Implication des facteurs cardiorespiratoires dans l’intolérance à l’effort de l’adolescent obèse

Introduction

To identify the parameters, which can explain the effort intolerance in young obese during standard cardiorespiratory evaluation at rest and exercise.

Synthesis

Fourty-two obese (degree 2) adolescents systematically underwent pulmonary function measurements and maximal graded exercise on ergocycle. Two subgroups were drawn on the basis of their VO2peak${\text{V}}_{{\text{O}}_{\text{2peak}}}$ (‘normal’ group: N is greater than 80% of predictive value, n = 14;‘abnormal’ group: A is less than 80% of predictive value) and compared for all the measured parameters. Forced vital capacity (FVC) and forced expiratory volume in the first second (FEV₁) though in the lower normal range were lower in A compared to N (P = 0.01 and P = 0.02, respectively). At the end of maximal exercise, maximal VT/FVC (P = 0.001) and VO2peak${\text{V}}_{{\text{O}}_{\text{2peak}}}$/HR_max (P = 0.04) obtained in A are lower too. VO2peak${\text{V}}_{{\text{O}}_{\text{2peak}}}$ was correlated to lean mass and spirometric data. In addition, spirometric data correlated with VO2peak${\text{V}}_{{\text{O}}_{\text{2peak}}}$/HR_max.

Conclusion

These results emphasized the possible involvement of ventilatory factors and the stress they may impose to central cardiovascular system in exercise intolerance of obese adolescent.     

Contribution à l’étude des effets d’un programme de réentraînement à l’effort sur les aptitudes physiques de patients atteints de bronchopneumopathie chronique obstructive

Aims

The purpose of this study was to evaluate the effect of a three-months’ training rehabilitation on the physical capacity of patients suffering from chronic obstructive pulmonary disease (COPD).

Methods

The aerobic and anaereobic capacity was evaluated in 36 patients (Stage 2) before and after a training rehabilitation period: (duration: three months, frequency: two sessions per week, intensity: 65% of aerobic threshold for 25 min, type: regular exercise on a bicycle).

Results

Training rehabilitation caused a statistically significant specific improvement of submaximal aerobic capacity and an increase of quadriceps and flexor of the fingers’ strength.     

Variations du cortisol salivaire au cours de 15 semaines d’entraînement mixte aérobie et anaérobie chez des lutteurs juniors de haut niveau : corrélations avec les performances

Introduction

The goal of this study was to verify if cortisol could be used as an indicator of work load during a mixed aerobic and anaerobic training.

Results

Throughout a 15-week training period in 12 young wrestlers, salivary cortisol was assayed every three weeks and the explosive stength was evaluated on weeks 4 and 15. The results show that the wrestlers who have the highest mean levels of cortisol are those which progress less in explosive force (r = −0.72, P < 0.01).

Conclusion

It seems that the follow-up of cortisol should be an indicator of the load of training.     

Improvement of multislice oxygen-enhanced MRI of the lung by fully automatic non-rigid image registration

Purpose

In oxygen-enhanced magnetic resonance imaging of the lung (O2-MRI), motion artifacts related to breathing hamper the quality of the parametric O2-maps. In this study, fully automatic non-rigid image registration was assessed as a post-processing method to improve the quality of O2-MRI.

Materials and methods

Twenty healthy volunteers were investigated on a 1.5 T MR system. O2-MRI was obtained in four coronal sections using an IR-HASTE sequence with TE/TI of 12/1200 ms. Each section was repeatedly imaged during oxygen and room-air ventilation. Spatial differences among the images were corrected by fully automatic non-rigid registration. Signal variability, relative enhancement ratio between oxygen and room air images, and spatial heterogeneity of lung enhancement were assessed before and after image registration.

Results

Motion artifacts were corrected in 5–10 s. Non-rigid registration reduced signal variability of the source images and heterogeneity of the O2-maps by 1.1 ± 0.2% and 11.2 ± 2.9%, respectively (p < 0.0001). Registration did not influence O2 relative enhancement ratio (p = 0.06).

Conclusion

Fully automatic non-rigid image registration improves the quality of multislice oxygen-enhanced MRI of the lung.     

Age-related differences in metabolites in the posterior cingulate cortex and hippocampus of normal ageing brain: a 1H-MRS study

Objective

To study age-related metabolic changes in N-acetylaspartate (NAA), total creatine (tCr), choline (Cho) and myo-inositol (Ins).

Materials and methods

Proton magnetic resonance spectroscopy (¹H-MRS) was performed in the posterior cingulate cortex (PCC) and the left hippocampus (HC) of 90 healthy subjects (42 women and 48 men aged 18–76 years, mean ± SD, 48.4 ± 16.8 years). Both metabolite ratios and absolute metabolite concentrations were evaluated. Analysis of covariance (ANCOVA) and linear regression were used for statistical analysis.

Results

Metabolite ratios Ins/tCr and Ins/H₂O were found significantly increased with age in the PCC (P < 0.05 and P ≤ 0.001, respectively), and in the HC (P < 0.01 for both). An increased tCr/H₂O was only observed in the PCC (P < 0.01). Following absolute quantification based on the internal water signal, significantly increased concentrations of Ins and tCr in the PCC confirmed the relative findings (P < 0.01 for both).

Conclusion

Age-related increases of tCr and Ins are found in the PCC, whereas this holds only true for Ins in the HC, indicating possible gliosis in the ageing brain. No age-dependent NAA decreases were observed in the PCC nor the HC. The ¹H-MRS results in these specific brain regions can be important to differentiate normal ageing from age-related pathologies such as mild cognitive impairment (MCI) and Alzheimer's disease.     

Routine chest and abdominal high-pitch CT: an alternative low dose protocol with preserved image quality

Objective

To investigate the radiation dose and image quality of the high-pitch dual source computer tomography (DSCT) for routine chest and abdominal scans.

Methods

130 consecutive patients (62 female, 68 male, median age 55 years) were included. All patients underwent 128-slice high-pitch DSCT (chest n = 99; abdomen n = 84) at a pitch of 3.2. Two observers independently rated image quality using a 4-point score (1: excellent to 4: non-diagnostic). Image noise was measured and operational radiation dose quantities were recorded. An additional group of 132 patients (chest, n = 80; abdomen n = 52) scanned with standard-pitch CT matched for age, gender, and body mass index (BMI) served as control group.

Results

Interobserver agreement for image quality rating was good (k = 0.74). Subjective image quality of high-pitch CT was diagnostic in all patients (median score chest; 2, median score abdomen: 2). Image noise of high-pitch CT was comparable to standard-pitch for the chest (p = 0.32) but increased in the abdomen (p < 0.0001). For high-pitch CT radiation dose was 4.4 ± 0.9 mSv (chest) and 6.5 ± 1.2 mSv (abdomen). These values were significantly lower compared to standard-pitch CT (chest: 5.5 ± 1.2 mSv; abdomen: 11.3 ± 3.8 mSv).

Conclusion

Based on the technical background high-pitch dual source CT may serve as an alternative scan mode for low radiation dose routine chest and abdominal CT.     

Hepatic arterial perfusion increases in the early stage of severe acute pancreatitis patients: evaluation by perfusion computed tomography

Purpose

Although hepatic perfusion abnormalities have been reported in patients with acute pancreatitis, hepatic perfusion with severe acute pancreatitis (SAP) has not been quantitatively evaluated in humans. Therefore, we investigated hepatic perfusion in patients with SAP using perfusion CT.

Materials and methods

Hepatic perfusion CT was performed in 67 patients with SAP within 3 days after symptom onset. The patients were diagnosed as having SAP according to the Atlanta criteria. Fifteen cases were established as a control group. Perfusion CT was obtained for 54 s beginning with a bolus injection of 40 ml of contrast agent (600–630 mgI/kg) at a flow rate of 4 ml/s. Perfusion data were analyzed by the dual-input maximum slope method to obtain hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP). Finally, we compared HAP and HPP in SAP patients with those in the control group, respectively.

Results

Average HAP was significantly higher in SAP patients than in the control group (75.1 ± 38.0 vs. 38.2 ± 9.0 ml/min/100 ml; p < 0.001). There was no significant difference in average HPP between SAP patients and the control group (206.7 ± 54.9 vs. 204.4 ± 38.5 ml/min/100 ml; p = 0.92).

Conclusion

Using quantitative analysis on perfusion CT, we first demonstrated an increase of HAP in the right hepatic lobe in SAP patients.     

Contrast timing in computed tomography: effect of different contrast media concentrations on bolus geometry

Objective

To assess the effect of low-osmolar, monomeric contrast media with different iodine concentrations on bolus shape in aortic CT angiography.

Materials and methods

Repeated sequential computed tomography scanning of the descending aorta of eight beagle dogs (5 male, 12.7 ± 3.1 kg) was performed without table movement with a standardized CT scan protocol. Iopromide 300 (300 mg I/mL), iopromide 370 (370 mg I/mL) and iomeprol 400 (400 mg I/mL) were administered via a foreleg vein with an identical iodine delivery rate of 1.2 g I/s and a total iodine dose of 300 mg I/kg body weight. Time-enhancement curves were computed and analyzed.

Results

Iopromide 300 showed the highest peak enhancement (445.2 ± 89.1 HU), steepest up-slope (104.2 ± 17.5 HU/s) and smallest full width at half maximum (FWHM; 5.8 ± 1.0 s). Peak enhancement, duration of FWHM, enhancement at FWHM and up-slope differed significantly between iopromide 300 and iomeprol 400 (p < 0.05). Except for enhancement at FWHM there were no significant differences between iopromide 300 and iopromide 370 and iopromide 370 and iomeprol 400 (p > 0.05).

Conclusions

Low viscous iopromide 300 results in a better defined bolus with a significantly higher peak enhancement, steeper up-slope and smaller FWHM when compared to iomeprol 400. These characteristics potentially affect contrast timing.     

Association of platelet-SDF-1 with hemodynamic function and infarct size using cardiac MR in patients with AMI

Purpose

Platelet-derived stromal-cell-derived factor-1 (SDF-1) plays an important role in trafficking hematopoetic progenitor cells for tissue regeneration and neovascularisation.The aim was to evaluate platelet-SDF-1 and CD34⁺ progenitor cells in patients with acute myocardial infarction (AMI) compared with hemodynamic function and infarct size using late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging.

Materials and methods

We consecutively evaluated 40 patients with AMI, who received coronary angiography for primary coronary intervention. Blood was sampled for flow cytometry to determine mean fluorescence intensity (MFI) of platelet-SDF-1 and for isolation of CD34⁺ progenitor cells. 48 h and three months after coronary stenting, all patients underwent 1.5 T CMR for volumetric assessment and LGE.

Results

Patients with enhanced platelet-SDF-1 expression (median ≥ 68.5 MFI) showed a significant amelioration of left ventricular ejection fraction (LVEF) (baseline vs. follow-up mean ± SD: 45 ± 6% vs. 56 ± 6%; P = 0.018) and of stroke volume (73.1 ± 19.1 mL vs. 89.9 ± 21.3 mL; P = 0.032) at three-month follow-up in contrast to patients with a decreased platelet-SDF-1 expression level (LVEF: 53 ± 8% vs. 56 ± 10%; P = 0.267; stroke volume: 85.6 ± 23.1 mL vs. 87.4 ± 23.2 mL; P = 0.803). Inversely, LGE infarct size showed significantly reduced in patients with enhanced platelet-SDF-1 expression at three months (18.9 ± 12 mL vs. 6.3 ± 5.1 mL; P = 0.002) compared to patients with decreased platelet-SDF-1 (12.7 ± 12.7 mL vs. 7.6 ± 8.4 mL; P = 0.156). Time-dependent autocorrelation coefficients shifted for both SV (lag 1: r = −0.368; P = 0.001) and the number of CD34⁺ cells (lag 1: r = 0.633; P = 0.001) to a positive autocorrelation (SV; lag 2: r = 0.295; P = 0.001; CD34⁺ cells; lag 2: r = 0.287; P = 0.001). Patients with increased number of CD34⁺ cells (median ≥ 420 cells/hpf) showed a significant amelioration of stroke volume in three-month follow-up (83.9 ± 5.3 mL vs. 99.4 ± 4.1 mL; P = 0.020) compared with patients with decreased number of CD34⁺ cells (69.3 ± 4.1 mL vs. 76.1 ± 3.2 mL; P = 0.282).

Conclusions

Platelet-SDF-1 and number of CD34⁺ progenitor cells are associated with CMR hemodynamic function in patients with AMI.     

Measurements and detection of abdominal aortic aneurysm growth: Accuracy and reproducibility of a segmentation software

Purpose

To validate the reproducibility and accuracy of a software dedicated to measure abdominal aortic aneurysm (AAA) diameter, volume and growth over time.

Materials and methods

A software enabling AAA segmentation, diameter and volume measurement on computed tomography angiography (CTA) was tested. Validation was conducted in 28 patients with an AAA having 2 consecutive CTA examinations. The segmentation was performed twice by a senior radiologist and once by 3 medical students on all 56 CTAs. Intra and inter-observer reproducibility of D-max and volumes values were calculated by intraclass correlation coefficient (ICC). Systematic errors were evaluated by Bland–Altman analysis. Differences in D-max and volume growth were compared with paired Student's t-tests.

Results

Mean D-max and volume were 49.6 ± 6.2 mm and 117.2 ± 36.2 ml for baseline and 53.6 ± 7.9 mm and 139.6 ± 56.3 ml for follow-up studies. Volume growth (17.3%) was higher than D-max progression (8.0%) between baseline and follow-up examinations (p < .0001). For the senior radiologist, intra-observer ICC of D-max and volume measurements were respectively estimated at 0.997 (≥0.991) and 1.000 (≥0.999). Overall inter-observer ICC of D-max and volume measurements were respectively estimated at 0.995 (0.990–0.997) and 0.999 (>0.999). Bland–Altman analysis showed excellent inter-reader agreement with a repeatability coefficient <3 mm for D-max, <7% for relative D-max growth, <6 ml for volume and <6% for relative volume growth.

Conclusion

Software AAA volume measurements were more sensitive than AAA D-max to detect AAA growth while providing an equivalent and high reproducibility.     

Features of time-intensity curve parameters of colorectal adenocarcinomas evaluated by double-contrast enhanced ultrasonography: initial observation

Purpose

This study is to investigate the value of double contrast-enhanced ultrasonography (DCEU) in assessing microcirculation of colorectal adenocarcinomas and to describe the perfusion features of the tumours.

Material and methods

DCEUS was performed in 42 patients with adenocarcinoma. The time–intensity curve parameters (arrival time (AT), time-to-peak (TTP), peak intensity (PI) and area under the curve (AUC)) within the tumours were extracted. The parameters were compared among the tumours with different CEUS features and stages.

Results

The mean values of AT, TTP, PI and AUC of the colorectal adenocarcinomas were 13.68 ± 13.36 s, 32.61 ± 19.56 s, 19.82 ± 16.54 dB and 271.10 ± 159.19 dB s, respectively. In the adenocarcinomas with necrosis, the mean values of AUC was significantly lower than that of the adenocarcinomas without (231.10 ± 219.27 dB s, 278.10 ± 123.20 dB s, p = 0.004). In the adenocarcinomas with necrosis, the AUC and PI of the non-necrotic part were significantly higher than that of the necrotic part (p = 0.007, 0.0025, respectively). AUC increased progressively in the subgroups of T2, T3 and T4 and the difference of AUC between T2 and T4 subgroup was significant (p = 0.008).

Conclusions

Double contrast-enhanced ultrasonography is a valuable technique for quantifying tumour vascularity of colorectal adenocarcinomas. AUC was significantly different in the subgroups of different T stage. AUC and PI could reflect the different perfusion status of tumours with or without necrosis.     

Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI?

Background

Quantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to choose.

Objective

To examine whether preoperative evaluation of abdominal blood flow using MRI could prove to be a useful and reliable alternative for the perioperative sonographic approach.

Methods

In this study portal and renal venous flow and hepatic arterial flow were sequentially quantified by preoperative MRI, preoperative and perioperative Duplex Doppler Ultrasound (DDUS). 55 Patients scheduled for major abdominal surgery were studied and methods and settings were compared. Additionally, average patient population values were compared.

Results

Mean (±SD) plasmaflow measured by perioperative DDUS, preoperative DDUS and MRI, respectively was 433 ± 200/423 ± 162/507 ± 96 ml/min (portal vein); 96 ± 70/74 ± 41/108 ± 91 ml/min (hepatic artery); 248 ± 139/201 ± 118/219 ± 69 ml/min (renal vein). No differences between the different settings of DDUS measurement were detected. Equality of mean was observed for all measurements. Bland Altman Plots showed widespread margins. Hepatic arterial flow measurements correlated with each other, but portal and renal venous flow correlations were absent.

Conclusions

Surgery and method (DDUS vs. MRI) do not affect mean flow values. Individual comparison is restricted due to wide range in measurements.Since MRI proves to be more reliable with respect to inter-observer variability, we recommend using mean MRI results in experimental setups.     

Technical and clinical outcome of transjugular intrahepatic portosystemic stent shunt: bare metal stents (BMS) versus viatorr stent-grafts (VSG)

Purpose

To compare retrospectively angiographical and clinical results in patients undergoing transjugular intrahepatic portosystemic stent-shunt (TIPS) using BMS or VSG.

Materials and methods

From February 2001 to January 2010, 245 patients underwent TIPS. From those, 174 patients matched the inclusion criteria with elective procedures and institutional follow-up. Group (I) consisted of 116 patients (mean age, 57.0 ± 11.1 years) with BMS. Group (II) consisted of 58 patients with VSG (mean age, 53.5 ± 16.1 years). Angiographic and clinical controls were scheduled at 3, 6 and 12 months, followed by clinical controls every 6 months. Primary study goals included hemodynamic success, shunt patency as well as time to and number of revisions. Secondary study goals included clinical success.

Results

Hemodynamic success was 92.2% in I and 91.4% in II (n.s.). Primary patency was significantly higher in II compared to I (53.8% after 440.4 ± 474.5 days versus 45.8% after 340.1 ± 413.8 days; p < 0.05). The first TIPS revision was performed significantly later in II compared to I (288.3 ± 334.7 days versus 180.1 ± 307.0 days; p < 0.05). In the first angiographic control, a portosystemic pressure gradient ≥15 mmHg was present in 73.9% in I and in 39.4% in II (p < 0.05). Clinical success was 73.7–86.2% after 466.3 ± 670.1 days in I and 85.7–90.5% after 617.5 ± 642.7 days in II (n.s.). Hepatic encephalopathy was 37.5% in I and 36.5% in II (n.s.).

Conclusion

VSG increased primary shunt patency as well as decreased time to and number of TIPS revisions. There was a trend of higher clinical success in VSG without increased hepatic encephalopathy.     

Radiation dose of digital tomosynthesis for sinonasal examination: comparison with multi-detector CT

Objective

Using an anthropomorphic phantom, we have investigated the feasibility of digital tomosynthesis (DT) of flat-panel detector (FPD) radiography to reduce radiation dose for sinonasal examination compared to multi-detector computed tomography (MDCT).

Materials and methods

A female Rando phantom was scanned covering frontal to maxillary sinus using the clinically routine protocol by both 64-detector CT (120 kV, 200 mA s, and 1.375-pitch) and DT radiography (80 kV, 1.0 mA s per projection, 60 projections, 40° sweep, and posterior–anterior projections). Glass dosimeters were used to measure the radiation dose to internal organs including the thyroid gland, brain, submandibular gland, and the surface dose at various sites including the eyes during those scans. We compared the radiation dose to those anatomies between both modalities.

Results

In DT radiography, the doses of the thyroid gland, brain, submandibular gland, skin, and eyes were 230 ± 90 μGy, 1770 ± 560 μGy, 1400 ± 80 μGy, 1160 ± 2100 μGy, and 112 ± 6 μGy, respectively. These doses were reduced to approximately 1/5, 1/8, 1/12, 1/17, and 1/290 of the respective MDCT dose.

Conclusion

For sinonasal examinations, DT radiography enables dramatic reduction in radiation exposure and dose to the head and neck region, particularly to the lens of the eye.     

Assessment of osteoporotic vertebral fractures using specialized workflow software for 6-point morphometry

Purpose

To evaluate the time required, the accuracy and the precision of a model-based image analysis software tool for the diagnosis of osteoporotic fractures using a 6-point morphometry protocol.

Materials and methods

Lateral dorsal and lumbar radiographs were performed on 92 elderly women (mean age 69.2 ± 5.7 years). Institutional review board approval and patient informed consent were obtained for all subjects. The semi-automated and the manual correct annotations of 6-point placement were compared to calculate the time consumed and the accuracy of the software. Twenty test images were randomly selected and the data obtained by multiple perturbed initialisation points on the same image were compared to assess the precision of the system.

Results

The time requirement data of the semi-automated system (420 ± 67 s) were statistically different (p < 0.05) from that of manual placement (900 ± 77 s). In the accuracy test, the mean reproducibility error for semi-automatic 6-point placement was 2.50 ± 0.72% [95% CI] for the anterior–posterior reference and 2.16 ± 0.5% [95% CI] for the superior–inferior reference. In the precision test the mean error resulted averaged over all vertebrae was 2.6 ± 1.3% in terms of vertebral width.

Conclusions

The technique is time effective, accurate and precise and can, therefore, be recommended in large epidemiological studies and pharmaceutical trials for reporting of osteoporotic vertebral fractures.     

Safety and feasibility in highly concentrated contrast material power injections for CT-perfusion studies of the brain using central venous catheters

Introduction

CT perfusion studies play an important role in the early detection as well as in therapy monitoring of vasospasm after subarachnoid hemorrhage. High-flow injections via central venous catheters are not recommended but may sometimes be the only possibility to obtain high-quality images.

Materials and methods

We retrospectively analyzed our data for CT perfusions performed with power injection of contrast material with an iodine concentration of 400 mg/ml via the distal 16G lumen of the Arrow three and five lumen central venous catheter with preset flow rates of 5 ml/s.

Results

104 examinations with central venous catheters were evaluated (67 with five lumen and 37 with three lumen). No complications were observed. Mean flow rates were 4.4 ± 0.5 ml/s using the three lumen catheter and 4.6 ± 0.6 ml/s using the five lumen catheter respectively. The mean injection pressure measured by the power injector was 200.7 ± 17.5 psi for the three lumen central venous catheter and 194.5 ± 6.5 psi for the five lumen catheter, respectively.

Conclusion

Following a strict safety protocol there were no complications associated with power injections of contrast material containing 400 mg iodine/ml with preset flow rates up to 5 ml/s via the distal 16G lumen of the Arrow multi-lumen central venous catheter. However, since power-injections are off-label use with Arrow central venous catheters, this procedure cannot be recommended until potential safety hazards have been ruled out by the manufacturer.     

Assessment of colorectal hepatic metastases by quantitative T2 relaxation time

Aim

To determine the T₂ relaxation time of colorectal hepatic metastases and changes in T₂ relaxation times following chemotherapy.

Materials and methods

42 patients with 96 hepatic colorectal metastases underwent baseline MRI. Axial T₁, T₂ and multi-echo GRASE sequences were acquired. ROIs were drawn on T₂ relaxation maps, obtained from GRASE images, encompassing metastasis and normal liver to record T₂ relaxation time values. In 11 patients with 28 metastases, MRI was repeated using same protocol at 6 weeks following chemotherapy. The median pre-treatment T₂ values of metastases and normal liver were compared using the Mann–Whitney test. The pre- and post-treatment median T₂ values of metastases were compared using the Wilcoxon–Rank test for responding (n = 16) and non-responding (n = 12) lesions defined by RECIST criteria. The change in T₂ values (ΔT₂) were compared and correlated with percentage change in lesion size.

Results

There was no difference in the pre-treatment median T₂ of metastases between responding (67.3 ± 8.6) and non-responding metastases (71.4 ± 16.5). At the end of chemotherapy, there was a decrease in the median T₂ of responding lesions (61.6 ± 12.6) p = 0.83, and increase in non-responding lesions (76.2 ± 18.4) p = 0.03, but these were not significantly different from the pre-treatment values. There was no significant difference in ΔT₂ of responding and non-responding lesions (p = 0.18) and no correlation was seen between size change and ΔT₂ (coefficient = 0.3).

Conclusion

T₂ relaxation time does not appear to predict response of colorectal liver metastasis to chemotherapy.     

Prevalence of hepatosplenomegaly in beta thalassemia minor subjects in Iran

Introduction

Thalassemia is the most common hereditary blood disorder in the world. Iran is located on the thalassemic belt and there is a high prevalence of the hepatosplenomegaly in beta thalassemia minor patients which is reported to be very variable. The goal of this research was to study the frequency of these signs in the cases with beta thalassemia minor patients in Iran.

Materials and methods

Two hundred and fifty-nine cases that referred to center for pre-marriage tests were divided into two groups according to their MCV, MCH, and HbA2 (beta thalassemia minor cases and control groups). Liver and spleen sizes were determined by ultrasonographic method and the two groups were compared with each other.

Results

Average spleen volumes in case and control groups were 163.48 ± 133.97 and 126.29 ± 53.98 mm³, respectively. Average spleen lengths in case and control groups were 10.71 ± 1.52 and 10.60 ± 5.4 cm, respectively.

Conclusion

In the regions with high frequency of beta thalassemia, in case of finding large spleen size in the ultrasonography, a probable harmless differential diagnosis will be beta thalassemia minor that is not indicative of any serious disease.Volumetric measurement of spleen is more reliable for detection of splenomegaly in these patients.     

Thoraco-abdominal high-pitch dual-source CT angiography: experimental evaluation of injection protocols with an anatomical human vascular phantom

Objective

To experimentally evaluate three different contrast injection protocols at thoraco-abdominal high-pitch dual-source computed tomography angiography (CTA), with regard to level and homogeneity of vascular enhancement at different cardiac outputs.

Materials and methods

A uniphasic, a biphasic as well as an individually tailored contrast protocol were tested using a human vascular phantom. Each protocol was scanned at 5 different cardiac outputs (3–5 L/min, steps of 0.5 L/min) using an extracorporeal cardiac pump. Vascular enhancement of the thoraco-abdominal aorta was measured every 5 cm. Overall mean enhancement of each protocol and mean enhancement for each cardiac output within each protocol were calculated. Enhancement homogeneity along the z-axis was evaluated for each cardiac output and protocol.

Results

Overall mean enhancement was significantly higher in the uniphasic than in the other two protocols (all p < .05), whereas the difference between the biphasic and tailored protocol was not significant (p = .76). Mean enhancement among each of the 5 cardiac outputs within each protocol was significantly different (all p < .05). Only within the tailored protocol mean enhancement differed not significantly at cardiac outputs of 3.5 L/min vs. 5 L/min (484 ± 25 HU vs. 476 ± 19 HU, p = .14) and 4 vs. 5 L/min (443 ± 49 HU vs. 476 ± 19 HU, p = .05). Both, uniphasic and tailored protocol yielded homogenous enhancement at all cardiac outputs, whereas the biphasic protocol failed to achieve homogenous enhancement.

Conclusion

This phantom study suggests that diagnostic and homogenous enhancement at thoraco-abdominal high-pitch dual-source CTA is feasible with either a uniphasic or an individually tailored contrast protocol.     

Is diffusion-weighted imaging useful in grading and differentiating histopathological subtypes of meningiomas?

Purpose

Meningiomas are mostly benign, however atypical or malignant subtypes with more aggressive clinical course and higher recurrence rates can also be seen. The purpose of this study was to determine whether histopathological subtypes of meningiomas could be assessed preoperatively using apparent diffusion coefficient (ADC) values.

Materials and methods

Conventional magnetic resonance (MR) and diffusion-weighted (DW) imaging of 177 adult patients with pathologically proven meningiomas were retrospectively evaluated. Tumor size and the degree of associated edema were noted. The signal intensity of the lesions on DW imaging was evaluated and graded. Mean ADC values were obtained as the mean of measurements from three regions of interests within the mass. ADC ratios of meningioma/contralateral normal appearing subcortical parietal white matter were also calculated.

Results

The histopathological analysis revealed 135 benign, 37 atypical and 5 malignant lesions. With classification according to the subtype, the mean ADC values and ratios of benign meningiomas were as 0.99 ± 0.12 × 10⁻³ mm²/s and 1.22 ± 0.07, respectively. ADC values for atypical and malignant groups were both 0.84 ± 0.1 × 10⁻³ mm²/s. The ADC ratios were 1.05 ± 0.1 and 0.96 ± 0.2 for atypical and malignant subtypes, respectively. There was no statistically significant difference between the mean ADC ratios of the three subtypes (ANOVA test; P ≥ 0.05). Gender, age of the patients and tumor size showed no statistically significant difference between the different histological groups.

Conclusion

DW MR imaging was not found to have any additional value in determining histological behaviour nor in differentiating histopathological subtypes of meningiomas.