Norbert Gritzmann
University of Innsbruck
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Featured researches published by Norbert Gritzmann.
Radiologic Clinics of North America | 2000
Dietmar Koischwitz; Norbert Gritzmann
Sonography, when performed by an experienced examiner, can be used for evaluation of many pathologies in the head and neck area. Some benign neck lesions, such as cysts, lipomas, carotid body tumors, and hyperplastic lymph nodes, have typical sonomorphology. Sonography has an accuracy rate of about 90% in cervical lymph node staging and can delineate subclinical lymph node recurrences. It is the method of choice for evaluation of tumor infiltrations of the wall of the great vessels. Salivary gland tumors in the superficial lobe can be delineated completely by sonography. Salivary stones can be detected and localized. Carcinoma of the tongue and floor of the mouth with T1 and T2 staging can be assessed by US. The use and contribution of color Doppler sonography for the assessment of pathologic entities in the neck is a method under clinical investigation. US-guided fine-needle aspiration biopsy of lymph nodes and tumors of the salivary glands is easy to perform and is characterized by high sensitivity and specificity. To perform US examinations of the head and neck area of the highest quality the examiner should be familiar with the anatomy of the head and neck, be informed about the clinical problem, and have experience in the interpretation of abnormal US findings. US of the head and neck area is one of the most difficult sonographic examinations and should be performed by an experienced physician.
European Radiology | 2001
Alois Hollerweger; Peter Macheiner; Thomas Rettenbacher; W. Brunner; Norbert Gritzmann
Abstract. Acute bowel inflammation frequently originates from thin-walled diverticula of the colon. Not the presence of diverticula, but the demonstration of an inflamed diverticulum, is diagnostic of diverticulitis in cases of bowel wall thickening and pericolic inflammation. The aim of this study was to investigate the sonographic appearance and detectability of inflamed diverticula. One hundred seventy-five consecutive patients with clinically suspected diverticulitis underwent sonographic examination. Outpouchings from the colonic wall centred in the pericolic inflammation were considered inflamed diverticula. Depending on the sonographic appearance they were divided into four groups: hypoechoic; predominantly hyperechoic; hyperechoic with surrounding hypoechoic rim; and hyperechoic with acoustic shadowing. Sonography showed inflamed diverticula in 79 (77%) of 102 patients with diverticulitis. Inflamed diverticula were hypoechoic in 37%, predominantly hyperechoic in 4%, hyperechoic with surrounding hypoechoic rim in 41% and hyperechoic with acoustic shadowing in 18% of patients. In 23 (23%) of 102 patients no inflamed diverticulum was demonstrable. This group included 17 patients with complicated diverticulitis and 6 false-negative cases. An inflamed diverticulum as a sign of diverticulitis yielded an overall sensitivity of 77% and a specificity of 99%. Sensitivity in uncomplicated disease was 96%. In patients with uncomplicated diverticulitis an inflamed diverticulum is a sign of diverticulitis with excellent sensitivity and specificity, usually with solitary and less frequently with more than one inflamed diverticulum being demonstrable. In patients with complicated diverticulitis an inflamed diverticulum is often not detectable.
Radiologic Clinics of North America | 2000
Norbert Gritzmann; Dietmar Koischwitz; Thomas Rettenbacher
Sonography is the first line modality for assessment of thyroid and parathyroid pathologies. Sonographic and color Doppler patterns of diffuse and focal pathologies of the thyroid are presented in this article. The accuracy of sonography in the localization of enlarged parathyroid glands is also discussed. The limitations of sonography in specifying focal thyroid diseases and the problems in localizing ectopic parathyroid adenoma are addressed.
Ultrasound in Medicine and Biology | 1997
Alois Hollerweger; Thomas Rettenbacher; Peter Macheiner; Norbert Gritzmann
In a prospective study, color Doppler sonograms (CDS) were performed in 142 patients with solid breast lesions (64 carcinomas, 53 fibroadenomas, 25 miscellaneous breast diseases). Exclusively intratumoral RI were determined, with only the highest and lowest value in the various vessels of a tumor being considered. We found that an RI < 0.80 is typical for benign breast conditions, but also frequently occurs in malignant lesions. A significant difference was seen for higher RIs. An RI > or = 0.80 was seen to be an indicator of malignancy with high specificity (96%) and a sensitivity of 55%. Moreover, RI differences in malignant lesions were markedly greater than in benign lesions. An RI difference > or = 0.20 among vessels of one tumor was a malignancy indicator with very high specificity (97%) but relatively low sensitivity (39%). An RI > or = 0.80 and RI differences > or = 0.20 are specific Doppler ultrasound (US) malignancy indicators.
European Radiology | 2002
Norbert Gritzmann; Alois Hollerweger; Peter Macheiner; Thomas Rettenbacher
Abstract. Like other cross-sectional imaging methods, transabdominal sonography is increasingly used for evaluation of gastrointestinal diseases. The potentials and limitations of sonography in evaluation of the gastrointestinal tract are discussed. Transabdominal sonography proved to be of clinical value in assessment of appendicitis, diverticulitis, bowel obstruction, chronic inflammatory bowel diseases, intussusception and infantile hypertrophic pyloric stenosis. The sonographic morphology of the most common gastrointestinal diseases is discussed. In experienced hands sonography can be used as primary imaging in several gastrointestinal diseases. The gastrointestinal tract should be included in the sonographic examination of the abdomen, especially if symptoms could be related to the intestine.
Ultrasound in Medicine and Biology | 2001
Thomas Rettenbacher; Peter Macheiner; Alois Hollerweger; Norbert Gritzmann; Christian Weismann; Boris Todoroff
The purpose of this study was to examine if suture granulomas display distinct sonographic signs and if these signs enable an accurate preoperative diagnosis. In a retrospective and prospective study, the sonographic findings of 22 consecutive suture granulomas were investigated and correlated with subsequent operative results. The sonographic appearance of various surgical sutures in a water bath was also investigated. Sonography was performed with commercially available 5- to 13-MHz linear transducers. The sonographic findings of the suture granulomas included hypoechoic lesions in all cases and hyperechoic double or single lines within the hypoechoic lesions in 20 of 22 cases. Sonography enabled the correct preoperative diagnosis for the investigating radiologists in 20 cases. The sonographic appearance of sutures in a water bath was that of hyperechoic double or single lines. The sonographic signs of suture granulomas (hyperechoic double or single lines within hypoechoic lesions) indicate the correct preoperative diagnosis in a high percentage of cases.
Digestive Diseases | 2004
Norbert Gritzmann; Peter Macheiner; Alois Hollerweger; Erich Hübner
Today, computed tomography (CT) is the most commonly used imaging method in the assessment of pancreatic tumors. The sensitivity of CT in detection of pancreatic tumors is more than 90% when direct and indirect signs are used for diagnosis. However, the potential to differentiate exocrine (non-endocrine) tumors of the pancreas is limited. CT is used in these lesions to perform an adequate staging, especially for surgical purposes. The operative resectability, primarily in regard to vessels, lymph node metastasis and hepatic metastasis, has to be assessed. Keeping in mind the limitations of this macromorphological imaging procedure, CT has the best reproducibility and overall accuracy of all imaging methods. Using multislice CT it is possible to perform non-axial reconstructions with high resolution. In functional endocrine tumors, multislice spiral CT will enhance the diagnostic capabilities, since the whole organ can be examined in thin slices, with high resolution during the rather short arterial phase of the contrast medium. Since some endocrine tumors are hypovascular, a scan during the portovenous phase is recommended too. The diagnosis of benign pancreatic tumors, like serous cystadenoma and pancreatic lipomas, is addressed. The most important pseudotumors of the pancreas are discussed.
Ultrasound in Medicine and Biology | 1998
Thomas Rettenbacher; Alois Hollerweger; Peter Macheiner; Norbert Gritzmann
In a prospective study, 200 healthy female breasts were examined using color Doppler sonography to study the detectability and the resistive indices (RIs) of arterial vessels. In each breast, we attempted to detect two to three vessels and recorded the frequency spectrum with RI of each vessel. Blood vessels (n = 522) could be demonstrated in 196 (98%) breasts. Continuous diastolic flow (RI < 1) was found in 520 (99.6%) vessels. The mean RI of premenopausal women was 0.64; that of postmenopausal women was 0.70. This difference is highly statistically significant (p < 0.0001), but there is a marked overlap between the RIs of both groups. The variation in RI values of all women (up to 0.45), as well as in the breasts of the same woman (up to 0.31), was considerable. We conclude that modern color Doppler devices permit the detection of blood flow in the breast with regularity. Continuous diastolic flow (RI < 1) is a typical flow pattern. The variations of RI between women, and even for the same woman, are remarkable. The mean RI of premenopausal women is lower than the value for postmenopausal women.
American Journal of Roentgenology | 2001
Thomas Rettenbacher; Alois Hollerweger; Peter Macheiner; Norbert Gritzmann; Thaddeus Gotwald; Robert Frass; Barbara Schneider
European Radiology | 2003
Norbert Gritzmann; Thomas Rettenbacher; Alois Hollerweger; Peter Macheiner; Hübner E