Biomedical subjects

K Cho

Publications and source records attributed to K Cho.

295 records · Page 17Linked to original sources

PubMedDate not supplied

Leiomyoblastoma: varied CT appearance.

Leiomyoblastoma is an uncommon tumor of the stomach. Usually exogastric in site, the tumor may grow to a significant size before it becomes symptomatic. Various appearances of the tumor include cystic and solid forms as well as a combination of both. Tumor hypervascularity may be identified on computed tomography (CT). The development of calcification in this tumor is rare. Late recurrence of the tumor may occur. The differential diagnosis should include leiomyosarcoma, leiomyoma, pancreatic pseudocyst, and cystadenoma.

Adult↗

PubMedDate not supplied

Development of respiratory gated myocardial SPECT system.

BACKGROUND: The superposition of the diaphragm and abdominal structures on the inferior wall of the left ventricle has often distorted single photon emission computed tomography (SPECT). We developed a respiratory gated SPECT (RGS) system to diminish artifacts caused by overlap between the inferior wall and upper abdomen and have validated its feasibility for clinical use. METHODS AND RESULTS: A 2-detector SPECT system equipped with a respiratory monitor based on impedance plethysmography and an original triggering apparatus was used for RGS in 7 healthy male volunteers. A pulse triggered 100 ms after every expiratory peak was processed in a SPECT system as well as an electrocardiogram (ECG) gating pulse. Inspiratory and expiratory frames were determined using the respiratory curve derived from fluctuation of the gall bladder uptake. Both sets of images were reoriented into short-axis and vertical long-axis slices. For quantification, data were reconstructed into polar plots and count density estimated in 9 myocardial segments. The mean percentage uptake of inferior segments at inspiration was significantly greater than that at expiration (81+/-8.3 versus 76+/-7.1; P < .0001). The inferior-lateral activity ratio improved from 0.78 at expiration to 0.81 at inspiration (P < .01). The coefficient of variance for each segment of inspiratory data was significantly smaller than that at expiration, indicating improved homogeneity of tracer distribution. The lowest cutoff threshold of the tomograms to separate the inferior uptake from that of the upper abdomen was significantly lower at inspiration than at expiration, suggesting smaller scatter from abdominal structures on inspiratory images. CONCLUSIONS: RGS yielded improved tracer uptake of the inferior wall in healthy male subjects and may be suitable as an alternative method for attenuation and scatter correction. However, further clinical validation is needed.

Adult↗

PubMedDate not supplied

Serial assessment of left ventricular function during dobutamine stress by means of electrocardiography-gated myocardial SPECT: combination with dual-isotope myocardial perfusion SPECT for detection of ischemic heart disease.

BACKGROUND: Technetium-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial single photon emission computed tomography (SPECT). The purpose of this study was to evaluate left ventricular performance during dobutamine stress by means of ECG-gated myocardial perfusion SPECT with short-time data collection. METHODS AND RESULTS: After administration of Tc-99m sestamibi or tetrofosmin (600-740 MBq), 67 patients with ischemic heart disease, including 35 with prior myocardial infarction, were examined by ECG-gated myocardial perfusion SPECT at rest and during dobutamine stress (at dosages of 4, 8, 12, 16, and 20 microg/kg/min, with increments every 8 minutes). The ECG-gated data collection time was 5 minutes for each dobutamine dosage. After acquisition of gated SPECT data at the highest dose, thallium 201 chloride (111 MBq) was injected, and dual-isotope SPECT was also performed to assess the myocardial ischemia. In 32 patients without prior myocardial infarction, the sensitivity of individual stenosed-vessel detection with dual-isotope perfusion SPECT, with wall motion abnormality obtained from gated SPECT, and with the combined method was 55.9%, 52.9%, and 73.5%, respectively, based on coronary angiography. ECG-gated SPECT during dobutamine infusion revealed regional wall motion abnormalities (worsening or biphasic response) in 19 (57.6%) of 33 infarcted areas with culprit coronary arterial stenosis. The prevalence of reversible perfusion defects on dual-isotope SPECT was higher in segments with wall motion abnormalities than in segments with normal wall motion response (89.5% vs 42.9%, P <.02). CONCLUSIONS: Myocardial perfusion and left ventricular function during dobutamine infusion were analyzed in a single examination by means of the combined method. This procedure has the potential to provide comprehensive information with which to evaluate patients with ischemic heart disease.

Blood Pressure↗

PubMedDate not supplied

Assessment of left ventricular diastolic function with electrocardiography-gated myocardial perfusion SPECT: comparison with multigated equilibrium radionuclide angiography.

BACKGROUND: Technetium-labeled myocardial perfusion tracers allow the simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial perfusion single photon emission computed tomography (SPECT). This study evaluates left ventricular systolic and diastolic function by ECG-gated SPECT with the use of higher framing (32 frames per cardiac cycle) data acquisition. METHODS AND RESULTS: After receiving an injection of technetium 99m tetrofosmin, 48 patients with cardiac diseases were examined by ECG-gated myocardial perfusion SPECT with a 3-headed gamma camera. During gated data collection, 32 frames per cardiac cycle were acquired over 360 degrees in 60 steps, each of which consisted of 60 beats. Immediately thereafter, the 32 frames taken at each projection angle were combined into 16-frame and 8-frame data sets. Left ventricular end-diastolic volume (LVEDV, in milliliters), left ventricular end-systolic volume (LVESV, in milliliters), and left ventricular ejection fraction (LVEF, percentage) were automatically calculated from the 32-frame, 16-frame, and 8-frame gated data sets. Left ventricular time-volume curves from the 3 data sets were generated by Fourier curve fitting analysis with the use of 3 harmonics, and then peak filling rate (PFR, per second) was measured. Twenty-nine patients also underwent multigated equilibrium radionuclide angiography (ERNA) to determine the LVEF and PFR. Combining the 32-frame data into 16-frame and 8-frame data sets from the 48 patients generated a smaller LVEDV and a larger LVESV, and LVEF was significantly lower in accordance with the decreasing number of frames. Compared with ERNA studies (n = 29), the Bland-Altman method showed underestimated LVEFs and larger 95% limits of agreement in lower framing gated SPECT. CONCLUSIONS: Left ventricular functional parameters obtained from 32-frame gated SPECT correlated closely with those determined by ERNA studies. ECG-gated SPECT with 32-frame data can provide comprehensive information with which to evaluate many types of cardiac diseases.

Adult↗

PubMedDate not supplied

Persistent detection of alfa-fetoprotein in the vagina without overt preterm premature rupture of the membranes. Clinical and chemical characterizations.

OBJECTIVES: The objectives of this study were to clinically characterize and seek risk factors for the patients with persistently detected alfa-fetoprotein (AFP) in the vagina without showing overt preterm premature rupture of the membranes (PROM). STUDY DESIGN: The cohort study was undertaken using vaginal-cervical specimens collected consecutively between 21 and 40 weeks of gestation from 25 consenting women. Demographic, obstetric, neonatal, and laboratory data from patients with persistent positive results of AFP kit tests without showing overt leakage of amniotic fluid were compared to those from controls. Cervical levels of interleukin-1 alpha, interleukin-1 beta, interleukin-6, interleukin-8, and granulocyte elastase were measured by immunoassay, and the uterine cervix was assessed by transvaginal ultrasonography. Statistical analysis involved Fisher's exact test and Mann-Whitney U test. RESULTS: The incidence of overt preterm PROM was significantly higher in the patients with persistently detected AFP in preterm (3 in 4 cases) than in controls (3 in 21 controls). At sampling before determination of persistently detected AFP, patients with persistently detected AFP had significantly higher cervical levels of interleukin-6 and significantly shorter cervical length than controls. CONCLUSIONS: Patients with persistently detected AFP in the vagina without showing overt preterm PROM have the risk of overt preterm PROM. Increased levels of interleukin-6 in cervical specimens and short cervical length may be risk factors for the occurrence of persistent detection of AFP in the preterm.

Cervix Uteri↗

PubMedDate not supplied

Intellectual status of children with cerebral palsy after elementary education.

Using Wechsler Intelligence Tests, we compared the intellectual status of children with cerebral palsy (CP) immediately before and 2 years after entering school. Verbal and performance IQs could be assessed for 23 children with spastic diplegia but only verbal IQs in six children with spastic quadriplegia. Performance IQs were much lower than verbal IQs in both the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) in children with spastic diplegia. After schooling, verbal IQ was significantly increased but there was no change in performance IQ, thus, the difference between these IQs became more pronounced. When comparing the school class types, the verbal IQs of children studying in ordinary classes became statistically higher than those of children in special classes. In contrast, since the increases in mean performance IQs were greater in children in special classes, the differences between these IQs became more pronounced in children studying in ordinary classes. We also found that although verbal IQs were lower for quadriplegic children than for diplegic children at preschool age, there was no difference after 2 years of schooling. These results underline the importance and benefits of appropriate education for children with CP.

Analysis of Variance↗

PubMedDate not supplied

Dynamic human glycogen and glucose metabolism detection utilizing in vivo 13C NMR.

The dynamic detection studies of glucose-glycogen metabolism of the human liver were performed with normal volunteers. A single tuned surface coil of 20-cm diameter was used for 13C (at 16.04 MHz). Natural glucose 100 g was administered for the natural abundance 13C MR dynamic study and 13C enriched (99%) 1-13C-D-glucose 1 g mixed 75 g glucose was administered to study the 13C enrichment effect. The total scan time of this dynamic study was 1 hr and each single scan time was 20 min. We did not use proton decoupling for the human 13C MR study. Localized (PRIME) proton shimming was performed and the shim value was less than 20 Hz. Glucose and glycogen spectra were clearly visible at 120 to 80 ppm and about 3 hr later both peaks almost disappeared. These data demonstrate that dynamic hepatic glucose-glycogen metabolism should be possible to detect which should allow for the direct diagnosis of hepatic glucose-glycogen metabolic disorders.

Carbon Isotopes↗