The role of follow-up ultrasound and clinical parameters after abdominal MDCT in patients with multiple trauma.

BACKGROUND: Beside its value during the initial trauma work-up (focused assessment with sonography for trauma), ultrasound (US) is recommended for early follow-up examinations of the abdomen in multiple injured patients. However, multidetector CT (MDCT) has proven to reliably diagnose traumatic lesions of abdominal organs, to depict their extent, and to assess their clinical relevance. PURPOSE: To evaluate the diagnostic impact of follow-up US studies after MDCT of the abdomen and to identify possible clinical parameters indicating the need of a follow-up US. MATERIAL AND METHODS: During a 30-month period, patients with suspected multiple trauma were allocated. Patients with admission to the ICU, an initial abdominal MDCT scan, and an US follow-up examination after 6 and 24 h were included. Two patient cohorts were defined: patients with normal abdominal MDCT (group 1), patients with trauma-related pathologic abdominal MDCT (group 2). In all patients, parameters indicating alteration of vital functions or hemorrhage within the first 24 h were obtained by reviewing the medical charts. RESULTS: Forty-four of 193 patients were included: 24 were categorized in group 1 (mean age, 41.1 years; range, 21-90 years), 20 in group 2 (mean age, 36.6 years; range, 16-71 years). In group 1, US did not provide new information compared to emergency MDCT. In group 2, there were no contradictory 6- and 24-h follow-up US findings. In patients with positive MDCT findings and alterations of clinical parameters, US did not detect progression of a previously diagnosed pathology or any late manifestation of such a lesion. In none of the patients with negative abdominal MDCT and pathological clinical parameters US indicated an abdominal injury. CONCLUSION: Routine US follow-up does not yield additional information after abdominal trauma. In patients with MDCT-proven organ lesions, follow-up MDCT should be considered if indicated by abnormal clinical and/or laboratory findings.

[Importance of multidetector CT imaging in multiple trauma]. / Stellenwert der Multidetektor-CT bei Polytrauma.

CLINICAL/METHODICAL ISSUE: Diagnostic imaging of complex multiple trauma remains a challenge for any department providing modern emergency radiology (ER) service. An early and comprehensive approach for ER imaging is crucial for a priority-oriented and timely therapy concept with the aim of identifying potentially life-threatening injuries early and initiating appropriate treatment. STANDARD RADIOLOGICAL METHODS: The basic diagnostic approach still consists of focused ultrasound using focused assessment with sonography for trauma (FAST) and conventional radiography (CR), usually limited to a single supine chest x-ray for triaging patients undergoing immediate operations. METHODICAL INNOVATIONS: Multidetector computed tomography (MDCT) has become established as early whole body CT (WBCT) as the undisputable diagnostic method. The detection rate of injuries by WBCT is outstanding and it improves the probability of survival by 20-25% compared with all other previous methods. At the same time, the spatial and temporal resolution of MDCT was improved resulting in considerably shortened examination times but WBCT is still associated with a significant radiation exposure, even in the acute single use setting. Using modern scanner and dose reduction technology, including iterative reconstruction, a dose reduction of up to 40% could be achieved. The substantial number of images in WBCT is another challenge; images must be processed priority-oriented, read and transferred to the picture archiving and communications system (PACS). For rapid diagnosis, volume image reading (VIR) offers additional options to keep the diagnostic process on time. ACHIEVEMENTS/PRACTICAL RECOMMENDATIONS: Modern WBCT after multiple trauma is performed early, comprehensively and personalized so that WBCT improves the probability of survival by 20-25%.

Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma.

AIM: To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively. MATERIALS AND METHODS: Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose-length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann-Whitney U and Wilcoxon's test were used. RESULTS: In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p < 0.001) and scan length (p = 0.01). There was no significant difference in the subjective image quality (p > 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR). CONCLUSION: The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma.

[Mechanical obstruction as a cause of acute abdomen. Radiological differential diagnosis]. / Mechanische Obstruktion als Ursache für ein akutes Abdomen: Radiologische Differenzialdiagnose.

Mechanical obstruction is a common cause of acute abdomen. Besides the diagnosis of the obstruction itself it is crucial to recognize the cause of the obstruction for planning of conservative or operative treatment.This article gives a general overview of the methods available for imaging obstructions in the setting of an acute abdomen. In the second part the differential diagnoses of the most common causes of obstruction will be discussed.

[Imaging of trauma with multi-detector computed tomography]. / Multidetektor-CT zur Diagnostik traumatologischer Notfälle.

Diagnosis of trauma-related injuries is a key task in modern radiology. Early, thorough and accurate detection of potentially life-threatening injuries is crucial for fast and targeted initiation of treatment. Conventional radiography (CR) and ultrasound (US) are well-established and still represent the basic diagnostic tools for trauma imaging. However, a number of studies have shown a lower detection rate of injuries for radiography and ultrasound compared with computed tomography (CT). Multi-detector CT (MDCT) with its shorter scan time and increased accuracy has become the gold standard for many indications in trauma imaging. As MDCT has a higher radiation dose, its use should be restricted and carefully indicated especially when dealing with a younger patient population. Careful optimization of imaging parameters has to be performed to minimize exposure and maximize diagnostic safety. Modern MDCT examinations produce a large number of images, which have to be limited to a reasonable number for interpretation. This review article focuses on optimization of examination protocols and on how to handle the flood of images for viewing and archiving.

[Multidetector computed tomography in the diagnosis of non-traumatic vascular emergencies]. / MDCT zur Diagnostik nichttraumatischer vaskulärer Notfälle.

Radiological imaging of the vascular system is an essential component in the clinical evaluation of vascular emergencies. Duplex ultrasound is still in use as a basic diagnostic means and enables initial diagnostic information. Digital subtraction angiography (DSA), the longtime gold standard, is now more often used with therapeutic interventions rather than purely diagnostic studies. However, over the past 10 years, there has been a rapid development of new technology that has deeply changed vascular imaging and allows a non-invasive depiction with a robust technique, greater speed and higher resolution. Advanced cross-sectional imaging techniques such as magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) angiography nowadays enable a dedicated diagnostic evaluation of acute aortic and peripheral arterial pathologies. Due to its enormous innovation and broad and quick availability angiographic multidetector computed tomography (MDCT) could replace catheter-based angiography in the diagnostic assessment. This article summarizes the performance of MDCT angiographic imaging and its diagnostic and therapeutic significance for the diagnostic assessment of non-traumatic aortic and peripheral arterial diseases.

[Advanced imaging of spine disease]. / Aktuelle bildgebende Diagnostik der Wirbelsäulenerkrankungen.

Imaging of the spine is an essential prerequisite in the clinical workup of spine disease. Conventional radiography (CR) is still used as a basic diagnostic tool and enables an initial diagnosis to clarify symptomatology. Advanced cross-sectional techniques such as magnetic resonance imaging and computed tomography enable a dedicated diagnostic workup only of complex spinal pathologies. Due to its enormous innovation and broad availability, multidetector computed tomography could replace spinal CR in the diagnostic workup of acute and multiply injured patients. Nuclear medicine bone scans and positron emission tomography serve as screening studies and are an adjunct to morphologic radiological imaging. This review article summarizes the radiological and nuclear medicine imaging modalities and their diagnostic and therapeutic significance for diagnostic workup of common spinal disorders.

Subspecialisation in Emergency Radiology: Proposal for a harmonised European curriculum.

Introduction: Radiology plays a crucial role in the emergency care setting by delivering early and precise diagnoses under pressure of time, right at the beginning of patient treatment. Although there is a need for postgraduate education in emergency radiology, most of the national bodies responsible do not offer it in a uniform fashion and a general proof of qualification is missing in Europe. Therefore, the European Society of Radiology (ESR) has founded the (Sub-)Society of Emergency Radiology (ESER), prompting them to develop a European curriculum. This trend, which is currently also encouraged in many other non-radiological specialties which demand the highest professional qualifications, often lacks expertise in medical education. Goals: The goal of this article is the general description of the curricular planning process for a European postgraduate subspecialisation programme, using the example of Emergency Radiology (European Diploma in Emergency Radiology, EDER), including the utilisation of TOOLS and recommendations derived from comparable projects. Project description: The project was divided into partial steps: the timeline displayed in a GANTT chart, and tasks and responsibilities assigned in a RASCI matrix. The curriculum was iteratively developed using the KERN approach and steps were prioritised using the PARETO principle. Furthermore, the following TOOLS were used: limitations and needs assessment, SWOT analysis, formulating learning objectives and categorising them after MILLER and SCLO, and using BLOOM's taxonomy for cognitive learning objectives and operationalising them according to MAGER. Psychomotoric and affective learning objectives were assigned to CANMEDS roles, grouped by topic using CLUSTERING, and then mapped by MATRIX analysis to appropriate learning and evaluation methods. Striving for continuous improvement, the curriculum was finally embedded in curricular quality management. Results: The standardisation of the EDER access, considering the different national conditions, the minimisation of European learners' attendance phases, restricting expenses by best possible use of existing structures, respecting the requirements and retaining the support of the European umbrella society ESR, finishing the project by a specific deadline and the demands of continuous improvement were particular challenges. A curriculum with the eligibility of five years' speciality training in general radiology has evolved on schedule. The subspeciality training lasts at least one year and is divided into webinars, workshops during congresses (e.g. the annual ESR and ESER congresses) and one year practical training at the individual learner's corresponding local hospitals, which adhere to a catalogue of requirements, comparable to national educational policies. The curriculum is completed by passing a written and oral exam (diploma) and re-accreditation every five years. Conclusions: Despite complex requirements, the TOOLS utilised allowed an almost seamless, resource-minimised, professional, location-independent distributed development of a European subspeciality curriculum within one year. The definitive implementation is still due. If any deviations from the draft presented should become necessary in the future, the embedment in the curricular quality management will lead to a redirection in the right way and, furthermore, secure a continuous improvement in the best way possible.

[CT-guided vertebroplasty and kyphoplasty: comparing technical success rate and complications in 101 cases]. / CT-gesteuerte Vertebro- und Kyphoplastie: Vergleichende Untersuchung zu technischem Erfolg und Komplikationen bei 101 Eingriffen.

PURPOSE: To compare the technical success and complication rates in CT-guided vertebroplasty and kyphoplasty. MATERIALS AND METHODS: From 2002 - 2005 69 patients (101 vertebrae) were treated with vertebroplasty (n = 82) or kyphoplasty (n = 19) using 4-slice MSCT with CT fluoroscopy as the sole guidance for the procedure. The underlying lesions were osteoporotic fractures in 78 vertebral bodies and 23 vertebral metastases. RESULTS: Technical success was achieved in all 101 procedures. Post-interventional CT demonstrated asymptomatic cement leakage in 51/101 vertebrae. Kyphoplasty resulted in leakage in 11/19 (57.9 %) and vertebroplasty in 40/82 (48.8 %) procedures. With p = 0.48 (Mann-Whitney Test) there was no significant difference between kyphoplasty and vertebroplasty with respect to the number of cement leakage occurrences. There was one minor complication of an L5 root irritation following radiofrequency ablation and vertebroplasty of a sarcoma metastasis which subsided without treatment after 8 weeks. There was one major complication of intraspinal cement leakage during tumor vertebroplasty causing T5 root compression and requiring laminectomy for cement removal. The overall rate of major complications requiring treatment was 0.99 %. CONCLUSION: Vertebroplasty and kyphoplasty can be safely performed using only MSCT fluoroscopy guidance. The rate of major complications is very low. There was a high rate of small asymptomatic cement leakages which may have remained undetected with conventional fluoroscopy (CF). There was no statistically significant advantage for kyphoplasty with respect to cement leakage and the technical success rate.

Elevated serum levels of S-100B reflect the extent of brain injury in alcohol intoxicated patients after mild head trauma.

Elevated systemic levels of S-100B are proposed as a potential indicator of brain damage in identifying high-risk patients after mild head trauma (MHT). Although incidence of alcohol intoxication is high in these patients, the influence of alcohol intoxication on S-100B levels is unclear. Therefore, the aim of our study was to investigate serum concentrations of S-100B in intoxicated (group 1) and sober (group 2) patients after MHT in comparison with those of mild (group 3) or severely intoxicated (group 4) individuals without trauma. S-100B was significantly increased in MHT patients exhibiting posttraumatic lesions in initial cranial computed tomography scan. Alcohol intoxication did not elevate S-100B levels in group 3 or 4 subjects. Our data indicate for the first time that alcohol intoxication does not influence the diagnostic value of S-100B measurements in patients after MHT.

[Sedation analgesia in interventional radiology]. / Analgosedierung in der interventionellen Radiologie.

PURPOSE: Development of a save and effective protocol for analgosedation of patients undergoing painful interventional procedures. MATERIAL AND METHODS: In a prospective trial a consecutive series of 72 adult patients underwent analgosedation during painful interventions. A radiologist performed the analgosedation, the patients received a combination of a shortly effective piperidine derivative (Alfentanil [Rapifen(R)]; 7.5 - 15 microgram/kg body weight) and Benzodiazepine (midazolam [Dormicum(R)]; 20 microgram/kg body weight). After pre-procedure oxygenation patients were continuously monitored. Pain and discomfort were scored using an established visual-analog pain score (0 - 10). A control group (n = 24) had received midazolam, pentazocine or fentanyl according to the study protocol. RESULTS: All procedures could be carried out by an interventional radiologist and a nurse and/or technologist only. In 69/72 cases adequate analgosedation could be achieved. Injection of alfentanil was titrated, with a rapid onset and short acting effect of the analgesia. Patients reported an average pain score of 2.6 vs. 4.5 in the control group. Over 55 % experienced no or mild pain (score 0 - 3), in the control group only 8 % reached this level. CONCLUSION: A combination of shortly effective alfentanil and midazolam allows interventional radiologists to perform major procedures alone under effective analgosedation. This medication scheme is superior to the medication upon demand.

[Temporary balloon occlusion as therapy of uncontrollable arterial hemorrhage in multiple trauma patients]. / Temporäre Ballonokklusion als Therapie unkontrollierbarer arterieller Blutungen bei Polytraumapatienten.

PURPOSE: Presentation of temporary balloon occlusion as an interventional radiological method for managing hemorrhage in multiply injured patients with uncontrollable loss of blood. METHOD: Temporary, non-selective arterial occlusion by introduction of a balloon catheter contralaterally to the source of bleeding has been performed since 1992 on 7 patients with multiple injuries, hemorrhagic shock requiring reanimation, and angiographic demonstration of an arterial hemorrhage in the supply region of the internal iliac artery with complex pelvic fracture. In each case a PTA balloon catheter was introduced transfemorally, non-selectively positioned proximal to the bleeding source, and left in place for 24-48 h under manometric control. Control angiographies were performed prior to catheter removal. RESULTS: The bleeding was stopped immediately in all 7 patients. The hemodynamic stability made transport and thus further surgical management and/or a short-term treatment in the intensive-care station possible. Control angiographies confirmed that the bleeding had stopped in all patients. CONCLUSIONS: We recommend temporary balloon occlusion as a rapid and effective method for the management of bleeding in otherwise uncontrollable traumatic hemorrhages in the supply region of the internal iliac artery.

[Radiological diagnosis in polytrauma: interdisciplinary management]. / Radiologische Diagnostik beim Polytrauma: Interdisziplinäres Management.

The presence of a radiologist within the admitting area of an emergency department and his capability as a member of the trauma team have a major impact on the role of diagnostic radiology in trauma care. The knowledge of clinical decision criteria, algorithms, and standards of patient care are essential for the acceptance within a trauma team. We present an interdisciplinary management concept of diagnostic radiology for trauma patients, which comprises basic diagnosis, organ diagnosis, radiological ABC, and algorithms of early clinical care. It is the result of a prospective study comprising over 2000 documented multiple injured patients. The radiologist on a trauma team should support trauma surgery and anesthesia in diagnostic and clinical work-up. The radiological ABC provides a structured approach for diagnostic imaging in all steps of the early clinical care of the multiple injured patient. Radiological ABC requires a reevaluation in cases of equivocal findings or difficulties in the clinical course. Direct communication of radiological findings with the trauma team enables quick clinical decisions. In addition, the radiologist can priority-oriented influence the therapy by using interventional procedures. The clinical radiologist is an active member of the interdisciplinary trauma team, not only providing diagnostic imaging but also participating in clinical decisions.

[Functional CT imaging: Load-dependent visualization of the subchondral mineralization by means of CT osteoabsorptiometry (CT-OAM)]. / Funktionelle Computertomographie: Beanspruchungsabhängige Darstellung der subchondralen Mineralisierung mittels CT gestützter Osteoabsorptiometrie (CTOAM).

PURPOSE: Functional computed tomography for visualization and quantification of subchondral bone mineralization using CT osteoabsorptiometry (CT-OAM). MATERIALS AND METHODS: Tarsometatarsal (TMT) and metatarsophalangeal (MTP) joints of 46 human hallux valgus (HV) specimens were examined (sagittal 1/1/1 mm) on a single slice CT scanner SCT (Somatom Plus 4, Siemens AG). Subchondral bone pixels were segmented and assigned to 10 density value groups (Delta 100 HU, range 200 - 1200 HU) the pixels using volume rendering technique (VRT). The data analysis considered the severity of HV as determined by the radiographically measured HV-angle (a. p. projection). RESULTS: CT-OAM could generate reproducible densitograms of the distribution pattern of the subchondral bone density for all four joint surfaces (TMT and MTP joints). The bone density localization enables the assignment to different groups, showing a characteristic HV-angle-dependent distribution of the maximum bone mineralization of the load-dependent densitogram (p < 0.001). CONCLUSION: CT-OAM is a functional CT technique for visualizing and quantifying the distribution of the subchondral bone density, enabling a noninvasive load-dependent assessment of the joint surfaces. Load-dependent densitograms of hallux valgus specimens show a characteristic correlation with an increase of the HV-angle.

[CT-guided aortic balloon occlusion in traumatic abdominal and pelvic bleeding]. / CT-gesteuerte Ballonokklusion der Aorta bei traumatischen abdominellen und pelvinen Massenblutungen.

PURPOSE: To introduce a new interventional method for CT-guided aortic balloon occlusion in patients with life-threatening abdominal or pelvic bleeding. MATERIALS AND METHODS: Three male patients (age 18, 30, and 45 years) with multiple trauma underwent CT-guided balloon occlusion of the aorta after CT identified an active abdominal or pelvic bleeding site and the patients became unstable (systolic blood pressure, BP < 80 mm Hg) despite resuscitation continuous volume. Using a right femoral approach, a 9F sheath was immediately introduced and the positions of the guide wire and balloon catheter (20 x 40 mm) were intermittently checked with CT scans and CT fluoroscopy. In one case, a C-clamp was applied to the pelvic ring under CT guidance for emergency stabilization of an unstable pelvic fracture. RESULTS: CT-guided aortic balloon occlusion and the mounting of the pelvic C-clamp were technically successful. Intervention time was 4 to 6 minutes for aortic balloon occlusion. All patients became at least temporarily stable hemodynamically with the blood pressure rising above 100 mmHg. The infrarenal occlusion catheters were left in place up to 60 minutes. Suprarenal occlusion was not performed. Two patients died due to protracted shock and complex injuries (injury severity score (ISS: 50 - 64). CONCLUSION: CT-guided aortic occlusion provides fast and effective bleeding control immediately after completion of the diagnostic CT. The procedure can be combined with other specific emergency surgical or interventional procedures. Experience with more patients is necessary for further evaluation of this new technique.

[Interdisciplinary interventional therapy for tracheobronchial stenosis with modern metal net stents]. / Interdisziplinäre interventionelle Therapie tracheobronchialer Stenosen mit modernen Metallmaschenstents.

STUDY OBJECTIVES: Assessment of the therapeutic potential of tracheobronchial stenting for obstructive tracheobronchial disease, in-vivo comparison of different stent types and development of helpful criteria for choosing the suitable stent type. MATERIAL AND METHODS: Prospective case analysis. Between 1993 and 1999 53 stents were implanted into the tracheobronchial system of 39 consecutive patients with benign or malignant airway obstruction. Every single stent (26 Strecker Stents, 18 Wallstents, 6 Accuflex Nitinolstents, 1 Dumon-, 1 Rüsch- and 1 Palmazstent) was recorded in an unified database. Analysis comprised clinical effectiveness, lung function if possible, relevant complications and radiologic follow-up parameters. The probability of their remaining within the tracheobronchial system, of their remaining undislocated and uncompressed was calculated using Kaplan-Meier analysis for three stent types. RESULTS: Stent placement proved itself to be an effective treatment in 86 % of the patients. Resistance could be normalized in 9/9 patients. Kaplan-Meier analysis clearly revealed a higher probability for the Wall- and Nitinolstent to remain within the tracheobronchial system and to remain uncompressed. Dislocation also occurred more rarely. Explantation of the Wallstent, however, if desired, was much more difficult compared to the Strecker stent. The Wallstent also occasionally led to the formation of granulation tissue especially at the proximal stent end and, as such, required reintervention. CONCLUSION: Any of the 3 stent types proved to be an effective therapeutic option in the management of obstructive tracheobronchial disease. Choise of the stent type should be determined through definition of the therapeutic intention. It is useful to distinguish between (a) benign stenosis, (b) malignant stenosis but curative therapeutic situation and (c) malignant stenosis in a palliative therapeutic situation with limited life expectancy. In spite of its superior mechanical properties the Wallstent is rather suited for a palliative situation because explantation may be difficult. The Strecker Stent requires more reinterventions but removal is easy to perform. The Nitinolstent possibly represents a reasonable compromise.

[Focal secondary malignant liver lesions: MnDPDP-enhanced MRT at 0.2 tesla vs. helical CT-arterioportography]. / Fokale maligne sekundäre Leberläsionen: Manganverstärkte Niederfeld-MRT bei 0,2 Tesla versus Spiral-CT-Arterioportographie.

PURPOSE: Prospective evaluation of the efficacy of MnDPDP- enhanced MRI using an open low-field scanner for the detection of focal malignant liver lesions in comparison with helical CT- arterioportography (CT AP). MATERIAL AND METHODS: As part of a phase III study, 27 consecutive patients we enrolled for comparison, with seven patients later eliminated for failing the inclusion criteria. Native and MnDPDP-enhanced MRI of the liver at a field-strength of 0.2 Tesla (Siemens Magnetom Open) and DSA with helical CT AP (Siemens Somatom Plus 4) were performed within one week. The lesions were compared collectively and after categorization by size: (a) < 1 cm, (b) 1 - 2 cm, and (c) > 2 cm. For statistical evaluation, the sign test with a significance level of p < 0.05 was used. RESULTS: CT AP depicted 114 lesions, whereas native MRI detected 62 and MnDPDP-enhanced MRI revealed 69 lesions. Significant differences were shown for collective comparison and for selective comparison of category (b), and of categories (a) and (b) combined. No significant differences were found between native and contrast-enhanced MRI. CONCLUSION: MnDPDP should be reserved for high-field strengths since low field strengths cannot be expected to confirm or exclude malignant liver lesions reliably.

[Studies on image quality, high contrast resolution and dose for the axial skeleton and limbs with a new, dedicated CT system (ISO-C-3 D)]. / Untersuchungen zur Bildqualität, Hochkontrastauflösung und Dosis am Stamm- und Gliedmassenskelett mit einem neuen dedizierten CT-System (ISO-C-3D).

PURPOSE: Evaluation of 3D-CT imaging of the axial skeleton and different joints of the lower and upper extremities with a new dedicated CT system (ISO-C-3D) based on a mobile isocentric C-arm image amplifier. MATERIAL AND METHODS: 27 cadaveric specimes of different joints of the lower and upper extremities and of the spinal column were examined with 3D-CT imaging (ISO-C-3D). All images were evaluated by 3 radiologists for image quality using a semiquantitative score (score value 1: poor quality; score value 4: excellent quality). In addition, dose measurements and measurements of high contrast resolution were performed in comparison to conventional and low-dose spiral CT using a high contrast phantom (Catphan, Phantom Laboratories). RESULTS: Adequate image quality (mean score values 3 - 4) could be achieved with an applied dose comparable to low-dose CT in smaller joints such as wrist, elbow, ankle and knee. A remarkably inferior image quality resulted in imaging of the hip, lumbar and thoracic spine (mean score values 2 - 3) in spite of almost doubling the dose (dose increased by 85 percent). The image quality of shoulder examinations was insufficient (mean score value 1). Phantom studies showed a high-contrast resolution comparable to helical CT in the xy-axis (9 lp/cm). CONCLUSION: Preliminary results show, that image quality of C-arm-based CT-imaging (ISO-C-3D) seems to be adequate in smaller joints. ISO-C-3D images of the hip and axial skeleton show a decreased image quality, which does not seem to be sufficient for diagnosing subtle fractures.

[Detection of tibial condylar fractures using 3D imaging with a mobile image amplifier (Siemens ISO-C-3D): Comparison with plain films and spiral CT]. / Frakturdiagnostik am Kniegelenk mit einem neuen mobilen CT-System (ISO-C-3D): Vergleich mit konventionellem Röntgen und Spiral-CT.

PURPOSE: To analyze a prototype mobile C-arm 3D image amplifier in the detection and classification of experimental tibial condylar fractures with multiplanar reconstructions (MPR). METHOD: Human knee specimens (n = 22) with tibial condylar fractures were examined with a prototype C-arm (ISO-C-3D, Siemens AG), plain films (CR) and spiral CT (CT). The motorized C-arm provides fluoroscopic images during a 190 degrees orbital rotation computing a 119 mm data cube. From these 3D data sets MP reconstructions were obtained. All images were evaluated by four independent readers for the detection and assessment of fracture lines. All fractures were classified according to the Müller AO classification. To confirm the results, the specimens were finally surgically dissected. RESULTS: 97 % of the tibial condylar fractures were easily seen and correctly classified according to the Müller AO classification on MP reconstruction of the ISO-C-3D. There is no significant difference between ISO-C and CT in detection and correct classification of fractures, but ISO-CD-3D is significant by better than CR. CONCLUSION: The evaluation of fractures with the ISO-C is better than with plain films alone and comparable to CT scans. The three-dimensional reconstruction of the ISO-C can provide important information which cannot be obtained from plain films. The ISO-C-3D may be useful in planning operative reconstructions and evaluating surgical results in orthopaedic surgery of the limbs.

[Evaluation of spine boards for X-Ray diagnostics]. / Evaluation von Wirbelsäulenbrettern für die Röntgendiagnostik.

PURPOSE: Spine boards are frequently used in preclinical emergency care. Different models were examined with regard to their feasibility for plain film radiography and computed tomography (CT). METHODS: Five current spine board models were measured for their dimensions and weight. Transmission of radiation [microGyls] and dose area product [cGy x cm(2)] were determined with a patient equivalent aluminium phantom. Image artifacts, image quality and resolution of anatomic details were evaluated with an anthropomorphic Alderson phantom. RESULTS: With only 6.3 kg new models show a 28 % reduction in weight, three spine boards generate lateral artifacts due to a narrow width of 41 - 42 cm. Radiation transmission of all boards was similar, however dose area products differed by up to 59 %. Image quality was impaired in 4 out of 5 boards because of image artifacts, CT scanning was not impaired with all boards. CONCLUSION: Only one board (Ferno Millenia(R)) showed sufficient properties for plain film radiography and CT. There is no suitable spine board for preclinical and clinical applications as well as for trauma radiology, further improvements of current designs are essential.