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To compare dynamic magnetic resonance imaging (MRI) with videofluoroscopy (VFS) regarding image quality and assessment of gap size between soft palate (SP) and posterior pharyngeal wall (PPW) in children and adolescents following surgical correction of velopharyngeal dysfunction (VPD). Twenty-one patients undergoing unenhanced 3-T MRI and contrast-enhanced VFS were included in this IRB-approved prospective study. The MRI scan protocol comprised refocused gradient-echo sequences in transverse and sagittal planes during speech, with TE 1.97 ms, TR 3.95 ms, flip angle 8°, matrix size 128 × 128, and 5-mm slice thickness. Radial k-space sampling and sliding window reconstruction were used to achieve an image acquisition rate of 28 frames per second (fps). VFS with 30 fps was similarly performed in both planes. Closure of the velopharyngeal port during phonation was evaluated by two experienced radiologists. Eleven (52.4%) patients displayed a complete closure, whereas ten (47.6%) patients showed a post-operative gap during speech. VFS and MRI equally identified the cases with persistent or recurrent VPD. Differences in SP-PPW distance between VFS (3.9 ± 1.6 mm) and MRI (4.1 ± 1.5 mm) were not statistically significant (p = 0.5). The subjective overall image quality of MRI was rated inferior (p

The aim of this study was to evaluate the accuracy of real-time magnetic resonance imaging (MRI) T1-based treatment monitoring for predicting volume of lesions induced by laser-induced thermotherapy (LITT) of liver metastases.This prospective study was approved by the institutional review board and informed consent from all included patients was obtained. In 151 patients, 237 liver metastases were ablated during 372 LITT procedures. 1.5 T MRI treatment monitoring was performed based on longitudinal relaxation time (T1) using fast low-angle shot (FLASH) sequences. Patients underwent additional contrast-enhanced MRI directly after LITT, 24 h after the procedure and during follow-up at 3, 6 and 12 months. The amount of energy necessary to induce a defined necrotic area was investigated within the various liver segments.The total amount of energy applied during LITT varied from 6.12-225.32 kJ (mean 48.96 kJ). Ablation in liver segments 5 (2.12 kJ/cm(3)) and 8 (2.16 kJ/cm(3)) required the highest energy. The overall pre-ablative metastasis volume ranged from 0.5-51.94 cm(3) (mean 1.99 cm(3), SD 25.49 cm(3)) while the volume measured in the last available T1 image varied from 0.78-120 cm(3) (mean 26.25 cm(3), SD 25.66 cm(3)). Volumes measured via MRI T1-based treatment monitoring showed a stronger correlation with necrosis 24 h after LITT (r = 0.933, p0.001) than contrast-enhanced MRI directly after the procedure (r = 0.888, p0.001).Real-time MRI T1-based treatment monitoring during LITT of liver metastases allows for precise estimation of the resulting lesion volume and improves control of the energy necessary during ablation.

Background: To evaluate a treatment protocol with repeated transarterial-chemoembolisation (TACE) downsizing before MR-guided laser-induced interstitial thermotherapy (LITT) using different chemotherapeutic combinations in patients with unresectable colorectal cancer (CRC) liver metastases. Methods: Two hundred and twenty-four patients were included in the current study. Transarterial-chemoembolisation (mean 3.4 sessions per patient) was performed as a downsizing treatment to meet the LITT requirements (number⩽5, diameter

Die MRT (Magnetresonanztomographie) gewinnt in der Diagnostik von Verletzungen im Kindes- und Jugendalter zunehmend an Bedeutung, die therapeutische Relevanz der hiermit gewonnenen Zusatzinformationen wird kontrovers diskutiert. Neben den Einsatzmoglichkeiten der MRT bei Verletzungen im Kindes- und Jugendalter werden eigene Ergebnisse einer retrospektiven Studie prasentiert, bei welcher die posttraumatischen Rontgenbilder und MRT-Aufnahmen in insgesamt 45 Fallen von jeweils 2 Radiologen und 2 Unfallchirurgen anonymisiert voneinander unabhangig standardisiert ausgewertet sowie bezuglich ihrer therapeutischen Relevanz beurteilt wurden. Zusammenfassend ist festzustellen, dass die MRT weniger der Akutdiagnostik von Frakturen dient als vielmehr der Verlaufsbeurteilung z. B. prolongierter Heilverlaufe, um Komplikationen aufzudecken. Haufig wird sie zur Planung weiterer therapeutischer Schritte genutzt. Zudem gibt es spezielle Indikationen, bei der sie eine zentrale Rolle spielt, wie zum Ausschluss von Kniebinnenschaden, von Begleitverletzungen nach Patella- oder Schulterluxation, zur Stadieneinteilung der Osteochondrosis dissecans, zur Darstellung posttraumatischer Durchblutungsstorungen und zur Abgrenzung zu Differenzialdiagnosen.

BACKGROUND AND PURPOSE: PCT studies hold short-term predictive value in patients treated with chemoradiotherapy. Our aim was to examine the long-term predictive value of baseline PCT studies for local tumor control and overall survival in SCCA of the upper aerodigestive tract treated with chemoradiotherapy. MATERIALS AND METHODS: Eighty-four patients with advanced SCCA underwent PCT followed by concomitant chemoradiation. The acquired perfusion maps represented BF, BV, MTT, and PS. Visual analysis of the parametric maps for identification of tumor perfusion patterns was conducted. ROC curves, t tests, and Kaplan-Meier survival curves were plotted for local disease control and overall survival. RESULTS: The median time of local tumor control was 24 months. The BF and PS values were significantly higher in patients who had no recurrence than in those with local failure (P ≤ .02). The BF and PS were predictive (P ≤ .0006) but BV and MTT held no significant predictive values for local tumor control. The patients with high BF and PS had a longer local tumor control than the patients with hypoperfused tumors (P = .0007). A visually detected BF-BV mismatch had a sensitivity/specificity of 63%/66% (P = .03) and 59%/69% (P = .03) for local tumor control and OS, respectively. Patients without mismatch lived significantly longer than patients with mismatch (P = .01). CONCLUSIONS: BF, PS, and mismatch of BF-BV are significant predictors of local tumor control after chemoradiation in SCCA of the upper aerodigestive tract.

Rationale and Objectives To evaluate the interchangeability of perfusion parameters between two software packages for the postprocessing of dynamic contrast-enhanced (DCE) computed tomographic images of head and neck tumors. Materials and Methods DCE computed tomographic images of 75 patients with head and neck tumors were postprocessed using a software package based on the maximum-slope approach and Patlak analysis, as well as a software package with deconvolution-based analysis incorporating an adiabatic approximation of tissue homogeneity (ATH) model. The evaluated perfusion parameters included blood flow (F), blood volume (v), and permeability–surface area product (PS). Region-of-interest (ROI) analysis of the tumors and the metastatic lymph nodes was performed. The perfusion parameters were compared using the Wilcoxon matched-pairs test and Bland-Altman plots. Results One hundred fifty-two ROIs of tumors and nodes were outlined and analyzed. Moderate to good correlations were demonstrated between the various perfusion values (r = 0.56–0.72, P Conclusion There were significant differences in the perfusion parameters obtained using the two software packages, and thus, these parameters are not directly interchangeable.

To analyze prospectively the interventional and clinical aspects of computed tomography-guided direct intratumoural injection of a novel chemotherapeutic administration and the parenchymal changes of tumour and necrosis in malignant liver tumours. Eight patients with 17 colorectal liver metastases were treated with a mean of 5.1 injections and nine patients with 13 hepatocellular carcinoma nodules with a mean of 3.1 treatments with computed tomography guided local applications of a novel cisplatin/epinephrine gel. This application provides a higher local and lower systemic drug concentration. Volumes of tumour and necrosis prior and after treatment were measured by computer generated volumetric analysis. Contrast enhanced studies verified pretherapeutic viable tumour volumes with a value of 77.4 ml in the metastases and 29.2 ml in the hepatocellular carcinoma nodules. Intratumoural drug application resulted in a significant increase of necrosis and a decrease in viable tumour volume to be 68.3 ml in metastases and 14.5 ml in hepatocellular carcinoma. Local therapy control rate for the follow up to 6 months was 38 and 71% for the group of metastases and hepatocellular carcinoma, respectively. Direct intratumoural injection of cisplatin/epinepthrine injectable gel is a feasible and good tolerated method and results in the development of a statistically significant increase in necrosis in malignant liver tumours. For hepatocellular carcinoma a higher local therapy control rate compared to colorectal metastases can be reported. British Journal of Cancer (2002) 86, 524–529. DOI: 10.1038/sj/bjc/6600116 www.bjcancer.com © 2002 Cancer Research UK

The objective of this pilot clinical study was to assess the safety, technical feasibility, pharmacokinetic (PK) profile and tumour response of DC Bead™ with irinotecan (DEBIRI™) delivered by intra-arterial embolisation for the treatment of metastatic colorectal cancer. Eleven patients with unresectable liver metastases from CRC, tumour burden

BACKGROUND AND PURPOSE: DECT offers additional image datasets with potential benefits, but its use for H&N imaging is not justified unless image quality is preserved without increased radiation dose. The aim of this work was to compare image quality and radiation dose between a DE-derived WA image dataset and a standard SECT acquisition of the H&N. MATERIALS AND METHODS: Thirty-two patients underwent DECT of the H&N (tube voltages 80 and Sn140 kVp) and were compared with the last 32 patients who underwent standard SECT (120 kVp) on the same dual-source scanner. WA images from the 2 DE tubes were compared with images obtained with an SE mode. Radiation doses and attenuation measurements of the internal jugular vein, submandibular gland, and sternomastoid and tongue muscles were compared. Objective image noise was compared at 5 anatomic levels. Two blinded readers compared subjective image quality by using 5-point grading scales. RESULTS: CTDIvol was 12% lower with DE than with SECT, a difference of 1.5 mGy, ( P .05). No significant differences in attenuation measurements were observed between DE and SECT ( P > .05). No significant differences in subjective image quality scores were observed between DE and SECT at any of the 5 anatomic levels ( P > .05). CONCLUSIONS: DE-derived WA images of the H&N are equivalent to standard SE acquisitions and thus can be used for routine diagnostic purposes. Multiple additional image datasets can be obtained with no radiation dose penalty. CI : confidence interval CTDIvol : CT volume dose index DE : dual-energy DECT : dual-energy CT DLP : dose-length product H&N : head and neck SE : single-energy SECT : single-energy CT WA : weighted-average

Background Initiated by a clinical case of critical endotracheal tube (ETT) obstruction, we aimed to determine factors that potentially contribute to the development of endotracheal tube obstruction by its inflated cuff. Prehospital climate and storage conditions were simulated. Methods Five different disposable ETTs (6.0, 7.0, and 8.0 mm inner diameter) were exposed to ambient outside temperature for 13 months. In addition, every second of these tubes was mechanically stressed by clamping its cuffed end between the covers of a metal emergency case for 10 min. Then, all tubes were heated up to normal body temperature, placed within the cock of a syringe, followed by stepwise inflation of their cuffs to pressures of 3 kPa and ≥12 kPa, respectively. The inner lumen of the ETT was checked with the naked eye for any obstruction caused by the external cuff pressure. Results Neither in tubes that were exposed to ambient temperature (range: -12°C to +44°C) nor in those that were also clamped, visible obstruction by inflated cuffs was detected at any of the two cuff pressure levels. Conclusions We could not demonstrate a critical obstruction of an ETT by its inflated cuff, neither when the cuff was over-inflated to a pressure of 12 kPa or higher, nor in ETTs that had been exposed to unfavorable storage conditions and significant mechanical stress.

The purpose of this study was to determine the efficacy and safety of radiofrequency ablation (RFA) of bone metastases of breast cancer and to compare RFA alone and RFA with additional bone cement application. The primary objectives were to compare pain reduction and quality of life during long-term follow-up in a prospective pilot study.Sixteen female patients with painful spinal bone metastases of human breast cancer were included in this prospective pilot study (mean age 59.5 years, range 52 - 69 years). RFA was performed with computed tomographic guidance and under local anesthesia. A bipolar and impedance-controlled radiofrequency system was used. Following RFA, bone cement was injected into the necrosis cavity in half of the patients (n=8). Pain, quality of life and complications were evaluated. Mean follow-up time was 20.4 months (range 8-36). Paired comparison procedures were used for analysis of the results. A review of the literature was carried out.In both groups (RFA alone and RFA with additional bone cement application), pain was reduced significantly (mean reduction of pain 51.7%, p=0.0065). Quality of life was improved up to 61%. All procedures were performed without side-effects and complications. Imaging showed a complete ablation of the bone tumor in all patients. No local tumor progression was seen.RFA is a safe and effective option in the palliative therapy of bone tumors. Application of bone cement into the necrosis cavity has no significant additional effect on the reduction of pain and the improvement in quality of life. In selected cases with big bone defects, combining RFA and bone cement application is a useful option to stabilize the bone.

BACKGROUND AND PURPOSE: Perfusion CT (PCT) provides a rapid, reliable, and non-invasive technique for assessing tumor vascularity. The purpose of this study was to assess whether pretreatment dynamic perfusion CT (PCT) may predict response to induction chemotherapy and midterm progression-free survival (PFS) in advanced oropharynx squamous cell carcinoma (SCCA) and to compare the results with those derived by tumor volume measurements. MATERIALS AND METHODS: Nineteen patients underwent routine contrast-enhanced CT (CECT), pretreatment PCT, and conventional endoscopy. Tumor response was determined according to radiologic (RECIST) criteria. The PCT parameters, tumor volume, radiologic response, and PFS were analyzed with use of Cox-proportional hazards model, receiver operating characteristic (ROC), and Kaplan-Meier analysis. RESULTS: The baseline blood flow (BF), blood volume (BV), and permeability surface area product (PS) were significantly higher, whereas mean transit time (MTT) was significantly lower in the responders than in the nonresponders (P ≤ .002). BV showed 100% sensitivity, MTT and PS had the highest specificity (100%), and BF showed 84.2% sensitivity and 66.7% specificity for prediction of tumor response after induction chemotherapy. The pretreatment tumor volume correlated with PFS in the pooled patients group (r = 0.4; P < .0001), whereas postinduction tumor volume correlated significantly with PFS in the responders and nonresponders (r = 0.22–0.64; P ≤ .006). Pretreatment tumor volume (P = .0001) and BF (P = .001) were significant predictors for PFS. CONCLUSIONS: Pretreatment PCT parameters may predict response after induction chemotherapy. Tumor volume and BF values may predict PFS in patients with advanced oropharyngeal SCCA.

To evaluate the interchangeability of perfusion parameters between two software packages for the postprocessing of dynamic contrast-enhanced (DCE) computed tomographic images of head and neck tumors.DCE computed tomographic images of 75 patients with head and neck tumors were postprocessed using a software package based on the maximum-slope approach and Patlak analysis, as well as a software package with deconvolution-based analysis incorporating an adiabatic approximation of tissue homogeneity (ATH) model. The evaluated perfusion parameters included blood flow (F), blood volume (v), and permeability-surface area product (PS). Region-of-interest (ROI) analysis of the tumors and the metastatic lymph nodes was performed. The perfusion parameters were compared using the Wilcoxon matched-pairs test and Bland-Altman plots.One hundred fifty-two ROIs of tumors and nodes were outlined and analyzed. Moderate to good correlations were demonstrated between the various perfusion values (r = 0.56-0.72, P.0001). The Wilcoxon test revealed a significant difference between the two methods (P.001), with the F, v, and PS values obtained using the maximum-slope approach and Patlak analysis higher than those obtained using deconvolution-based analysis with the assumptions of the ATH model. The Bland-Altman plots for F and v values revealed a proportionality trend with outliers, which were strongly associated with the magnitudes of the parameters. Analysis of the PS values did not show any systematic bias.There were significant differences in the perfusion parameters obtained using the two software packages, and thus, these parameters are not directly interchangeable.

To evaluate the accuracy of ultrasmall paramagnetic iron oxide (USPIO: Sinerem)-enhanced MRI in patients with head and neck cancer and enlarged lymph nodes compared with current staging examinations using histology as a gold standard.Seventeen patients with a histologically proven squamous cell cancer of the head and neck (SCCHN) and different N-stages underwent a non-enhanced and a USPIO-enhanced MRI examination. Signal intensity (SI) was measured in a region of interest evaluation. Pathohistological examination was used as a reference.On a patient basis, USPIO-enhanced MRI showed a higher specificity and diagnostic accuracy (94%) compared with non-enhanced MRI (53%). One patient showed a lymph node of 6 mm in the short axial diameter which was suggested as being metastatic in Sinerem-enhanced MRI according to the enhancement pattern of Sinerem. This patient was staged as N1 with Sinerem-enhanced MRI. The histopathological examination did not confirm the Sinerem-enhanced MRI result.The high values for the specifity and diagnostic accuracy of Sinerem- enhanced MRI justifies further investigations with this contrast agent. USPIO-enhanced MRI could be advantageous in avoiding surgical overtreatment.

Objective To assess the feasibility and accuracy of predicting electrode insertion depth necessary in cochlear implantations for electric-acoustic stimulation by means of preoperative high-resolution computed tomography (HRCT). Design Human temporal bone study with evaluation of cochlear dimensions. Setting Tertiary care medical center. Methods Eight fresh human temporal bones were scanned, and basal cochlear structures were reconstructed and measured. Standard cochlear implantations with a free-fitting array were performed, and the bones then underwent histologic analysis using a technique that allows sectioning of undecalcified bones. After embedding, all bones underwent conventional radiologic analysis with further insertion measurements. Preimplantation HRCT data were compared with radiologic and histologic data. Results Preimplantation HRCT-based measurements correlated very well with postimplantation radiologic data. A mean failure of 0.3 mm was found. Mean values for the first 360° ranged from 18.8 to 22.0 mm. Conclusions Preimplantation HRCT-based prediction of cochlear implant insertion depths is both feasible and accurate. It is especially useful when aiming for hearing preservation, where insertion depths of 360° are necessary.

Seit November 2002 wird in den Kliniken der Autoren ein Traumanavigationssystem getestet, welches eine kabellose Navigation mit einer Systemplattform ermoglicht, die uber eine Infrarotkamera speziell entwickelte Patienten- und Tooltracker, Zeigeinstrumente, Kalibrierstation und den Tracker des Fluoroskops im Raum erkennt und am Computerbildschirm virtuell darstellt. Die Bilder werden den entsprechenden Rontgenbildern uberlagert. Das System wurde inzwischen bei verschiedenen operativen Eingriffen eingesetzt und verbessert. Durch den Einsatz des Verfahrens konnte die Durchleuchtungszeit deutlich reduziert werden, die Verlangerung der Operationszeit betrug zwischen 15 und 30 min. Ungenauigkeiten bzw. ein Versagen des Systems waren meist durch Lockerung des Patiententrackers und die Instabilitat bzw. Verbiegung des Bohrers bei der Navigation bedingt. Die Navigation der Frakturreposition am Oberschenkel hat sich als schwierig erwiesen und ist nicht bei allen Frakturtypen moglich. Das Navigationssystems ist fur die Frakturversorgung im Bereich der Extremitaten einsetzbar. Es werden insbesondere die Strahlenbelastung reduziert und die Genauigkeit verbessert. Bis zum Routineeinsatz sind jedoch noch Optimierungen notwendig.