Biomedical subjects

Oliver Kress

Publications and source records attributed to Oliver Kress.

4 recordsLinked to original sources

PubMed2006

Accuracy of single-session extracranial radiotherapy for simple shaped lung tumor or metastasis using fast 3-D CT treatment planning.

BACKGROUND: This study is situated in the area of measuring set-up accuracy and time periods of single-session extracranial radiotherapy (SSRT) for simple-shaped targets (e.g., spherical or rotational symmetrical) definitively located in the peripheral lung. METHODS AND MATERIALS: After adaptation of the stereotactic body frame, the patient has to remain in the vacuum pillow during planning computed tomography (CT), fast three-dimensional (3-D) treatment planning, and direct irradiation after verification. Fast preplanning is performed by using virtual simulation software to accelerate the method. RESULTS: In our new procedure, SSRT is applied in approximately 1.5 h. The mean setup accuracy vector was 2.4+/-0.7 mm in the range of 1.34 to 4 mm. Mean intrafractional patient movement in the stereotactic body frame before and after radiation was 0.70 mm+/-0.5 mm and 0.76+/-0.76 mm in the range of 0 to 2.8 mm. Mean time period steps were measured at (1) planning CT with 3-D treatment planning: 76+/-12 min; (2) irradiation and verification: 33+/-7 min; and (3) complete procedure duration: 109+/-11 min (range, 89-169). CONCLUSIONS: The main difference between the positioning technique of SSRT and that of conventional extracranial radiosurgery is the tighter patient fixation, which guarantees minimal patient movement. The main advantages are procedure acceleration and omission of CT simulation. SSRT is a preliminary stage of real-time treatment.

Aged↗

PubMed2003

1-molar gadobutrol as a contrast agent for computed tomography: results from a comparative porcine study.

RATIONALE AND OBJECTIVES: To evaluate prospectively the efficacy of gadobutrol as contrast agent for computed tomography (CT) compared with iodinated contrast media in a porcine animal model. METHODS: In 8 domestic pigs (35 +/- 4 kg body weight [BW]), continuous spiral CTs of the chest and abdomen were performed using either 2 mmol/kg BW Gadovist 1.0 (1 mol/L gadobutrol) intravenously or Ultravist (300 mg I/mL iopromide) (slice 5 mm, table feed 7.5 mm, reconstruction increment 5 mm). One week later, the same animals were examined using the same protocol with the other contrast agent. In 2 additional animals, serial CTs were performed at the same level using gadobutrol or iopromide on day 1 and the alternate agent on day 8 inches order to determine contrast media kinetics, peak enhancement, and time enhancement-product in important vascular regions and parenchymal organs (abdominal aorta, inferior vena cava, liver, and renal parenchyma). Peak enhancement (net increase compared with nonenhanced baseline values) was measured in Hounsfield units (HU) in defined regions of interest. RESULTS: In vivo, the mean peak enhancement 5, 15, 30, and 120 seconds in the abdominal aorta after injection of 2 mL/kg BW gadobutrol and iopromide was 200 +/- 11, 224 +/- 10, 261 +/- 13, and 95 +/- 9 HU versus 232 +/- 10, 298 +/- 10, 152 +/- 11, and 123 +/- 10 HU, respectively. Differences in enhancement of vascular structures was statistically significant (P < 0.05) in carotid arteries (235 +/- 20 HU for gadobutrol and 264 +/- 19 HU for iopromide) and the aortic arch (261 +/- 14 HU for gadobutrol and 279 HU +/- 13 HU for iopromide). No statistical significance was seen in all other measured vascular structures and parenchymal organs. CONCLUSION: Contrast-enhanced CT with 1 mol/L gadobutrol in a dose of 2 mmol/kg BW resulted in an excellent vascular and parenchymal enhancement in most vascular regions and parenchymal organs similar to an equivalent volume of 300 mg/mL iodinated contrast media.

Animals↗

PubMed2002

Superselective embolization with coils in high-flow priapism.

Priapism can be divided into "low-flow" veno-occlusive priapism and, especially in children, rare "high-flow" arterial priapism. We report a 5-year-old boy who developed arterial priapism after blunt perineal trauma that was successfully treated by superselective embolization with microcoils.

Angiography↗

PubMed2002

X-ray digital subtraction angiography with 1 mol/L gadobutrol: results from a comparative porcine study With iodinated contrast agents.

RATIONALE AND OBJECTIVES: To evaluate prospectively diagnostic accuracy of 1 mol/L gadobutrol as a contrast agent for intraarterial x-ray digital subtraction angiography (DSA) in comparison to iodinated, nonionic contrast media and 0.5 mol/L gadolinium-DTPA. METHODS: Flush arteriograms (ascending, descending, abdominal aorta, iliac, and femoral arteries) and selective angiograms (carotid, renal, and visceral arteries) were obtained from bilateral femoral arterial access (5 F sheaths) in 10 domestic pigs (70 kg body weight). Digital subtracted angiograms were obtained during injection of undiluted 1 mol/L gadobutrol, 300 mg I/mL iopromide, or 0.5 mol/L gadopentetate. Injection parameters (volume and velocity) were similar for all three contrast agents. In paired arteries, two different contrast media were used during the same angiographic run. Diagnostic quality and accuracy of the angiograms were evaluated on a three-step scale by three independent blinded investigators. RESULTS: Sufficient nonselective angiographic images were obtained in 90% of cases using iodinated contrast material. Gadobutrol achieved sufficient nonselective angiograms in 64%. Selective angiograms were sufficient in 98% using iodinated contrast material, 90% using 1 mol/L Gadobutrol and 48% using 0.5 mol/L Gd-DTPA. Adverse reactions to any of the used contrast agents were not noted. CONCLUSION: One mol/L Gadobutrol solution allows x-ray digital subtraction angiography with a diagnostic accuracy equivalent to 300 mg/mL iodinated contrast media, if selective injections are performed. Flush aortograms are of inferior image quality to iodinated contrast material.

Angiography, Digital Subtraction↗