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Biomedical subjects

A Kurjak

Publications and source records attributed to A Kurjak.

At least 37 records · Page 2Linked to original sources
PubMed2000

Three-dimensional ultrasonographic and power Doppler characterization of ovarian lesions.

OBJECTIVE: To determine whether three-dimensional ultrasound (3D US) and 3D power Doppler can improve the ability to differentiate benign from malignant ovarian lesions. METHODS: Transvaginal ultrasound, transvaginal color Doppler, 3D US and 3D power Doppler were performed on 90 patients with ovarian lesions during the week prior to surgery. Four independent sonographers were blinded to the results of other ultrasound studies. RESULTS: Color Doppler studies added to transvaginal gray-scale characterization of ovarian lesions resulted in sensitivity of 88.89% and specificity of 97.53% in diagnosing ovarian malignancy. Qualitative analysis of tumor vascularity by 3D power Doppler added to morphological features obtained by 3D US is clinical pertinent and reached sensitivity and specificity of 100 and 98.76%, respectively. CONCLUSION: Three-dimensional ultrasound and power Doppler can enhance and facilitate the morphologic and functional evaluation of both benign and malignant ovarian lesions. Introduction of the 3D quantitative technique for measurements of blood flow and vascularization may increase clinical relevance of these studies.

Adolescent↗
PubMed2000

Three-dimensional sonography in prenatal diagnosis: a luxury or a necessity?

Three-dimensional sonography revolutionized ultrasound imaging with its capacity to depict an unlimited number of planes in which the object of interest can be displayed. The addition of numerous modalities of image rendering promotes three-dimensional sonography to the top of the spectrum of diagnostic imaging in obstetrics and gynecology. The aim of this article is to present our experience in 3-D sonography during the second and third trimester of pregnancy and to give a comparative review of literature. 247 patients in gestational age ranging from 12 to 40 weeks of gestation were examined over a three year period. The majority of patients entered the study because fetal anomaly was suspected at two-dimensional sonography. Some patients were sent on to three-dimensional sonography because it was not possible to depict clearly normal fetal anatomy by two dimensional sonography. Out of 170 fetal anomalies three-dimensional sonographic analysis failed in only three cases. In all three anomaly was accompanied with severe oligohydramnios. Main advantages of three-dimensional ultrasound in perinatal medicine and antenatal diagnosis include scanning in the coronal plane, improved assessment of complex anatomic structures, surface analysis of minor defects, volumetric measuring of organs, "plastic" transparent imaging of fetal skeleton, spatial presentation of blood flow arborization and, finally, storage of scanned volumes and images. It is our decided opinion that three-dimensional sonography has gained a valuable place in prenatal diagnosis, becoming a necessity for every modern perinatal unit.

Congenital Abnormalities↗
PubMed2000

Vascular impedance of uterine, inferior vesicle, and ophthalmic arteries in postmenopausal women receiving hormonal replacement therapy: comparative Doppler study.

AIM: To investigate the effects of combined hormone replacement therapy (HRT) on vascular impedance of the uterine, the inferior vesicle, and the ophthalmic arteries. METHODS: Thirty-five postmenopausal patients were divided in two groups: 21 patients with 1-5 years of menopause and 14 patients with =6 years of menopause. Each group was examined in basal condition and after 1, 3, and 6 months of HRT. Blood flow impedances of the uterine, the inferior vesicle, and the ophthalmic arteries were analyzed by color Doppler. Estradiol plasma concentrations were assayed on the day of Doppler examination. RESULTS: Analysis of the uterine and inferior vesicle arteries flow velocities showed a significant positive correlation between the resistance index (RI) and years of menopause. Higher impedance values were found in patients with longer menopause duration (p<0.05). In patients with =6 years of menopause, impedances of the uterine and the inferior vesicle arteries were 0. 94+/-0.03 and 0.91+/-0.04, respectively, whereas in patients with 1-5 years of menopause impedances were 0.89+/-0.04 and 0.98+/-0.02, respectively. We noticed no significant correlation between baseline RI and duration of menopause at the level of the ophthalmic artery in either group (0.72 vs. 0.73, respectively; p<0.05). After six months of HRT, plasma estradiol concentrations inversely correlated with RI of the uterine (r=0.2556; p=0.021), the inferior vesicle (r=0.2653; p=0.023), and the ophthalmic (r=-0.2211; p=0.017) arteries. CONCLUSION: Doppler studies of the uterine, the inferior vesicle, and the ophthalmic arteries can provide specific and precise pathophysiological information to assess blood flow variations in correlation with combined HRT.

Analysis of Variance↗
PubMed2000

What do contrast media add to three-dimensional power Doppler evaluation of adnexal masses?

AIM: To investigate the potential usefulness of contrast-enhanced three-dimensional (3D) power Doppler sonography in the differentiation of benign and malignant adnexal lesions. METHODS: Thirty one patients with complex adnexal lesions of uncertain malignancy at transvaginal B-mode and/or color Doppler sonography were prospectively evaluated with three-dimensional power Doppler sonography before and after injection of a contrast agent. Presence of a penetrating pattern and a mixed penetrating and/or peripheral pattern suggested adnexal malignancy. The results were compared with histopathologic findings. RESULTS: There were 10 cases of ovarian malignancy and 21 benign adnexal lesions. Of 10 ovarian cancers, 6 showed vascular distribution suggestive of malignancy at nonenhanced 3D power Doppler sonography. After injection of contrast agent, a penetrating vascular pattern and/or mixed penetrating and peripheral pattern were detected in all cases of ovarian malignancy as well as in 2 benign lesions (fibroma and cystadenofibroma), which were misdiagnosed as malignant. The use of contrast agent with three-dimensional power Doppler sonography showed diagnostic efficiency of 96.7%, superior to that of nonenhanced 3D power Doppler sonography (93.5%). CONCLUSION: Contrast-enhanced 3D power Doppler sonography provides better visualization of tumor vascularity in complex adnexal masses. If used together with 3D morphological ultrasound assessment, enhanced 3D power Doppler imaging may precisely discriminate benign from malignant adnexal lesions.

Adnexa Uteri↗
PubMed1999

First trimester malformation screening.

First trimester fetal malformation screening still represents a diagnostic challenge in modem obstetrics. Being solely dependent on ultrasound instrumentation, and the skill and experience of the operator, recently improved by introducing high frequency transvaginal approach and digital image processing. This opens a new field of ultrasound in obstetrics called sonoembriology. Until now sonoembriology in routine clinical practice resulted in numerous reports about early detection of rare anomalies and uncommon syndromes. The reported sensitivity of sonoembriology with a respect to a final pregnancy outcome was more than 60% of all malformations in total, while in combination with ultrasound screening in second trimester, increases to in excess of 80%. The commonest anomalies detected by sonoembriology are anomalies of the head and brain, heart, abdominal wall, unbilical cord, urinary tract and skeleton. There is an important role of sonoembriology in the assessment of the nuchal translucency in the screening programme for chromosomal anomalies. This changes the well-known concept "fetus as a patient" to "embryo as a patient" and opens new frontiers in fetal diagnosis and therapy.

Congenital Abnormalities↗
PubMed1999

Ultrasonic markers of fetal chromosomal abnormalities.

OBJECTIVE: The aim of this brief investigation was to correlate the most common sonographically detectable markers with certain type of chromosomal disorder diagnosed by available karyotyping procedures. STUDY DESIGN: During the 3 year study period fetal karyotyping was performed in 1055 patients for a variety of clinical indication. Twenty one percent (21%; 222/1055) of procedures were done because of sonographically detectable structural disorders related to phenotype expression of chromosomopathies. Sonographic examinations and karyotyping procedures were performed between the 10th and 36th week. The average maternal age was 27 years, unselected. RESULTS: The fetal karyotype was abnormal in 13.5% of cases (30/222). Within the group of single marker, 11.6% (7/60) of karyotypes were abnormal. Multiple markers of chromosomal abnormalities resulted in 14.2% (23/162) of abnormal karyotypes. The most frequent chromosomal disorder detected in sonographic screening is trisomy 18 (50%; 15/30). The data on the frequency of different types of chromosomal abnormalities are given. CONCLUSIONS: The incidence of chromosomal abnormalities for ultrasonographically detectable malformations is much higher than the incidence reported in screening studies based on maternal age or biochemical screening. Trisomy 21 showed the relative lack of variety in phenotypic expression, and nuchal translucency screening has to be accepted rationally. Associated numerous major and minor malformations were the most prominent factors leading to the diagnosis of chromosomopathies, particularly trisomy 18.

Adolescent↗
PubMed1999

Volume and vascularity of the yolk sac studied by three-dimensional ultrasound and color Doppler.

The aim of our study was to assess the volume of the gestational sac and yolk sac throughout the first trimester of pregnancy, and to establish the relationship between the yolk sac volume measurements and vascularity visualization rates. Eighty women with uncomplicated singleton pregnancies between 5 and 12 weeks were evaluated by three-dimensional and color Doppler ultrasound (Combison 530, Kretztechnik). Regression analysis revealed exponential rise of the gestational sac volume with gestational age throughout the first trimester. An exponential rise of the yolk sac volume was noticed between gestational weeks 5 and 8, followed by gradual increase of the yolk sac volume between the gestational weeks 8 and 10. After reaching the plateau from 10 to 11 weeks, yolk sac volume started to decrease. The highest visualization rates for the yolk sac vessels were obtained between gestational weeks 7 and 8. When yolk sac reached the maximum size between 10 and 11 weeks, reduced vascularity was demonstrated. Three-dimensional ultrasound allowed estimation of the gestational sac and yolk sac volumes throughout the first trimester of pregnancy. Both of these measurements seem to be useful prognostic parameters for the pregnancy outcome. The combination of functional and volumetric data provides much useful information on early human development.

Female↗
PubMed1999

Three-dimensional transvaginal ultrasound improves measurement of nuchal translucency.

The aim of the study was to correlate intra-observer reproducibility of the nuchal translucency measurements by two-dimensional and three-dimensional transvaginal ultrasound. Examinations were performed on 120 women undergoing ultrasound screening at 10 to 14 weeks' gestation. They were examined by two experienced ultrasonographers using both methods two times consecutively. Statistical analysis for the assessment of intra-observer reproducibility was paired t-test. Nuchal translucency measurements were obtained in 100% of cases with three-dimensional sonography compared to only 85% with two-dimensional sonography. Better intra-observer reproducibility was obtained for three-dimensional than for two-dimensional ultrasound. Three-dimensional transvaginal ultrasound improves accuracy of nuchal translucency measurement allowing appropriate mid-sagittal section of the fetus and clear distinction of the nuchal region from the amniotic membrane.

Adult↗
PubMed1999

The study of morphology and circulation of early embryo by three-dimensional ultrasound and power Doppler.

Three-dimensional (3-D) ultrasound plays an important role in obstetrics predominantly for assessing fetal anatomy. Presenting volume data in a standard anatomic orientation assists both ultrasonographers and pregnant patients to recognize anatomy more readily. Three-dimensional ultrasound is advantageous for the study of normal embryonic and/or fetal development, as well as providing information for families at risk for specific congenital anomalies by confirming normality. This method offers advantages in assessing the embryo in the first trimester as it is able to obtain multiplanar images through endovaginal volume acquisition. Rotation of the embryo and close scrutiny of the volume allow the systematic review of anatomic structures such as cord insertion, limb buds, cerebral cavities, stomach and bladder. Using this modality one can easily obtain the volumes of the gestational sac and yolk sac and can evaluate their relationship to prediction of pregnancy outcome. Three-dimensional power Doppler sonography has the potential to study process of placentation and evaluate the development of the embryonic and fetal cardiovascular systems. Three-dimensional ultrasound imaging in vivo compliments pathologic and histologic evaluation of the developing embryo, giving rise to a new term: 3-D sonoembryology. Rapid technological development will allow real-time 3-D ultrasound to provide improved and expanded patient care on the one side, and increased knowledge of developmental anatomy on the another.

Female↗
PubMed1999

Are color and pulsed Doppler sonography safe in early pregnancy?

Diagnostic ultrasound has been used for many years with a remarkable history of safety during the standard clinical practice. Introduction of color and pulsed Doppler modes resulted with higher levels of transmitted and absorbed ultrasonic energy. This fact raised the question for the safety of its use in early pregnancy. This article presents the pros and contras regarding the safety and summarized actual guidelines and safety limits suggested and prescribed by several instances that supervise the use of ultrasound in medicine (WFUMB, ECMUS, ECURS, AIUM/NEMA). In addition, different clinical and experimental applications of Doppler ultrasound in early pregnancy are discussed regarding the safety limits. Generally, there are no strictly defined limits for the use of Doppler ultrasound in the early pregnancy. However, there is an unequivocal demand for carefulness that is best expressed by the ALARA principle. The prudent use of Doppler takes into account benefits against the possible theoretical risks, rather than prohibiting clinically useful technology or applications.

Female↗
PubMed1999

Three dimensional ultrasound and power doppler in assessment of uterine and ovarian angiogenesis: a prospective study.

AIM: To determine whether three-dimensional power Doppler can improve the recognition of pelvic tumor morphology and angiogenesis. METHODS: Using this technique we analyzed 180 adnexal masses and 110 uterine lesions. Tumor volume, morphology, and vascularity were evaluated in each patient. Irregular and randomly dispersed vessels with complex branching depicted by comprehensive three dimensional display were suggestive of pelvic malignancy, while linear-like vascular morphology, single vessel arrangement and regular branching were typical for benign structures. RESULTS: Addition of qualitative analysis of vascular architecture of adnexal tumor to morphological parameters reached 96.15% sensitivity and 98.73% specificity. When endometrial lesions were prospectively analyzed, sensitivity and specificity were 91.67% and 98.49%, respectively. Because the lowest positive predictive value of 16.67% was obtained for myometrial lesions, this method should not be advised for their eva luation. CONCLUSION: Good results achieved by three dimensional ultrasound can be explained by improved recognition of the pelvic lesion anatomy, characterization of the surface features, detection of the tumor infiltration, and precise depiction of the size and volume. Three dimensional power Doppler imaging can detect structural abnormalities of the malignant tumor vessels, such as arteriovenous shunts, microaneurysms, tumoral lakes, disproportional calibration, coiling, and dichotomous branching. Therefore it enhances and facilitates the morphologic and functional evaluation of both benign and malignant pelvic tumors.

Adnexa Uteri↗
PubMed1999

Prenatal diagnosis of spinal muscular atrophy type I (Werdnig- hoffmann) by DNA deletion analysis of cultivated amniocytes.

AIM: Presentation of a prenatally diagnosed case of Werdnig-Hoffmann disease, the most severe type of spinal muscular atrophy. METHODS: DNA obtained from cultivated amniocytes was analyzed for deletions in the survival motor neuron gene and neuronal apoptosis inhibitory protein gene. RESULTS: The fetus was diagnosed as an affected homozygote for deletions in exon 7 and exon 8 of the survival motor neuron gene. No deletions of exon 5 in the neuronal apoptosis inhibitory protein gene were found. CONCLUSION: Direct DNA deletion analysis of the survival motor neuron gene and neuronal apoptosis inhibitory protein gene in affected families represents a highly reliable and fast method for prenatal diagnosis of Werdnig-Hoffmann disease.

Adult↗
PubMed1999

[Study of intervillous blood circulation using color and pulsed doppler ultrasound].

Studies of the formation and hemodynamics of intervillous circulation aroused great scientific interest in the past few years. The reason for this is development of the technology of color Doppler ultrasound, which can non-invasively in vivo follow-up changes in intervillous circulation during all three trimesters of gestation. The results of Doppler ultrasound measurements have been compared to histological and embryological findings. Different experimental findings and theories induced intensive scientific discussions about the timing of the formation of intervillous circulation, as well as about possible significance of hemodynamic changes in physiological and pathological processes in early and late gestation. In this review article we tried to acquaint the broader professional readership with this interesting subject, and to present our results and viewpoints after several years of the study of intervillous circulation with color Doppler.

Chorionic Villi↗
PubMed1998

Ultrasound screening for fetal anomalies in developing countries: wish or reality?

The main problems related to the screening of fetal anomalies in developing countries do include general ones of limited resources for health care and specific ones related to ultrasonographic practice, education, and instrumentation. The strategy to improve the detection of fetal anomalies is reliable, but has to be targeted to the following cornerstones: maintenance of obligate minimum of quality in perinatal care, establishment of three ultrasonographic examinations as a basic prerequisite of antenatal care, enhanced importance of first trimester screening, and a uniform program of education of sonographers, emphasizing the standardization of basic examination. Because of limited resources for perinatal care, we have to be highly responsible in selection of echographic instrumentation and appropriate education, subject to rigorous cost-benefit analysis.

Algorithms↗
PubMed1998

Preoperative diagnosis of primary fallopian tube carcinoma.

INTRODUCTION: Transvaginal color and pulsed Doppler can detect areas of neovascularization within the tubal carcinoma and can distinguish it from other benign adnexal pathology. SUBJECTS AND METHODS. During a 7-year period eight cases of Fallopian tube carcinoma were detected using transvaginal color and pulsed Doppler. RESULTS: Transvaginal sonography revealed complex, sausage-shaped, and/or cystic structures in the adnexal region. Additional color Doppler examination depicted low vascular impedance (RI ranged from 0.29 to 0.40). Histopathology reported different types of Fallopian tube carcinoma. CONCLUSION: Transvaginal color Doppler may aid in diagnosis of Fallopian tube malignancy more reliably than using other costly diagnostic procedures.

Adenocarcinoma↗