The appliacation of retrospective ECG-gated 256 slices spiral CT technique in inferior phrenic artery angiography / 实用放射学杂志

Objective To evaluate the value of retrospective ECG-gated 256 slices spiral CT technique in the scanning of inferior phrenic artery (IPA).Methods 80 patients with underdone abdominal CTA were divided randomly into two groups (40 patients each)as regular abdominal CTA scanning group and retrospective ECG-gated technique group.And further analysis was done to evaluate the display of IPA branches and the image quality.Results 80 patients were all scanned successfully.40 cases LIPA and 40 cases RIPA were showed in the regular group.80 cases showed 1st level branches of IPA,73 cases with 2nd level,59 cases with 3rd and 43 ca-ses showing 4th level.40 cases LIPA and 40 cases RIPA were showed in ECG-gated group.And the numbers of IPA branches levels were 80,79,71,65,respectively.There is no significant difference in the ability of showing the1st level IPA or their image quality between those two groups (P >0.05);and there is a statistical significance in the ability of showing other levels of IPA and their im-age quality.Conclusion It is feasible that we use retrospective ECG-gated 256 slices spiral CT scanning technique to show the IPA. And it could improve the ability of showing the IPA branches as well as the image quality.

Feasibility of prospective ECG gated scan and adaptive cardio sequence scan for dual-source CT coronary angiography / 实用放射学杂志

Objective To investigate the feasibility and clinical application of prospective ECG-gated scan and adaptive cardio se-quence scan of dual-source CT coronary angiography.Methods 255 patients who underwent coronary CT angiography using a dual-source CT scanner were divided into two groups:group A underwent prospective scan,group B underwent retrospective scan.The two groups were further subdivided into low heart rate group and high heart rate group,recorded as A1(n=51),A2(n=89),B1(n=26), B2(n=89),respectively.Group A1 preceded with prospective ECG gated scan;group A2 performed with adaptive cardio sequence scan;group B1 and B2 underwent retrospective scan.All of them applied ATCM (automatic tube current modulation)technique. Effective dose was recorded.The image quality was assessed by two experienced radiologists with a four-point grading scale.Results The excellent or good image quality (score 1 and 2)of the four groups were above 95%,and no statistical differences in images scores was detected in A1 and B1 (P =0.726),A2 and B2 (P =0.079).Effective dose was significantly different in A1 and B1(P <0.001),A2 and B2 (P <0.001),and the former decreased 50% and 40% as compared with the latter.Conclusion Using prospective ECG gated scan and adaptive cardio sequence scan,assessable image quality of coronary artery can be acquired with dual source CT (heart rate<90 beast per minute),and radiation dose can be obviously reduced.

Left ventricular mass correlation between quantitative ECG-gated myocardial SPECT (QGS) and echocardiography

Left ventricular mass (LV mass) is an independent prognostic indicator of cardiovascular complications, and its regression due to therapy translates to positive clinical outcomes. Good correlation of LV mass between qualitative ECG-gated SPECT (OGS) and echocardiography has been reported, and this study aims to verify if such relationship applies in the local setting. Forty-five consecutive patients with normal myocardial perfusion SPECT and recent plain echocardiograms done in the same institution were retrospectively analyzed. Results show a significant correlation (y = 0.296x + 75.962, r = 0.491, p = 0.001) between the LV mass of the two imaging modalities, which was also observed in the TI-201  group (y= 0.256x + 80.325, r_=_0.442, p = 0.006), but not in the Tc-99m sestamibi group (y= 0.402x + 63.456, r_=_0.443, p = 0.272). The mean LV mass by OGS (122.0 ± 26.9) is significantly smaller compared with the mean LV mass by echo cardiography (155.5 ± 44.6), and the difference between the two procedures (mean ± SD: 39.7 ± 32.6, p

A Case of Hemolytic Anemia Associated with an Inverted Inner Felt Strip on a Proximal Anastomotic Site for Replacement of the Ascending Aorta for Acute Aortic Dissection / 日本心臓血管外科学会雑誌

A 62-year-old man underwent replacement of the ascending aorta for a Stanford type A acute aortic dissection. The proximal stump was reinforced with using internal and external PTFE felt strips, fibrin glue and cellulose fibers. However, hemolytic anemia and hematuria occurred postoperatively. ECG-gated reconstruction CT demonstrated that the hemolytic anemia was induced by collision of red blood cells on the inverted felt strip of the proximal anastomosis. The patient underwent a reparative procedure 1 week subsequent to the initial operation. During reoperation, half of the inner felt strip used for proximal stump fixation was found to be turned up and protruding into the inner lumen. An incision was made in the synthetic graft and the inverting felt material was removed as much as possible, and then a bovine pericardial patch was used as a means of covering the internal felt strip. Here, we report a rare case of hemolytic anemia at the site of an inverted inner PTFE felt strip used for reinforcement of proximal anastomosis. We found that an ECG-gated reconstruction CT is particularly useful in diagnosing this complication around a beating heart.

Anatomy of the Sinoatrial Nodal Branch in Korean Population: Imaging with MDCT

OBJECTIVE: To evaluate, on a retrospective basis, the anatomic characteristics of the arterial supply to the sinoatrial node (SAN) in the Korean population using an ECG-gated multi-detector CT (MDCT). MATERIALS AND METHODS: The electrocardiographic-gated MDCTs of 500 patients (258 men and 242 women; age range, 17-83 years; mean age, 58.6 +/- 12.04 years) were analyzed retrospectively. In each case, the SAN artery (arteries) was named according to a special nomenclature with regard to origin, course, and termination. RESULTS: A total of 516 SAN arteries were visualized in 496 patients. The SAN was supplied by a single artery in 476 (96.4%) cases and by 2 arteries in 18 (3.6%) cases. The SAN originated from the right coronary artery in 265 (53.4%) cases and from the left circumflex in 213 (43%) cases. CONCLUSION: This study can provide basic data on variations of the SAN artery in the Korean population.

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

OBJECTIVE: To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. MATERIALS AND METHODS: Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 +/- 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. RESULTS: There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 +/- 0.306 [group A] vs. 1.084 +/- 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 +/- 0.16 mSv in group A and 7.1 +/- 1.05 mSv in group B (p = 0.001). CONCLUSION: In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

Evaluation of Reperfused Myocardial Infarction by Low-Dose Multidetector Computed Tomography Using Prospective Electrocardiography (ECG)-Triggering: Comparison with Magnetic Resonance Imaging

PURPOSE: To evaluate the potential of prospective electrocardiography (ECG)-gated 64-slice multidetector computed tomography (MDCT) for evaluation of myocardial enhancement, infarct size, and stent patency after percutaneous coronary intervention (PCI) with stenting in patients with myocardial infarction. MATERIALS AND METHODS: Seventeen patients who were admitted with acute myocardial infarction were examined with prospective ECG-gated 64-slice cardiac MDCT and magnetic resonance (MR) imaging after reperfusion using PCI with stenting. Cardiac MDCT was performed with two different phases: arterial and delayed phases. We evaluated the stent patency on the arterial phase, and nonviable myocardium on the delayed phase of computed tomography (CT) image, and they were compared with the results from the delayed MR images. RESULTS: Total mean radiation dose was 7.7 +/- 0.5 mSv on the two phases of CT images. All patients except one showed good patency of the stent at the culprit lesion on the arterial phase CT images. All patients had hyperenhanced area on the delayed phase CT images, which correlated well with those on the delayed phase MR images, with a mean difference of 1.6% (20 +/- 10% vs. 22 +/- 10%, r = 0.935, p = 0.10). Delayed MR images had a better contrast-to-noise ratio (CNR) than delayed CT images (27.1 +/- 17.8% vs. 4.3 +/- 2.1%, p < 0.001). CONCLUSION: Prospective ECG-gated 64-slice MDCT provides the potential to evaluate myocardial viability on delayed phase as well as for stent patency on arterial phase with an acceptable radiation dose after PCI with stenting in patients with myocardial infarction.

Respiratory Motion Detection and Correction in ECG-Gated SPECT: a New Approach

OBJECTIVE: Gated myocardial perfusion single-photon emission computed tomography (GSPECT) has been established as an accurate and reproducible diagnostic and prognostic technique for the assessment of myocardial perfusion and function. Respiratory motion is among the major factors that may affect the quality of myocardial perfusion imaging (MPI) and consequently the accuracy of the examination. In this study, we have proposed a new approach for the tracking of respiratory motion and the correction of unwanted respiratory motion by the use of respiratory-cardiac gated-SPECT (RC-GSPECT). In addition, we have evaluated the use of RC-GSPECT for quantitative and visual assessment of myocardial perfusion and function. MATERIALS AND METHODS: Twenty-six patients with known or suspected coronary artery disease (CAD)-underwent two-day stress and rest (99m)Tc-Tetrofosmin myocardial scintigraphy using both conventional GSPECT and RC-GSPECT methods. The respiratory signals were induced by use of a CT real-time position management (RPM) respiratory gating interface. A PIO-D144 card, which is transistor-transistor logic (TTL) compatible, was used as the input interface for simultaneous detection of both ECG and respiration signals. RESULTS: A total of 26 patients with known or suspected CAD were examined in this study. Stress and rest myocardial respiratory motion in the vertical direction was 8.8-16.6 mm (mean, 12.4 +/- 2.9 mm) and 7.8-11.8 mm (mean, 9.5 +/- 1.6 mm), respectively. The percentages of tracer intensity in the inferior, inferoseptal and septal walls as well as the inferior to lateral (I/L) uptake ratio was significantly higher with the use of RC-GSPECT as compared to the use of GSPECT (p < 0.01). In a left ventricular ejection fraction (LVEF) correlation analysis between the use of rest GSPECT and RC-GSPECT with echocardiography, better correlation was noted between RC-GSPECT and echocardiography as compared with the use of GSPECT (y = 0.9654x + 1.6514; r = 0.93, p < 0.001 versus y = 0.8046x + 5.1704; r = 0.89, p < 0.001). Nineteen (19/26) patients (73.1%) showed abnormal myocardial perfusion scans with reversible regional myocardial defects; of the 19 patients, 14 (14/26) patients underwent coronary angiography. CONCLUSION: Respiratory induced motion can be successfully corrected simultaneously with the use of ECG-gated SPECT in MPI studies using this proposed technique. Moreover, the use of ECG-gated SPECT improved image quality, especially in the inferior and septal regions that are mostly affected by diaphragmatic attenuation. However, the effect of respiratory correction depends mainly on the patient respiratory pattern and may be clinically relevant in certain cases.

A Serial MR Imaging of Myocardial Infarction with Non-Surgical Animal Model

Objectives: The purpose of study is to evaluate serial MR imaging of myocardial infarction using non-surgical model of myocardial infarction after percutaneous transcatheter coronary arterial embolization in dogs. MATERIALS AND METHODS: We evaluated serial pre- and post-contrast MR images with Gd-DTPA (gadolinium-diethylenetriamine-pentaacetic acid) of heart of the eleven mongrel dogs (immediate group (n=3), one week group (n=3), three weeks group (n=5)) after making non-surgically induced myocardial infarction. We confirmed the infarct with TTC staining and microscopically. The location and extents of the myocardial infarction were correlated. RESULTS: A total of 24 MR images were archived; 11 images of the immediate post-embolic period, 8 images of one-week follow-up, and five of 3-week follow-up images. Comparing with the signal intensity of normal myocardium, immediate post-embolic MR images showed low or iso signal intensities (SI) of the infarct area on T1-weighted images (T1WI) and high SI on T2-weighted images (T2WI). No contrast enhancement with Gd-DTPA was made in all cases of the immediate post-embolic MRI. One-week and 3-week follow-up MR images showed low or iso SI on T1WI and slight high or iso SI on T2WI. Contrast enhancement images in both one-week and 3-week follow-up MRI showed denser enhancement of infarct area in one-week follow-up. The myocardial wall thinning was seen in 5 of eight dogs after one week and in 3 of five after 3 weeks. CONCLUSION: In non-surgical animal models of myocardial infarction, MR images showed low or iso SI on T1WI, and high SI on T2WI in various stages, and contrast enhancement was maximum after one week and gradual decrease to 3 weeks. The myocardial wall thinning was seen in one-to 3-week follow-up MR images.