Increased Intracranial Arterial Pulsatility and Microvascular Brain Damage in Pseudoxanthoma Elasticum

BACKGROUND AND PURPOSE

Carotid siphon calcification might contribute to the high prevalence of cerebrovascular disease in pseudoxanthoma elasticum through increased arterial flow pulsatility. This study aimed to compare intracranial artery flow pulsatility, brain volumes, and small-vessel disease markers between patients with pseudoxanthoma elasticum and controls and the association between arterial calcification and pulsatility in pseudoxanthoma elasticum.

MATERIALS AND METHODS

Fifty patients with pseudoxanthoma elasticum and 40 age- and sex-matched controls underwent 3T MR imaging, including 2D phase-contrast acquisitions for flow pulsatility in the assessment of ICA and MCA and FLAIR acquisitions for brain volumes, white matter lesions, and infarctions. All patients with pseudoxanthoma elasticum underwent CT scanning to measure siphon calcification. Flow pulsatility (2D phase-contrast), brain volumes, white matter lesions, and infarctions (3D T1 and 3D T2 FLAIR) were compared between patients and controls. The association between siphon calcification and pulsatility in pseudoxanthoma elasticum was tested with linear regression models.

RESULTS

Patients with pseudoxanthoma elasticum (mean age, 57 [SD, 12] years; 24 men) had significantly higher pulsatility indexes (1.05; range, 0.94-1.21 versus 0.94; range, 0.82-1.04; P = .02), lower mean GM volumes (597 [SD, 53] mL versus 632 [SD, 53] mL; P < .01), more white matter lesions (2.6; range, 0.5-7.5 versus 1.1; range, 0.5-2.4) mL; P = .05), and more lacunar infarctions (64 versus 8, P = .04) than controls (mean age, 58 [SD, 11] years; 20 men). Carotid siphon calcification was associated with higher pulsatility indexes in patients with pseudoxanthoma elasticum (β = 0.10; 95% CI, 0.01-0.18).

CONCLUSIONS

Patients with pseudoxanthoma elasticum have increased intracranial artery flow pulsatility and measures of small-vessel disease. Carotid siphon calcification might underlie the high prevalence of cerebrovascular disease in pseudoxanthoma elasticum.

Halved contrast medium dose coronary dual-layer CT-angiography - phantom study of tube current and patient characteristics

Virtual mono-energetic images (VMI) using dual-layer computed tomography (DLCT) enable substantial contrast medium (CM) reductions. However, the combined impact of patient size, tube voltage, and heart rate (HR) on VMI of coronary CT angiography (CCTA) remains unknown. This phantom study aimed to assess VMI levels achieving comparable contrast-to-noise ratio (CNR) in CCTA at 50% CM dose across varying tube voltages, patient sizes, and HR, compared to the reference protocol (100% CM dose, conventional at 120 kVp). A 5 mm artificial coronary artery with 100% (400 HU) and 50% (200 HU) iodine CM-dose was positioned centrally in an anthropomorphic thorax phantom. Horizontal coronary movement was matched to HR (at 0, < 60, 60-75, > 75 bpm), with varying patient sizes simulated using phantom extension rings. Raw data was acquired using a clinical CCTA protocol at 120 and 140 kVp (five repetitions). VMI images (40-70 keV, 5 keV steps) were then reconstructed; non-overlapping 95% CNR confidence intervals indicated significant differences from the reference. Higher CM-dose, reduced VMI, slower HR, higher tube voltage, and smaller patient sizes demonstrated a trend of higher CNR. Regardless of HR, patient size, and tube voltage, no significant CNR differences were found compared to the reference, with 100% CM dose at 60 keV, or 50% CM dose at 40 keV. DLCT reconstructions at 40 keV from 120 to 140 kVp acquisitions facilitate 50% CM dose reduction for various patient sizes and HR with equivalent CNR to conventional CCTA at 100% CM dose, although clinical validation is needed.

The effect of six-month oral vitamin K supplementation on calcification propensity time in individuals with type 2 diabetes mellitus: A post hoc analysis of a randomized, double-blind, placebo-controlled trial

BACKGROUND AND AIMS

Experimental studies suggested that vitamin K supplementation may retard arterial calcification. Recently, serum calcification propensity time (T50) has been suggested as a functional biomarker for arterial wall calcification propensity. In this post-hoc analysis of a clinical trial, we evaluated the effect of six-month oral vitamin K supplementation on T50 and assessed the correlation between T50 and imaging arterial calcification parameters in people with type 2 diabetes (T2DM).

METHODS

This double-blind, randomized, placebo-controlled trial included 68 participants (age = 69 ± 8 years, 76% male) with T2DM. Participants were assigned to menaquinone-7 (360 μg/day; n = 35) or placebo (n = 33). T50 was measured via nephelometry in serum collected at baseline, three and six months. Arterial calcification was measured at baseline and six months via 18F-Na PET-CT and conventional CT using Target-to-Background ratio (TBR) and Agatston score. Longitudinal analysis of covariance adjusted for baseline T50 was used to study the treatment effect. Spearman's correlation was used to assess the correlation between T50 and imaging calcification parameters.

RESULTS

Median baseline T50 was similar in the vitamin K (350 [321-394] minutes) and placebo groups (363 [320-398]). There was no significant difference in T50 between treatment arms over time (ẞ = 1.00, 95%C.I. = 0.94-1.07, p = 0.982). The correlation coefficient of T50 with TBR and Agatston score at baseline were -0.185 (p = 0.156) and -0.121 (p = 0.358), respectively.

CONCLUSIONS

No effect of vitamin K supplementation on T50 was observed in T2DM. Moreover, T50 did not correlate with TBR and Agatston score. Further research on vitamin K in arterial calcification and on the validity of T50 as arterial calcification marker is warranted.

Impact of body composition and physical strength changes during chemoradiotherapy on complications and survival after oesophagectomy

BACKGROUND

The aim of this study was to assess body composition and physical strength changes during neoadjuvant chemoradiotherapy (nCRT) and assess their predictive value for (severe) postoperative complications and overall survival in patients who underwent oesophagectomy for oesophageal cancer.

METHODS

Consecutive patients who underwent nCRT and oesophagectomy with curative intent in a tertiary referral center were included in the study. Perioperative data were collected in a prospectively maintained database. The CT images before and after nCRT were used to assess skeletal muscle index (SMI), subcutaneous fat index (SFI), and visceral fat index (VFI). To assess physical strength, handgrip strength (HGS) and the exercise capacity of the steep ramp test (SRT Wpeak) were acquired before and after nCRT.

RESULTS

Between 2015 and 2020, 126 patients were included. SMI increased in female subgroups and decreased in male subgroups (35.38 to35.60 cm2/m2 for females, P value 0.048, 46.89 to 45.34 cm2/m2 for males, P value < 0.001). No significant changes in SFI, VFI, HGS, and SRT Wpeak were observed. No predictive value of changes in SMI, HGS, and SRT Wpeak was shown for (severe) postoperative complications and overall survival.

CONCLUSIONS

A significant but minimal decrease in SMI during nCRT was observed for males only, it was not associated with postoperative complications or overall survival. Physical strength measurements did not decrease significantly over the course of nCRT. No associations with postoperative complications or overall survival were observed.

Systemic arterial calcium burden in patients with chronic limb-threatening ischemia

INTRODUCTION

5-year mortality of chronic limb-threatening ischemia (CLTI) is 50-60% and coronary artery disease (CAD) is the main cause of death of CLTI patients, followed by stroke. The aim of this study is to quantify and qualify the calcium load in different arterial territories in patients with CLTI.

METHODS

Prospectively, 60 patients with CLTI were included and received a full-body CT scan. 6 patients were excluded. Different arterial territories (the peripheral lower extremity arteries, coronary arteries, extracranial and intracranial carotid arteries, thoracic and abdominal aorta) were analyzed. Analysis and interrelations of both quantitative and semi-quantitative CT measurements was performed.

RESULTS

Mean age was 72 years (range 47-95; SD 11.4). Almost all CLTI patients had calcified arterial beds (femoropopliteal 100%, crural 98.1%, coronary 100%, carotid bifurcation 96.2%, internal carotid artery 98.1%, thoracic aorta 96.2%, abdominal aorta 92.3%). Nearly all arterial territories had severe calcifications. 57% had a very high coronary Agatston score (>1000), and 35% extremely high (>2000). Calcifications in the lower extremity were significantly correlated to CAC score, carotid artery bifurcation calcification score, and to a lesser extent correlated to annular calcifications in the aorta. Very high and extremely high total CAC scores were strongly correlated with severe lower extremity arterial calcifications and severe carotid and intracranial internal carotid artery, thoracic and abdominal aorta calcifications in patients with CLTI patients.

CONCLUSIONS

In CLTI patients nearly all arterial territories are severely calcified, suggesting that systemic calcification plays an important role in the poor outcome of this disease.

Treatment of arterial calcification in patients with chronic limb threatening ischemia with etidronate: protocol of an investigator-initiated multicenter, double blind, placebo-controlled, randomized clinical trial

Background

Pathologic studies have shown that in patients with critical limb threatening ischaemia (CLTI) medial arterial calcifications are frequently found and may be responsible for aggravating the disease. These extensive calcifitcations are found not only in arteries of the leg but also in the coronary arteries and the aorta. The progression of these calcifications is fast and they stiffen the vessel wall and may thus increase the cardiovascular risk.

Reduction of progression of calcification may not only reduce the burden of CLTI but may also reduce the high residual cardiovascular risk. Medial calcifications have been halted by etidronate in other trials. Its potential to reduce the burden from peripheral vascular disease in CLTI and residual cardiovascular risk remains to be established.

Methods

This is an investigator-initiated multicenter, double blind, placebo-controlled, randomized trial comparing the effects of etidronate versus placebo in patients with CLTI.

Subjects will be randomized to either treatment with etidronate for 12 months (cyclical 20 mg/kg for 2 weeks on and 10 weeks off) orally or placebo for 12 months (in a similar routine).

The primary endpoint is the change in arterial calcification as quantified by CT-scan.

Secondary endpoints are the number of amputations above and below the ankle, mortality, number of vascular interventions and quality of life.

Discussion

Up to now, the inert end stage of vascular disease in patients with CLTI, has been considered calcification of vessel walls. We believe there is reason to reverse causation and hypothesize that calcification causes vascular disease. This reversal can be proven in a clinical trial if halting the calcification process improves the outcome of the patient. Therefore we use etidronate, a bisphosphate that has proven to stop the calcification in several rare monogenetic calcifying diseases. We aim to perform this mechanistic proof-of-concept study hopefully leading to a clinical outcome study later on.

Patients with diffuse idiopathic skeletal hyperostosis have an increased burden of thoracic aortic calcifications

Objectives.

DISH has been associated with increased coronary artery calcifications and incident ischaemic stroke. The formation of bone along the spine may share pathways with calcium deposition in the aorta. We hypothesized that patients with DISH have increased vascular calcifications. Therefore we aimed to investigate the presence and extent of DISH in relation to thoracic aortic calcification (TAC) severity.

Methods.

This cross-sectional study included 4703 patients from the Second Manifestation of ARTerial disease cohort, consisting of patients with cardiovascular events or risk factors for cardiovascular disease. Chest radiographs were scored for DISH using the Resnick criteria. Different severities of TAC were scored arbitrarily from no TAC to mild, moderate or severe TAC. Using multivariate logistic regression, the associations between DISH and TAC were analysed with adjustments for age, sex, BMI, diabetes, smoking status, non-high-density lipoprotein cholesterol, cholesterol lowering drug usage, renal function and blood pressure.

Results.

A total of 442 patients (9.4%) had evidence of DISH and 1789 (38%) patients had TAC. The prevalence of DISH increased from 6.6% in the no TAC group to 10.8% in the mild, 14.3% in the moderate and 17.1% in the severe TAC group. After adjustments, DISH was significantly associated with the presence of TAC [odds ratio (OR) 1.46 [95% CI 1.17, 1.82)]. In multinomial analyses, DISH was associated with moderate TAC [OR 1.43 (95% CI 1.06, 1.93)] and severe TAC [OR 1.67 (95% CI 1.19, 2.36)].

Conclusions.

Subjects with DISH have increased TACs, providing further evidence that patients with DISH have an increased burden of vascular calcifications.

The ISCON-trial protocol: laparoscopic ischemic conditioning prior to esophagectomy in patients with esophageal cancer and arterial calcifications

Background

Anastomotic leakage is the most important surgical complication following esophagectomy. A major cause of leakage is ischemia of the gastric tube that is used for reconstruction of the gastrointestinal tract. Generalized cardiovascular disease, expressed by calcifications of the aorta and celiac axis stenosis on a pre-operative CT scan, is associated with an increased risk of anastomotic leakage. Laparoscopic ischemic conditioning (ISCON) aims to redistribute blood flow and increase perfusion at the anastomotic site by occluding the left gastric, left gastroepiploic and short gastric arteries prior to esophagectomy. This study aims to assess the safety and feasibility of laparoscopic ISCON in selected patients with esophageal cancer and concomitant arterial calcifications.

Methods

In this prospective single-arm safety and feasibility trial based upon the IDEAL recommendations for surgical innovation, a total of 20 patients will be included recruited in 2 European high-volume centers for esophageal cancer surgery. Patients with resectable esophageal carcinoma (cT1-4a, N0–3, M0) with “major calcifications” of the thoracic aorta accordingly to the Uniform Calcification Score (UCS) or a stenosis of the celiac axis accordingly to the modified North American Symptomatic Carotid Endarterectomy Trial (NASCET) score on preoperative CT scan, who are planned to undergo esophagectomy are eligible for inclusion. The primary outcome variables are complications grade 2 and higher (Clavien-Dindo classification) occurring during or after laparoscopic ISCON and before esophagectomy. Secondary outcomes include intra- and postoperative complications of esophagectomy and the induction of angiogenesis by biomarkers of microcirculation and redistribution of blood flow by measurement of indocyanine green (ICG) fluorescence angiography.

Discussion

We hypothesize that in selected patients with impaired vascularization of the gastric tube, laparoscopic ISCON is feasible and can be safely performed 12–18 days prior to esophagectomy. Depending on the results, a randomized controlled trial will be needed to investigate whether ISCON leads to a lower percentage and less severe course of anastomotic leakage in selected patients.

Trial registration

Clinicaltrials.gov, NCT03896399. Registered 4 January 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09231-x.

Validation of skeletal muscle mass assessment at the level of the third cervical vertebra in patients with head and neck cancer

BACKGROUND

Low skeletal muscle mass (SMM) is associated with adverse outcomes. SMM is often assessed at the third lumbar vertebra (L3) on abdominal imaging. Abdominal imaging is not routinely performed in patients with head and neck cancer (HNC). We aim to validate SMM measurement at the level of the third cervical vertebra (C3) on head and neck imaging.

MATERIAL AND METHODS

Patients with pre-treatment whole-body computed tomography (CT) between 2010 and 2018 were included. Cross-sectional muscle area (CSMA) was manually delineated at the level of C3 and L3. Correlation coefficients and intraclass correlation coefficients (ICCs) were calculated. Cohen's kappa was used to assess the reliability of identifying a patient with low SMM.

RESULTS

Two hundred patients were included. Correlation between CSMA at the level of C3 and L3 was good (r = 0.75, p < 0.01). Using a multivariate formula to estimate CSMA at L3, including gender, age, and weight, correlation improved (r = 0.82, p < 0.01). The agreement between estimated and actual CSMA at L3 was good (ICC 0.78, p < 0.01). There was moderate agreement in the identification of patients with low SMM based on the estimated lumbar skeletal muscle mass index (LSMI) and actual LSMI (Cohen's κ: 0.57, 95%CI 0.45-0.69).

CONCLUSIONS

CSMA at C3 correlates well with CSMA at L3. There is moderate agreement in the identification of patients with low SMM based on the estimated lumbar SMI (based on measurement at C3) and actual LSMI.

Pulsatility Attenuation along the Carotid Siphon in Pseudoxanthoma Elasticum

We compared velocity pulsatility, distensibility, and pulsatility attenuation along the intracranial ICA and MCA between 50 patients with pseudoxanthoma elasticum and 40 controls. Patients with pseudoxanthoma elasticum had higher pulsatility and lower distensibility at all measured locations, except for a similar distensibility at C4. The pulsatility attenuation over the siphon was similar between patients with pseudoxanthoma elasticum and controls. This finding suggests that other disease mechanisms are the main contributors to increased intracranial pulsatility in pseudoxanthoma elasticum.

Residual cardiovascular risk reduction guided by lifetime benefit estimation in patients with symptomatic atherosclerotic disease: effectiveness and cost-effectiveness

AIMS

To determine the (cost)-effectiveness of blood pressure lowering, lipid-lowering, and antithrombotic therapy guided by predicted lifetime benefit compared to risk factor levels in patients with symptomatic atherosclerotic disease.

METHODS AND RESULTS 

For all patients with symptomatic atherosclerotic disease in the UCC-SMART cohort (1996-2018; n = 7697) two treatment strategies were compared. The lifetime benefit-guided strategy was based on individual estimation of gain in cardiovascular disease (CVD)-free life with the SMART-REACH model. In the risk factor-based strategy, all patients were treated the following: low-density lipoprotein cholesterol (LDL-c) < 1.8 mmol/L, systolic blood pressure <140 mmHg, and antithrombotic medication. Outcomes were evaluated for the total cohort using a microsimulation model. Effectiveness was evaluated as total gain in CVD-free life and events avoided, cost-effectiveness as incremental cost-effectivity ratio (ICER). In comparison to baseline treatment, treatment according to lifetime benefit would lead to an increase of 24 243 CVD-free life years [95% confidence interval (CI) 19 980-29 909] and would avoid 940 (95% CI 742-1140) events in the next 10 years. For risk-factor based treatment, this would be an increase of 18 564 CVD-free life years (95% CI 14 225-20 456) and decrease of 857 (95% CI 661-1057) events. The ICER of lifetime benefit-based treatment with a treatment threshold of ≥1 year additional CVD-free life per therapy was €15 092/QALY gained and of risk factor-based treatment €9933/QALY gained. In a direct comparison, lifetime benefit-based treatment compared to risk factor-based treatment results in 1871 additional QALYs for the price of €36 538/QALY gained.

CONCLUSION 

Residual risk reduction guided by lifetime benefit estimation results in more CVD-free life years and more CVD events avoided compared to the conventional risk factor-based strategy. Lifetime benefit-based treatment is an effective and potentially cost-effective strategy for reducing residual CVD risk in patients with clinical manifest vascular disease.

Sex differences in intracranial and extracranial atherosclerosis in patients with acute ischemic stroke

Background and aim

To investigate sex differences with respect to presence and location of atherosclerosis in acute ischemic stroke patients.

Methods

Participants with acute ischemic stroke were included from the Dutch acute stroke trial, a large prospective multicenter cohort study performed between May 2009 and August 2013. All patients received computed tomography/computed tomography-angiography within 9 h of stroke onset. We assessed presence of atherosclerosis in the intra- and extracranial internal carotid and vertebrobasilar arteries. In addition, we determined the burden of intracranial atherosclerosis by quantifying internal carotid and vertebrobasilar artery calcifications, resulting in calcium volumes. Prevalence ratios between women and men were calculated with Poisson regression analysis and adjusted prevalence ratio for potential confounders (age, hypertension, hyperlipidemia, diabetes, smoking, and alcohol use).

Results

We included 1397 patients with a mean age of 67 years, of whom 600 (43%) were women. Presence of atherosclerosis in intracranial vessel segments was found as frequently in women as in men (71% versus 72%, adjusted prevalence ratio 0.95; 95% CI 0.89–1.01). In addition, intracranial calcification volume did not differ between women and men in both intracranial internal carotid (large burden 35% versus 33%, adjusted prevalence ratio 0.93; 95% CI 0.73–1.19) and vertebrobasilar arteries (large burden 26% versus 40%, adjusted prevalence ratio 0.69; 95% CI 0.41–1.12). Extracranial atherosclerosis was less common in women than in men (74% versus 81%, adjusted prevalence ratio 0.86; 95% CI 0.81–0.92).

Conclusions

In patients with acute ischemic stroke the prevalence of intracranial atherosclerosis does not differ between women and men, while extracranial atherosclerosis is less often present in women compared with men.

An automated workflow based on hip shape improves personalized risk prediction for hip osteoarthritis in the CHECK study

OBJECTIVE

To design an automated workflow for hip radiographs focused on joint shape and tests its prognostic value for future hip osteoarthritis.

DESIGN

We used baseline and 8-year follow-up data from 1,002 participants of the CHECK-study. The primary outcome was definite radiographic hip osteoarthritis (rHOA) (Kellgren-Lawrence grade ≥2 or joint replacement) at 8-year follow-up. We designed a method to automatically segment the hip joint from radiographs. Subsequently, we applied machine learning algorithms (elastic net with automated parameter optimization) to provide the Shape-Score, a single value describing the risk for future rHOA based solely on joint shape. We built and internally validated prediction models using baseline demographics, physical examination, and radiologists scores and tested the added prognostic value of the Shape-Score using Area-Under-the-Curve (AUC). Missing data was imputed by multiple imputation by chained equations. Only hips with pain in the corresponding leg were included.

RESULTS

84% were female, mean age was 56 (±5.1) years, mean BMI 26.3 (±4.2). Of 1,044 hips with pain at baseline and complete follow-up, 143 showed radiographic osteoarthritis and 42 were replaced. 91.5% of the hips had follow-up data available. The Shape-Score was a significant predictor of rHOA (odds ratio per decimal increase 5.21, 95%-CI (3.74-7.24)). The prediction model using demographics, physical examination, and radiologists scores demonstrated an AUC of 0.795, 95%-CI (0.757-0.834). After addition of the Shape-Score the AUC rose to 0.864, 95%-CI (0.833-0.895).

CONCLUSIONS

Our Shape-Score, automatically derived from radiographs using a novel machine learning workflow, may strongly improve risk prediction in hip osteoarthritis.

Eliminating biasing signals in lung cancer images for prognosis predictions with deep learning

Deep learning has shown remarkable results for image analysis and is expected to aid individual treatment decisions in health care. Treatment recommendations are predictions with an inherently causal interpretation. To use deep learning for these applications in the setting of observational data, deep learning methods must be made compatible with the required causal assumptions. We present a scenario with real-world medical images (CT-scans of lung cancer) and simulated outcome data. Through the data simulation scheme, the images contain two distinct factors of variation that are associated with survival, but represent a collider (tumor size) and a prognostic factor (tumor heterogeneity), respectively. When a deep network would use all the information available in the image to predict survival, it would condition on the collider and thereby introduce bias in the estimation of the treatment effect. We show that when this collider can be quantified, unbiased individual prognosis predictions are attainable with deep learning. This is achieved by (1) setting a dual task for the network to predict both the outcome and the collider and (2) enforcing a form of linear independence of the activation distributions of the last layer. Our method provides an example of combining deep learning and structural causal models to achieve unbiased individual prognosis predictions. Extensions of machine learning methods for applications to causal questions are required to attain the long-standing goal of personalized medicine supported by artificial intelligence.

The accuracy of diagnostic Imaging techniques in patients with a suspected Fracture-related Infection (IFI) trial: study protocol for a prospective multicenter cohort study

INTRODUCTION

The optimal diagnostic imaging strategy for fracture-related infection (FRI) remains to be established. In this prospective study, the three commonly used advanced imaging techniques for diagnosing FRI will be compared. Primary endpoints are (1) determining the overall diagnostic performances of white blood cell (WBC) scintigraphy, fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) in patients with suspected FRI and (2) establishing the most accurate imaging strategy for diagnosing FRI.

METHODS AND ANALYSIS

This study is a non-randomised, partially blinded, prospective cohort study involving two level 1 trauma centres in The Netherlands. All adult patients who require advanced medical imaging for suspected FRI are eligible for inclusion. Patients will undergo all three investigational imaging procedures (WBC scintigraphy, FDG-PET and MRI) within a time frame of 14 days after inclusion. The reference standard will be the result of at least five intraoperative sampled microbiology cultures, or, in case of no surgery, the clinical presence or absence of infection at 1 year follow-up. Initially, the results of all three imaging modalities will be available to the treating team as per local protocol. At a later time point, all scans will be centrally reassessed by nuclear medicine physicians and radiologists who are blinded for the identity of the patients and their clinical outcome. The discriminative ability of the imaging modalities will be quantified by several measures of diagnostic accuracy.

ETHICS AND DISSEMINATION

Approval of the study by the Institutional Review Board has been obtained prior to the start of this study. The results of this trial will be disseminated by publication of peer-reviewed manuscripts, presentation in abstract form at scientific meetings and data sharing with other investigators through academically established means.

TRIAL REGISTRATION NUMBER

The IFI trial is registered in the Netherlands Trial Register (NTR7490).

Arterial stiffness as a risk factor for cardiovascular events and all-cause mortality in people with Type 2 diabetes

AIM

To quantify the risk of different non-invasive arterial stiffness measurements with macrovascular disease and all-cause mortality in high-risk people with Type 2 diabetes.

METHODS

We conducted a prospective cohort study of 1910 people with Type 2 diabetes included in the Second Manifestations of ARTerial disease (SMART) study. Arterial stiffness was assessed by brachial artery pulse pressure, normal range (≥0.9) ankle-brachial index and carotid artery distension. Cox regression was used to evaluate the effects of arterial stiffness on risk of cardiovascular events (composite of myocardial infarction, stroke and vascular mortality) and all-cause mortality.

RESULTS

A total of 380 new cardiovascular events and 436 deaths occurred during a median (interquartile range) follow-up of 7.5 (4.1-11.0) years. A 10-mmHg higher brachial pulse pressure was related to higher hazard of cardiovascular events (hazard ratio 1.09, 95% CI 1.02 to 1.16) and all-cause mortality (hazard ratio 1.10, 95% CI 1.03 to 1.16). A 0.1-point lower ankle-brachial index within the normal range was related to a higher hazard of cardiovascular events (hazard ratio 1.13, 95% CI 1.01 to 1.27) and all-cause mortality (hazard ratio 1.17, 95% CI 1.04 to 1.31). A one-unit (10^-3 ×kPa^-1 ) lower carotid artery distensibility coefficient was related to a higher hazard of vascular mortality (hazard ratio 1.04, 95% CI 1.00 to 1.09) and all-cause mortality (hazard ratio 1.04, 95% CI 1.00 to 1.07).

CONCLUSION

Increased arterial stiffness, as measured by either increased pulse pressure, normal-range ankle-brachial index or carotid artery distensibility coefficient, is related to increased hazard of cardiovascular events and all-cause mortality in people with Type 2 diabetes.

The Effects of Iodine Attenuation on Pulmonary Nodule Volumetry using Novel Dual-Layer Computed Tomography Reconstructions

OBJECTIVES

To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions.

METHODS

A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel dual-layer spectral CT system. Conventional reconstructions as well as VNC and mono-energetic images at different keV levels were used for nodule volumetry.

RESULTS

Twenty-four patients with a total of 63 nodules were included. Conventional reconstructions showed a median (interquartile range) volume and diameter of 174 (87 - 253) mm3 and 6.9 (5.4 - 9.9) mm, respectively. VNC reconstructions resulted in a significant volume reduction of 5.5% (2.6 - 11.2%; p<0.001). Mono-energetic reconstructions showed a correlation between nodule attenuation and nodule volume (Spearman correlation 0.77, (0.49 - 0.94)). Lowering the keV resulted in increased volumes while higher keV levels resulted in decreased pulmonary nodule volumes compared to conventional CT.

CONCLUSIONS

Novel dual-layer spectral CT offers the possibility to reconstruct VNC and mono-energetic images. Those reconstructions show that higher pulmonary nodule attenuation results in larger nodule volumes. This may explain the reported underestimation in nodule volume on non-contrast enhanced compared to contrast-enhanced acquisitions.

KEY POINTS

• Pulmonary nodule volumes were measured on virtual non-contrast and mono-energetic reconstructions • Mono-energetic reconstructions showed that higher attenuation results in larger volumes • This may explain the reported nodule volume underestimation on non-contrast enhanced CT • Mostly metastatic pulmonary nodules were evaluated, results might differ for benign nodules.

A sex-specific association between incident radiographic osteoarthritis of hip or knee and incident peripheral arterial calcifications: 8-year prospective data from Cohort Hip and Cohort Knee (CHECK)

OBJECTIVES

There is sparse evidence for a relationship between cardiovascular disease (CVD) and osteoarthritis (OA). We investigated the association between incidence of arterial calcifications and incidence of radiographic knee and/or hip OA.

DESIGN

We used baseline and 8-year follow-up data of Cohort Hip and Cohort Knee (CHECK). Knees and hips were either Kellgren-Lawrence (KL) grade 0 or 1 at baseline. Arterial calcifications were scored on hip and knee radiographs using a four-grade scale. Scores were summed for patient-level analyses. To investigate incidence, participants with arterial calcifications at baseline or missing follow-up were excluded. Incident OA was defined per joint as KL ≥ 2 or prosthesis at year eight. The association between incidenct of arterial calcifications and incident OA was studied using mixed-effects logistic regression.

RESULTS

Of 763 participants included, 623 (82%) were women. Mean (sd) age was 56 (5.1) years, mean (sd) body mass index (BMI) 26.2 (4.1) kg/m². Arterial calcifications developed in 174 participants (283 joints). OA developed in 456 participants (778 joints). Sex modified the association between arterial calcification and OA. In women, incident arterial calcification around a joint was positively associated with incident OA in that joint (adjusted OR 2.51 (95% CI 1.57-4.03)). In men, no association was observed on joint-level, but at patient-level the arterial calcification sum score was negatively associated with incident OA (adjusted OR per point increase 0.70 (95% CI 0.54-0.90)) indicating a systemic effect.

CONCLUSIONS

We observed sex-dependent associations between incident arterial calcification and incident radiographic knee and/or hip OA, which differs between joint- and patient-level.

Osteochondral lesion depth on MRI can help predict the need for a sandwich procedure

PURPOSE

Autologous subchondral bone grafting in combination with autologous chondrocyte implantation (ACI) (sandwich procedure) is a well-accepted procedure for the treatment of osteochondral lesions of the knee. This requires a different surgical technique and preoperative planning compared to ACI alone. In addition, pain from bone marrow donor site locations can be expected and should be part of patient consent and expectations. This study evaluates whether the MRI made as part of the standard preoperative cartilage patient work up has the diagnostic accuracy to predict the need for a sandwich procedure.

METHODS AND MATERIALS

Retrospectively, 185 preoperative MRI scans (PD and T2 sequences) of patients planned for ACI were included. The integrity of the subchondral bone and lamina was scored by four different observers (3 radiologists, and 1 orthopaedic resident). The depth of the defect was measured perpendicular from articulating surface to the bottom of the bony lesion. The area under the curve (AUC) for subchondral defect on MRI (i.e. lamina or bone defect or expert impression), depth measurements and eventual sandwich procedure were calculated. Also inter-observer Kappa values were determined.

RESULTS

The AUCs for lamina (0.74-0.80) and bone defect (0.73-0.79) were fair and inter-observer Kappas ranged from 0.49 to 0.76, indicating a moderate-good inter-observer agreement and moderate prediction of the need for a sandwich procedure based on the presence of lamina and or subchondral bone defect on MRI. However, depth measurements resulted in an AUC of 0.90 (95% CI: 0.84-0.95,) with an optimal cut-off point at 6.5mm depth of the lesion (90% sensitivity, 80% specificity) to predict the need for a sandwich procedure.

CONCLUSION

Ours is the first study examining MRI as a diagnostic tool in predicting the need for a sandwich procedure. Our results show that the integrity of the subchondral layer on MRI has a moderate role in predicting the need for an eventual autologous bone graft to augment ACI whereas in our cohort a depth of the lesion above 6.5mm accurately predicts the need for a sandwich procedure. This can aid in optimising the preoperative planning and patient consent.

Improving early diagnosis of pulmonary infections in patients with febrile neutropenia using low-dose chest computed tomography

We performed a prospective study in patients with chemotherapy induced febrile neutropenia to investigate the diagnostic value of low-dose computed tomography compared to standard chest radiography. The aim was to compare both modalities for detection of pulmonary infections and to explore performance of low-dose computed tomography for early detection of invasive fungal disease. The low-dose computed tomography remained blinded during the study. A consensus diagnosis of the fever episode made by an expert panel was used as reference standard. We included 67 consecutive patients on the first day of febrile neutropenia. According to the consensus diagnosis 11 patients (16.4%) had pulmonary infections. Sensitivity, specificity, positive predictive value and negative predictive value were 36%, 93%, 50% and 88% for radiography, and 73%, 91%, 62% and 94% for low-dose computed tomography, respectively. An uncorrected McNemar showed no statistical difference (p = 0.197). Mean radiation dose for low-dose computed tomography was 0.24 mSv. Four out of 5 included patients diagnosed with invasive fungal disease had radiographic abnormalities suspect for invasive fungal disease on the low-dose computed tomography scan made on day 1 of fever, compared to none of the chest radiographs. We conclude that chest radiography has little value in the initial assessment of febrile neutropenia on day 1 for detection of pulmonary abnormalities. Low-dose computed tomography improves detection of pulmonary infiltrates and seems capable of detecting invasive fungal disease at a very early stage with a low radiation dose.

Bone density loss on computed tomography at 3-year follow-up in current compared to former male smokers

OBJECTIVES

Cigarette smoking negatively affects bone quality and increases fracture risk. Little is known on the effect of smoking cessation and computed tomography (CT)-derived bone mineral density (BMD) decline in the spine. We evaluated the association of current and former smoking with BMD decline after 3-year follow-up.

METHODS

Male current and former smokers participating in a lung cancer screening trial who underwent baseline and 3-year follow-up CT were included. BMD was measured by manual placement of a region of interest in the first lumbar vertebra and expressed in Hounsfield Unit (HU). Multiple linear regression analysis was used to evaluate the association between pack years smoked and smoking status with BMD decline.

RESULTS

408 participants were included with median (25th-75th percentile) age of 59.4 (55.9-63.5) years. At the start of the study, 197 (48.3%) participants were current smokers and 211 (51.7%) were former smokers and had a similar amount of pack years. Current smokers had quit smoking for 6 (4-8) years prior to inclusion. There was no difference in BMD between current and former smokers at baseline (109±34 HU vs. 108±32 HU, p=0.96). At 3-year follow-up, current smokers had a mean BMD decline of -3±13 HU (p=0.001), while BMD in former smokers did not change as compared to baseline (1±13 HU, p=0.34). After adjustment for BMD at baseline and body mass index, current smoking was independently associated with BMD decline (-3.8 HU, p=0.003). Age, pack years, and the presence of a fracture at baseline did not associate with BMD decline.

CONCLUSIONS

Current smokers showed a more rapid BMD decline over a 3-year period compared to former smokers. This information might be important to identify subjects at risk for osteoporosis and emphasizes the importance of smoking cessation in light of BMD decline.

Imaging of pediatric great vessel stents: Computed tomography or magnetic resonance imaging?

Background

Complications might occur after great vessel stent implantation in children. Therefore follow-up using imaging is warranted.

Purpose

To determine the optimal imaging modality for the assessment of stents used to treat great vessel obstructions in children.

Material and methods

Five different large vessel stents were evaluated in an in-vitro setting. All stents were expanded to the maximal vendor recommended diameter (20mm; n = 4 or 10mm; n = 1), placed in an anthropomorphic chest phantom and imaged with a 256-slice CT-scanner. MRI images were acquired at 1.5T using a multi-slice T₂-weighted turbo spin echo, an RF-spoiled three-dimensional T₁-weighted Fast Field Echo and a balanced turbo field echo 3D sequence. Two blinded observers assessed stent lumen visibility (measured diameter/true diameter *100%) in the center and at the outlets of the stent. Reproducibility of diameter measurements was evaluated using the intraclass correlation coefficient for reliability and 95% limits of agreement for agreement analysis.

Results

Median stent lumen visibility was 88 (IQR 86–90)% with CT for all stents at both the center and outlets. With MRI, the T₂-weighted turbo spin echo sequence was preferred which resulted in 82 (78–84%) stent lumen visibility. Interobserver reliability and agreement was good for both CT (ICC 0.997, mean difference -0.51 [-1.07–0.05] mm) and MRI measurements (ICC 0.951, mean difference -0.05 [-2.52 –-2.41] mm).

Conclusion

Good in-stent lumen visibility was achievable in this in-vitro study with both CT and MRI in different great vessel stents. Overall reliability was good with clinical acceptable limits of agreement for both CT and MRI. However, common conditions such as in-stent stenosis and associated aneurysms were not tested in this in-vitro study, limiting the value of the in-vitro study.

Bone shape difference between control and osteochondral defect groups of the ankle joint

OBJECTIVE

The etiology of osteochondral defects (OCDs), for which the ankle (talocrural) joint is one of the common sites, is not yet fully understood. In this study, we hypothesized that bone shape plays a role in development of OCDs. Therefore, we quantitatively compared the morphology of the talus and the distal tibia between an OCD group and a control group.

METHODS

The shape variations of the talus and distal tibia were described separately by constructing two statistical shape models (SSMs) based on the segmentation of the bones from ankle computed tomography (CT) scans obtained from control (i.e., 35 CT scans) and OCD (i.e., 37 CT scans) groups. The first five modes of shape variation for the SSM corresponding to each bone were statistically compared between control and OCD groups using an analysis of variance (ANOVA) corrected with the Bonferroni for multiple comparisons.

RESULTS

The first five modes of variation in the SSMs respectively represented 49% and 40% of the total variance of talus and tibia. Less than 5% of the variance per mode was described by the higher modes. Mode 5 of the talus (P = 0.004) primarily describing changes in the vertical neck angle and Mode 1 of the tibia (P < 0.0001) representing variations at the medial malleolus, showed statistically significant difference between the control and OCD groups.

CONCLUSION

Shape differences exist between control and OCD groups. This indicates that a geometry modulated biomechanical behavior of the talocrural joint may be a risk factor for OCD.

New horizons in cardiac CT

Until recently, cardiovascular computed tomography angiography (CCTA) was associated with considerable radiation doses. The introduction of tube current modulation and automatic tube potential selection as well as high-pitch prospective ECG-triggering and iterative reconstruction offer the ability to decrease dose with approximately one order of magnitude, often to sub-millisievert dose levels. In parallel, advancements in computational technology have enabled the measurement of fractional flow reserve (FFR) from CCTA data (FFRCT). This technique shows potential to replace invasively measured FFR to select patients in need of coronary intervention. Furthermore, developments in scanner hardware have led to the introduction of dual-energy and photon-counting CT, which offer the possibility of material decomposition imaging. Dual-energy CT reduces beam hardening, which enables CCTA in patients with a high calcium burden and more robust myocardial CT perfusion imaging. Future-generation CT systems will be capable of counting individual X-ray photons. Photon-counting CT is promising and may result in a substantial further radiation dose reduction, vastly increased spatial resolution, and the introduction of a whole new class of contrast agents.

Chest Computed Tomography-Based Scoring of Thoracic Sarcoidosis: Inter-rater Reliability of CT Abnormalities

PURPOSE

To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis.

MATERIALS AND METHODS

CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented.

RESULTS

Median age of the 51 patients (36 men, 70%) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities.

CONCLUSIONS

In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings.

KEY POINTS

• Thoracic sarcoidosis is common; knowledge on reliability of CT scoring is limited. • Scoring CT abnormalities in pulmonary sarcoidosis can achieve good inter-rater agreement. • CT scoring validation in thoracic sarcoidosis is important for diagnostic and prognostic studies.

Inter- and intrascanner variability of pulmonary nodule volumetry on low-dose 64-row CT: an anthropomorphic phantom study

OBJECTIVE

To assess inter- and intrascanner variability in volumetry of solid pulmonary nodules in an anthropomorphic thoracic phantom using low-dose CT.

METHODS

Five spherical solid artificial nodules [diameters 3, 5, 8, 10 and 12 mm; CT density +100 Hounsfield units (HU)] were randomly placed inside an anthropomorphic thoracic phantom in different combinations. The phantom was examined on two 64-row multidetector CT (64-MDCT) systems (CT-A and CT-B) from different vendors with a low-dose protocol. Each CT examination was performed three times. The CT examinations were evaluated twice by independent blinded observers. Nodule volume was semi-automatically measured by dedicated software. Interscanner variability was evaluated by Bland-Altman analysis and expressed as 95% confidence interval (CI) of relative differences. Intrascanner variability was expressed as 95% CI of relative variation from the mean.

RESULTS

No significant difference in CT-derived volume was found between CT-A and CT-B, except for the 3-mm nodules (p<0.05). The 95% CI of interscanner variability was within ±41.6%, ±18.2% and ±4.9% for 3, 5 and ≥8 mm nodules, respectively. The 95% CI of intrascanner variability was within ±28.6%, ±13.4% and ±2.6% for 3, 5 and ≥8 mm nodules, respectively.

CONCLUSION

Different 64-MDCT scanners in low-dose settings yield good agreement in volumetry of artificial pulmonary nodules between 5 mm and 12 mm in diameter. Inter- and intrascanner variability decreases at a larger nodule size to a maximum of 4.9% for ≥8 mm nodules.

ADVANCES IN KNOWLEDGE

The commonly accepted cut-off of 25% to determine nodule growth has the potential to be reduced for ≥8 mm nodules. This offers the possibility of reducing the interval for repeated CT scans in lung cancer screenings.

Generalisability of the results of the Dutch-Belgian randomised controlled lung cancer CT screening trial (NELSON): does self-selection play a role?

The degree of self-selection in the Dutch-Belgian randomised controlled lung cancer screening trial (NELSON) was determined to assess the generalisability of the study results. 335,441 (mainly) men born in 1928-1953 received a questionnaire. Of the respondents (32%), eligible subjects were invited to participate (19%). Fifty-five percent gave informed consent and was randomised. Background characteristics were compared between male respondents on the first questionnaire (n = 92,802), eligible subjects among them (n = 18,570) and those randomised (n = 10,627) and Statistics Netherlands 2002-2005 (SN) (n = 5289) or GLOBE study-data (Dutch cohort) (n = 696). Initial respondents were less likely to be highly educated (OR(adj) = 0.84; 95% CI: 0.74-0.96) and comprised of significantly less current smokers (OR(adj) = 0.65; 95% CI: 0.61-0.69) compared to the general population. These current smokers smoked more heavily (OR(adj) = 1.23; 95% CI: 1.10-1.37), but for a shorter time-period (respondents: 31, SN: 42 years, p < 0.001). Age, general health, BMI, alcohol use and cancer prevalence were comparable. The randomised population was younger (Age 50-65) (randomised subjects: 85.3%, SN: 72% (p < 0.01)) comprised of more heavy current smokers (OR = 2.08; 95% CI: 1.75-2.44), that smoked for a shorter period of time (randomised subjects: 37, SN_selection: 42 years (p < 0.001)). Both the respondents (32%) of the first questionnaire as well as the randomised population of the NELSON trial appeared to differ slightly on smoking characteristics, but the differences were limited and probably balance each other. Results of the NELSON trial will be roughly applicable to the Dutch and probably other populations that fulfil our selection criteria.

The relationship between lung function impairment and quantitative computed tomography in chronic obstructive pulmonary disease

OBJECTIVES

To determine the relationship between lung function impairment and quantitative computed tomography (CT) measurements of air trapping and emphysema in a population of current and former heavy smokers with and without airflow limitation.

METHODS

In 248 subjects (50 normal smokers; 50 mild obstruction; 50 moderate obstruction; 50 severe obstruction; 48 very severe obstruction) CT emphysema and CT air trapping were quantified on paired inspiratory and end-expiratory CT examinations using several available quantification methods. CT measurements were related to lung function (FEV(1), FEV(1)/FVC, RV/TLC, Kco) by univariate and multivariate linear regression analysis.

RESULTS

Quantitative CT measurements of emphysema and air trapping were strongly correlated to airflow limitation (univariate r-squared up to 0.72, p < 0.001). In multivariate analysis, the combination of CT emphysema and CT air trapping explained 68-83% of the variability in airflow limitation in subjects covering the total range of airflow limitation (p < 0.001).

CONCLUSIONS

The combination of quantitative CT air trapping and emphysema measurements is strongly associated with lung function impairment in current and former heavy smokers with a wide range of airflow limitation.

Quantitative computed tomography in COPD: possibilities and limitations

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that is characterized by chronic airflow limitation. Unraveling of this heterogeneity is challenging but important, because it might enable more accurate diagnosis and treatment. Because spirometry cannot distinguish between the different contributing pathways of airflow limitation, and visual scoring is time-consuming and prone to observer variability, other techniques are sought to start this phenotyping process. Quantitative computed tomography (CT) is a promising technique, because current CT technology is able to quantify emphysema, air trapping, and large airway wall dimensions. This review focuses on CT quantification techniques of COPD disease components and their current status and role in phenotyping COPD.

High-resolution computed tomography and pulmonary function in children with common variable immunodeficiency

High-resolution computed tomography (HRCT) may be useful to monitor lung disease in children with common variable immunodeficiency disorder (CVID). We evaluated interobserver agreement and correlation with pulmonary function tests (PFTs) for automated quantification and visual scoring of air trapping and airway wall thickening on HRCT in paediatric CVID patients. In a cohort of 51 children with CVID, HRCT was analysed visually and automated for presence of air trapping and airway wall thickening. PFTs were expressed as % predicted. Disease duration, physician-diagnosed pneumonias and antibiotic prophylaxis were recorded. Interobserver agreement for automated airway wall thickening was good with an intra-class correlation coefficient of 0.88, compared with 0.51 for visual scoring. Presence of air trapping on HRCT correlated significantly with PFTs and disease duration, but was not associated with previous pneumonias. Airway wall thickening did not correlate significantly with PFTs or disease duration and was not associated with previous pneumonias or prophylactic antibiotic use. In children with CVID disorders, HRCT air trapping measurements are significantly correlated with PFTs and disease duration. Quantitative air trapping is a feasible and promising technique for small airway disease quantification that may be applied to monitor (silent) disease progression in CVID.

Airway and interstitial lung disease are distinct entities in paediatric common variable immunodeficiency

Common variable immunodeficiency (CVID) is a common primary immune deficiency, caused by undefined defects in lymphocyte function, and is treated routinely by immunoglobulin substitution. CVID complications include airway disease (AD) and interstitial lung disease (ILD). It was not known if AD and ILD in CVID have a common immunological aetiology and should be considered separate features of the same disease, or as distinct syndromes that require specialized monitoring and treatment. We used high-resolution computed tomography (CT) to diagnose AD or ILD in paediatric CVID patients. Spirometry and body plethysmography did not differentiate between ILD and AD. Patients with AD (n = 11, 20%) developed more pneumonias while children with ILD (n = 8, 15%) showed immune dysregulation characterized by autoimmune complications, more severe memory B cell reduction and expansion of non-naive cytotoxic T cells. In conclusion, ILD and AD in CVID have dissimilar clinical and immunological characteristics, suggesting distinct aetiology requiring tailored monitoring and treatment of these patient subgroups.

Modified Chrispin-Norman chest radiography score for cystic fibrosis: observer agreement and correlation with lung function

Objective

To test observer agreement and two strategies for possible improvement (consensus meeting and reference images) for the modified Chrispin-Norman score for children with cystic fibrosis (CF).

Methods

Before and after a consensus meeting and after developing reference images three observers scored sets of 25 chest radiographs from children with CF. Observer agreement was tested for line, ring, mottled and large soft shadows, for overinflation and for the composite modified Chrispin-Norman score. Correlation with lung function was assessed.

Results

Before the consensus meeting agreement between observers 1 and 2 was moderate-good, but with observer 3 agreement was poor-fair. Scores correlated significantly with spirometry for observers 1 and 2 (−0.72<R<−0.42, P < 0.05), but not for observer 3. Agreement with observer 3 improved after the consensus meeting. Reference images improved agreement for overinflation and mottled and large shadows and correlation with lung function, but agreement for the modified Chrispin-Norman score did not improve further.

Conclusion

Consensus meetings and reference images improve among-observer agreement for the modified Chrispin-Norman score, but good agreement was not achieved among all observers for the modified Chrispin-Norman score and for bronchial line and ring shadows.

Computed tomographic estimation of lung dimensions throughout the growth period

The aim of the current study was to use computed tomography (CT) to estimate airway wall and lumen, and arterial and parenchyma dimensions in children throughout the growth period, and to provide normative data to study alterations caused by pulmonary disease. Clinical CT scans reported as normal that were performed in children for nonpulmonary and noncardiac reasons were analysed for lung weight, gas volume, lung expansion, lung surface/volume ratio, airway wall area, airway lumen area, airway lumen perimeter, arterial area and airway surface length/area ratio. The age range of the 50 subjects was 0-17.2 yrs. The data showed only little increase in lung expansion throughout childhood (n = 32). There was substantial variability in lung expansion between subjects. Airway wall and lumen and arterial area were exponentially associated with subjects' height (n = 50). Airway surface length/area ratio was linearly associated to alveolar surface/volume ratio. The data from the current study provide normative computed tomography estimates of airway wall and lumen, and arterial and parenchyma dimensions throughout the growth period that may be useful for the study of alterations in disease.

Bronchiolitis obliterans following lung transplantation: early detection using computed tomographic scanning

BACKGROUND

Computed tomographic (CT) scanning may enable earlier diagnosis of chronic lung allograft dysfunction than forced expiratory volume in 1 second (FEV1). A study was undertaken to determine intra-observer and inter-observer agreement of composite and air trapping CT scores, to examine the association of FEV1 with the composite and air trapping CT score, and to relate the baseline composite CT score to changes in FEV1 and changes in the composite CT score over 1 year.

METHODS

Lung function and baseline CT scans following transplantation and at subsequent annual follow ups were analysed in 38 lung transplant recipients. Scans were randomly scored by two observers for bronchiectasis, mucus plugging, airway wall thickening, consolidation, mosaic pattern, and air trapping, and re-scored after 1 month. CT scores were expressed on a scale of 0-100 and correlated with FEV1 as a percentage of the post-transplant baseline value.

RESULTS

The mean (SD) interval between baseline and follow up CT scans was 11.2 (4.7) months. Inter-observer and intra-observer agreement was good for both the composite and air trapping CT scores. There was a significant association between FEV1 and the composite CT score, with each unit of worsening in the baseline composite CT score predicting a 1.55% and 1.37% worsening in FEV1 over the following year (p<0.0001) and a 1.25 and 1.12 unit worsening in the composite CT score (p<0.0001) for observers 1 and 2, respectively.

CONCLUSION

These findings indicate a potential role for a composite CT scoring system in the early detection of bronchiolitis obliterans.

Progression of lung disease on computed tomography and pulmonary function tests in children and adults with cystic fibrosis

BACKGROUND

A study was undertaken to compare the ability of computed tomographic (CT) scores and pulmonary function tests to detect changes in lung disease in children and adults with cystic fibrosis (CF).

METHODS

CT scans and pulmonary function tests were retrospectively studied in a cohort of patients with CF aged 5-52 years for whom two or three CT scans at 3 year intervals were available, together with pulmonary function test results. All CT scans were scored by two observers. Pulmonary function results were expressed as percentage predicted and Z scores.

RESULTS

Of 119 patients studied, two CT scans were available in 92 patients and three in 24. CT (composite and component) scores and lung function both deteriorated significantly (p<0.02). Peripheral bronchiectasis worsened by 1.7% per year in children (p<0.0001) and by 1.5% per year in adults (p<0.0001). Bronchiectasis worsened in 68 of 92 patients while forced expiratory volume in 1 second (FEV1) worsened in 54 of 92 patients; bronchiectasis also deteriorated in 27 patients with stable or improving FEV1. The CT score (and its components) and pulmonary function tests showed similar rates of deterioration in adults and children (p>0.09).

CONCLUSION

The peripheral bronchiectasis CT score deteriorates faster and more frequently than lung function parameters in children and adults with CF, which indicates that pulmonary function tests and CT scans measure different aspects of CF lung disease. Our data support previous findings that the peripheral bronchiectasis CT score has an added value to pulmonary function tests in monitoring CF lung disease.

Computed tomographic imaging of the airways: relationship to structure and function

Alterations in the structure of the airways, collectively termed airway remodelling, contribute to airflow obstruction in a variety of chronic lung diseases. While histology has provided valuable insights into the structure of airway wall remodelling, this technique is invasive and does not allow the longitudinal analysis of airway wall dimensions. Technical advances in computed tomography allow the assessment of airway wall dimensions, and are ideally suited for the noninvasive investigation of the pathogenesis of airway wall remodelling and the evaluation of new therapeutic interventions. The aim of this article is to review the use of computed tomography in the investigation of airway structure and function in health and disease.

Carbohydrate solution intake during labour just before the start of the second stage: a double-blind study on metabolic effects and clinical outcome

OBJECTIVE

To study the effects of oral carbohydrate ingestion on clinical outcome and on maternal and fetal metabolism.

DESIGN

Prospective, double-blind, randomised study.

SETTING

Leyenburg Hospital, The Hague, The Netherlands.

POPULATION

Two hundred and two nulliparous women.

METHODS

In labour, at 8 to 10 cm of cervical dilatation, the women were asked to drink a solution containing either 25 g carbohydrates or placebo. In a subgroup of 28 women, metabolic parameters were measured.

MAIN OUTCOME MEASURES

Number of instrumental deliveries, fetal and maternal glucose, free fatty acids, lactate, pH, Pco2, base excess/deficit and beta-hydroxybutyrate.

RESULTS

Drinking a carbohydrate-enriched solution just before starting the second stage of labour did not reduce instrumental delivery rate (RR 1.1, 95% CI 0.9-1.3). Caesarean section rate was lower in the carbohydrate group, but the difference did not reach statistical significance (1% vs 7%, RR 0.2, 95% CI 0.02-1.2). In the carbohydrate group, maternal free fatty acids decreased and the lactate increased. In the umbilical cord there was a positive venous-arterial lactate difference in the carbohydrate group and a negative one in the placebo group, but the differences in pH and base deficit were comparable.

CONCLUSION

Intake of carbohydrates just before the second stage does not reduce instrumental delivery rate. The venous-arterial difference in the umbilical cord suggested lactate transport to the fetal circulation but did not result in fetal acidaemia.

Progressive damage on high resolution computed tomography despite stable lung function in cystic fibrosis

For effective clinical management of cystic fibrosis (CF) lung disease it is important to closely monitor the start and progression of lung damage. The aim of this study was to investigate the ability of high-resolution computed tomography (HRCT) scoring systems and pulmonary function tests (PFT) to detect changes in lung disease. CF children (n=48) had two HRCT scans in combination with two PFT 2 yrs apart. Their scans were scored using five scoring systems (Castile, Brody, Helbich, Santamaria and Bhalla). "Sensitivity" was defined as the ability to detect disease progression. In this group of children, HRCT scores worsened. PFT remained unchanged or improved. Of the HRCT parameters, mucous plugging and the severity, extent and peripheral extension of bronchiectasis worsened significantly. Relationships between changes in HRCT scores and PFT were weak. Substantial structural lung damage was evident in some children who had normal lung function. These data show that high-resolution computed tomography is more sensitive than pulmonary function tests in the detection of early and progressive lung disease, and suggest that high-resolution computed tomography may be useful in the follow up of cystic fibrosis children and as an outcome measure in studies that aim to reduce lung damage.

Estimation of lung growth using computed tomography

Anatomical studies suggest that normal lungs grow by rapid alveolar addition until about 2 yrs of age followed by a gradual increase in alveolar dimensions. The aim of this study was to examine the hypothesis that normal lung growth can be monitored by computed tomography (CT). Therefore, the gas volume per gram of lung tissue was estimated from measurements of lung density obtained from CT scans performed on children throughout the growth period. CT scans were performed on 17 males and 18 females, ranging in age from 15 days-17.6 yrs. CT-measured lung weight was correlated with predicted post mortem values and CT measured gas volume with predicted values of functional residual capacity. The median value for lung expansion was 1.86 mL x g(-1) at 15 days, decreased to 0.79 mL x g(-1) by 2 yrs and then increased steadily to 5.07 mL x g(-1) at 17 yrs. Computed tomography scans can be used to estimate lung weight, gas volume and expansion of normal lungs during the growth period. The increase in the lung expansion after the age of 2 yrs suggests progressive alveolar expansion with increasing lung volume.

Fetal and maternal energy metabolism during labor in relation to the available caloric substrate

AIM

To discuss maternal and fetal metabolic events during labor and the possible role of glucose administration.

RESULTS

The oxidative pathway covers the largest part of the energy demand of labor, although in the second stage or, in polysystolic labor, the non-oxidative pathway becomes important as well. Glucose is the main maternal energy source, but the rise in ketobodies, even during normal labor, suggests a relative shortage. In the first stage of labor, a combination of a respiratory alkalosis, and to a lesser extent, a metabolic acidosis, result in a rise in the maternal pH. In the second stage of labor, the maternal pH decreases due to an increasing metabolic acidosis. Glucose is also the main fetal energetic fuel. In fetal hypoxia, lactate is produced, which in most cases is transferred to the maternal circulation. High maternal lactate concentrations, however, may interfere with this process. Furthermore, fetal hyperglycemia may lead to an increased fetal lactate production.

CONCLUSIONS

Maternal hyperglycemia, may lead to an increase in maternal and fetal lactate production resulting in metabolic acidosis. Unlike high dosage intravenous glucose administration, it is not likely that oral intake of carbohydrates leads to maternal and fetal hyperglycemia and subsequently to metabolic acidosis, but studies are rare.

Eating and drinking in labor: the influence of caregiver advice on women's behavior

BACKGROUND

Although there is much debate about eating and drinking during labor, little scientific data about its influence on the course of labor exist. In The Netherlands, most midwives and obstetricians allow women to eat and drink during normal labor. The objective of this study was to examine whether or not women were actively advised to eat and drink and if this advice affected eating and drinking behavior.

METHODS

A randomly selected group of midwives and obstetricians from across The Netherlands identified 211 consecutive nulliparous women to participate in the study. In a questionnaire with open-ended questions, women were asked after their delivery whether or not they were advised about eating and drinking during labor, and if so, about the nature of this advice and what they had consumed. Data were analyzed at the Leyenburg Hospital in The Hague.

RESULTS

Sixty-six percent of the women were not given advice about eating and drinking during labor. Women who were given advice usually followed it. In the total group, 37 percent of the women had intake other than water and of these, 75 percent ate solid food. After adjusting for other prognostic factors, the incidence of an instrumental delivery due to a nonprogressing second stage was lower in women with caloric intake (13% vs 24%, p = 0.04).

CONCLUSION

The study design did not enable us to draw conclusions about the cause and effect between caloric intake and labor progress. Scientific data with respect to the giving of evidence-based advice about eating and drinking during labor are lacking. Should such advice become available, women are likely to follow it.

Angiotensin sensitivity test revisited

OBJECTIVE

To determine the validity of a single angiotensin sensitivity test as predictor of pregnancy-induced hypertension with special reference to the dietary sodium intake at the time of testing.

METHODS

The angiotensin sensitivity test was successfully performed at 32 weeks' gestation in 104 women. In 90 of these women, the 24-h urinary sodium-creatinine ratio was known. Using an effective pressure dose of 10 ng/kg/min as the cutoff level, test characteristics were assessed in both the total population and after subdivision into a sodium restricted (n = 23) and an unrestricted diet group (n = 67).

RESULTS

The incidence of pregnancy-induced hypertension was 13.4%. The number of positive angiotensin sensitivity tests was 7.5%. Test characteristics showed poor sensitivity (22.2%) and high specificity (94.8%); positive and negative predictive values were 40.0% and 88.7%, respectively. None of the sodium-restricted women was angiotensin sensitive. Sodium restriction did not have a significant influence on sensitivity, specificity, and predictive values of the test.

CONCLUSION

The angiotensin sensitivity test is not an appropriate screening test to predict hypertensive disorders of pregnancy. No significant effect of dietary sodium restriction was found.

Effect of angiotensin infusion on plasma endothelin in pregnancy

OBJECTIVE

To study a possible role of plasma endothelin in angiotensin-induced vasoconstriction.

STUDY DESIGN

Plasma endothelin levels were measured before and after an angiotensin sensitivity test at 32 gestational weeks in 19 nulliparous women.

RESULTS

No significant change in plasma endothelin occurred as a result of angiotensin infusion.

CONCLUSION

The angiotensin-induced rise in diastolic blood pressure is not associated with changes in plasma endothelin.

Diurnal variation in angiotensin sensitivity in pregnancy

OBJECTIVE

Our purpose was to study the diurnal variation in angiotensin II sensitivity.

STUDY DESIGN

Angiotensin sensitivity tests were performed at 9 AM and at 2 PM in 12 normotensive pregnant women, with each woman serving as her own control.

RESULTS

In all patients the effective pressor dose was higher in the afternoon.

CONCLUSION

We suggest the greater sensitivity to angiotensin in the morning is related to an intrinsic circadian variation in vascular reactivity. When the result of an angiotensin sensitivity test is interpreted, the time of day it is performed should be taken into account.

Effects of maternal smoking on neonatal morbidity

In this paper a prospective study of the association between maternal smoking and neonatal morbidity variables is presented. Caucasian nulliparous women (n = 115) were studied throughout pregnancy, childbirth and puerperal period. Birthweight(-centiles), Apgar scores, mode of delivery, umbilical arterial and venous blood gas analyses, admission incidence to the neonatal ward and the neurological examination according to Prechtl were considered to be representatives for the starting condition of the newborns. The babies of smokers were statistically significantly at a disadvantage compared to babies of non-smokers for birthweight(-centiles), pH of the umbilical vein (medians: smokers 7.29, non-smokers 7.30) and the score of the neurological examination (medians: smokers 57, non-smokers 58).