The International Journal of Cardiovascular Imaging

doi: 10.1023/A:1017417026843pmid: 12123315

Koning, Gerhard; Dijkstra, Jouke; von Birgelen, Clemens; Tuinenburg, Joan; Brunette, Jean; Tardif, Jean-Claude; Oemrawsingh, Pranobe; Sieling, Christian; Melsa, Sören; Reiber, Johan

doi: 10.1023/A:1015551920382pmid: 12123316

Intracoronary ultrasound (ICUS) provides high-resolution transmural images of the arterial wall. By performing a pullback of the ICUS transducer and three-dimensional reconstruction of the images, an advanced assessment of the lumen and vessel wall morphology can be obtained. To reduce the analysis time and the subjectivity of boundary tracing, automated segmentation of the image sequence must be performed. The Quantitative Coronary Ultrasound – Clinical Measurement Solutions (QCU-CMS) (semi)automated analytical software package uses a combination of transversal and longitudinal model and knowledge-guided contour detection techniques. On multiple longitudinal sections through the pullback stack, the external vessel contours are detected simultaneously, allowing mutual guidance of the detection in difficult areas. Subsequently, luminal contours are detected on these longitudinal sections. Vessel and luminal contour points are transformed to the individual cross-sections, where they guide the vessel and lumen contour detection on these transversal images. The performance of the software was validated stepwise. A set of phantoms was used to determine the systematic and random errors of the contour detection of external vessel and lumen boundaries. Subsequently, the results of the contour detection as obtained in in vivo image sets were compared with expert manual tracing, and finally the contour detection in in vivo image sequences was compared with results obtained from another previously validated ICUS quantification system. The phantom lumen diameters were underestimated by 0.1 mm, equally by the QCU-CMS software and by manual tracing. Comparison of automatically detected contours and expert manual contours, showed that lumen contours correspond very well (systematic and random radius difference: −0.025 ± 0.067 mm), while automatically detected vessel contours slightly overestimated the expert manual contours (radius difference: 0.061 ± 0.037 mm). The cross-sectional vessel and lumen areas as detected with our system and with the second computerized system showed a high correlation (r = 0.995 and 0.978, respectively). Thus, use of the new QCU-CMS analytical software is feasible and the validation data suggest its application for the analysis of clinical research.

Mittal, S.R.; Pancholi, N.

doi: 10.1023/A:1015504609150pmid: 12123317

Left ventricular outflow tract (LVOT) presystolic flow velocities were studied using pulse doppler echocardiography in 30 normal persons. Thirty patients of mild hypertension with transmitral flow velocity pattern suggestive of impaired relaxation were also studied. Transmitral flow velocity pattern was correlated with LVOT presystolic flow velocities in the two groups. Hypertensive patients had significantly higher transmitral A wave velocity (p < 0.001) and significantly lower transmitral E wave/A wave velocity ratio (p < 0.001) as compared to normal group. LVOT presystolic flow velocities had significant direct correlation with transmitral A wave velocity (p < 0.01) and significant inverse relation with transmitral E wave/A wave velocity ratio (p < 0.05). Our observations suggest that increased LVOT presystolic flow peak velocity can also be used as another marker of impaired left ventricular compliance during atrial contraction. More work is needed to establish exact status of this preliminary observation.

Borges, Adrian; Richter, Wolf; Witzel, Christian; Witzel, Matthias; Grohmann, Andrea; Reibis, Rona; Rutsch, Wolfgang; Küchler, Ingeborg; Munz, Dieter; Baumann, Gert

doi: 10.1023/A:1015529431982pmid:

Kulhanek, Jan; Sorrell, Vincent; Ershadi, Reza; Cabarrus, Brian; Short, Douglas; Movahed, Assad

doi: 10.1023/A:1015525311510pmid: 12123319

Safety of performing adenosine myocardial perfusion stress testing as early as 24 h after acute uncomplicated myocardial infarction is not known. We evaluated 31 (14 females and 17 males, average age 72, range 46–89 years) consecutive patients with uncomplicated myocardial infarction, who underwent adenosine myocardial perfusion stress imaging, 24–72 h after infarction for risk stratification. Adenosine was infused at a rate of 140 μg/kg/min for 6 min. Twenty patients were presented with non-ST-elevation myocardial infarction. Eleven patients were admitted with acute ST-elevation myocardial infarction. Patients were monitored for signs of complication during and immediately after the stress test. The average time from admission to performance of stress tests was 51 ± 19 h, ranging from the minimum of 24 h to maximum 72 h. No complications related to adenosine infusion were detected. In conclusion, our data suggest that a further large study of early adenosine myocardial perfusion SPECT imaging may be safe in a carefully selected group of patients after uncomplicated myocardial infarction.

Ueshima, Kenji; Miyakawa, Tomohisa; Taniguchi, Yasuyo; Nishiyama, Osamu; Musha, Takehiko; Saitoh, Masahiko; Kamata, Junnya; Okajima, Toshiya; Aisaka, Mami; Nagamine, Masayuki; Hiramori, Katsuhiko

doi:

doi: 10.1023/A:1017416220561pmid: 12123321

Vrachliotis, Thomas; Bis, Kostaki; Shetty, Anil; Ravikrishan, Korembeth

doi: 10.1023/A:1015541931895pmid: 12123322

Contrast-enhanced three-dimentional MR angiography has evolved into a promising technique in the study of the pulmonary vasculature. Both congenital and acquired entities can be now morphologically demonstrated in a non-invasive manner obviating the need for conventional pulmonary angiography. Due to spatial resolution limitations, however, it is still premature to routinely apply the method in the detection of small subsegmental emboli, in cases of suspected pulmonary embolism, and further technical developments will be required. In this paper we present a spectrum of congenital and acquired disorders affecting the pulmonary vascular tree as demonstrated with contrast-enhanced three-dimensional MR angiography.

Knez, Andreas; Becker, Christoph; Becker, Alexander; Leber, Alexander; White, Carl; Reiser, Maximilian; Steinbeck, Gerhard

doi: 10.1023/A:1015536705455pmid: 12123323

Electron-beam Computed Tomography (EBCT) has been used for years to quantify coronary artery calcification as a marker of coronary atherosclerosis. The aim of this study was to determine the diagnostic accuracy of a new scanner, the Multi-slice Spiral CT (MSCT), for the assessment of coronary calcification and to compare this new technique to EBCT. The study population consisted of 99 male patients, aged 60 ± 10 years with suspected or known coronary artery disease. With EBCT 40 axial slices, ECG-triggered (scan time = 100 ms, slice thickness = 3 mm), were acquired in one breath-hold (35 ± 5 s). For MSCT simultaneous acquisition of four axial slices (scan time = 250 ms, slice thickness = 2.5 mm), allowed the entire heart (48 slices) to be covered in one breath-hold of 25 ± 5 s. For quantification of coronary calcium the Volumetric Calcium Score (VCS) was calculated. There was an excellent correlation for the VCS (r = 0.994, p = 0.01, mean difference = 97 ± 115) between both scanners. Comparison of low (1–100), moderate (101–400), high (401–1000) and very high score values (>1000) showed no significant differences. The number of calcified lesions and densities were statistically not different. Mean variability of the two scans was 17%. The MSCT scanner is equivalent to EBCT for the determination and quantification of coronary calcium and can therefore be used for calcium screening. With application of the spiral mode technique further improvement in variability can be expected, thus allowing for follow-up studies to determine progression or regression of atherosclerosis with high accuracy.

Sato, Masato; Terada, Yasushi; Mitsui, Toshio; Miyashita, Tsuyoshi; Kandori, Akihiko; Tsukada, Keiji

doi: 10.1023/A:1015597910933pmid: 12123324

We tried to visualize normal atrial excitatory process by magnetocardiogram (MCG) measured from both anterior chest and back using our newest multi-channel SQUID system. Twenty normal subjects were studied. After measuring the normal (B z) component of the magnetic field, we constructed an isomagnetic and vector arrow map from spatial derivatives of the normal (B z) component in the tangential direction. By the MCG measurement from the anterior chest, current arrows were recognized in the right upper portion which were directed to the left lower from the beginning of the P wave to the P-wave peak. By the measurement from the back, current arrows were able to be visualized in the right to middle upper portion which were directed to the left or left lower just before the P-wave peak. We conclude that we successfully recognized the right atrial excitation and its spread to the left atrium and observed the time course of normal atrial excitatory process by the MCG measurement from not only anterior chest but also back using 64-channel SQUID system.