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PubMedDate not supplied

Real-Time Four-dimensional Imaging of the Heart with Multi-Detector Row CT.

An interactive four-dimensional (4D) visualizing system for the heart was developed by the authors. The system realizes high-resolution three-dimensional (3D) imaging with temporal resolution in a beating heart by using eight or more data sets reconstructed from multi-detector row computed tomography (MDCT) with a retrospective electrocardiograph-gated reconstruction algorithm. The motion of heart walls, papillary muscles, septa, and valves can now be observed in 4D multiplanar reformations (MPRs), as with sonography, while coronary arteries, coronary sinuses, and cardiac veins can be analyzed during the optimal phase in 4D volume-rendering images, as with angiography. All parameters such as window width, window level, field of view, panning, tilt, thresholds, opacity, color, and segmentation function are completely interactive in 4D imaging. Two longitudinal views and one latitudinal view of a heart can be simultaneously visualized in the three relative 4D MPR views. These newly developed capabilities in viewing both 3D volume and temporal resolution data, functional data, and even multiphase data with registration add considerable diagnostic potential. The advent of this real-time 4D visualizing system has enhanced the capabilities of MDCT.

Algorithms↗

PubMedDate not supplied

Real-time four-dimensional imaging of the heart with multi-detector row CT.

An interactive four-dimensional (4D) visualizing system for the heart was developed by the authors. The system realizes high-resolution three-dimensional (3D) imaging with temporal resolution in a beating heart by using eight or more data sets reconstructed from multi-detector row computed tomography (MDCT) with a retrospective electrocardiograph-gated reconstruction algorithm. The motion of heart walls, papillary muscles, septa, and valves can now be observed in 4D multiplanar reformations (MPRs), as with sonography, while coronary arteries, coronary sinuses, and cardiac veins can be analyzed during the optimal phase in 4D volume-rendering images, as with angiography. All parameters such as window width, window level, field of view, panning, tilt, thresholds, opacity, color, and segmentation function are completely interactive in 4D imaging. Two longitudinal views and one latitudinal view of a heart can be simultaneously visualized in the three relative 4D MPR views. These newly developed capabilities in viewing both 3D volume and temporal resolution data, functional data, and even multiphase data with registration add considerable diagnostic potential. The advent of this real-time 4D visualizing system has enhanced the capabilities of MDCT.

Echocardiography, Four-Dimensional↗

PubMedDate not supplied

Intercomparison of dose distribution between gamma knife and C-arm-mounted linac.

Although the Gamma Knife is widely used as a standard tool of radiosurgery for intracranial diseases, recent innovations in medical accelerators have actualized equivalent dose distribution. Most commonly, multiple non-coplanar arc beams through a combination of gantry and couch rotations are used in linac-based radiosurgery, but beam entry geometry is different from that with the Gamma Knife. We have developed a C-arm-mounted medical accelerator and realized conical beam entry without couch rotation. A combination of several conical rotation beams with different C-arm angles comprises multi-orbit dynamic conical radiation therapy (MODCRT) and resembles radiation beam entry with the Gamma Knife. Intercomparison of dose distributions and dose-volume histograms for the same brain tumor demonstrated that MODCRT delivers a similar dose fall-off pattern to that obtained with the Gamma Knife, though the low-dose spread patterns differ.

Brain Neoplasms↗

PubMedDate not supplied

Communicating vein between the left renal vein and left ascending lumber vein: incidence and significance on abdominal CT.

PURPOSE: To examine the incidence and appearance of the communicating vein between the left renal vein (LRV) and the left ascending lumbar vein (LALV) on abdominal CT. MATERIALS AND METHODS: We reviewed the appearance of the communicating vein on contrast-enhanced CT obtained by multidetector-row CT (MDCT) scanner. One hundred patients without known abnormality in this region were randomly chosen and the following findings were recorded: (1) presence or absence of the visible communicating vein, (2) diameter of the communicating vein, (3) visible length of the vein (none, partial, or total), (4) laterality of the ascending lumbar vein, (5) distance between the superior mesenteric artery and the aorta. RESULTS: The communicating vein was visible in 35 patients (35%). In 20 cases, this vein was visualized within the paraaortic region and could not be traced toward the LALV. The distance between the superior mesenteric artery and the aorta was narrower in the patients with visible communicating vein than in those without it, however, no statistically significant difference was demonstrated. CONCLUSION: This vein is commonly visible in the general population, and care should be taken not to confuse it with lymphadenopathy because this communicating vein was partially visualized within the paraaortic region in 20% of the cases.

Adult↗

PubMedDate not supplied

Re-appearance of power Doppler signals in the tumor nodules of hepatocellular carcinoma after transarterial embolization reflects residual viable tumor cells: histological confirmation.

BACKGROUND/AIMS: A recent advance in ultrasonography is the use of power Doppler for detecting low-velocity angle-independent blood flow at the microvascular level. The present study was prospectively performed to elucidate the relationship between the power Doppler signals of hepatocellular carcinoma after transarterial embolization and histological confirmation of viable tumor cells. METHODOLOGY: The observance of hepatocellular carcinoma-related Doppler signals in 48 patients with 67 nodules was examined after transarterial embolization, and its correlation with the presence of viable tumor cells using ultrasound-guided biopsy specimens was analyzed. RESULTS: Power Doppler signals disappeared in 54 out of 67 nodules (80%) one day after transarterial embolization, but the signals re-appeared in 55-53% of the specimens at 4-7 days and 10-14 days after treatment. Viable tumor cells were histologically proven in 27 of 34 nodules (79%) presenting power Doppler signals, while only 5 of the 22 nodules (23%) negative for Doppler signals confined viable tumor cells (P<0.001). Univariate and multivariate analysis showed that the detection of power Doppler signals after transarterial embolization was related to the size of the tumor and the presence of viable tumor cells (both, P<0.001). CONCLUSIONS: These results indicate that the presence of power Doppler signals may reflect the presence of viable tumor cells after transarterial embolization, leading to the need for further treatment of hepatocellular carcinoma nodules.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

A case of renal angioleiomyoma with rapid growing: CT findings with histopathological correlation.

We present a rare case of renal angioleiomyoma with rapid growing during one-year and seven-months' follow-up. The CT findings correlated well with the histopathological findings. The patient was a 62-year-old man with right renal mass that was incidentally found on CT. The first CT showed a solitary mass lesion that was 2.0 cm in diameter with a well-defined margin at the right renal medulla. It was gradually enhanced on contrast-enhanced CT. Follow-up CT was performed after one year and seven months, and the mass had grown to 3.8 cm in diameter and showed heterogeneous density on unenhanced CT. The mass had an early enhanced area in the corticomedullary phase, and this enhancement lasted into the nephrographic phase. Another area was gradually enhanced heterogeneously. Right radical nephrectomy was performed, and the histopathological diagnosis was renal angioleiomyoma. The early enhanced area of the mass corresponded to large vessels filled with blood, and the other area was mainly composed of bundles of smooth muscle, fibrous tissue, and minute blood vessels. It is important to know that the CT findings of real angioleiomyoma may show hypervascularity but are atypical for renal cell carcinoma (RCC), and a tendency for growth may be present.

Angiomyoma↗

PubMedDate not supplied

Light emission requires exposure to the atmosphere in ex vivo bioluminescence imaging.

The identification of organs bearing luciferase activity by in vivo bioluminescence imaging (BLI) is often difficult, and ex vivo imaging of excised organs plays a complementary role. This study investigated the importance of exposure to the atmosphere in ex vivo BLI. Mice were inoculated with murine pro-B cell line Ba/F3 transduced with firefly luciferase and p190 BCR-ABL. They were killed following in vivo BLI, and whole-body imaging was done after death and then after intraperitoneal air injection. In addition, the right knee was exposed and imaged before and after the adjacent bones were cut. Extensive light signals were seen on in vivo imaging. The luminescence disappeared after the animal was killed, and air injection restored the light emission from the abdomen only, suggesting a critical role of atmospheric oxygen in luminescence after death. Although no substantial light signal at the right knee was seen before bone cutting, light emission was evident after cutting. In conclusion, in ex vivo BLI, light emission requires exposure to the atmosphere. Bone destruction is required to demonstrate luciferase activity in the bone marrow after death.

Air↗

PubMedDate not supplied

The intergroup/RTOG 85-01 concurrent chemoradiation regimen for Japanese esophageal cancer.

BACKGROUND/AIMS: To evaluate outcome of the U.S. RTOG/Intergroup Protocol 85-01 for 44 Japanese esophageal cancer patients. METHODOLOGY: Between 1996 and 2004, patients with esophageal cancer received the Intergroup concurrent chemoradiation therapy regimen for the primary treatment (n=44, group A). We compared the data with those of patients receiving radiotherapy (RT) combined with the weekly chemotherapy regimen (n=12, group B) and with those of patients receiving RT combined with the daily low-dose chemotherapy regimen (n=24, group C). RESULTS: The median survival period was 14.9 months in group A, 5.7 months in group B, and 6.3 months in group C. The survival rates at 1 and 3 years were 56% and 26% in group A, 42% and 21% in group B (p=0.3307), and 27% and 18% in group C (p=0.0462), respectively. CONCLUSIONS: The prognosis of patients who received the Intergroup regimen for esophageal cancer was significantly better than that of patients who received the daily low-dose chemotherapy regimen. The Intergroup regimen is well tolerable for the Japanese patients too.

Adult↗