Biomedical subjects

Stavros C Efremidis

Publications and source records attributed to Stavros C Efremidis.

12 recordsLinked to original sources

PubMed2006

Cyclic contrast-enhanced harmonic voiding urosonography for the evaluation of reflux. Can we keep the cost of the examination low?

The purpose of this study was to evaluate whether a second cycle of contrast-enhanced voiding urosonography (VUS) with no added contrast medium (CM) can increase the detection rate of vesicoureteral reflux (VUR). One hundred twelve consecutive children with a mean age of 2.9 years with 224 kidney-ureter units (KUU) underwent two cycles of contrast-enhanced harmonic VUS. The first cycle of VUS was performed with 3.5-12.5 ml of suspension 300 mg/ml SH U 508 A and was followed immediately by a second cycle with only saline without adding CM. VUR was detected in 57 KUU from 44 children (39%) at the first cycle of VUS. Eight of the remaining 68 non-refluxing children (12%) demonstrated VUR at the second cycle (P=0.045). Most cases of missed reflux at the first cycle were grade II (75%). However, in two KUU from two children missed reflux was grade III. In one child reflux (grade II) was missed on the second cycle. Comparing the second cycle of VUS with the first cycle, concordant findings regarding the presence or absence as well as the grade of reflux were found in 94% of KUU. A second cycle of contrast-enhanced harmonic VUS with no added CM discloses significantly more cases of VUR at no additional cost for the examination.

Adolescent↗

PubMed2006

Magnetic resonance imaging quantification of hand synovitis in patients with rheumatoid arthritis treated with adalimumab.

OBJECTIVE: To investigate the clinical response and to evaluate by magnetic resonance imaging (MRI) the inflammatory tissue changes in patients with refractory rheumatoid arthritis (RA) treated with adalimumab. METHODS: Thirteen patients with refractory RA who were treated with adalimumab (40 mg every 2 weeks subcutaneously) were examined with MRI of the dominant affected wrist and hand before treatment and one year after therapy. The volume of the enhanced inflammatory tissue (VEIT) was evaluated in fat-suppressed contrast-enhanced T1-weighted MRI images using the Analyse 4.0 software. Disease activity was evaluated using the Disease Activity Score 28-joint (DAS-28). Clinical improvement was evaluated according to the American College of Rheumatology 20% response criteria (ACR20%). RESULTS: We studied 12 women and one man, with mean age 52.0 +/- 10.9 years and mean disease duration 13.0 +/- 8.5 years. Eight patients had positive IgM rheumatoid factor. One year after treatment, 11 (84.6%) patients showed a decrease of the VEIT. Moreover the values of C-reactive protein (CRP; 4.3 +/- 6.6 mg/l), the erythrocyte sedimentation rate (ESR; 26.3 +/- 19.5 mm/h), the DAS-28 (3.5 +/- 1.1), and the VEIT (21.6 +/- 10.7 cm3) after treatment were significantly lower compared to the corresponding values before treatment (CRP 41.6 +/- 39.2), (ESR 54.3 +/- 28.6) (DAS-28 5.8 +/- 0.8), and (VEIT 36.9 +/- 16.8) (p < 0.01). All but 3 (76.9%) patients with RA achieved the ACR20% response, while 7 (53.8%) and 5 (38.5%) patients achieved ACR50% and ACR70% response, respectively. A positive correlation between VEIT, swollen joint count, and ESR was found before treatment (r = 0.59, r = 0.64, respectively; p < 0.05). CONCLUSION: In patients with refractory RA, treatment with adalimumab resulted in improvement of clinical, laboratory, and MRI findings. MRI assessment of the VEIT may represent an additional tool for investigation of joint disease activity and responsiveness to treatment.

Adalimumab↗

PubMed2005

Magnetic resonance imaging quantification of hand synovitis in patients with rheumatoid arthritis treated with infliximab.

AIM: To investigate the clinical response and to evaluate by magnetic resonance imaging the inflammatory tissue changes in refractory rheumatoid arthritis patients treated with infliximab. METHODS: Sixteen refractory rheumatoid arthritis patients who were treated with intravenous infliximab (3 mg/kg) at weeks 0, 2, 6 and every 8 weeks thereafter were examined with magnetic resonance imaging of the dominant affected wrist and hand before treatment and 1 year after therapy. The volume of the enhancing inflammatory tissue was evaluated in fat suppressed contrast enhanced T1-weighted images by using the Analyse 4.0 software. Disease activity was evaluated by assessing the disease activity score for 28 joint indices. The clinical improvement was evaluated according to the American College of Rheumatology 20% response criteria. RESULTS: There were 13 females and 3 males with mean age 49.5 (17.0) years and mean disease duration 10.5 (8.0) years. Ten patients had positive IgM rheumatoid factor. One year after treatment, a significant reduction of the erythrocyte sedimentation rate, the C-reactive protein, the disease activity score for 28 joint indices and the volume of the enhancing inflammatory tissue was observed. All but two of the rheumatoid arthritis patients achieved the American College of Rheumatology 20% response criteria, while 9 (56.25%) and 5 (31.25%) patients achieved the 50% and 70% American College of Rheumatology response criteria, respectively. A positive correlation among the volume of the enhancing inflammatory tissue, swollen joint count, tender joint count, as well as disease activity score for 28 joint indices (r=0.66, r=0.79, r=0.57 respectively) was found before treatment. CONCLUSIONS: In refractory rheumatoid arthritis patients, the addition of infliximab therapy may result in clinical, laboratory and magnetic resonance imaging improvement. Magnetic resonance imaging assessment of the volume of the enhancing inflammatory tissue may represent an additional tool for the investigation of joint disease activity and responsiveness to treatment.

Adult↗

PubMed2005

Radiological cervical spine involvement in patients with rheumatoid arthritis: a cross sectional study.

OBJECTIVE: To investigate the frequency and the severity of radiological cervical spine involvement in patients with rheumatoid arthritis (RA). METHODS: We investigated 165 consecutive unselected patients with RA who fulfilled the revised American College of Rheumatology criteria for RA. All patients had a complete physical and laboratory evaluation. Patients had a radiological evaluation that included hand and wrist radiographs, as well as cervical spine radiographs in anteroposterior, lateral, and lateral in full flexion views. Hand radiographs were evaluated according to the Larsen criteria, while cervical radiographs were evaluated according to Winfield classification. RESULTS: There were 143 women and 22 men, with a mean age of 59.6 +/- 12.5 and disease duration 12.3 +/- 13.9 years. Positive rheumatoid factor was found in 63.6% of patients. One hundred forty-six patients presented radiological findings related to cervical spine involvement: atlantoaxial subluxations were found in 20.6% and erosions of the odontoid process in 2.4%; none presented vertical subluxation. Subaxial subluxations were found in 43.6%, disc space narrowing at C2-C3, C3-C4, C4-C5 levels in 66.1%, and vertebral plate sclerosis and erosions in 43.6%. CONCLUSION: Cervical spine radiological involvement is a frequent finding in our patients with RA, but the severity of the disease is rather mild, possibly related to the ethnic background.

Aged↗

PubMed2004

Pituitary gland signal in pre-term infants during the first year of life: an MRI study.

Our purpose was to determine the pituitary gland signal of premature neonates and infants. We retrospectively measured, in a midline sagittal T1-weighted MRI scan, the pituitary signal of 121 premature infants (mean gestational age: 32.8 weeks, mean chronological age: 6.9 months, mean corrected age: 5.2 months). The relative signal intensity of the adenohypophysis and neurohypophysis was measured as (A-V)/V and (P-V)/V, respectively (where A, P, V are the mean signal intensities of the adenohypophysis, neurohypophysis and vermis white matter, respectively). On visual inspection the adenohypophysis was rated relative to the vermis white matter (VWM) and scored as hyperintense (grade 3), isointense (grade 2) and hypointense (grade 1). (A-V)/V and (P-V)/V had a negative correlation with chronological age (r=-0.38, r=-0.35, respectively, P<0.01) and corrected age (r=-0.42, r=-0.40, respectively, P<0.01). The (A-V)/V was different in the three grade groups; significant difference was found between grades 3 and 2 and grades 3 and 1. The adenohypophysis was bright in 93% of babies under 2 months of chronological age. In five babies of mean gestational age 29.1 weeks a hyperintense adenohypophysis was observed at 2.9-3.7 months of chronological age (corrected age 0.37-2 months). We conclude that in pre-term babies the adenohypophysis appears in hypersignal that may persist up to 2 months of corrected age. The adenohypophyseal and neurohypophyseal signals decrease with age.

Age Factors↗

PubMed2003

Spontaneous intracranial hypotension: morphological findings and CSF flow dynamics studied by MRI.

We report on a case of spontaneous intracranial hypotension (SIH) presenting with classic MR findings, such as diffuse smooth thickening and intense contrast enhancement of the dura matter, increased size of the pituitary gland and downward displacement of the brain. In this case an engorgement of the cavernous sinuses is reported as an additional imaging finding of SIH. Moreover, phase-contrast MR study of the CSF flow dynamics revealed at the level of the aqueduct a decrease of the systolic and diastolic flow volume of CSF. A normalization of the flow volume was observed when SIH subsided.

Adult↗

PubMed2002

MRI of the liver and the pituitary gland in patients with beta-thalassemia major: does hepatic siderosis predict pituitary iron deposition?

Our objective was to study, in thalassemic patients, if hepatic siderosis evaluated by MRI could predict the pituitary iron overload. In 36 thalassemic patients (age range 6-44 years, mean age 21.7 years) the liver/fat ratio (L/F), the pituitary/fat ratio (P/F), the liver and pituitary T2 relaxation times were evaluated, by using a multiecho spin-echo sequence. Serum ferritin levels were measured and an extensive endocrine evaluation was performed. The L/F, the P/F and pituitary T2 showed a good correlation with serum ferritin ( r=-0.55, r=-0.55 and r=-0.53, respectively; p<0.01). Liver T2 did not show significant correlation with serum ferritin. The variability of L/F explained only the 10.8% of the variability of pituitary T2 and of the P/F. When ferritin was added to the model it predicted only the 26.85% and the 30.8% of the variability of pituitary T2 and of the P/F, respectively. The P/F and pituitary T2 were lower in patients with hypogonadotropic hypogonadism (group 1) compared with those without pituitary dysfunction (group 2). No significant differences of L/F were found between the two groups. Hepatic iron overload evaluated by MR is a poor predictor of pituitary siderosis. The MR studies of the pituitary gland might be necessary to evaluate the pituitary iron overload.

Adolescent↗

PubMed2002

Loss of FEV1 in cystic fibrosis: correlation with HRCT features.

The purpose of this study was to determine which high-resolution computed tomography (HRCT) features in patients with cystic fibrosis are most strongly associated with functional impairment as expressed by forced expiratory volume in one second (FEV1). Forty-seven patients with cystic fibrosis underwent chest HRCT and had pulmonary function tests. The HRCT examinations were evaluated for 11 features scored using a modification of Bhalla system and FEV1 was recorded as percentage of the predicted value. Univariate and multivariate correlations between HRCT scores and FEV1 were performed. The most common HRCT feature was bronchiectasis (98%) followed by atelectasis-consolidation (81%), bronchial wall thickening (77%), tree-in-bud sign (74%), mucous plugging (72%) and mosaic perfusion pattern (47%). On univariate analysis the following features correlated strongly with FEV1: bronchial wall thickening ( p<0.0000001), tree-in-bud sign ( p<0.0000001), mucous plugging ( p<0.0000001), atelectasis-consolidation (p<0.0000001), thickening of interlobular septa ( p<0.0002), severity ( p<0.0002) and extent of bronchiectasis ( p<0.0002). On multivariate analysis bronchial wall thickening and atelectasis-consolidation were the strongest independent determinants of the FEV1. We found a regression equation between FEV1 and the two HRCT features: FEV1=constant variable+a multiplied by bronchial wall thickening+b multiplied by atelectasis-consolidation (a and b=regression coefficients, R(2)=0.48). The major morphological determinants of functional abnormality in cystic fibrosis, as expressed by the loss of FEV1, are bronchial wall thickening and atelectasis-consolidation.

Adolescent↗

PubMed2002

Familial intussusception.

Intussusception, although a common cause of emergency in pediatric surgery, occurs rarely in more than one member in the same family. A genetic predisposition has been suggested in some cases. The authors report on 4 members of a family in 3 generations who suffered each an episode of idiopathic ileocolic intussusception over a period of 52 years. This is the only instance we found after reviewing 99 cases of intussusception in our hospital during the last 10 years. There was no recurrence of intussusception in any case, and no underlying anatomic abnormality was found in the 2 patients who underwent surgery.

Colonic Diseases↗

PubMed2002

The clinical significance of aortic compliance and its assessment with magnetic resonance imaging.

The biophysical properties of the aortic wall seems to play a significant role in the pathogenesis of cardiovascular disease such as atherosclerosis, hypertension, aneurysm formation, Marfan's syndrome, and in normal aging. The presence and the proportion of smooth muscle, collagen, and elastin proteins contribute to the compliance of the vessel wall with the latter being the most extensible component. However, elastin fibers fracture at low stresses contributing to a decrease of the aortic compliance and consequently to an elevation of the pulse pressure, which is a risk factor of cardiovascular disease. Early detection of a decrease in the aortic compliance could help to identify early cardiovascular disease in asymptomatic patients and monitor the results of the therapeutic interventions. Therefore, estimation of the aortic compliance can be used for both screening as well as long-term follow-up. Magnetic resonance imaging which is a noninvasive, accurate, and reproducible method can estimate the compliance of the aortic wall either by measuring the relative change in cross sectional area of a chosen segment using ECG-triggered spin echo or gradient echo sequences or by measuring the pulse wave velocity through the aorta using the phase contrast-magnetic resonance imaging (PC-MRI) technique. Both techniques have been validated and many sudies suggest MRI as a valuable tool for evaluating aortic wall function. However, large prospective studies are mandatory for the method to be established as a screening tool.

Aorta↗

PubMed2001

The multistep process of hepatocarcinogenesis in cirrhosis with imaging correlation.

Hepatocarcinogenesis in the cirrhotic liver has recently become a subject of intense investigation. The development of hepatocellular nodules demonstrating varying degrees of cellular and architectural atypia suggests that these nodular lesions represent a pathway of carcinogenesis in cirrhosis of different etiologies. This pathway involves processes, such as capillarization and neoangiogenesis, leading to a gradual change in blood supply from portal to arterial, as a dysplastic nodule becomes hepatocellular carcinoma. These changes in intranodular blood supply create different enhancement patterns in the two phases of liver circulation after an intravenous contrast injection on multi-phase helical CT or dynamic gadolinium-enhanced MRI. This article reviews the current concepts regarding the vascular changes occurring in dysplastic nodules in the multistep process of hepatocarcinogenesis, along with the associated imaging manifestations. Some practical issues and dilemmas regarding the follow-up and biopsy of these lesions are also discussed.

Carcinoma, Hepatocellular↗

PubMed2001

Cyclic voiding cystourethrography: is vesicoureteral reflux missed with standard voiding cystourethrography?

Vesicoureteral reflux (VUR) may occur intermittently and cyclic voiding cystourethrography (VCUG) can enhance the ability of the method to detect reflux. We undertook this prospective study to assess how often VUR may occur intermittently during VCUG and to evaluate the reliability of the method by performing cyclic VCUG. Two hundred seventy-five children younger than 2 years underwent two cycles of VCUG. Ninety-seven refluxing kidney-ureter units (KUU) from 68 children were identified during the two cycles. In 18 children VUR was demonstrated in the first, and in 50 children only in the second, cycle. Discrepancy between the two cycles regarding the presence and/or grade of VUR was observed in 85 KUU from 63 of 275 children (23%). In 21 of these 63 children VUR was > or = grade III. In the presence of reflux in the first cycle, discordant findings in the second cycle were found in 11 of 23 KUU (48%) or in 13 of 18 children (72.2%). In the absence of VUR in the first cycle, the second cycle disclosed reflux in 50 of 257 children (19.5%). In conclusion, intermittent VUR occurred in up to 23% of children undergoing VCUG. In more than one-third of them VUR was of major degree. Cyclic VCUG can enhance the ability of the method to detect and grade reflux.

Child, Preschool↗