Search results for "Spiral ct"

Gadodiamide and gadopentetate dimeglumine in MRI versus spiral CT in the diagnosis of liver lesions.

2002

Bolus-enhanced renal spiral CT: technique, diagnostic value and drawbacks

1994

Abstract In addition to pre- and postcontrast renal CT scans, early bolus-enhanced spiral scans during demarcation of the corticomedullary junction were acquired in 85 patients. The diagnostic value and drawbacks of the three imaging series in the evaluation of renal disease were assessed. Renal calcifications and calculus disease detected at precontrast scans (18%) were obscured after contrast administration and excretion in most cases. In the detection of renal lesions bolus-enhanced spiral CT and delayed postcontrast scans had an identical diagnostic yield (94%). Bolus-enhanced spiral CT was superior in the assessment of lesion vascularity and vascular anatomy as well as opacification of…

The use of spiral CT in the detection and management of a permanent maxillary first molar with single root and single canal : a rare occurrence

2017

A sound knowledge of the normal tooth morphology and its numerous variations is essential to the success of endodontic therapy. While extra canals and lateral canals are routinely encountered and documented, there also exists the rare possibility of a fewer number of canals than normal. Early detection of such an occurrence is critical to the prevention of iatrogenic errors during endodontic treatment. The advent of spiral CT as a diagnostic tool serves as a much needed confirmation to understand the complex three dimensional anatomy of teeth. The aim of this case report is to highlight one such case reporting unusual morphology of the permanent maxillary first molar displaying single canal…

Three-Dimensional Contrast-Enhanced Magnetic Resonance Angiography in a Patient With Chronic Thromboembolic Pulmonary Hypertension Before and After T…

1999

The patient was a 69-year-old man with progressive dyspnea during the previous 5 years and no history of thromboembolic events. By means of spiral CT scanning and multiplanar digital subtraction angiography of the pulmonary arteries, chronic thromboembolic pulmonary hypertension was diagnosed. Mean pulmonary artery pressure and pulmonary vascular resistance were elevated to 46 mm Hg and 890 …

Automatische Berechnung des Milzvolumens aus Spiral-CT-Daten mit Hilfe neuronaler Netze und „Fuzzy Logik”∗

2000

PURPOSE To assess spleen segmentation and volumentry in spiral CT scans with and without pathological changes of splenic tissue. METHODS The image analysis software HYBRIKON is based on region growing, self-organized neural nets, and fuzzy-anatomic rules. The neural nets were trained with spiral CT data from 10 patients, not used in the following evaluation on spiral CT scans from 19 patients. An experienced radiologist verified the results. The true positive and false positive areas were compared in terms to the areas marked by the radiologist. The results were compared with a standard thresholding method. RESULTS The neural nets achieved a higher accuracy than the thresholding method. Cor…

Automatische Klassifikation der Lebersegmente nach Couinaud: Entwicklung eines neuen Algorithmus und Evaluierung an Spiral-CT-Datensätzen

2003

Purpose: To develop a software tool that analyzes the anatomy of the portal vein branches and assigns segmental and subsegmental branches according to Couinaud's classification system and to evaluate its accuracy. Materials and Methods: The algorithm was developed in C++ on a PC. The algorithm recognizes the three major branching patterns of the portal vein. Segmental and subsegmental branches are assigned to 8 segments following Couinaud and encoded by 8 colors. The software was evaluated using CT data sets of 39 patients. After the individual segmental anatomy of each patient was determined by an experienced radiologist, automatic classification was performed and the results were compared…

Phantomuntersuchung zur Optimierung der Spiral-CT und 3 D-Rekonstruktion des Tracheobronchialsystems

1996

PURPOSE To optimise three-dimensional spiral CT of the tracheobronchial tree using adequate acquisition and reconstruction parameters for spiral CT of the chest. MATERIAL AND METHODS Qualitative and quantitative assessment of different 3 D reconstructions of two test objects of the tracheobronchial tree depending on section thickness, reconstruction interval, pitch, and reconstruction algorithm used in spiral CT (Siemens, Somatom plus S) of the chest. The frequency of volume and stairstep artifacts was evaluated. The 3 D reconstructions were generated using a seeded VOI-technique (Allegro, ISG). RESULTS Reduction of artifacts was achieved by decreasing section thickness. Increasing overlap …

Evaluation eines neuen Softwareassistenten zur automatischen Volumenbestimmung von intrahepatischen Tumoren

2004

Purpose: Computed tomography has become the preferred method in detecting liver carcinomas. The introduction of spiral CT added volumetric assessment of intrahepatic tumors, which was unattainable in the clinical routine with incremental CT due to complex planimetric revisions and excessive computing time. In an ongoing clinical study, a new software tool was tested for the automatic detection of tumor volume and the time needed for this procedure. Materials and Methods: We analyzed patients suffering from hepatocellular carcinoma (HCC). All patients underwent treatment with repeated transcatheter chemoembolization of the hepatic arteria. The volumes of the HCC lesions detected in CT were m…

Spiral-CT und 3 D-Rekonstruktion des Tracheobronchialbaumes zur Auswahl geeigneter Doppellumentuben vor Einzellungenbeatmung

1997

Purpose To assess the potential of 3-D spiral CT in the selection of adequate double-lumen tubes (DLT) for one-lung-ventilation. Materials and methods 3-D spiral CT of eight different DLTs was performed with standardized acquisition parameters: section thickness 4 mm, table speed 6 mm/s, increment 3 mm and standardised thresholds, window settings and magnification zoom. The accuracy was confirmed by measuring 3-D objects on screen and original DLTs by vernier caliper. 3-D spiral CT was performed in 20 patients preoperatively with slice thickness 4-8 mm, pitch 1-1.5, increment 4-8 mm. To select the adequate DLT size the 3-D reconstructions of the patient's tracheobronchial tree and of the DL…

Möglichkeiten und Grenzen der Spiral-CT bei der Untersuchung von Nierenbeckenkarzinomen

1994

PURPOSE To assess the value of spiral CT in comparison to conventional CT in the staging of renal pelvic carcinoma. PATIENTS AND METHODS 35 patients with renal pelvic carcinoma underwent preoperative CT; conventional technique (n = 21) and spiral CT (n = 14) with the reconstruction of thin sections were compared. RESULTS Non-invasive or minimal invasive tumours (TA, T1, T2) could not be differentiated with either technique. Small, flat tumours (TA) or multicentric tumours may be missed, even if spiral scanning is applied. The separation of local tumour growth from infiltration is significantly improved by spiral CT (12 of 12 patients instead of 18 out of 21 patients with the conventional te…