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We evaluated the vascular territory of accessory renal arteries in cases where the vessel might be overlapped by an aortic stent-graft. Spiral CT during selective accessory renal artery angiography was performed in four patients with abdominal aortic aneurysms (including one with a horseshoe kidney). The volume of the vascular territory of each renal artery was measured using a software program provided by the CT unit manufacturer. The supernumerary renal arteries perfused 32%, 37%, 15%, and 16% of the total renal mass, respectively. In two patients, stent-grafts were implanted, which resulted in occlusion of the supernumerary renal artery. The volume of the renal infarction was equal to the volume perfused by the artery as calculated before implantation of the stent-graft. The method proposed is accurate for estimating the size of the expected renal infarction. It might help to determine whether placement of a stent-graft is acceptable. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this work was to compare nonfunctional and functional spiral CT in the tumor (T) staging of laryngeal and hypopharyngeal tumors and to correlate the CT results with microlaryngoscopy and postoperative pathology., Method: Twenty-six patients (3 women, 23 men) with clinically suspected laryngeal and hypopharyngeal tumors underwent both nonfunctional CT during quiet breathing and functional spiral CT during either a modified Valsalva (n = 19) or E phonation (n = 7) maneuver. CT slice thickness was 3 mm, table feed was 3 mm, and 40-80 ml of intravenous contrast material was administered at a flow of 1.5 ml/s. T stages as determined by nonfunctional and functional CT were compared and correlated with postoperative pathology or microlaryngoscopy., Results: The T stages determined with functional CT were better correlated with postoperative pathology (rS = 0.88, p = 0.001) and microlaryngoscopy (rS = 0.77, p = 0.008) than T stages determined with nonfunctional CT (rS = 0.80, p = 0.001; and rS = 0.51, p = 0.13, respectively). Twelve of 26 patients (46%) had a lower T stage on functional than on nonfunctional CT. In 14 of 26 patients (54%), the T stage was identical with both modalities. In no patients was the T stage increased by functional CT., Conclusion: Functional CT appears to be more accurate than nonfunctional CT in the T staging of laryngeal and hypopharyngeal carcinomas. Functional CT also results in lower T stages than nonfunctional CT in a substantial number of patients.

Purpose: To calculate cutoff levels for quantitative ultrasonography (US) performed to distinguish healthy individuals and those with osteoporosis identified with dual x-ray absorptiometry., Materials and Methods: In 1,357 patients (856 females, aged 55.1 years +/- 15.4 [mean +/- SD]; 501 males, aged 50.4 years +/- 15), bone mineral density measurements of the lumbar spine (posteroanterior, L1 through L4) and femoral neck were obtained, and quantitative US was performed to determine the stiffness of the calcaneus. Individuals with a T score less than -2.5 (osteoporotic) at the spine and femur were identified, and upper T-score cutoff values (3 SDs from the mean) in the groups of male and female patients with osteoporosis were identified., Results: Females with dual x-ray absorptiometric values that were indicative of osteoporosis of the spine had an upper T-score cutoff value of -1.0 (males, -0.2). Females who had femoral osteoporosis showed an upper quantitative US T-score cutoff value of -0.6 (males, 0)., Conclusion: Cutoff values may permit the use of quantitative US to screen for the presence of osteoporosis in the spine and femur. Quantitative US will help to prevent unnecessary dual x-ray absorptiometric and conventional radiographic examinations.

The role of subchondral bone in the pathogenesis of cartilage damage has likely been underestimated. Subchondral bone is not only an important shock absorber, but it may also be important for cartilage metabolism. Contrary to many drawings and published reports, the subchondral region is highly vascularized and vulnerable. Its terminal vessels have, in part, direct contact with the deepest hyaline cartilage layer. The perfusion of these vessels accounts for more than 50% of the glucose, oxygen, and water requirements of cartilage. Bony structure, local metabolism, hemodynamics, and vascularization of the subchondral region differ within a single joint and from one joint to another. Owing to these differences, repetitive, chronic overloading or perfusion abnormalities may result in no pathological reaction at all in one joint, while in another joint, these same conditions may lead to osteonecrosis, osteochondritis dissecans, or degenerative changes. According to this common etiological root, similar pathological reactions beginning with marrow edema and necrosis and followed by bone and cartilage fractures, joint deformity, and insufficient healing processes are found in osteonecrosis, osteochondritis dissecans, and degenerative disease as well.

Background: The pharynx, being part of the digestive as well as the respiratory system, is embedded in the complex spatial anatomy of the neck and, due to its function and location, represents a very sophisticated region., Diagnosis: Cross-sectional imaging with CT and MR imaging plays an indispensable complementary role to clinical work-up, as far as submucosal and deep cervical spaces are concerned. However, as dysphagia is a common symptom in clinical practice, interpretation of double contrast studies and videofluoroscopic investigations are also on frequent demand in the daily routine., Conclusion: Close interdisciplinary co-operation and the radiologist's familiarity with the anatomy of the region are required in order to use the diagnostic tools in an optimal fashion.

Development: The first part of this article is supposed to present a brief overview on the development of tissues and structures related to the pharynx, as far as they provide a better understanding of the most congenital lesions in this area of the body., Benign Lesions: The second part of this article focuses on benign lesions originating in the pharynx or in neighbouring structures. Functional pharynx abnormalities are beyond the scope of this paper.

To date, MR imaging is absolutely contraindicated in cochlear-implanted patients. The aim of this study is to document the potential value of MR imaging in such patients, without injurious or side effects and without technical device failure. After in vitro experimental testing, 25 cochlear implanted patients underwent MRI. Radiological evaluation was also possible. The use of 1-Tesla fast spin echo sequences minimised artifacts. All cochlear implants are still in working order; no changes in fitting data or a reduction in speech understanding were observed. MR helped to avoid other invasive medical procedures.

Until recently, conventional dental radiology was performed by dentists and orofacial surgeons. Due to the rapid development of radiological technique, the demand of radiological advice is increasing. The radiologists see more and more dental patients in their daily routine. The aim of this article is to give an overview on established dental radiology and a glimpse into the future. Conventional dental radiology and digital radiography are presently in use. Intraoral technique comprises dental films, bite-wing views and occlusal radiographs. Panoramic views and cephalometric radiographs are done with extraoral technique. Digital radiography lacks all processes in behalf of film development. It leads to dose reduction and enables image manipulation.

Purpose: To demonstrate the usefulness of Dental-MRT for imaging of anatomic and pathologic conditions of the mandible and maxilla., Methods: Seven healthy volunteers, 5 patients with pulpitis, 9 patients with dentigerous cysts, 5 patients after tooth transplantation and 12 patients with atrophic mandibles were evaluated. Studies of the jaws using axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been to performed. The acquired images were reconstructed with a standard dental software package on a workstation as panoramic and cross sectional views of the mandible or maxilla., Results: The entire maxilla and mandibula, teeth, dental pulp and the content of the mandibular canal were well depicted. Patients with inflammatory disease of the pulp chamber demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media application marked enhancement of the dental pulp can be found., Conclusion: Dental-MRT provides a valuable tool for visualization and detection of dental diseases.

Purpose: To determine the value of computed tomography (CT) in the diagnosis of dental vertical root fractures relative to the value of conventional dental radiography., Materials and Methods: Thirty-seven patients with 42 teeth in which vertical root fracture was clinically suspected underwent dental radiography and axial CT. Two radiologists evaluated the images independently and by consensus for a fracture line. The results were compared with intraoperative findings., Results: Twenty-eight of the 42 teeth were proved intraoperatively to be fractured. The sensitivity and specificity averaged for the two reviewers in the assessment of vertical fractures were 23% and 70%, respectively, with dental radiography and 100% and 100%, respectively, with CT. Consensus reading showed sensitivities of 25% for dental radiography and 75% for CT. Eight (reviewer A) or nine (reviewer B) false-negative CT findings were encountered in cases in which metallic artifacts obscured parts of the root and in cases in which the root was very small in diameter. Interobserver agreement was 95% for dental radiography and 93% for CT., Conclusion: CT is superior to dental radiography in the detection of dental vertical root fractures.

Purpose: To assess the value of bedside sonography in the detection of diaphragmatic paralysis in patients in the intensive care unit., Methods: In this study, 100 patients who were admitted to the intensive care unit after thoracic operations were evaluated. Sonography of each hemidiaphragm was performed with coronal scans at the mid-axillary line on both sides with the patient supine. Absent and paradoxical diaphragmatic movement was considered to be indicative of diaphragmatic paralysis. All patients underwent additional fluoroscopy within 5 days., Results: In 13 patients (13%) sonography revealed diaphragmatic paralysis. All these results were confirmed with fluoroscopy resulting in a sensitivity and specificity for sonography of 100%., Conclusion: Bedside sonography of the diaphragm at the intensive care unit is a reliable tool for diagnosing diaphragmatic paralysis.

Purpose: Our aim was to evaluate the MR compatibility of Med EL cochlear implants by performing in vitro and in vivo tests., Method: All experiments were done on a 1.0 T machine. Potential movement of the cochlear electrode relative to a scale was recorded. Potential dislodgment of the magnetic receiver coil was evaluated with the coil fixed to the retroauricular skin of a volunteer. Temperature changes were measured with temperature sensors fixed to the electrode, performing standard MR sequences. In 11 patients, MRI of the brain was performed 1 day before explantation of the devices using standard MR sequences. Testing of the auditory abilities was done before and after the examination. All explanted devices were assessed for function., Results: There was no detectable movement of the electrode or the receiver coil nor any temperature change. There were no adverse events for the patients. All 11 explanted cochlear implants retained their function., Conclusion: Med EL cochlear implants are not a firm contraindication for MRI.

Purpose: Evaluation of sonography in the assessment of changes of the biliary system of newborn infants receiving total parenteral nutrition., Patients and Methods: In 20 premature infants on mechanical ventilation, the influence of two different amino acid solutions (Vaminolac, Paedamin) in the development of neonatal cholestasis was analysed. The patients were randomised in two groups. Group 1 (n = 11) received Paedamin, group 2 (n = 9) received Vaminolac., Results: There was no statistically significant influence of the amino acid solution on the development of cholestasis. However, the majority of the children with cholestasis (8 of 11) presented with sepsis., Conclusion: Bacterial infections seem to be closely related to the development of cholestasis. Sludge formation within the bile ducts represents a sensitive sonographic parameter for the diagnosis and follow-up of cholestasis secondary to total parenteral nutrition.