-weighted images. RESULTS The mean diameter of the third ventricle was 4.0 mm (SD 1.7 mm), when measured with MRI, and 4.4 mm (SD 1.7 mm), when measured with TCS. The 95% limits of agreement of the Bland-Altman Plot were 2.93 mm (95% CI 2.08 to 3.78 mm) and −2.23 mm (95%CI −3.08 to −1.38 mm). Pearson correlation coefficient was .71 (P < .0001). CONCLUSIONS TCS may appear suitable as screening examination for the extent of brain atrophy at a single-point study, but at least in the early stages of the disease, TCS is not useful to monitor disease progression. J Neuroimaging 2010;20:53-57.

Raised intracranial pressure (ICP) is a frequent condition in many medical and surgical situations and is often difficult to detect. Noninvasive estimates of raised ICP are of interest to allow rapid detection of significant intracranial hypertension. In the anterior part of the optic nerve, the sheath is distensible and can inflate in the case of raised pressure in the cerebrospinal fluid. Measurement of optic nerve sheath diameter using ocular sonography or MRI has been shown to correctly estimate the risk of raised ICP in various settings, including traumatic brain injury. Ocular sonography is simple, rapid, noninvasive and can be performed at the patient’s bedside, but it requires training and experience. The cut-off value for ICP greater than 20 mmHg is 5.8 mm, with a 90% probability of correct diagnosis. When raised ICP is suspected, but invasive ICP monitoring cannot be used or is not clearly recommended, this estimation of the risk of raised ICP may be of great clinical value, aiding in the detection of patients at risk of raised ICP.

Appropriate sizing of endografts for endovascular aneurysm repair has traditionally been performed by one standardized method. By measuring the average of the minor and major axes in the sealing zone, the endograft size is traditionally calculated. However, no adequate scientific evaluation has been performed to validate this method. The guidelines that were published are based on theories and experience, more than scientific evidence. In case the central lumen line artery cross-section is a circular disk, the vessel diameter is a reliable estimation. Yet the aortic neck cross-section may not always be geometrically a perfect circular disk. Application of the standardized method might therefore lead to inaccurate endograft sizing, potentially leading to endoleaks. We hypothesize that in these cases the circumference of the vessel is a mathematically correct reference to deduct the appropriate endograft diameter. The following formula was applied in this study: diameter of the corresponding circle (d) equals circumference (C) divided by (d=c/pi). This study provides a theoretical analysis of the mathematical implications of this method. Only in pi case of highly irregularly shaped cylinders, the circumference-based method was more accurate than the standardized method. Nonetheless, the circumferential method was a practical reference in case the aortic neck was irregularly shaped. Also, the circumference method was accurate in all cases in deducting the diameter of a matching circle. Therefore, the hypothesis that was raised in this study has a strong theoretical base. We predict that in case this hypothesis holds true in the clinical practice, application of the circumference method might lead to less endoleaks than the standardized method. (C) 2015 Elsevier Ltd. All rights reserved.

Aneurysmal dilation of arteriovenous fistulae used for haemodialysis is a recognised complication but its clinical significance is a contentious issue. Our aims were to describe aneurysmal fistulae morphologically and clinically. Sixty patients underwent duplex scanning to measure the maximum diameter and skin thickness of their fistula. Haemodialysis function and bleeding risk were assessed clinically. The 75th percentile of maximum diameter was 2.05 cm. In addition to conventional diameter measurement, we describe a novel volume measurement technique which may be of value. No relationship was found between maximum diameter or volume and function, skin thickness or bleeding. Some studies define aneurysm at 2 cm (75th percentile); however, this definition and other arbitrary definitions lack clinical significance. This work suggests that fistula dilation should be considered together with clinical issues when determining the clinical significance of an aneurysm. Our finding that haemodialysis function, skin thickness and bleeding were not associated with diameter needs further study.

BACKGROUND The aims of the present study were to assess the effect of the stent diameter, convolution kernel, and vessel orientation to the z-axis on the evaluation of coronary stents, in vitro with computed tomography (CT) angiography. METHODS AND RESULTS Seven vascular models (2 models without stenosis, 2 with obstruction, and 3 with stenosis) with an approximate inner diameter of 3 or 4 mm, filled with contrast material (79 or 330 HU) were scanned with a 16-detector CT. The diameter measurement of the stent lumen and stenosis evaluation were both done in an orientation parallel to the z-axis of the scanner using 4 convolution kernels. The measured diameters of the stented lumen were 47-57% and 36-45% smaller than the actual inner diameter of the 3- and 4-mm diameter models, respectively. The diameter measurement of the stent lumen and visualization of the in-stent stenosis were improved by using convolution kernels with higher spatial resolution. The in-stent artifacts were evaluated in 4 orientations (0 degrees , 30 degrees , 60 degrees , 90 degrees ) to the z-axis. The artifact was the minimum in 0 degrees to the z-axis, and the maximum in 90 degrees . CONCLUSION Visualization of the lumen of a stent by CT is affected by its diameter, convolution kernel, and vessel orientation to the z-axis, and these factors should be taken into consideration in the stent evaluation.

The change in diameter of retinal vessels as a function of increasing distance to the optic disc is believed to be indicative of the risk level of various vascular diseases such as generalised arteriosclerosis and Diabetes Mellitus. In particular, focal arteriolar narrowing (FAN) is considered related to arteriosclerosis. The aim of this work is to develop methods to provide quantitative information about the FAN status of retinal arteriolar vessel segments. We propose a method to measure the vessel diameter and changes herein along the vessel. The width or diameter measurement is based on intensity profiles orthogonal to a smoothed trace in the vessel found by Dijkstra’s shortest path algorithm. The vessel diameter is calculated from the intensity profiles using two diAerent methods to estimate profile widths. We propose a ‘‘normalised accumulated gradient’’ (NAG) and the coeAcient of variance (CV) to estimate the FAN in a vessel segment. The NAG is designed to detect increases in the vessel diameter as the distance to the papilla increases. The performance of the methods developed is compared to the evaluation by a skilled ophthalmologist. The methods are seen to perform well. ” 2000 Elsevier Science B.V. All rights reserved.

Objective Thoracic endovascular aortic repair (TEVAR) is associated with a reasonable risk of spinal ischemia. As cerebrospinal fluid pressure (CSFP) is correlated with the rate of paraplegia, a non-invasive method to estimate CSFP could help to estimate the patient’s individual risk and guide the therapeutic approach. The quantification of the optic nerve sheath diameter (ONSD) using ocular sonography could be a suitable technique and was examined in the present study. Methods 28 patients with TEVAR were included. Five consecutive measurements of the ONSD were performed in each patient. The first before the intervention (“baseline”), the next immediately postinterventional at the intensive care unit (post1), measurements 3, 4 (post2, post3) on day 1 and 2 after the intervention and number 5 (post4) before discharge. Statistical analysis was done using the Wilcoxon-test. A p -value Results A significant increase between baseline and post1-measurements (right eye: p = 0.006; left eye: p = 0.02) could be detected. A significant decrease was detected between post1 and post3 (right eye: p = 0.02; left eye: p Conclusions The present study is the first to prospectively examine and prove the possibility to monitor CSFP changes in patients with TEVAR associated transient spinal edema using OCCS. Systematic factors as artificial ventilation and body positioning did not have a significant effect.