Evaluation of Cerebral Blood Flow Dynamics in Transient Ischemic Attacks Patients with Fast Cine Phase Contrast Magnetic Resonance Angiography.

Fast cine phase contrast magnetic resonance angiography (PC-MRA) has the potential to provide a quantitative measurement method for the diagnosis and treatment of cerebrovascular disease. To evaluation the changes of cerebral blood flow and the characteristics of artery lesion distribution in the patients of transient ischemic attacks (TIA). In all, 98 normal subjects and 106 TIA patients who underwent MRI examination within 72 h after the last symptom onset including the DWI sequence to exclude acute cerebral infarction were enrolled. The blood flow of the cranial total, the area of the internal carotid artery and vertebral artery, the average velocity, and the average blood flow were obtained and compared in normal subjects and TIA group. Analysis of Variance (ANOVA), t-test, and Kruskal-Wallis test were used for statistical assessments. The total cerebral blood flow of the TIA group and normal control group was no significant statistical difference (P > 0.05). The total blood flow decreased with increasing age, and the TIA group was much lower than the control group. The blood flow of the right internal carotid artery in the TIA group had a significant difference compared with controls (P < 0.05). However, the same situation did not happen in both of the left internal carotid artery and vertebral artery. Phase contrast magnetic resonance imaging has the potential to evaluate the change of cerebral blood flow in TIA patients. The decrease in the total blood flow and the symptom onset of TIA is consistent. Phase contrast magnetic resonance imaging could provide guidance to the diagnosis of TIA.

Angiographically-derived SYNTAX score and its prognostic value in dialysis patients: comparison with the Khan index.

BACKGROUND: The aim of this study was to assess the value of the angiographically-derived Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score in predicting mortality and major adverse cardiac events (MACEs) during a 3-year follow-up of dialysis patients undergoing a percutaneous coronary intervention or coronary artery bypass graft operation. We compared the aforementioned results with the clinical Khan index. METHODS: The SYNTAX score was calculated for 87 of 110 dialysis patients after coronary angiography. RESULTS: The mean SYNTAX score was 12.75 ± 14.49. During the 3-year follow-up, 58% of the patients died, and 74% had at least 1 MACE. In a Kaplan-Meier survival analysis, the risk of death and MACEs increased in parallel with the SYNTAX score. A score greater than 12.75 was strongly associated with mortality and MACE (both Ps < 0.01). In receiver operating characteristic (ROC) curve analysis, the areas under the curves (AUCs) of the SYNTAX score and Khan index were significantly higher (both Ps < 0.001) than the area of diagnostic indifference. The predictive values for death as indicated by the SYNTAX score and the Khan index, respectively, were almost identical in the ROC analysis (AUC SYNTAX score, 0.6436; AUC Khan index, 0.6475; P = 0.9532). Areas under the ROC curves of both methods according to MACE were also significantly different from those for the random model (both Ps < 0.001). CONCLUSIONS: The SYNTAX score is a powerful predictor of mortality and MACEs in dialysis patients undergoing percutaneous coronary intervention or coronary artery bypass graft during a 3-year follow-up. The score provides prognostic information similar to that provided by the Khan index.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy diagnostic task force criteria: impact of new task force criteria.

BACKGROUND: Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) Diagnostic Task Force Criteria (TFC) proposed in 1994 are highly specific but lack sensitivity. A new international task force modified criteria to improve diagnostic yield. A comparison of diagnosis by 1994 TFC versus newly proposed criteria in 3 patient groups was conducted. METHODS AND RESULTS: In new TFC, scoring by major and minor criteria is maintained. Structural abnormalities are quantified and TFC highly specific for ARVD/C upgraded to major. Furthermore, new criteria are added: terminal activation duration of QRS > or = 55 ms, ventricular tachycardia with left bundle-branch block morphology and superior axis, and genetic criteria. Three groups were studied: (1) 105 patients with proven ARVD/C according to 1994 TFC, (2) 89 of their family members, and (3) 39 patients with probable ARVD/C (ie, 3 points by 1994 TFC). All were screened for pathogenic mutations in desmosomal genes. Three ARVD/C patients did not meet the new sharpened criteria on structural abnormalities and thereby did not fulfill new TFC. In 62 of 105 patients with proven ARVD/C, mutations were found: 58 in the gene encoding Plakophilin2 (PKP2), 3 in Desmoglein2, 3 in Desmocollin2, and 1 in Desmoplakin. Three patients had bigenic involvement. Ten additional relatives (11%) fulfilled new TFC: 9 (90%) were female, and all carried PKP2 mutations. No relatives lost diagnosis by application of new TFC. Of patients with probable ARVD/C, 25 (64%) fulfilled new TFC: 8 (40%) women and 14 (56%) carrying pathogenic mutations. CONCLUSIONS: In this first study applying new TFC to patients suspected of ARVD/C, 64% of probable ARVD/C patients and 11% of family members were additionally diagnosed. ECG criteria and pathogenic mutations especially contributed to new diagnosis. Newly proposed TFC have a major impact in increasing diagnostic yield of ARVD/C.

Neonatal doses from X ray examinations by birth weight in a neonatal intensive care unit.

The aim of this study was to investigate the frequency and type of X ray examinations performed on neonates classified according to their birth weight in a neonatal intensive care unit (NICU). In this study, the radiology records of 2408 neonates who were admitted to the NICU of Oita Prefectural Hospital between January 1994 and September 1999 were investigated. This study revealed that the neonates with earlier gestational ages and lower birth weights required longer NICU stays and more frequent X ray examinations made using a mobile X ray unit. The average number of X ray examinations performed on neonates of less than 750 g birth weight was 26 films per neonate. In regard to computed tomography and fluoroscopy, no significant relationship was found between the birth weight and number of X rays. This study revealed that the entrance-surface dose per neonate was dependent upon the birth weight, while the maximum dose was not dependent upon the birth weight. The average neonatal dose in the NICU was predominantly from computed tomography and fluoroscopy. The individual dose varied widely among neonates.

Methodologic drift in the assessment of TIMI grade 3 flow and its implications with respect to the reporting of angiographic trial results. The TIMI Study Group.

BACKGROUND: The Thrombolysis in Myocardial Infarction (TIMI) Study Group originally defined TIMI grade 3 flow (complete perfusion) as antegrade flow into the bed distal to the obstruction that occurs as promptly as antegrade flow into the bed proximal to the obstruction. Recently, several groups have defined TIMI grade 3 flow as opacification of the coronary artery within 3 cardiac cycles. METHODS AND RESULTS: On the basis of heart rate data at the time of the cardiac catheterization and the time for dye to go down the artery (TIMI frame count/30 = seconds), we estimated the number of patients who would meet the 3 cardiac cycle criterion and compared this with the number of patients with TIMI grade 3 flow by using the original definition in 1157 patients from 3 recent TIMI trials (10 A, 10B, and 14). In 74 patients without acute myocardial infarction and normal coronary arteries, the fraction of a cardiac cycle required for dye to traverse the artery was a mean of 0.93 +/- 0.34 cardiac cycles (n = 74) (median 0.80, minimum 0.44, maximum 2.1, none >3.0 cycles). The mean heart rate at 90 minutes after thrombolysis in the TIMI 14 trial was 79.6 +/- 16.8 beats/min (n = 194), and the duration of 3 cardiac cycles was a mean of 2.36 seconds, or a TIMI frame count of 70.8 frames. In all trials, the rate of TIMI grade 3 flow was 57.3% (n = 663/1157) with the original definition and 66.8% (n = 743/1113) with the <3 cardiac cycle definition (P <.001). CONCLUSIONS: A duration of 3 cardiac cycles for dye to traverse the artery lies approximately 6 SD above that observed in normal coronary arteries. A 3 cardiac cycle definition of TIMI grade 3 flow results in rates of normal perfusion that are approximately 10% higher than if the original definition of TIMI grade 3 flow is applied. Application of this simple correction factor may help place data reported with the 3 cardiac cycle definition of TIMI grade 3 flow in context.

Model-based morphological segmentation and labeling of coronary angiograms.

A method for extraction and labeling of the coronary arterial tree (CAT) using minimal user supervision in single-view angiograms is proposed. The CAT structural description (skeleton and borders) is produced, along with quantitative information for the artery dimensions and assignment of coded labels, based on a given coronary artery model represented by a graph. The stages of the method are: 1) CAT tracking and detection; 2) artery skeleton and border estimation; 3) feature graph creation; and iv) artery labeling by graph matching. The approximate CAT centerline and borders are extracted by recursive tracking based on circular template analysis. The accurate skeleton and borders of each CAT segment are computed, based on morphological homotopy modification and watershed transform. The approximate centerline and borders are used for constructing the artery segment enclosing area (ASEA), where the defined skeleton and border curves are considered as markers. Using the marked ASEA, an artery gradient image is constructed where all the ASEA pixels (except the skeleton ones) are assigned the gradient magnitude of the original image. The artery gradient image markers are imposed as its unique regional minima by the homotopy modification method, the watershed transform is used for extracting the artery segment borders, and the feature graph is updated. Finally, given the created feature graph and the known model graph, a graph matching algorithm assigns the appropriate labels to the extracted CAT using weighted maximal cliques on the association graph corresponding to the two given graphs. Experimental results using clinical digitized coronary angiograms are presented.

A new method for evaluating right ventricular dimensions and volume by cineangiography.

The aim of the present study was to establish a new method to evaluate the right ventricular dimensions and volume. Biplane right ventriculography of steep left anterior oblique view (LAO) and right anterior oblique view perpendicular to LAO were performed in 32 patients. The right ventricular volume and ejection fraction calculated from the three axial dimensions of the right ventricular cavity (the septum-free wall dimension, the anterior-posterior dimension, and either the long axis dimension or the tricuspid valve-apex dimension at end-diastole and end-systole) were well correlated to those from Simpson's method. In conclusion, we developed a new method for estimating right ventricular dimensions and volume.

Effects of the intracoronary infusion of cocaine on coronary arterial dimensions and blood flow in humans.

This study was done to assess the influence of large concentrations of cocaine (infused into the left coronary artery) on coronary arterial dimensions and blood flow in humans. In 20 subjects undergoing cardiac catheterization, incrementally increasing doses of (1) saline solution (n = 10, controls) or (2) cocaine hydrochloride (n = 10) were infused into the left coronary artery, and the effects on heart rate, systemic arterial pressure, coronary sinus blood flow, and coronary arterial dimensions were measured. Saline solution induced no change in any variable. With the infusion of cocaine, there was an incremental increase in its concentration in the systemic (femoral arterial) and coronary (coronary sinus) circulations (maximal concentrations, 0.14 +/- 0.06 [mean+/-SD] and 3.50 +/- 0.70 mg/L, respectively). At the maximal cocaine infusion rate, heart rate and diastolic arterial pressure increased slightly, but coronary sinus blood flow and the dimensions of nondiseased and diseased coronary arterial segments did not change. Thus, intracoronary infusion of cocaine in an amount sufficient to achieve a high concentration in the coronary circulation does not induce epicardial coronary arterial vasoconstriction or alter blood flow.

Angiographic determination of left and right ventricular volumes and left ventricular mass in normal infants and children.

Left and right ventricular (LV and RV) volumes and LV mass were assessed by angiography in 63 infants and children without major cardiovascular abnormalities. LV and RV end-diastolic volumes (EDV) were excellently expressed as a function of body surface area (BSA) with an exponential equation: LVEDV = 83.7 (BSA)1.29 ml (r = 0.96, p < 0.001), RVEDV = 87.9 (BSA)1.29 ml (r = 0.94, p < 0.001). LV ejection fraction (EF) averaged 64 +/- 6 (mean +/- standard deviation) %, and RVEF 56 +/- 5%, each of which was independent of BSA. LV mass was well expressed as a function of BSA with an exponential equation: LV mass = 75.4 (BSA)1.22 g (r = 0.86, p < 0.001). LV mass/LVEDV was constant, and averaged 0.96 +/- 0.22 g/ml. Thus, the values of LVEDV, RVEDV, and LV mass in infants and children with various heart diseases may be estimated with reasonable accuracy as a percentage of normal values predicted from their BSA by using the above-proposed exponential equations. The normal values of LVEF, RVEF and LV mass/LVEDV themselves can be compared with these parameters in pediatric patients with heart diseases because of their independence of BSA.

Comparison of gradient echo with spin echo magnetic resonance imaging and echocardiography in the evaluation of major aortopulmonary collateral arteries.

This study compared gradient echo magnetic resonance imaging, spin echo magnetic resonance imaging, echocardiography, and echocardiography with x-ray cineangiography in the evaluation of major aortopulmonary collateral arteries. Twelve patients (ages 9 months to 35 years, mean 11 +/- 11 years) with known or suspected major aortopulmonary collateral arteries were studied. The aortic insertion and proximal course of 29 major aortopulmonary collateral arteries demonstrated by x-ray contrast angiography were shown in all 29 cases by gradient echo magnetic resonance imaging but in only 23 of the 29 cases by spin echo magnetic resonance imaging. Color Doppler-echocardiography detected aortopulmonary collateral arteries in four patients but did not define the proximal course or distal anatomy. Gradient echo images of distal aortopulmonary collateral anatomy were qualitatively superior to spin echo images. The contrast-to-noise ratio between the vessel lumen and adjacent lung was greater for gradient echo (6.06 +/- 2.91) than for spin echo (1.45 +/- 1.13)(p < 0.05). Gradient echo magnetic resonance imaging is a useful method for identification and characterization of aortopulmonary collateral arteries in patients of all ages and is superior to spin echo magnetic resonance imaging and echocardiography.

Optimal sampling interval and edge detection algorithm for measurement of blood vessel diameter on a cineangiogram.

RATIONALE AND OBJECTIVES: The authors studied the effects of image magnification and the type of edge detection filter on the precision of measuring blood vessel diameters on coronary angiograms. METHOD: A blood vessel phantom containing five channels of various diameters filled with contrast medium was filmed. The magnifications examined were x4, x10, and x20, and the edge detection filters used were the first derivative, second derivative, composite, and entropy filters. The regression line y = a+bx was introduced, where x represents the nominal diameter and y the diameter measured by the edge-detection filters. Determination criteria were the offset, slope, and residual variance from the regression equation. RESULTS: The best value among three criteria was obtained with a magnification of x10 or x20. The entropy filter gave the best value of slope and residual variance. The composite filter gave the best value of offset. CONCLUSION: The most precise measurement is obtained when the entropy filter and a magnification of x10 or x20 are applied.

A new method for assessment of collateral development after acute myocardial infarction.

OBJECTIVES: The purpose of this study was to test the hypothesis that the diameter of the recipient coronary artery of the well developed collateral circulation in patients with acute myocardial infarction increases because of the augmented intravascular pressure caused by subsequent collateral development. BACKGROUND: It is well known that collateral circulation develops after acute myocardial infarction. However, some patients have a well developed collateral circulation at the onset of infarction, which may limit the angiographic evaluation of further development of collateral circulation. METHODS: We measured the diameter of the donor and recipient arteries of the collateral circulation by means of a computer-assisted analysis system in seven patients with acute myocardial infarction who had a totally occluded infarct-related coronary artery during the acute and chronic stages of infarction. All coronary angiograms were obtained after the administration of sublingual nitroglycerin. The measurement was repeated immediately after (within 6 h) and late after (42 +/- 11 days) the onset of acute myocardial infarction. RESULTS: The diameter of the donor artery remained unchanged (1.32 +/- 0.98 vs. 1.42 +/- 1.12 mm). In contrast, the diameter of the recipient artery increased from 1.25 +/- 0.63 to 1.55 +/- 0.61 mm (p < 0.01). These changes in coronary artery diameter were associated with an improvement in regional myocardial wall motion at rest in infarct areas (6.7 +/- 7.0% vs. 13.6 +/- 10.7%, p < 0.05). CONCLUSIONS: These findings indicate that serial measurement of coronary artery diameter is useful for the evaluation of collateral development after acute myocardial infarction.

Complications of pediatric cardiac catheterization: a 3-year study.

To determine the current risk of pediatric cardiac catheterization, the complications and incidents of all catheterizations performed in a pediatric laboratory between January 1986 and October 1988 were prospectively recorded and compared with results from a 1974 study from the same institution. In the current study 1,037 catheterizations, 885 diagnostic and 152 diagnostic/interventional procedures, were performed in 888 patients (aged 1 day to 27 years, median 15.6 months). There were 15 major complications (1.4%), 70 minor complications (6.8%) and 30 incidents (2.9%). Two patients died as a result of the procedure and two as a result of pericatheterization clinical deterioration caused by the cardiac abnormality. The great majority of complications were successfully treated or were self-limited and the patients had no residua. Of patients with 13 nonfatal major complications and 70 minor complications, residua were evident in 7 patients and 3 without evident residua had the potential for sequelae (0.7% and 0.3% of catheterizations). A comparison of the diagnostic and balloon atrial septostomy cases in the present study with similar cases in the 1974 study shows that the incidence of major complications has decreased from 2.9% to 0.9% (p less than 0.0001); minor complications and incidents have decreased from 11.7% to 7.9% (p less than 0.006) and pericatheterization deaths not attributable to catheterization have decreased from 2.8% to 0.2% (p less than 0.0001). Changes in pericatheterization medical management, patient selection for catheterization and catheterization techniques probably account for these improvements.

[Caudal-angle aortography. Its usefulness for defining the coronary anatomy in cases of transposition of the great vessels]. / Aortografía con angulación caudal. Su utilidad para la definición de la anatomía coronaria en casos de transposición de grandes arterias.

With the purpose of obtaining an accurate definition of coronary arteries anatomy in complete transposition of the great arteries (concordant atrio-ventricular connection and discordant ventriculo-arterial connection), we performed a new angiographic technique in 14 patients with d-transposition of the great arteries and 1 patient with double-outlet right ventricle. This technique consists of using a balloon catheter with the frontal X ray tube cine-angiographic camera in caudal angulation (about 45 degrees), with balloon occlusion of the ascending aorta during the injection of the contrast medium. The results were compared with echocardiograms and surgical results. In all our cases, except 2, the technique gave us a very clear definition of the coronary anatomy and we were able to define the origin and course of the coronary arteries without difficulty. In the most common coronary artery pattern, the left coronary artery arose from sinus #1 (left aortic sinus) and gave origin to the anterior descending and left circumflex arteries, while the right coronary artery arose from aortic sinus #2 (right aortic sinus). In our series, the coronary arteries always originated from one or both facing sinuses of the aorta and the angiographic correlation with the surgical reports was accurate in all the cases. The anatomical and angiographic findings of this series are discussed. In conclusion, we find the aortogram with caudal angulation a very useful technique to improve the visualization of coronary anatomy in d-transposition of the great arteries, which has surgical significance in those cases which are candidates for anatomical correction.