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Objectives To evaluate the performance of radiomic features extracted from high-resolution computed tomography (HRCT) for the differentiation between cholesteatoma and middle ear inflammation (MEI), and to investigate the impact of post-reconstruction harmonization and data resampling. Methods One hundred patients were included in this retrospective dual-center study: 48 with histology-proven cholesteatoma (center A: 23; center B: 25) and 52 with MEI (A: 27; B: 25). Radiomic features (co-occurrence and run-length matrix, absolute gradient, autoregressive model, Haar wavelet transform) were extracted from manually defined 2D-ROIs. The ten best features for lesion differentiation were selected using probability of error and average correlation coefficients. A multi-layer perceptron feed-forward artificial neural network (MLP-ANN) was used for radiomics-based classification, with histopathology serving as the reference standard (70% of cases for training, 30% for validation). The analysis was performed five times each on (a) unmodified data and on data that were (b) resampled to the same matrix size, and (c) corrected for acquisition protocol differences using ComBat harmonization. Results Using unmodified data, the MLP-ANN classification yielded an overall median area under the receiver operating characteristic curve (AUC) of 0.78 (0.72–0.84). Using original data from center A and resampled data from center B, an overall median AUC of 0.88 (0.82–0.99) was yielded, while using ComBat harmonized data, an overall median AUC of 0.89 (0.79–0.92) was revealed. Conclusion Radiomic features extracted from HRCT differentiate between cholesteatoma and MEI. When using multi-centric data obtained with differences in CT acquisition parameters, data resampling and ComBat post-reconstruction harmonization clearly improve radiomics-based lesion classification. Key Points • Unenhanced high-resolution CT coupled with radiomics analysis may be useful for the differentiation between cholesteatoma and middle ear inflammation. • Pooling of data extracted from inhomogeneous CT datasets does not appear meaningful without further post-processing. • When using multi-centric CT data obtained with differences in acquisition parameters, post-reconstruction harmonization and data resampling clearly improve radiomics-based soft-tissue differentiation.

Purely torsional spontaneous nystagmus almost always has a central vestibular cause. We describe a man with spontaneous pulse-synchronous torsional nystagmus in which the clockwise component corresponded to his pulse upswing, in keeping with a peripheral vestibular cause; following imaging we diagnosed left-sided superior canal dehiscence syndrome. Identifying pulse synchronicity of spontaneous nystagmus may help to distinguish central from peripheral vestibular torsional nystagmus, and is readily confirmed at the bedside using Frenzel’s glasses and a pulse oximeter.

Objective: The aim of this study was to evaluate whether stapes prostheses can be visualized with less metal artifacts and therefore more accurately on cone beam computed tomography in comparison to computed tomography imaging. Recent studies have shown that cone beam computed tomography has advantages when imaging metal artifacts. Patients with hearing loss or vertigo, who have undergone stapedotomy, often present a challenge for otologic surgeons. Imaging studies can deliver crucial additional information. Methods: A retrospective analysis of imaging studies and clinical data in a tertiary care center were carried out. Forty-one patients with forty-five implanted ears were evaluated in the study. All included patients had been implanted with a platinum–fluoroplastic (n = 19) or titanium (n = 26) piston and subsequently had undergone imaging months or years after surgery for various reasons. Patients underwent computed tomography or cone beam computed tomography of the temporal bone depending on availability. Piston visualization, prosthesis length, vestibular intrusion and audiologic results were compared between the groups. Piston position on imaging studies were compared to intraoperative findings. Results: Functional length measurements of all prostheses were carried out with a mean error of −0.17 mm (±0.20). Platinum–fluoroplastic protheses were significantly underestimated in length compared to titanium prostheses. To analyze the material-dependent difference in the measurement errors of the imaging techniques the interaction was tested in an ANOVA model and showed no statistically significant result (p = 0.24). The blinded neuroradiologist viewed two implants, both platinum–fluoroplastic pistons, as located outside of the vestibule due to an underestimation of the prothesis length and the missing radiodensity of the lower end of the prosthesis. Conclusion: Surgeons and radiologists should be aware of the different types and radiologic features of stapes prostheses and the missing radiodensity of some protheses parts. Cone beam computed tomography is an imaging alternative with a potential advantage of reduced radiation in patients after stapes surgery suffering from vertigo or hearing loss to evaluate piston position.

Background Taxane-based checkpoint inhibitor combination therapy might improve the outcome in recurrent/metastatic (R/M) head and neck cancer (HNSCC) patients. Thus, we investigated the efficacy and safety of docetaxel (DTX) plus pembrolizumab (P) in a prospective phase I/II trial. Methods Platinum-resistant R/M HNSCC patients received DTX 75 mg/m^2 plus P 200 mg for up to six cycles followed by P maintenance therapy. The primary endpoint was overall response rate (ORR) and safety. Secondary endpoints comprised disease control rate (DCR), overall survival (OS) and progression free survival (PFS). Results Twenty-two patients were enrolled. Nine patients (40.9%) had a primary tumor in the oropharynx, 8 (36.4%) in the oral cavity, 3 (13.6%) in the hypopharynx and 2 (9.1%) in the larynx. The ORR was 22.7% (95% CI 10.1%-43.4%) and one (4.5%) complete response was achieved. The DCR was 54.6% (95% 34.7%-73.1%). The median PFS was 5.8 months (95% CI 2.7–11.6) and the median OS 21.3 months (95% CI 6.3–31.1). The 1-year PFS and OS rates were 27.3% and 68.2%, respectively. While the most frequent adverse event (AE) was myelosuppression, which was reported in all 22 patients, 3 (13.6%) patients experienced grade 3 febrile neutropenia. The most common immune-related AEs were grade skin rash (40.9%) and hypothyroidism (40.9%). One patient (4.5%) experienced grade 5 immune thrombocytopenia. Conclusion DXT in combination with P shows promising activity accompanied with a manageable side effect profile in pre-treated R/M HNSCC patients.

Die Magnetresonanztomographie (MRT) des Huftgelenkes kommt zur Diagnostik bei vielen klinischen Zustandsbildern zum Einsatz. Zur Abklarung von Pathologien des Huftgelenkes wird einerseits die konventionelle MRT und anderseits die MR-Arthrographie verwendet. Knochenmarklasionen, die Osteonekrose, differenzialdiagnostisch die aktivierte Arthrose sowie entzundliche und tumorose Veranderungen werden mit der MRT zum Teil auch nach intravenoser Kontrastmittelgabe untersucht. Die MR-Arthrographie, bei welcher es durch die intraartikulare Applikation verdunnten Kontrastmittels zu einer Distension des Gelenkes kommt, ist exzellent zur Abklarung von Lasionen des Labrum acetabulare, Knorpelschadigungen und freien Gelenkskorpern geeignet. In neuerer Zeit erfolgt die MR-Arthrographie mit Traktion der zu untersuchenden Extremitat, da es hierdurch zu einer deutlichen Distension der Gelenkskonstituenten kommt und hierdurch vor allem auch Lasionen des Labrums mit Knorpelbeteiligungen noch besser erfasst werden konnen. Die folgende Arbeit soll einen Uberblick uber die magnetresonanztomographischen Bilder und ihre Genauigkeit zur Erfassung labraler Lasionen und den Einfluss auf das therapeutische Vorgehen geben.

Aim: To evaluate whether texture-based analysis of standard MRI sequences can help in the discrimination between benign and malignant head and neck tumors. Materials and Methods: The MR images of 100 patients with a histologically clarified head or neck mass, from two different institutions, were analyzed. Texture-based analysis was performed using texture analysis software, with region of interest measurements for 2 D and 3 D evaluation independently for all axial sequences. COC, RUN, GRA, ARM, and WAV features were calculated for all ROIs. 10 texture feature subsets were used for a linear discriminant analysis, in combination with k-nearest-neighbor classification. Benign and malignant tumors were compared with regard to texture-based values. Results: There were differences in the images from different field-strength scanners, as well as from different vendors. For the differentiation of benign and malignant tumors, we found differences on STIR and T2-weighted images for 2 D, and on contrast-enhanced T1-TSE with fat saturation for 3 D evaluation. In a separate analysis of the subgroups 1.5 and 3 Tesla, more discriminating features were found. Conclusion: Texture-based analysis is a useful tool in the discrimination of benign and malignant tumors when performed on one scanner with the same protocol. We cannot recommend this technique for the use of multicenter studies with clinical data. Key Points: Citation Format: • Fruehwald-Pallamar J., Hesselink J. R., Mafee M. F. et al. Texture-Based Analysis of 100 MR Examinations of Head and Neck Tumors – Is It Possible to Discriminate Between Benign and Malignant Masses in a Multicenter Trial?. Fortschr Rontgenstr 2016; 188: 195 – 202

To test the feasibility and accuracy of MR-guided soft tissue tumour biopsy at 3T, using the dynamic contrast-enhanced (DCE) information from staging MRI for intralesional targeting. After obtaining written informed consent for this institutional review board-approved study, 53 patients with suspected soft tissue tumours prospectively underwent preoperative staging MRI at 3T, including DCE, and subsequent MR-guided core needle biopsy. In 44/53 cases, DCE was heterogeneous and was used for intralesional biopsy targeting. Surgical, whole-specimen histology was used as the gold standard in 43/44 patients and revealed 42 soft tissue tumours (24 men; 18 women; mean age, 52 years; range, 19 – 84). Final surgical histology revealed eight benign lesions, six tumours of intermediate dignity, and 28 malignancies. All malignancies had shown heterogeneous DCE. The diagnostic yield of the biopsies was 100 % (42/42). Histological accuracy rates of biopsy were 100 % in predicting the dignity (42/42; 95 % CI [0.916 – 1.000]), 95.2 % for the tissue-specific entity (40/42; 95 % CI [0.847 – 0.987]), and 90.5 % for the tumour grade (38/42; 95 % CI [0.779 – 0.962]). Our preliminary study indicates that biopsy of soft tissue tumours can be performed accurately and safely with DCE targeted MR-guidance at 3T, using a combined staging/biopsy MRI protocol. • MR-guided soft tissue tumour biopsy using DCE for intralesional targeting is feasible. • Targeting by staging-MRI allows reliable planning of the biopsy approach. • The method seems accurate and safe as a combined staging/biopsy procedure in outpatients. • DCE-targeted biopsy seems useful in challenging large and heterogeneous tumours.

Objective Matrix-associated chondrocyte transplantation is routinely used in joints of the extremities but not in the temporomandibular joint (TMJ). Study Design We report the first case series in 7 patients of a tissue engineering approach to regenerate severely degraded articulating surfaces in the TMJ by simultaneously completely resurfacing both the mandibular condyle and the articular eminence/glenoid fossa with a commercially available collagen sponge seeded with autologous cells stabilized within a fibrin matrix. To facilitate healing, we temporarily employed a silicone membrane to protect the engineered tissues. The indications for surgery were posttraumatic fibro-osseous ankylosis, ankylosing osteoarthritis, or late-stage osteoarthritis. Results Six of the patients were recalled for follow-up after 3 years 6 months to 12 years 1 month. The maximum incisal opening was 18.2 ± 9.2 mm (range, 9-33 mm) before and 31.2 ± 13.6 mm (range, 12-47 mm) at the latest follow-up. Histologic specimens taken at 4 months showed beginning differentiation of fibrocytes into chondrocytes, whereas at 3 and 11 years, mature hyaline cartilage—not typical for the TMJ—was present. Conclusions We conclude that the reconstruction of TMJ surfaces by matrix-associated chondrocyte transplantation may become a routine method for cartilage regeneration in the TMJ in the future.

Multidetector computed tomography (MDCT) has become the essential tool for the evaluation of malformations, trauma, and especially tumors of the head and neck region. Important for an adequate evaluation of pathologic findings in the head and neck region is a profound knowledge of the anatomic compartments, their content, and their neighboring relation. The head and neck region requires a very high soft tissue and bone resolution in order to precisely delineate the pathology. Therefore, CT scanning of different head and neck regions should be fitted for the special needs of the investigated anatomic region, for example, particular adjusted protocols for the evaluation of the larynx. The rapid technical improvement of MDCT in recent years has made CT the fist–choice imaging modality in many clinical conditions. The thinner slice collimation with improved anatomic detail visualization, the considerably reduced scanning time, and the possibility to calculate multiplanar reconstructions (MPR) from the scanned volume data set have contributed to the ascent of CT scanning in head and neck oncology. The ability of cross–sectional imaging to exactly reveal pathologic conditions that are not detectable by endoscopy or in the setting of staging underestimated due to submucosal spread is a strength of MDCT. Another modality – dual–energy MDCT – has been established in recent years to image head and neck tumors (Toepker et al. 2014).

The purpose of this study was to evaluate whether texture-based analysis of standard MRI sequences and diffusion-weighted imaging can help in the discrimination of parotid gland masses. The MR images of 38 patients with a biopsy- or surgery-proven parotid gland mass were retrospectively analyzed. All patients were examined on the same 3.0 Tesla MR unit, with one standard protocol. The ADC (apparent diffusion coefficient) values of the tumors were measured with three regions of interest (ROIs) covering the entire tumor. Texture-based analysis was performed with the texture analysis software MaZda (version 4.7), with ROI measurements covering the entire tumor in three slices. COC (co-occurrence matrix), RUN (run-length matrix), GRA (gradient), ARM (auto-regressive model), and WAV (wavelet transform) features were calculated for all ROIs. Three subsets of 10 texture features each were used for a linear discriminant analysis (LDA) in combination with k nearest neighbor classification (k-NN). Using histology as a standard of reference, benign tumors, including subtypes, and malignant tumors were compared with regard to ADC and texture-based values, with a one-way analysis of variance with post-hoc t-tests. Significant differences were found in the mean ADC values between Warthin tumors and pleomorphic adenomas, as well as between Warthin tumors and benign lesions. Contrast-enhanced T1-weighted images contained the most relevant textural information for the discrimination between benign and malignant parotid masses, and also for the discrimination between pleomorphic adenomas and Warthin tumors. STIR images contained the least relevant texture features, particularly for the discrimination between pleomorphic adenomas and Warthin tumors. Texture analysis proved to differentiate benign from malignant lesions, as well as pleomorphic adenomas from Warthin tumors, based on standard T(1w) sequences (without and with contrast). Of all benign parotid masses, Warthin tumors had significantly lower ADC values than the other entities.

To retrospectively assess the detection rate for intracranial hematomas achieved with use of curved maximum intensity projections (MIPs) that parallel the inner table of the skull compared with the rate achieved by reading transverse sections of computed tomography (CT) only.This retrospective study was approved by the institutional review board, which waived informed consent. A total of 314 consecutive patients who underwent CT for cranial trauma (155 male, 159 female; mean age ± standard deviation, 58 years ± 24 [range, 2-98 years]) were included. The algorithm unfolded the meningeal spaces into four images per patient. Four radiologists independently evaluated all cases. Hematomas less than 3 mm thick were considered thin. Radiologists were blinded to patient names, and patient and group orders were randomly assigned. The results were compared with a reference standard built by two experts. Logistic regression with repeated measurements was used for statistical analysis.Use of the reference standard helped confirm 121 intracranial hematomas in 39 patients. For all readers, reading time for hematoma detection was significantly shorter (3-5 times shorter, P.001) for curved MIPs. Mean lesion-based detection rate for all readers was 80% (193 of 242) for transverse sections and 83% (200 of 242) for curved MIPs. For thin hematomas, the mean detection rate increased from 20% (eight of 40) with transverse sections to 83% (33 of 40) with curved MIPs.Curved MIPs of the meningeal spaces may shorten detection time for epidural and subdural hematomas, increase sensitivity (especially for thin hematomas), and reduce the required operator experience for detection.

Objective To define normal growth of the fetal maxillary dental arch using magnetic resonance imaging. Method Four hundred twenty-four consecutive fetuses (18 to 37 weeks) with a morphologically normal anatomy or only minor malformations, not affecting bone growth and face anatomy were included. On axial T2-weighted images the dental arch length and width were measured. The measurements were correlated with gestational age and the biparietal diameter (BPD) of the fetal head using correlation and regression analysis. Results A linear growth relationship was observed between the dental arch length and gestational age (r = 0.86; p =

To investigate the diagnostic accuracy, through quantitative analysis, of contrast-enhanced ultrasound (CEUS), using a microbubble contrast agent, in the differentiation of thyroid nodules.This prospective study enrolled 46 patients with solitary, scintigraphically non-functional thyroid nodules. These patients were scheduled for surgery and underwent preoperative CEUS with pulse-inversion harmonic imaging after intravenous microbubble contrast medium administration. Using histology as a standard of reference, time-intensity curves of benign and malignant nodules were compared by means of peak enhancement and wash-out enhancement relative to the baseline intensity using a mixed model ANOVA. ROC analysis was performed to assess the diagnostic accuracy in the differentiation of benign and malignant nodules on CEUS.The complete CEUS data of 42 patients (31/42 [73.8%] benign and 11/42 [26.2%] malignant nodules) revealed a significant difference (P0.001) in enhancement between benign and malignant nodules. Furthermore, based on ROC analysis, CEUS demonstrated sensitivity of 76.9%, specificity of 84.8% and accuracy of 82.6%.Quantitative analysis of CEUS using a microbubble contrast agent allows the differentiation of benign and malignant thyroid nodules and may potentially serve, in addition to grey-scale and Doppler ultrasound, as an adjunctive tool in the assessment of patients with thyroid nodules.• Contrast-enhanced ultrasound (CEUS) helps differentiate between benign and malignant thyroid nodules. • Quantitative CEUS analysis yields sensitivity of 76.9% and specificity of 84.8%. • CEUS may be a potentially useful adjunct in assessing thyroid nodules.

The purposes of this study were: (a) to prospectively assess the correlation between apparent diffusion coefficient (ADC) values and maximum standardized uptake values (SUVmax) in patients with head and neck squamous cell carcinomas (SCC); and (b) to assess ADC and SUVmax values in relation to different tumour grades and stages in our patient population.The study group comprised 31 consecutive patients with biopsy-proven head and neck squamous cell carcinoma who were examined using a 3T MRI scanner with a 16-channel head and neck coil. In addition to routine sequences, axial (DWIBS) and sagittal (DW-EPI) diffusion-weighted sequences were obtained using b-values of 0 mm(2)/s and 800 mm(2)/s. The ADC maps were calculated automatically. The ADC values of the tumours were measured with three regions of interest (ROIs) of standard size, and an ROI covering the entire tumour. In all patients, contrast-enhanced, whole-body (18)F-FDG PET/CT was performed within 2 weeks of the MRI examination. SUVmax was measured for every tumour using a 3-D freehand ROI that covered the entire tumour. Two-way repeated measures ANOVA was used for group comparisons. The Spearman rank correlation test was performed for ADC values.Mean ADC values in the 31 SCC were 0.902 (± 0.134) with a ROI of standard size, and 0.928 (± 0.160) with the large ROI measurements on the axial DWIBS sequence. The ADC values of the tumours were significantly higher when measured with the sagittal DW-EPI sequence: 1.051 (± 0.211) and 1.082 (± 0.208). We observed no significant differences in ADC values and SUVmax between the various T stages or histological grades of the tumours. SUVmax values (26.5 ± 12) did not correlate with ADC values on DWIBS or EPI.There is no correlation between the FDG uptake and the ADC value in head and neck SCC. The three different tumour grades and four tumour stages present in our study population could not be differentiated based on ADC values or SUV.

Objective To assess the imaging findings in Chachapoyan mummies of Peru through multidetector computed tomography (MDCT). Materials and methods Twelve human mummies and three burial objects from Laguna de los Condores, Peru, about 500–1000 years old, were studied, using a MDCT unit. In addition to the standard whole-body acquisitions, high-resolution scans from areas of particular interest were acquired individually (e.g., temporal bone, teeth). Results Eight mummies were female, three male, and sex was indeterminable in one mummy; the age of the mummies included newborn, 0.7 years, 2.5 years, 13 years, 13 years, 16 years, and six between 20 and 40 years old. The stature of the mummies was reconstructed (mean ± standard deviation; adults: 145 ± 14 cm, adolescents: 116 ± 17 cm, 2.5 years old child: 72 cm, newborns: 41 ± 3 cm). Dental conditions were compromised in seven and excellent in five mummies. Besides a dislocation of the ossicles, temporal bones and ears were normal in all mummies. An occipital osteoma, a tuberculous spondylodiscitis, and also probable tuberculous erosions at one tarsal joint and one sacral bone, osteoarthritis or tuberculous affection of a sacroiliac joint, as well as five cases of pulmonary tuberculosis were observed. Ten mummies were buried in the fetal position, two were found packaged in bundles; the burial technique was studied in detail. A necklace was found with one mummy. The added burial objects were identified as skeletal parts of two leopardis pardalis and one lagothrix flavicauda. Conclusions MDCT non-invasively revealed information about age, sex, stature, diseases, burial practices and other cultural aspects of the Chachapoyas.

Objective The authors report imaging findings in a series of 16 patients with MCC, a rare tumour which is often managed primarily by a dermatologist. To our knowledge, no equivalent series of MCC has been described in the nuclear medicine literature. Material and Methods In this IRB-approved retrospective noncomparative case series 16 patients with biopsy-proven Merkel cell carcinoma were included between January 1999 and October 2007. Twenty-nine whole body PET scans (18F-FDG n = 24, 18F-FDOPA n = 5) in 16 patients were retrospectively reviewed with regard to tracer uptake in six anatomical sites per patient. For 127/144 of FDG-PET evaluated regions and 68/144 of regions depicted by conventional imaging methods, a valid standard of reference could be obtained. A combined standard of reference was applied, which consisted of histopathology (lymphadenectomy or biopsy) or clinical or radiological follow-up for at least 12 months. Results: the mean FDG uptake over the clinicopatholigical verified FDG avid areas was 4.7 SUV (1.5–9.9 SUV). The region based assessment of diagnostic value, in consideration of the standard of reference, resulted in a sensitivity of 85.7% and a specificity of 96.2% of FDG-PET (n = 127) and in a combined sensitivity of 95.5% and a specificity of 89.1% for morphological imaging methods (n = 68). Differences between methods did not reach statistical significance (p = 1.00, p = 0.18). Conclusions FDG-PET is a highly useful whole body staging method of comparable value compared to conventional imaging methods with restricted field of view. The lessons learned from case series are discussed.

Inflammatory processes as well as primary and secondary tumorous changes may involve cranial nerves causing neurological deficits. In addition to neurologists, ENT physicians, ophthalmologists and maxillofacial surgeons, radiologists play an important role in the investigation of patients with cranial nerve symptoms. Multidetector computed tomography (MDCT) and particularly magnetic resonance imaging (MRI) allow the depiction of the cranial nerve anatomy and pathological neural changes. This article briefly describes the imaging techniques in MDCT and MRI and is dedicated to the radiological presentation of inflammatory and tumorous cranial nerve pathologies.

Dem Huftgelenk als grostem Gelenk des menschlichen Korpers kommt eine besondere Bedeutung in der muskuloskelettalen Radiologie zu. Entsprechend wichtig ist auch die radiologische Beurteilung von Huftgelenkendoprothesen, die z. B. infolge degenerativer Gelenkerkrankungen, einer Huftkopfnekrose oder einer Fraktur eingesetzt werden. Die Projektionsradiographie ist weiterhin die primare Modalitat zur Beurteilung von Huftgelenkendoprothesen, direkt postoperativ und zur langerfristigen Verlaufskontrolle. Diese Methode erlaubt in der Mehrzahl der Falle eine suffiziente Antwort auf die Frage nach Lockerung, periprothetischer Fraktur oder Prothesenmaterialbruch, Luxation, Infektion und Weichteilkalzifikation. Computertomographie (CT) und Magnetresonanztomographie (MRT) haben sich im Laufe der Jahre fur spezielle Fragestellungen und bei unklarem projektionsradiographischem Befund etabliert. So lassen sich entzundliche Prozesse mit (CT) oder auch ohne (MRT) Kontrastmittel ausgezeichnet beurteilen. Unabhangig von der bildgebenden Modalitat ist in jedem Fall eine Korrelation mit der klinischen Symptomatik des Patienten unerlasslich.

Das Spektrum pathologischer Veranderungen in den anatomischen Sektionen des Hypopharynx erstreckt sich von benignen Pathologien bis zum Hypopharynxkarzinom (CA). Neben dem klinischen Befund und einer endoskopischen Abklarung durch den Hals-Nasen-Ohren-Arzt kommt den bildgebenden Verfahren im Rahmen der pra- und posttherapeutischen Diagnostik sowie im Follow-up hypopharyngealer Krankheitsbilder, insbesondere bei bosartigen Veranderungen, eine entscheidende Rolle zu. Die konventionelle Rontgenschluckuntersuchung sowie die kontrastmittelverstarkte Multidetektorcomputertomographie (MDCT) und Magnetresonanztomographie (MRT) und auch die Positronenemissionstomographie (PET) und Positronenemissionstomographie-Computertomographie (PET-CT) kommen hier je nach Fragestellung bzw. Krankheitsbild zum Einsatz. Insbesondere in der radiologischen Onkologie ist es wichtig, in klinisch schwierig beurteilbaren Regionen die exakte Lokalisation und Ausdehnung hypopharyngealer Pathologien zu erfassen, um fur den Patienten die optimale Therapie zu planen.

The larynx and the pharynx represent anatomically as well as functionally a very complex organ which serves as an airway and a nutrition channel. Knowledge of anatomy and anatomical topography is therefore a fundamental basis for the evaluation of any pathological process. Beside the clinical examination and endoscopy performed by ear, nose and throat specialists, imaging techniques play a crucial role in pre-therapeutic and post-therapeutic diagnostics. The radiologist employs a conventional x-ray swallow examination, as well as contrast-enhanced multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), positron emission tomography (PET) and positron emission tomography-computed tomography (PET-CT), depending on the medical problem in question. The following article demonstrates the functional and especially the structural anatomy of the larynx and the pharynx. Furthermore, the broad range of imaging techniques in clinical use is discussed.

Objective Cutaneous invasion by direct infiltration and metastasis, in malignant head and neck tumors, has a distinct impact on therapeutic options, especially surgical procedures, curative intent, and overall prognosis. Therefore, the purpose of this study was to determine the diagnostic accuracy of MDCT in detecting cutaneous invasion by malignant head and neck tumors. Materials and methods Nineteen patients with malignant head and neck tumors and clinical suspicion of cutaneous invasion routinely underwent contrast-enhanced 16-row MDCT (Philips MDCT MX 8000) of the region of interest in the axial plane before surgical intervention. The following parameters were used: 16 mm × 0.75 mm detector collimation; 3 mm reconstructed slice thickness; 1.5 mm increment; 0.75 s rotation speed; 120 kV, 200 mAs; and 100 ml non-ionic contrast agent, i.v., with a flow of 2.0 ml/s and a scan delay of 50 s. The studies were reconstructed with a soft tissue algorithm (W400, L100 HU), and coronal and sagittal planes were also reconstructed. The axial images were retrospectively reviewed in consensus by two radiologists for the evidence of cutaneous invasion blinded to the histological results. The MDCT results were correlated with histology that was obtained by punch biopsy or surgery. Results MDCT correctly revealed 11 of 11 cases with cutaneous invasion, and correctly excluded 4 of 8 cases without cutaneous invasion. The diagnostic accuracy of MDCT in detecting cutaneous invasion showed a sensitivity of 100%, a specificity of 50%, and an overall accuracy of 79%. Conclusion MDCT reconstructed with a soft tissue algorithm has a good sensitivity and moderate overall accuracy in detecting cutaneous invasion by malignant head and neck tumors.

BACKGROUND AND PURPOSE: The characterization of cold nodules of the thyroid gland is mandatory because approximately 20% of these nodules are of malignant origin. The purpose of this study was to evaluate the distinction of cold thyroid nodules by using quantitative diffusion-weighted MR imaging (DWI). MATERIALS AND METHODS: In 25 patients with cold nodules on scintigraphy and suggestive findings at fine-needle aspiration, thyroid carcinoma was suggested. In these patients, cold nodules and the normal parenchyma of the contralateral thyroid lobe were prospectively investigated with quantitative DWI (echo-planar imaging sequence; maximum b-value, 800 s/mm(2)) before surgery. The differences in the mean apparent diffusion coefficient (ADC) values in benign and malignant nodules were tested by using a Mann-Whitney U test. RESULTS: Histologically, there were 20 carcinomas with a minimum size of 8 mm and 5 adenomas. The mean ADC values (in 10(−3) mm(2)/s) differed significantly among carcinoma, adenoma, and normal parenchyma (P < .05). The ranges (95% confidence interval) of the ADC values for carcinoma (2.43–3.037), adenoma (1.626–2.233), and normal parenchyma (1.253–1.602) showed no overlap. When an ADC value of 2.25 or higher was used for predicting malignancy, the highest accuracy of 88%, with 85% sensitivity and 100% specificity, was obtained. CONCLUSIONS: Quantitative DWI seems to be a feasible tool with which to differentiate thyroid carcinomas from adenomas; however, further studies are required including larger numbers of patients to confirm our results.

Perineural tumor spread (PNS) of head and neck malignancies is a course of disease in which tumor metastasizes along the endoneurium or perineurium. Perineural tumor spread is a potentially devastating complication of head and neck cancer and has a high impact on the therapeutical management and overall prognosis. Imaging plays an important role in the detection of this condition, especially in view of a large number of clinically asymptomatic patients with PNS. Magnetic resonance imaging is the modality of choice in the assessment of PNS because of its multiplanar capability and its superior soft-tissue contrast. Knowledge of normal cranial nerve anatomy and the imaging appearance of perineural tumor extension is imperative in the evaluation of PNS which represents a special challenge in head and neck radiology.

Aim: In this study we present and evaluated a new registration technology for the jaw-bone surface. It is based on a micromechatronic device for the generation of a "mechanical image" of the bone surface by means of an array of micro-needles that are penetrating the soft tissue until they touch the surface of the bone. This "mechanical impression image" is aligned with the CT data set. Material and Methods: Based on laboratory measurements on 10 specially prepared jawbone models we evaluate the accuracy of this new registration method. Results: Our measurements of the 10 specimens revealed a maximum overall location error of 0.97 mm (range: 0.35-0.97 mm). Conclusions: From the technical point of view the presented registration technology has the potential to improve the performance (i.e. accuracy and avoidance of errors) of the registration process for bony structures in selected applications of image-guided surgery.

The radiological interpretation of postoperative changes of the paranasal sinuses requires knowledge of why and how the surgical intervention was performed and what the basic clinical findings were. It is important to know whether there was an inflammation, a reconstructive procedure, or a tumorous process. Multidetector computed tomography (MDCT) evaluated in a high-resolution bone window level setting represents the method of choice for imaging after nonfunctional and functional procedures after inflammatory changes as well as for imaging after reconstructive surgery because of facial trauma or before dental implantation. In the postoperative follow-up of tumor patients contrast-enhanced MDCT evaluated in a soft tissue window and bone window and especially magnetic resonance imaging (MRI) represent the standard. In many cases it is possible to differentiate tumor recurrence from inflammation with the help of contrast-enhanced multiplanar MRI and to detect bone marrow changes prior to CT.

To evaluate the image quality of two fast dynamic magnetic resonance imaging (MRI) sequences: True fast imaging with steady state precession (TrueFisp) was compared with half-Fourier acquired single turbo-spin-echo (HASTE) sequence for the characterization of velopharyngeal insufficiency (VPI) in repaired cleft palate patients. Twenty-two patients (10 female and 12 male; mean age, 17.7 ± 10.6 years; range, 9–31) with suspected VPI underwent 3-T MRI using TrueFisp and HASTE sequences. Imaging was performed in the sagittal plane at rest and during phonation of “ee” and “k” to assess the velum, tongue, posterior pharyngeal wall and a potential VP closure. The results were analysed independently by one radiologist and one orthodontist. HASTE performed better than TrueFisp for all evaluated items, except the tongue evaluation by the orthodontist during phonation of “k” and “ee”. A statistically significant difference in favour of HASTE was observed in assessing the velum at rest and during phonation of “k” and “ee”, and also in assessing VP closure in both raters (p

Tumorose Veranderungen der Innenohr- und Kleinhirnbruckenwinkelregion sind sehr selten und konnen in benigne und maligne Erkrankungen eingeteilt werden. In dieser Arbeit sollen die CT- und MRT-Charakteristika dieser Tumoren erlautert und dargestellt werden. Die hochauflosende Computertomographie (HRCT) kommt in axialer Schichtfuhrung, in der Auswertung im hochauflosenden Knochenfenster, zum Einsatz. Die koronalen Schichten konnen aus den axialen Datensatzen rekonstruiert oder in einzelnen Fallen in koronaler Ebene untersucht werden. Die HRCT zeigt exzellent die knochernen Veranderungen, und es kann in Einzelfallen — wie z. B. bei Exostosen — genugen, lediglich eine HRCT des Schlafenbeins anzufertigen, wahrend auch mit der HRCT exzellent Knochenveranderungen erfasst werden konnen, die Ruckschlusse auf einen eher benignen oder malignen Tumortyp erkennen lassen. Die MRT hingegen zeigt aufgrund ihres sehr hohen Weichteilkontrasts exzellent die genaue Tumorausdehnung. Somit liefern HRCT- und MRT-Aufnahmen der Innenohr- und Kleinhirnbruckenwinkelregion sehr aussagekraftige Bilder bei der Darstellung und Einordnung tumoroser Lasionen. Die Methoden sollten nicht als konkurrierend, sondern , komplementar betrachtet werden, und haben u. U. einen grosen Einfluss auf das therapeutische Vorgehen.

Chondrosarcoma of the skull base is a rare tumor and must be considered potentially lethal. There are high demands on imaging techniques, neurosurgical intervention and radiation therapy. We describe a case of chondrosarcoma solitarily located in the area of the petrous apex in an adult female person initially suffering from diplopia. Data sets of computed tomography (CT) and magnetic resonance imaging (MRI) were used to perform CT–MR image data fusion to support preoperative planning and intraoperative image guidance for computer assisted skull base surgery with the help of a navigation system.

In childhood, tumors and tumor-like lesions of the neck are rare and tend to be benign. Very common are congenital cystic lesions (thyroglossal duct cysts, branchial cysts, dermoid cysts, lymphangiomas, cystic hygromas). Common neoplastic lesions are hemangiomas and papillomas. The most common malignant tumors in the head and neck region are lymphomas and rhabdomyosarcomas. Lymph node enlargements, reactive or/and infectious, account also for a significant amount of cervical masses.

To evaluate the prevalence of localized hypoattenuating areas in the cochlear otic capsule at temporal-bone thin-section computed tomography (CT) in pediatric patients and correlate the findings with clinical information.Temporal-bone thin-section CT images obtained in 73 patients aged 0-9 years (20 Austrian, 53 Finnish; 36 female and 37 male patients) were evaluated for the presence of localized hypoattenuating foci in the region of the fissula ante fenestram of the otic capsule. Clinical information collected for all patients was also evaluated. The data were analyzed with a logistic regression model.Hypoattenuating areas in the region of the fissula ante fenestram were observed in 23 of 73 patients (32%). Hypoattenuating foci were substantially more prevalent in patients younger than 3 years than in those 3 years or older (odds ratio, 0.14; 95% CI: 0.04, 0.52; P =.001). The prevalence did not differ between sexes or according to clinical diagnosis. Only three of the 23 patients with hypoattenuating foci had clinical findings suggestive of otosclerosis, and none had osteogenesis imperfecta. After adjustment for age and sex, the finding was more prevalent among the Finnish patients (odds ratio, 5.4; 95% CI: 1.19, 24.52; P =.02) than among the Austrian patients.Hypoattenuating areas in the region of the fissula ante fenestram in the otic capsule at thin-section CT are prevalent among children younger than 3 years in the absence of clinical evidence of otosclerosis or osteogenesis imperfecta and appear in children up to 9 years old.

Objective: To assess feasibility of automated edge detection in magnetic resonance (MR) flow calculations in a clinical setting with critically ill patients. Material and methods: Velocity encoded cine-MR (VEC-MR) flow measurements cross-sectional area (CSA), mean spatial velocity (MSV), instantaneous flow (IF), flow (F), 0.5 T Philips, TR 800–800, TE=8 ms, 30° flip angle, FOV 280 mm, 128×256 matrix, temporal resolution 16 time frames/RR, VENC=120 cm/s) were obtained in 20 major thoracic human vessels (ascending aorta, main, right and left pulmonary artery—AAO, MPA, RPA, LPA) of five patients, suffering from severe chronic thromboembolic pulmonary hypertension (CTEPH). Flow maps were evaluated by two independent observers using conventional manual edge detection (INTER m/m). Flow calculations were performed by one observer using both, manual and automated edge detection (INTRA m/a), by a second observer using automated edge detection two times (INTRA a/a) and by two independent observers using automated edge detection (INTER a/a). Evaluation time was measured. Linear regression analysis and Student's t -test were performed. Results: Overall regression coefficients ( r 2 ) for INTER m/m, INTRA m/a, INTER a/a and INTRA a/a, respectively, were as follows: CSA, 0.91, 0.91, 0.96, 0.98; MSV, 0.97, 0.99, 0.99, 0.99; IF, 0.98, 0.99, 0.99, 0.99; F, 0.98, 0.99, 0.99, 0.99. Manual CSA values differed significantly from automated data in MPA ( P =0.01), RPA ( P =0.0008) and LPA ( P =0.02). No difference was found for the other assessed parameters of the pulmonary circulation. Average evaluation time per vessel was 20.2±2.6 min for manual and 2.1±0.7 min for automated edge detection ( P Conclusion: The software program used provided reproducible data, lead to a 90% reduction in evaluation and calculation time and, therefore, might excel the utilization of VEC-MR flow measurements. Despite variations in the evaluation of the pulmonary circulation CSAs, flow assessment is feasible in critically ill patients.

Recent studies in the USA and Europe state that computed tomography (CT) scans compromise only 3-5% of all radiological exams, but they contribute 35-45% of total radiation dose to the patient population. These studies lead to concern by several public authorities. Basis of CT-dose measurements is the computed tomography dose index (CTDI), which was established 1981. Nowadays there are several modifications of the CTDI values, which may lead to confusion. It is suggested to use the standardized CTDI-100 w. value together with the dose length product in all CT-examinations. These values should be printed on all CT-images and allows an evaluation of the individualized patient dose. Nowadays, radiologist's aim must be to work at the lowest maximal diagnostic acceptable signal to noise ratio. To decrease radiation dose radiologist should use low kV and mA, but high pitches. Newly developed CT-dose-reduction soft-wares and filters should be installed in all CT-machines. We should critically compare the average dose used for a specific examination with the reference dose used in this country and/or Europe. Greater differences should caution the radiologist. Finally, we as radiologists must check very carefully all indications and recommend alternative imaging methods. But we have also to teach our customers-patients and medical doctors who are non-radiologists-that a 'good' image is not that which show all possible information, but that which visualize 'only' the diagnostic necessary information.

Durch Aufstellung und komplette digitale Integration von Flachbild-(Festkorper-) Detektoren anstelle von Film-Folien- bzw. Phosphorspeicherplattensystemen kommt es in einer radiologischen Abteilung zu einer Straffung des Arbeitsablaufes.Unter Einsatz der Flachbilddetektorentechnologie reduziert sich der eigentliche Bilderzeugungsprozess (von Patientenlagerung bis zur Bildfertigstellung) um uber 30%.Wesentliche Vorteile dieser Totalintegration von RIS,PACS und Flachbilddetektorsystem sind die enorm gesteigerte Qualitat durch fehlende Verwechslungsmoglichkeit von Bild- und Befunddaten, leichteres Handling, da in 95% aller Falle keine Kassetten verwendet werden, und die Moglichkeit zur Bildnachbearbeitung. Die diagnostische Qualitat der Skelettbilder ist im Vergleich zu konventionellen Rontgenaufnahmen zumindest adaquat, in den meisten Fallen zeigen sich jedoch deutliche Verbesserungen der Beurteilungsparameter bei einer Erniedrigung der Strahlenexposition um 30–50%.In Anbetracht der zahlreichen Vorteile der digitalen Aufnahmetechniken wird die Flachbildradiographie trotz der bis jetzt deutlich hoheren Beschaffungskosten mit sehr hoher Wahrscheinlichkeit die konventionellen Rontgenaufnahmen mittelfristig ersetzen konnen.

The objective of this study was to evaluate the feasibility and accuracy of a novel surgical computer-aided navigation system for the placement of endosseous implants in patients after ablative tumour surgery. Pre-operative planning was performed by developing a prosthetic concept and modifying the implant position according to surgical requirements after high-resolution computed tomography (HRCT) scans with VISIT, a surgical planning and navigation software developed at the Vienna General Hospital. The pre-operative plan was transferred to the patients intraoperatively using surgical navigation software and optical tracking technology. The patients were HRCT-scanned again to compare the position of the implants with the pre-operative plan on reformatted CT-slices after matching of the pre- and post-operative data sets using the mutual information-technique. A total of 32 implants was evaluated. The mean deviation was 1.1 mm (range: 0-3.5 mm). The mean angular deviation of the implants was 6.4 degrees (range: 0.4 degrees - 17.4 degrees, variance: 13.3 degrees ). The results demonstrate, that adequate accuracy in placing endosseous oral implants can be delivered to patients with most difficult implantologic situations.

Objective: To describe and compare imaging findings of 3D magnetic resonance imaging (3D MRI) and high resolution computed tomography (HRCT) in children with sensorineural hearing loss. Materials and methods: Sixty-two children (mean age, 8.1±5.47 years) with clinical signs of sensorineural hearing loss underwent 3D MRI and HRCT of the inner ear and cerebellopontine angle. MRI was performed by three-dimensional (3D) T2-weighted fast spin-echo (slice thickness 0.7 mm) and 3D T1-weighted gradient-echo sequences (slice thickness 1.0 mm) before and after the application of gadopentate dimeglumine. HRCT was performed in the axial plane with a section thickness of 1.0 mm using a high-resolution bone window-level setting. The inner ear, internal auditory canal, and cerebellopontine angle were evaluated for abnormal morphology and signal intensities by two blinded groups of observers. Pearson correlation and κ statistics were calculated. Results: Forty-one patients (66%) showed no abnormalities on HRCT and 39 (63%) showed no abnormalities on MRI. Twenty-one patients (34%) showed abnormalities of the inner ear, and/or the internal auditory canal, and/or the cerebellopontine angle on both HRCT and 3D MRI. Congenital abnormalities were found in 17 of these patients (27%), and acquired abnormalities, such as chronic inflammatory changes, were evident in four patients (6%). On 3D MRI, two patients demonstrated signs of acute inflammation that were not depicted on HRCT. Three patients (5%) with a narrow internal auditory canal on HRCT showed absence of the cochlear nerve on 3D MRI. There was an overall good agreement between MRI and HRCT findings as demonstrated by correlation coefficients ranging from 0.67 to 1 and κ values between 0.62 and 1. Conclusion: In addition to HRCT, 3D MRI proved very useful and, thus, should play a major role in the evaluation of children with sensorineural hearing-loss.

Tumorose Veranderungen des Schlafenbeins und Kleinhirnbruckenwinkels sind selten. Diese Tumoren konnen in benigne und maligne Veranderungen eingeteilt werden.In dieser Arbeit sollen die CT- und MRT-Charakteristika der Tumoren des Schlafenbeins und Kleinhirnbruckenwinkels gezeigt werden. Die Computertomographie (HRCT) wird in axialer Schichtfuhrung in der Auswertung mit hochauflosendem Knochenfenster durchgefuhrt. Die koronalen Schichten konnen aus dem axialen Datensatz rekonstruiert oder direkt in koronaler Ebene hergestellt werden.Mit der MRT kann zunachst mit einer FLAIR-Sequenz in axialer Ebene das gesamte Gehirn untersucht werden, um einen Tumoreinbruch nach intrakraniell auszuschliesen oder nachzuweisen.Danach werden axiale T2-gewichtete Fast-(Turbo-) Spinechosequenzen oder fettunterdruckte Inversion-recovery-Sequenzen in hochauflosender Technik uber die Schlafenbeinregion angefertigt, gefolgt von axialen T1-gewichteten Spinechosequenzen vor und nach Kontrastmittel-(KM-)Gabe in hochauflosender Technik.Zuletzt konnen koronale T1-gewichtete Spinechosequenzen in hochauflosender Technik mit Fettunterdruckung nach KM-Gabe uber die Schlafenbeinregion durchgefuhrt werden.Die HRCT kann die knocherne Ausdehnung und dazugehorige Knochenveranderungen darstellen, die MRT erfasst genau die Tumorausdehnung in den Weichteilen. Mit der HRCT und der MRT gemeinsam lasst sich die exakte Tumorausdehnung zur therapeutischen Planung bestimmen. Die HRCT zeigt die knochernen Veranderungen ausgezeichnet. In Einzelfallen – wie z.B. bei Exstosen des auseren Gehorgangs – kann es genugen, lediglich eine HRCT des Schlafenbeins durchzufuhren.Aufgrund des Aggressivitatsverhaltens des Tumors in der HRCT sind auch Ruckschlusse auf einen eher benignen oder malignen Tumortyp moglich. Mit der MRT konnen aufgrund des sehr hohen Weichteilkontrastes auch manche Tumoren – insbesondere vaskulare wie z.B. Glomustumoren – gewebemasig charakterisiert und in eher benigne und maligne unterteilt werden.Somit sind die HRCT und die MRT des Schlafenbeins exzellente Methoden, um tumorose Lasionen darzustellen und einzuordnen.Die Methoden sollten nicht als konkurrierend, sondern als komplementar betrachtet werden und haben u. U. einen grosen Einfluss auf das therapeutische Vorgehen.

CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination. CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous changes while MRI best depicts soft tissue changes. HRCT and MRI are not concurrent methods but should better be used as complementary methods for imaging acquired abnormalities of inner ear and cerebellopontine angle.

Congenital abnormalities of the temporal bone are mostly accompanied by conductive or sensori-neural hearing loss. Before any therapeutic procedures are done high resolution CT (HRCT) and magnetic resonance imaging (MRI) should be performed to establish the correct diagnosis and to plan the potentially surgical intervention. HRCT best depicts osseous changes especially those of the external auditory canal and the middle ear containing the ossicles and the osseous structures of the temporal bone and the petrous bone containing the inner ear. MRI excellently shows soft tissue changes of the inner ear especially on the high resolution 3DT2-weighted sequences which give a superb contrast between the nerves and the cerebro-spinal fluid. Malformations of the external auditory canal consists of aplasia or hypoplasia and those of the middle ear range form extreme hypoplasia or aplasia to very mild deformations of the ossicles. Malformations of the inner ear also range form complete aplasia to very mild hypoplasia of the organs of the inner ear as well as malformations concerning the nerves in the internal auditory canal range from aplasia to hypoplasia. Malformations of the temporal bone can either occur isolated or in combination in which malformations of the external and middle ear may be accompanied by those of the inner ear. Furthermore, malformations of the temporal bone may also occur in otofacial, otocervical or otoskeletal syndromes. These syndromes may be accompanied by certain malformations of the temporal bone. HRCT and MRI are both excellent methods to depict congenital abnormalities of the temporal bone and of the inner ear and should be used as complementary methods because HRCT best depicts osseous changes and MRI superbly depicts soft tissue changes. Both methods are important to establish the correct diagnosis to plan the therapeutic procedures.

In dieser Arbeit wird die Rolle der hochauflosenden Computertomographie (HRCT) und der Magnetresonanztomographie (MRT) zur Abklarung pra- und postoperativ bedingter Komplikationen erworbener Cholesteatome beschrieben.Die Bildgebung wurde sowohl mit der HRCT als auch mit der MRT durchgefuhrt. Die HRCT und die MRT wurden in axialer und koronaler Ebene (auch rekonstruiert) durchgefuhrt.Die MRT wurde mit T2- und T1-gewichteten Sequenzen vor und nach Kontrastmittelgabe durchgefuhrt.Aufgrund der klinischen Zuweisung wurde auf pra- oder postoperativ bedingte Komplikation durch sekundare Cholesteatome geachtet. Die praoperativ durch ein Cholesteatom bedingten knochernen Komplikationen, wie Erosionen der Gehorknochelchen sowie des Attiksporns, des knochernen Fazialiskanals im Mittelohr sowie der Wande des Cavum tympani und auch des Labyrinths, sind am besten mit der HRCT darzustellen.Veranderungen, welche im Sinne einer Labyrinthitis zu deuten sind oder Hirnabszessen entsprechen, lassen sich hingegen am besten mit der MRT nachweisen.Auch postoperativ zeigt die HRCT die knochernen Verhaltnisse am besten,wahrend Weichteilveranderungen oder aber diskrete Veranderungen wie Entzundungen des N.facialis, einer Labyrinthitis oder von Meningoenzephalozelen am besten in der MRT gezeigt werden. Die HRCT und die MRT sind exzellente Methoden,um einerseits knocherne und andererseits Weichteilveranderungen,welche durch erworbene Cholesteatome hervorgerufen worden sind, abzuklaren.Die HRCT und die MRT sind im Nachweis von Cholesteatomkomplikationen als komplementare Methoden zu sehen.Die HRCT ist dabei die primare Methode,wahrend die MRT als weiterfuhrende Diagnostik eingesetzt werden sollte.

Background: The authors retrospectively compared the results of three different treatment modalities (surgery, conventional radiotherapy and gamma knife radiosurgery) in patients with paragangliomas of the temporal bone, in order to determine the optimal current treatment concept. Method: Between 1978 and August 2001, 53 patients (12 men and 41 women; mean age, 58.3 years; range, 17 to 84 years) with paragangliomas of the temporal bone were treated at the neurosurgery and ENT departments of the University of Vienna. According to the Fisch classification, 6 patients had class B tumours, 20 had class C, and 27 patients had class D tumours. Thirty-two patients (mean age, 57.0 years; 6 B, 14 C, 12 D) underwent surgery. In 17 cases the tumour was embolised prior to surgery. Nine patients (mean age, 73.9 years; 6 C, 3 D) received primary radiotherapy (median total dose, 46.8 Gy). Six patients (mean age, 73.5 years; 6 D) underwent primary radiosurgery (median centre dose 24, Gy) and 6 patients (6 D) admitted from other departments with recurrent tumours adjuvant radiosurgery (median centre dose, 25.5 Gy). Findings: In 20 of the surgical cases (62.5%) complete tumour resection was achieved and the patients required no further treatment over a mean follow-up period of 9.1 years. Of the 12 patients with incomplete tumour resection, 9 (5 C, 4 D) received postoperative adjuvant radiotherapy and three patients (3 D) adjuvant radiosurgery. In 15 (83.4%) of the 18 patients who underwent radiotherapy the tumours showed no signs of progression and the patients remained clinically unchanged over a mean period of 9.4 years. Three patients (16,6%) experienced progression of their tumour within an average period of 2.8 years. In the 15 patients who underwent primary radiosurgery, an objective 100% tumour control rate with no evidence of progression of disease was observed. Interpretation: The results indicate that the most effective current treatment option for patients with paragangliomas of the temporal bone is a single-stage radical tumour resection, performed in advanced tumours as an interdisciplinary neuro-otosurgical procedure. For subtotally resected or non-resectable tumours, gamma knife radiosurgery has proved to be a safe and effective treatment modality.

To retrospectively assess the use of a combination of cancellous bone reconstructions (CBR) and multiplanar reconstructions (MPRs) for the detection of bone metastases at thoracoabdominal computed tomography (CT) compared with the use of MPRs alone.The study was approved by the local institutional review board. Included were 156 consecutive patients with confirmed cancer who underwent a whole-body positron emission tomography (PET)/CT examination for clinical purposes (93 male and 63 female patients; mean age ± standard deviation, 59.8 years ± 14.9; range, 11-85 years). Only the CT images were processed with the CBR algorithm, which segments the bones and removes the cortical layer from the images. The PET images served as part of the reference standard. Images from 15 patients were used as a training set. Four radiologists independently evaluated images of half of the remaining 141 patients by using CBRs and MPRs together, and the other half by using MPRs only. Radiologists were blinded to patient names, and patient order was randomized. Results for detection rates and reporting time were recorded and compared with a standard of reference for each patient that was created by one senior radiologist and one nuclear medicine specialist by using all available CT and PET data, CBRs, and follow-up examinations. General estimation equations were used for statistical analysis.There were 349 lesions found in 103 patients, with 203 classified as malignant. Each patient was assessed by two readers per method, leading to a total of 698 lesions. The detection rate for all bone lesions was 35% (247 of 698) for MPRs and 74% (520 of 698) when CBRs and MPRs were used together, which was significantly higher (P.001). The average reading time decreased from 85 to 43 seconds (P.001) when both reconstructions were used.Advanced visualization of cancellous bone significantly increased the detection of bone metastases and reduced the time for interpretation.

Die Krankheitsbilder, die zu einer Mitbeteiligung der Kiefergelenke fuhren, unterscheiden sich prinzipiell nicht von jenen, welche die ubrigen Gelenke im Korper betreffen. Aus diesem Grund sind auch die radiologischen Veranderungen im Prinzip ahnlich. Aufgrund der komplexen Morphologie und Funktion des Kiefergelenks ist es jedoch wichtig, die Vielfalt von Erkrankungen zu kennen, welche zu morphologischen und funktionellen Veranderungen am Kiefergelenk fuhren konnen. Durch die funktionelle Einheit beider Kiefergelenke kann jede einseitige Erkrankung in weiterer Folge auch zur Dysfunktion der kontralateralen Seite fuhren. Der Radiologe sollte mit den Prinzipien der Funktionen sowie mit der Vielfalt der pathologischen Veranderungen der Kiefergelenke vertraut sein.

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.

The aim of this study was to depict and characterize inflammatory soft tissue proliferations caused by rheumatoid arthritis (RA) in the craniocervical region by unenhanced and contrast-enhanced CT. Computed tomography of the craniocervical region was performed in 35 patients in the axial plane before and after the i. v. administration of contrast material. According to the densities and contrast enhancement of the inflammatory soft tissue proliferations, four groups were classified. Ancillary findings, such as a compression of the dural sac or spinal cord, erosions of the bony structures, and atlantoaxial subluxation, were also evaluated. Inflammatory soft tissue proliferations were depicted in 28 of 35 patients and could be differentiated by unenhanced and contrast-enhanced CT according to the above defined criteria: effusion in 6 patients (17 %); hypervascular pannus in 8 (23 %); hypovascular pannus in 5 (14 %); and fibrous tissue in 9 patients (26 %). A compression of the dural sac was seen in 11 (31 %) patients; 3 of these had neurological symptoms. Erosions of the odontoid process were found in 20 (57 %) patients; 16 (80 %) of these also showed erosions of the atlas. Atlantoaxial subluxation was seen in 11 (31 %) patients. Inflammatory soft tissue proliferations in the craniocervical region caused by RA can be reliably demonstrated and classified by unenhanced and contrast-enhanced CT, which can differentiate between joint effusion and various forms of pannus and depict ancillary findings. Computed tomography is an alternative method for patients unable to undergo an MRI examination.