Duplication 6q22-->qter: definition of the phenotype

Color Doppler sonographic detection of tumor flow within superficial melanoma metastases was investigated to determine if tumor size, vessel size, or vessel number influences signal detection. Color Doppler imaging of 32 pathologically proved melanoma metastases was performed at 6 MHz with color Doppler imaging parameters optimized for each lesion scanned. All lesions were measured in three dimensions and the presence or absence of internal flow was documented. Seven surgically excised metastases underwent immunohistochemical staining for endothelial markers. Internal flow was detected in 21 of 32 masses and was completely absent in 11. In comparison to all masses without flow, the masses with flow had significantly greater anteroposterior dimensions (P < 0.00036) and volumes (P < 0.01). Histologically, mean vessel diameter in masses with flow was significantly greater (P < 0.05) than in those without flow, but mean vessel number was not significantly different. In conclusion, detectability of tumor blood flow in superficial melanoma metastasis may be related more to tumor size and vessel size than vessel number. Failure to detect color signal within a superficial melanoma mass does not indicate a lack of internal vascularity.     

The 3D and 2D color flow display of breast masses

A prospective study was performed in 24 women with breast masses on mammography going on to surgical biopsy. 2D and 3D power mode and frequency shift color flow Doppler scanning and display were compared. Vessels were displayed as rotatable color volumes in 3D, superimposed on gray-scale slices. The latter were stepped sequentially through the imaged volume. Radiologists rated the masses in each display (3D, 2D and videotapes) on a scale of 1 to 5 (5 = most suspicious) for each of six conventional gray-scale and six new vascular criteria. Thirteen masses proved to be benign and 11 were malignant. 3D provided a stronger subjective appreciation of vascular morphology and allowed somewhat better ultrasound discrimination of malignant masses than did the 2D images or videotapes (specificities of 85%, 79% and 71%, respectively, at a sensitivity of 90%). Only in 3D did the vascularity measures display a trend towards significance in this small study.     

Virulence and colonization-associated properties of Helicobacter pylori isolated from children and adolescents

OBJECTIVE: We describe the sonographic appearance and vascularization of hemangiomas and determine if vessel density and peak systolic Doppler shifts distinguish hemangiomas from other superficial soft-tissue masses. SUBJECTS AND METHODS: Our pilot study included 20 infants and children with hemangiomas who were to undergo biopsy before treatment with interferon alpha-2b. We used Doppler sonography to determine the number of vessels per square centimeter, peak arterial Doppler shift, resistive index, and signs of arteriovenous shunting. All hemangiomas showed high vessel density (more than five per square centimeter) and high Doppler shifts (more than 2 kHz), and these two factors became our diagnostic criteria. A prospective study of 116 patients was then carried out. One hundred sixteen consecutive pediatric patients with superficial soft-tissue masses were examined using Doppler sonography; sonographic findings were compared with the final diagnoses that were established by biopsy, CT, or clinical follow-up. RESULTS: The final diagnoses included 70 hemangiomas, 20 venous malformations, three arteriovenous malformations, three arteriolocapillary malformations, and 20 other masses. Fifty-nine lesions showing high vessel density (more than five per square centimeter) and a peak arterial Doppler shift exceeding 2 kHz were correctly diagnosed as hemangiomas (sensitivity, 84%; specificity, 98%). One arteriovenous malformation showed high vessel density and high Doppler shifts, but none of the other masses that were not hemangiomas did. Eleven patients with hemangiomas who were being treated with interferon at the time of the study fulfilled only one of the two diagnostic criteria. CONCLUSION: High vessel density and high peak arterial Doppler shift can be used to distinguish hemangiomas from other soft-tissue masses.     

Genetic analysis of the glucose-6-phosphate dehydrogenase deficiency in a southern Croatia

PURPOSE: To evaluate objectively the effects of a microbubble contrast agent on the color Doppler ultrasound (US) examination of breast lesions. MATERIALS AND METHODS: Forty-seven patients aged 23-71 years underwent color Doppler US before and after intravenous injection of a microbubble contrast agent. A 3-minute computer-assisted assessment of the color pixel density (CPD) was used to evaluate objectively the increase in the number of color Doppler US signals, the transit time of the microbubble bolus, and the potential additional differential diagnostic information. RESULTS: Peak CPD at contrast agent-enhanced color Doppler US was 14.3% +/- 8.1 (mean +/- 1 standard deviation) for carcinomas and 9.3% +/- 4.9 for benign lesions (P = .04). The time to peak enhancement was shorter in carcinomas (38 seconds +/- 20) than in benign tumors (71 seconds +/- 48, P = .02). Final CPD was close or equal to baseline values. With the median of 13% for peak CPD as a threshold, the sensitivity for this parameter was 55%, the specificity was 79%, and the accuracy was 62% (P = .04). For a median time to peak of 50 seconds, the sensitivity was 84%, the specificity was 57%, and the accuracy was 76%. CONCLUSION: After microbubble contrast agent injection, carcinomas and benign lesions behave differently in degree, onset, and duration of Doppler US enhancement. High interindividual variability and temporal variations in the Doppler US signal still limit the value of these criteria for prospective diagnosis.     

Ovarian torsion in prepubertal and pubertal girls: sonographic findings

OBJECTIVE: The purpose of this study is to report the range of gray-scale and color Doppler findings of ovarian torsion in prepubertal and pubertal girls to determine whether there is a difference in appearance between the two age groups. MATERIALS AND METHODS: The study population consisted of 20 patients, 11 who were prepubertal (ages 2 days to 6 years) and nine who were pubertal (ages 12-16 years), who had gray-scale sonograms and surgical confirmation of ovarian torsion. Color Doppler studies were obtained in 14 of 20 patients. All sonograms were reviewed retrospectively by two radiologists with attention to location of the twisted ovary, internal characteristics, and evidence of color Doppler flow. The results were then compared in the prepubertal and pubertal groups. RESULTS: Sonographic findings of torsion in 11 prepubertal patients included complex mass with septations and debris (6/11), cystic mass (1/11), and solid mass with peripheral cysts (4/11). The masses were located in the right lower quadrant (5/11), left lower quadrant (3/11), right adnexa (2/11), and right inguinal canal (1/11). Eight of nine pubertal patients had solid masses, and one had a thick-walled cystic mass. Torsion involved the right ovary in nine patients and the left in 11. Color patterns included central flow (3/14), peripheral flow (6/14), and absence of flow (5/14) and did not correlate with age or gray-scale findings. CONCLUSION: Sonographic findings of ovarian torsion vary with age. Neonates and young children have extrapelvic cystic or complex cystic masses, whereas pubertal girls have predominantly solid masses in an adnexal location. In both groups of patients, color Doppler signal can be documented in many twisted ovaries.     

Triple procedure with phacoemulsification prior to grafting

OBJECTIVE: To evaluate the value of transesophageal color Doppler echocardiography in the diagnosis of intrathoracic masses. METHODS: Twenty patients with intrathoracic masses were examined by transesophageal echocardiography (TEE), including 12 patients with central lung masses and 8 with mediastinal masses. The neoplasms were explored by two-dimensional realtime ultrasonography, Doppler color flow imaging (DCFI) and pulsed Doppler (PD). The results were compared with computed tomography (CT), operative and pathological examination findings. RESULTS: We were able to identify the size, structure (solid or cystic), anatomic relationship, metastatic lymph nodes and venous carcinoembolus of the masses. Furthermore, the hemodynamic data in the vasculature inside the masses were detected. CONCLUSIONS: As a new method, TEE with Doppler technique is not only valuable in differentiating malignant and benign neoplasms but also useful for preoperative evaluation of the mass resectability in patients with intrathoracic neoplasms.     

Temporal variability of vena contracta and jet areas with color Doppler in aortic regurgitation: a chronic animal model study

OBJECTIVE: The purpose of our study was to determine the temporal variability of regurgitant color Doppler jet areas and the width of the color Doppler imaged vena contracta for evaluating the severity of aortic regurgitation. METHODS: Twenty-nine hemodynamically different states were obtained pharmacologically in 8 sheep 20 weeks after surgery to produce aortic regurgitation. Aortic regurgitation was quantified by peak and mean regurgitant flow rates, regurgitant stroke volumes, and regurgitant fractions determined using pulmonary and aortic electromagnetic flow probes and meters balanced against each other. The regurgitant jet areas and the widths of color Doppler imaged vena contracta were measured at 4 different times during diastole to determine the temporal variability of this parameter. RESULTS: When measured at 4 different temporal points in diastole, a significant change was observed in the size of the color Doppler imaged regurgitant jet (percent of difference: from 31.1% to 904%; 233% +/- 245%). Simple linear regression analysis between each color jet area at 4 different periods in diastole and flow meter-based severity of the aortic regurgitation showed only weak correlation (0.23 < r < 0.49). In contrast, for most conditions only a slight change was observed in the width of the color Doppler imaged vena contracta during the diastolic regurgitant period (percent of difference, vena contracta: from 2.4% to 12.9%, 5.8% +/- 3.2%). In addition, for each period the width of the color Doppler imaged vena contracta at the 4 different time periods in diastole correlated quite strongly with volumetric measures of the severity of aortic regurgitation (0.81 < r < 0.90) and with the instantaneous flow rate for the corresponding period (0.85 < r < 0.87). CONCLUSIONS: Color Doppler imaged vena contracta may provide a simple, practical, and accurate method for quantifying aortic regurgitation, even when using a single frame color Doppler flow mapping image.     

A modification of hepatic portoenterostomy (Kasai operation) for biliary atresia

BACKGROUND AND AIMS: The aim of the present study was to compare power Doppler imaging with traditional color Doppler imaging and with contrast enhanced computer tomography in the evaluation of intratumoral vascularity of hepatocellular carcinomas at diagnosis and in response to percutaneous ethanol injection. PATIENTS AND METHODS: Sixteen patients with hepatocellular carcinoma underwent colour Doppler, power Doppler and computed tomography at diagnosis. Seventeen patients were studied by the three techniques one month after percutaneous ethanol injection treatment. RESULTS: At baseline evaluation, power Doppler and color Doppler were always in agreement and, with the exception of one case, were also in agreement with the computerized tomography scan. On the contrary, power Doppler and computerized tomography are more sensitive than color Doppler in the evaluation of residual vascularized tumoral tissue after percutaneous ethanol injection. In 3 patients, residual vascularity was demonstrated only by computerized tomography while color and power Doppler were negative. In another 3 cases, a positive power Doppler signal, with a typical arterial Doppler spectrum, was observed while color Doppler and computerized tomography were negative. In these patients, cancer relapse was clinically evident after a few months and treatment was repeated to obtain complete necrosis. CONCLUSIONS: We conclude that only the integration of the results of all these techniques can reliably evaluate tumoral vascularity after percutaneous ethanol injection.     

Color Doppler signal enhancement with SH/TH-508 in pancreatic tumors

In this report, we showed the efficacy of a new contrast agent (SH/TA-508, Schering AG, Germany) for color Doppler imaging of the pancreatic tumors. In pancreatic ductal cancer, no enhancement of the lesion was observed, but vascular invasion by cancer became to be easily evaluated. On the other hand, hypervascular tumors such as islet cell tumor and cystadenocarcinoma, were increased in color Doppler signals of vessels by SH/TA-508. We concluded that SH/TA-508 was useful for evaluating the vascular invasion by pancreatic cancer as well as vascularity of hypervascular mass and solid component of cystic neoplasma.     

Vascular pathology of malignant cervical lymphadenopathy: qualitative and quantitative assessment with power Doppler ultrasound

BACKGROUND: Malignant vascular pathology has traditionally been studied with invasive angiography or in vitro immunohistochemistry. The objective of this study was to investigate the vascular patterns and vascular density of benign and malignant cervical lymphadenopathy using power Doppler ultrasound combined with a computed quantitative image processing system. METHODS: Investigations of 189 cervical lymph node lesions were undertaken prospectively using a 5-10 MHz linear array transducer in power mode. The types of vascular patterns displayed with power Doppler ultrasound, after sweep-scanning over the whole lymph node, were classified as hilar, spotted, peripheral, or mixed. Quantitative assessment of vascularity was made by sampling three parallel planes of each lymph node. A computed image processing system automatically calculated the density of vascular signals (called the "vascularity index" in this study) within the lymph node plane. RESULTS: Malignant lymph node lesions were shown to have higher vascularity indices (0.169+/-0.147, P < 0.01). The vascular patterns of benign lesions were mostly of avascular or hilar type (in 83% of cases). Malignant lesions were characterized by patterns of mixed (47%), spotted (20%), or peripheral type (11%). When vascular pattern (nonhilar type) and vascularity index (maximum > or = 0.09) were combined, the specificity for diagnosing malignant lymphadenopathy was as high as 97%. Variance in tumor vascularity was noted in both the benign and malignant groups. CONCLUSIONS: Power Doppler ultrasound combined with a computed image processing system provided an objective tool for assessing tumor vascularity quantitatively. Using this modality, the vascular pathology of malignant lymphadenopathy was found to be characterized by higher vascular density and aberrant vascular patterns.     

Septate uterus: detection and prediction of obstetrical complications by different forms of ultrasonography

The aims of the study were to compare the accuracy of transvaginal ultrasonography, transvaginal color Doppler sonography, hysterosonography, and three-dimensional ultrasonography in detection of septate uterus and to evaluate the occurrence of obstetrical complications in relation to septal dimension and vascularity. Each patient underwent transvaginal ultrasonography and color Doppler examination, whereas hysterosonography and three-dimensional ultrasonography were carried out in 76 and 86 patients, respectively. The sensitivity of different sonographic imaging modalities ranges between 95.21% and 99.29%. Color and pulsed Doppler sonographic studies of the septal area revealed vascularity in 71.22%. Patients with vascularized septa had a higher prevalence of obstetrical complications than those with avascularized septa (P < 0.05). Three-dimensional ultrasonography and hysterosonography are highly accurate diagnostic tools for detection of uterine septa. We found no correlation between septal dimension and rate of obstetrical complications, although pregnancy loss was most likely to occur in patients with vascularized septa.     

Disruption of p53 function in immortalized human cells does not affect survival or apoptosis after taxol or vincristine treatment

OBJECTIVE: We assessed the feasibility of contrast-enhanced color Doppler, power Doppler, and spectral duplex sonography for visualization and quantification of flow through transjugular intrahepatic portosystemic shunts (TIPS) in patients in whom the baseline sonographic evaluation was unsatisfactory. SUBJECTS AND METHODS: Thirty-three patients underwent color Doppler, power Doppler, and spectral duplex sonography after TIPS insertion or before TIPS revision (mean time interval +/- SD, 1 +/- 1 day). All sonograms were obtained before and after patients received echo-enhancing contrast material. Sonography was evaluated with regard to presence or absence of flow in the mid portion, portal segment, and hepatic segment of the shunt. The maximal peak velocity was measured in the mid portion of the shunt. For identifying and quantifying stenoses, the percentage of luminal diameter reduction was calculated at the tightest part of the shunt. Shunt angiography and measurements of portosystemic pressure gradients were independently evaluated and compared with the sonographic findings. RESULTS: Flow visualization on unenhanced color Doppler sonography was significantly improved through the use of power Doppler sonography and contrast-enhanced color Doppler and power Doppler sonography (p < .01). Between contrast-enhanced power Doppler and contrast-enhanced color Doppler sonography, a significant difference was found in the portal and hepatic segments (p < .05). All shunt stenoses (n = 8) and occlusions (n = 3) were revealed by power Doppler sonography, whereas color Doppler sonography failed to reveal six of eight stenoses. Compared with unenhanced sonography, the quality of spectral duplex sonography was improved in eight patients after contrast enhancement (p < .05). Maximal peak velocity ranged from 54 to 252 cm/sec (mean +/- SD, 132.7 +/- 52.1 cm/sec) in normal shunts and from 24.5 to 70.0 cm/sec (mean +/- SD, 45.0 +/- 18.9 cm/sec) in stenosed shunts. No correlation was found between maximal peak velocity and portosystemic pressure gradients (r = .28). CONCLUSION: Unenhanced power Doppler and contrast-enhanced color and power Doppler sonography can be helpful in the assessment of TIPS status in patients who previously underwent unsatisfactory sonography. These techniques may allow anatomic evaluation and quantification of shunt stenosis in most patients. Contrast enhancement may also considerably improve the quality of spectral duplex sonography.     

Color Doppler regurgitant jet area for evaluating eccentric mitral regurgitation: an animal study with quantified mitral regurgitation

OBJECTIVES: The purpose of the present study was to rigorously evaluate the accuracy of the color Doppler jet area planimetry method for quantifying chronic mitral regurgitation. BACKGROUND: Although the color Doppler jet area has been widely used clinically for evaluating the severity of mitral regurgitation, there have been no studies comparing the color jet area with a strictly quantifiable reference standard for determining regurgitant volume. METHODS: In six sheep with surgically produced chronic mitral regurgitation, 24 hemodynamically different states were obtained. Maximal color Doppler jet area for each state was obtained with a Vingmed 750. Image data were directly transferred in digital format to a microcomputer. Mitral regurgitation was quantified by the peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions determined using mitral and aortic electromagnetic flow probes. RESULTS: Mean regurgitant volumes varied from 0.19 to 2.4 liters/min (mean [+/- SD] 1.2 +/- 0.59), regurgitant stroke volumes from 1.8 to 29 ml/beat (mean 11 +/- 6.2), peak regurgitant volumes from 1.0 to 8.1 liters/min (mean 3.5 +/- 2.1) and regurgitant fractions from 8.0% to 54% (mean 29 +/- 12%). Twenty-two of 24 jets were eccentric. Simple linear regression analysis between maximal color jet areas and peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions showed correlation, with r = 0.68 (SEE 0.64 cm2), r = 0.63 (SEE 0.67 cm2), r = 0.63 (SEE 0.67 cm2) and r = 0.58 (SEE 0.71 cm2), respectively. Univariate regression comparing regurgitant jet area with cardiac output, stroke volume, systolic left ventricular pressure, pressure gradient, left ventricular/left atrial pressure gradient, left atrial mean pressure, left atrial v wave pressure, systemic vascular resistance and maximal jet velocity showed poor correlation (0.08 < r < 0.53, SEE > 0.76 cm2). CONCLUSIONS: This study demonstrates that color Doppler jet area has limited use for evaluating the severity of mitral regurgitation with eccentric jets.     

Parallel Doppler assessment of yolk sac and intervillous circulation in normal pregnancy and missed abortion

This study assessed yolk sac morphology and vascularity and intervillous blood flow in normal early pregnancy and missed abortion. Transvaginal colour and pulsed Doppler were used in a prospective analysis of 87 normal pregnancies and 48 missed abortions between 6 and 12 weeks gestation. The Kruskal-Wallis rank test was used to calculate the difference in yolk sac diameter and vascularity visualization rate between gestational weeks. Repeated measures analysis of variance was used for comparison of the intervillous circulation between groups. The growth of the yolk sac was considered statistically significant between gestational weeks 6 and 9, being most prominent between 9 and 10 weeks of gestation. Vascularity of the yolk sac, characterized by low velocity and absence of diastolic flow, was demonstrated in 67 per cent of normal pregnancies. Yolk sac blood flow was detected in 19 per cent of the patients with missed abortion. Doppler analysis of the intervillous circulation demonstrated decreased peak velocity of the continuous flow in patients with missed abortion for gestational weeks 11 and 12. It is concluded that progressive decrease of yolk sac vascularity coincides with visualization of more prominent colour-coded areas within the intervillous space. In patients with missed abortion, such changes do not occur.     

Surgical management of thoracic manifestations in human immunodeficiency virus-positive patients: indications and results

PURPOSE: To quantify color Doppler (CD) signals reflected by breast lesions to improve differential diagnosis and serial comparisons. MATERIALS AND METHODS: Frame-grabbed color-capture scans were remapped to original velocities on a pixel-by-pixel basis for statistical analysis. Total CD area and its percentage, peak and mean velocities, standard deviation of velocity, and integral CD velocity and its percentage were calculated. These indexes were applied to scans of 44 cancers, 16 fibroadenomas, and 14 benign breast changes in 74 patients. RESULTS: With the region of interest confined to the lesion and a 5-mm margin, no CD signals were reflected by the benign breast changes. All carcinomas and 12 fibroadenomas (those that were vascular) reflected CD signals, and, except for mean and peak velocity, all scores for cancers were significantly higher than for fibroadenomas (P < .0001). Integral CD velocity was the best discriminator, with no overlap between carcinomas (range, 1,128-50,228 cm3/sec) and fibroadenomas (range, 0-1,027 cm3/sec). CONCLUSION: Automatic CD quantification improved differential diagnosis of breast masses.     

Technetium-99m-MAG3 renal studies in spinal cord injury patients: normal range, reproducibility, and change as a function of duration and level of injury

The normal range, reproducibility, and change as a function of duration and level of injury for Tc-99m-MAG3 renal studies were quantitated in spinal cord injury (SCI) patients. METHODS: Five SCI patients without evidence of renal disease in each of four groups: less than 2 months, 2-12 months, 1-2 years, and greater than 2 years from time of injury, were each studied twice. There were at least two patients with paraplegia and two with tetraplegia in each group. Renal clearance (camera based method), percent function in each kidney, time of peak renal parenchymal activity, and half time of parenchymal activity following the peak were evaluated. The peak and half times were determined with regions of interest (ROIs) over the entire kidney and over just the cortex. All results were compared to normal ranges previously established in normal subjects of the same age range using the same methodology. RESULTS: Renal clearance in the less than 2 month SCI patients was not significantly different from normal subjects in either paraplegic or in tetraplegic individuals. However, clearance in tetraplegics was increased by 28.5% at 2-12 month, increased by 50.6% at 1-2 years, and decreased by 25.9% at greater than 2 years compared to normal subjects (all P < 0.02). Clearance in those with paraplegia showed a similar, but less marked, trend (P = NS). The time of peak parenchymal activity when measured with cortical ROIs did not vary among patient groups or level of injury, but was increased compared to normal subjects (P < 0.05). The percent function in each kidney and half time following the peak were symmetrical, did not differ among patient groups or with level of injury, and did not differ from normal subjects. The parenchymal peak time was significantly shorter with cortical rather than renal ROIs in all patient groups (P < 0.05). In serial studies in the same patient the percent standard deviation in total renal clearance was less than between single studies in different patients, but the decrease was significant for only the right kidney (P < 0.03), and the decrease was not as great as in normal subjects. In addition, the percent standard deviation for percent function in each kidney was significantly less than the percent standard deviations in single studies (P < 0.02). There were no significant differences between intra- and interpatient studies for any other parameter. CONCLUSION: We conclude that: (1) renal clearance measured with Tc-99m-MAG3 in tetraplegic patients increases significantly during the first 2 years following injury and decreases significantly thereafter; there is a similar, but much less marked, trend in paraplegics, (2) parenchymal peak times with cortical ROIs occur later for SCI patients than for normal subjects, and (3) there is more intrapatient variation in total renal clearance and percent renal clearance on a side in SCI patients than in normal subjects suggesting that it may be harder to study SCI patients reproducibly. These findings should be taken into account when performing and interpreting Tc-99m-MAG3 renal studies in SCI patients.     

Intratumoral blood flow in uterine myoma correlated with a lower tumor size and volume, but not correlated with cell proliferation or angiogenesis

OBJECTIVE: To investigate the correlation of intratumoral blood flow in uterine myoma with cell proliferation, angiogenesis, tumor size, and tumor volume. METHODS: Thirty-nine patients who had been scheduled for surgery because of symptomatic uterine myomas were evaluated by transvaginal sonography and color Doppler ultrasound before surgery. The largest dimension of each tumor and the volumes of myomas were determined ultrasonographically. Pulsatility index (PI) was determined by color Doppler ultrasound according to the maximum systolic, end-diastolic, and the mean flow velocities measured within the uterine nodules. After surgery, the paraffin-embedded slides containing representative leiomyoma tissues were stained with hematoxylin and eosin, proliferating cell nuclear antigen for measurement of cell proliferation, and factor VIII for quantitation of microvessel density. The ultrasonographic findings were correlated postoperatively with pathologic findings, and the data were analyzed by simple linear regression and Fisher r to z transformation. RESULTS: Simple regression analysis of the intratumoral PI values on the sizes of myomas showed a negative correlation (r = -0.47, P = .003; n = 39), whereas a less significant correlation between PI values and tumor volumes was observed (r = -0.42, P = .008). In contrast, no statistically significant correlation was observed between the intratumoral PI values and the values of the proliferating cell nuclear antigen index (r = 0.10, P = .547) or microvessel density counts (r = 0.18, P = .282). CONCLUSION: The intratumoral blood flow by transvaginal color Doppler ultrasound correlated with a reduced tumor size and tumor volume, but did not correlate with cell proliferation or angiogenesis.     

Automatic cardiac MR image segmentation using edge detection by tissue classification in pixel neighborhoods

A highly sensitive edge detector has been developed that uses tissue classification of pixels based on analysis of data in their local neighborhoods. In conjunction with recursive region growing, it has been used successfully to define regions of interest (ROI) when applied specifically to gradient echo MR images of the heart. The detector adapts to nonuniformity by carrying out an independent analysis at each location. If two tissues are present in a neighborhood and the pixel at that location cannot be classified with the seed pixel, a region edge has been crossed and recursion is stopped. No geometric assumptions relating to object shape such as definition of a region center and radial search are required. The detector was applied to multi-slice, multi-phase images of the heart from 26 subjects. A segmentation strategy specified slice processing order, graded ROIs, and used successfully detected ROIs to guide subsequent detection. Segmentation of all images resulted in a 90.3% median edge pixel detection efficiency.     

Percutaneous ethanol injection under general anesthesia for hepatocellular carcinoma: 3 year survival in 112 patients

OBJECTIVE: The aim of this study was to determine whether the expression of thymidine phosphorylase by ovarian cancer cells correlates with the density of microvessels within the tumor, and with ultrasound-derived indices of blood flow. METHODS: Transvaginal ultrasonography with color Doppler imaging and pulsed Doppler spectral analysis was used to scan patients with an overt ovarian mass immediately before laparotomy. Sections of malignant tumors were analyzed for the cellular expression of thymidine phosphorylase and the intratumoral density of microvessels by immunohistochemistry using monoclonal antibodies to thymidine phosphorylase and factor VIII-related antigen, respectively. The main outcome measures were the histological classification of the tumor, the stage of the disease, whether or not the tumor cells were positive or negative for thymidine phosphorylase, the microvessel count and the peak systolic velocity (PSV). RESULTS: Forty-two tumors were studied (three of low malignant potential, 29 epithelial, four granulosa cell, two germ cell and four metastatic); 18 were stage I, six stage II, 11 stage III and three stage IV. Twenty-seven tumors (64%) were classified as thymidine phosphorylase-positive. The proportion of stage I tumors that was thymidine phosphorylase-positive (44%) was significantly lower (p = 0.022) than the corresponding value for stages II-IV (85%), but the values for microvessel count and PSV were similar. The microvessel count in thymidine phosphorylase-positive tumors was significantly higher than in thymidine phosphorylase-negative tumors (p = 0.005). Similarly, the PSV was significantly higher in thymidine phosphorylase-positive tumors (p = 0.009). There was a significant correlation between the microvessel count and the PSV (r = 0.354, p = 0.022). CONCLUSIONS: The expression of thymidine phosphorylase by malignant tumor cells is associated with an increase in microvessel density and PSV in patients with ovarian cancer.     

Visualization of tumor vessels in hepatocellular carcinoma. Power Doppler compared with color Doppler and angiography

PURPOSE: To assess the visualization of tumor vessels in hepatocellular carcinoma (HCC) by power Doppler sonography. MATERIAL AND METHODS: We examined 40 patients with 47 HCC lesions by means of power Doppler sonography and compared its visualization of tumor vessels with those of color Doppler and angiography. RESULTS: In 38 (81%) of the 47 lesions, power Doppler sonography improved the visualization of tumor vessels compared with color Doppler sonography; in the remaining lesions no significant difference was noted. In lesions located within 7 cm in depth, there was no significant difference between power Doppler sonography and angiography. In 10 (83%) out of 12 small (< or = 2 cm in diameter) lesions and in 11 (85%) out of 13 hypovascular lesions, power Doppler sonography performed considerably better than angiography. In deeper-seated lesions, however, angiography was significantly superior to power Doppler sonography. CONCLUSION: Power Doppler sonography is more sensitive in detecting the fine tumor vessels in most HCCs than color Doppler sonography. In addition, power Doppler sonography can replace angiography in evaluating tumor vascularity in HCCs except in lesions that are deep-seated or located near the heart. In these lesions, angiography can complement power Doppler sonography in demonstrating tumor vessels.