Is It Possible to Replace Conventional Radiography (CR) with a Dose Neutral Computed Tomography (CT) of the Cervical Spine in Emergency Radiology-An Experimental Cadaver Study.

The purpose of this experimental study on recently deceased human cadavers was to investigate whether (I) the radiation exposure of the cervical spine CT can be reduced comparable to a dose level of conventional radiography (CR); and (II) whether and which human body parameters can be predictive for higher dose reduction potential (in this context). MATERIALS AND METHODS: Seventy serial CT scans of the cervical spine of 10 human cadavers undergoing postmortem virtual autopsy were taken using stepwise decreasing upper limits of the tube current (300 mAs, 150 mAs, 110 mAs, 80 mAs, 60 mAs, 40 mAs, and 20 mAs) at 120 kVp. An additional scan acquired at a fixed tube current of 300 mAs served as a reference. Images were reconstructed with filtered back projection and the upper (C1-4) and lower (C4-7) cervical spine were evaluated by three blinded readers for image quality, regarding diagnostic value and resolution of anatomical structures according to a semiquantitative three-point-scale. Dose values and individual physical parameters were recorded. The relationship of diagnostic IQ, dose reduction level, and patients' physical parameters were investigated. The high-contrast resolution of the applied CT protocols was tested in an additional phantom study. RESULTS: The IQ of the upper cervical spine was diagnostic at 1.69 ± 0.58 mGy (CTDI) corresponding to 0.20 ± 0.07 mSv (effective dose) in all cadavers. IQ of the lower cervical spine was diagnostic at 4.77 ± 1.86 mGy corresponding to 0.560 ± 0.21 mSv (effective dose) in seven cadavers and at 2.60 ± 0.93 mGy corresponding to 0.31 ± 0.11 mSv in four cadavers. Significant correlation was detected for BMI (0.8366; p = 0.002548) and the anteroposterior (a.p.) chest diameter (0.8363; p = 0.002566), shoulder positioning (0.79799; p = 0.00995), and radiation exposure. CONCLUSIONS: Conventional radiography can be replaced with a nearly dose-neutral CT scan of the cervical spine.

Dose reduction in 64-row whole-body CT in multiple trauma: an optimized CT protocol with iterative image reconstruction on a gemstone-based scintillator.

OBJECTIVE: Evaluation of potential dose savings by implementing adaptive statistical iterative reconstruction (ASiR) on a gemstone-based scintillator in a clinical 64-row whole-body CT (WBCT) protocol after multiple trauma. METHODS: Dose reports of 152 WBCT scans were analysed for two 64-row multidetector CT scanners (Scanners A and B); the main scanning parameters were kept constant. ASiR and a gemstone-based scintillator were used in Scanner B, and the noise index was adjusted (head: 5.2 vs 6.0; thorax/abdomen: 29.0 vs 46.0). The scan length, CT dose index (CTDI) and dose-length product (DLP) were analysed. The estimated mean effective dose was calculated using normalized conversion factors. Student's t-test was used for statistics. RESULTS: Both the mean CTDI (mGy) (Scanner A: 53.8 ± 2.0, 10.3 ± 2.5, 14.4 ± 3.7; Scanner B: 48.7 ± 2.2, 7.1 ± 2.3, 9.1 ± 3.6; p < 0.001, respectively) and the mean DLP (mGy cm) (Scanner A: 1318.9 ± 167.8, 509.3 ± 134.7, 848.8 ± 254.0; Scanner B: 1190.6 ± 172.6, 354.6 ± 128.3, 561.0 ± 246.7; p < 0.001, respectively) for the head, thorax and abdomen were significantly reduced with Scanner B. There was no relevant difference in scan length. The total mean effective dose (mSv) was significantly decreased with Scanner B (24.4 ± 6.0, 17.2 ± 5.8; p < 0.001). CONCLUSION: The implementation of ASiR and a gemstone-based scintillator allows for significant dose savings in a clinical WBCT protocol. ADVANCES IN KNOWLEDGE: Recent technical developments can significantly reduce radiation dose of WBCT in multiple trauma. Dose reductions of 10-34% can be achieved.

Emergency imaging after a mass casualty incident: role of the radiology department during training for and activation of a disaster management plan.

In the setting of mass casualty incidents (MCIs), hospitals need to divert from normal routine to delivering the best possible care to the largest number of victims. This should be accomplished by activating an established hospital disaster management plan (DMP) known to all staff through prior training drills. Over the recent decades, imaging has increasingly been used to evaluate critically ill patients. It can also be used to increase the accuracy of triaging MCI victims, since overtriage (falsely higher triage category) and undertriage (falsely lower triage category) can severely impact resource availability and mortality rates, respectively. This article emphasizes the importance of including the radiology department in hospital preparations for a MCI and highlights factors expected to influence performance during hospital DMP activation including issues pertinent to effective simulation, such as establishing proper learning objectives. After-action reviews including performance evaluation and debriefing on issues are invaluable following simulation drills and DMP activation, in order to improve subsequent preparedness. Historically, most hospital DMPs have not adequately included radiology department operations, and they have not or to a little extent been integrated in the DMP activation simulation. This article aims to increase awareness of the need for radiology department engagement in order to increase radiology department preparedness for DMP activation after a MCI occurs.

Incidence of delayed and missed diagnoses in whole-body multidetector CT in patients with multiple injuries after trauma.

BACKGROUND: Whole-body CT (WBCT) is the imaging modality of choice during the initial diagnostic work-up of multiple injured patients in order to identify serious injuries and initiate adequate treatment immediately. However, delayed diagnosed or even missed injuries have been reported frequently ranging from 1.3% to 47%. PURPOSE: To highlight commonly missed lesions in WBCT of patients with multiple injuries. MATERIAL AND METHODS: A total of 375 patients (age 42.8 ± 17.9 years, ISS 26.6 ± 17.0) with a WBCT (head to symphysis) were included. The final CT report was compared with clinical and operation reports. Discrepant findings were recorded and grouped as relevant and non-relevant to further treatment. In both groups, an experienced trauma radiologist read the CT images retrospectively, whether these lesions were missed or truly not detectable. RESULTS: In 336 patients (89.6%), all injuries in the regions examined were diagnosed correctly in the final reports of the initial CT. Forty-eight patients (12.8%) had injuries in regions of the body that were not included in the CT. Fourteen patients (3.7%) had injuries that did not require further treatment. Twenty-five patients (6.7%) had injuries that required further treatment. With secondary interpretation, 85.4% of all missed lesions could be diagnosed in retrospect from the primary CT data-set. Small pancreatic and bowel contusions were identified as truly non-detectable. CONCLUSION: In multiple traumas, only a few missed injuries in initial WBCT reading are clinically relevant. However, as the vast majority of these injuries are detectable, the radiologist has to be alert for commonly missed findings to avoid a delayed diagnosis.

Filtered back projection, adaptive statistical iterative reconstruction, and a model-based iterative reconstruction in abdominal CT: an experimental clinical study.

PURPOSE: To compare objective and subjective image quality parameters of three image reconstruction algorithms of different generations at routine multidetector computed tomographic (CT) examinations of the abdomen. MATERIALS AND METHODS: This institutional review board-approved study included 22 consecutive patients (mean age, 56.1 years ± 15.8 [standard deviation]; mean weight, 79.1 kg ± 14.8) who underwent routine CT examinations of the abdomen. A low-contrast phantom was used for objective quality control. Raw data sets were reconstructed by using filtered back projection (FPB), adaptive statistical iterative reconstruction (ASIR), and a model-based iterative reconstruction (MBIR). Radiologists used a semiquantitative scale (-3 to +3) to rate subjective image quality and artifacts, comparing both FBP and MBIR images with ASIR images. The Wilcoxon test and the intraclass correlation coefficient were used to evaluate the data. Measurements of objective noise and CT numbers of soft tissue structures were compared with analysis of variance. RESULTS: The phantom study revealed an improved detectability of low-contrast targets for MBIR compared with ASIR or FBP. Subjective ratings showed higher image quality for MBIR, with better resolution (median value, 2; range, 1 to 3), lower noise (2; range, 1 to 3), and finer contours (2; range, 1 to 2) compared with ASIR (all P < .001). FBP performed inferiorly (0, range, -2 to 0]; -1 [range, -3 to 0]; 0 [range, -1 to 0], respectively; all, P < .001). Mean interobserver correlation was 0.9 for image perception and 0.7 for artifacts. Objective noise for FBP was 14%-68% higher and for MBIR was 18%-47% lower than that for ASIR (P < .001). CONCLUSION: The MBIR algorithm considerably improved objective and subjective image quality parameters of routine abdominal multidetector CT images compared with those of ASIR and FBP.

Imaging of acute pulmonary embolism using a dual energy CT system with rapid kVp switching: initial results.

PURPOSE: Computed tomography pulmonary angiography (CTPA) is considered as clinical gold standard for diagnosing pulmonary embolism (PE). Whereas conventional CTPA only offers anatomic information, dual energy CT (DECT) provides functional information on blood volume as surrogate of perfusion by assessing the pulmonary iodine distribution. The purpose of this study was to evaluate the feasibility of lung perfusion imaging using a single-tube DECT scanner with rapid kVp switching. MATERIALS AND METHODS: Fourteen patients with suspicion of acute PE underwent DECT. Two experienced radiologists assessed the CTPA images and lung perfusion maps regarding the presence of PE. The image quality was rated using a semi-quantitative 5-point scale: 1 (=excellent) to 5 (=non-diagnostic). Iodine concentrations were quantified by a ROI analysis. RESULTS: Seventy perfusion defects were identified in 266 lung segments: 13 (19%) were rated as consistent with PE. Five patients had signs of PE at CTPA. All patients with occlusive clots were correctly identified by DECT perfusion maps. On a per patient basis the sensitivity and specificity were 80.0% and 88.9%, respectively, while on a per segment basis it was 40.0% and 97.6%, respectively. None of the patients with a homogeneous perfusion map had an abnormal CTPA. The overall image quality of the perfusion maps was rated with a mean score of 2.6 ± 0.6. There was a significant ventrodorsal gradient of the median iodine concentrations (1.1mg/cm(3) vs. 1.7 mg/cm(3)). CONCLUSION: Lung perfusion imaging on a DE CT-system with fast kVp-switching is feasible. DECT might be a helpful adjunct to assess the clinical severity of PE.

64-MDCT in mass casualty incidents: volume image reading boosts radiological workflow.

OBJECTIVE: The purpose of this study was to evaluate the impact of the use of 64-MDCT and volume image reading on the radiologic workflow during a mass casualty incident simulation. MATERIALS AND METHODS: For this simulation, casualties were taken to our level I trauma center, and triage was done with whole-body 64-MDCT. The complete raw dataset of thin-section images was sent to a dedicated 3D workstation for further interpretation and simultaneous reformations. This new reading method is called volume image reading. Several time frames were documented to evaluate the workflow: examination time, time needed for image processing, and mean image transfer rates. The results were compared with those of a previous study using a 4-MDCT with axial images only and transfer of data to a PACS. RESULTS: The time for complete image processing (acquisition, reconstruction, and transfer) for 64-MDCT was 4.1 minutes (range, 3.9-4.3 minutes) compared with 9.0 minutes (range, 6.4-10.2 minutes) for 4-MDCT (p ≤ 0.001). The image processing capacity was 14.8 examinations/h for 64-MDCT compared with 6.7 examinations/h for 4-MDCT. The mean number of images was 953 for 64-MDCT compared with 202 for 4-MDCT (p ≤ 0.001). There were no significant differences between 64- and 4-MDCT for the time needed to prepare patients. CONCLUSION: The use of 64-MDCT with volume image reading led to evident advantages in the radiologic trauma workflow compared with 4-MDCT. Reading of the full image set including reformations can be initiated earlier with volume image reading.

Emergency percutaneous needle decompression for tension pneumoperitoneum.

BACKGROUND: Tension pneumoperitoneum as a complication of iatrogenic bowel perforation during endoscopy is a dramatic condition in which intraperitoneal air under pressure causes hemodynamic and ventilatory compromise. Like tension pneumothorax, urgent intervention is required. Immediate surgical decompression though is not always possible due to the limitations of the preclinical management and sometimes to capacity constraints of medical staff and equipment in the clinic. METHODS: This is a retrospective analysis of cases of pneumoperitoneum and tension pneumoperitoneum due to iatrogenic bowel perforation. All patients admitted to our surgical department between January 2005 and October 2010 were included. Tension pneumoperitoneum was diagnosed in those patients presenting signs of hemodynamic and ventilatory compromise in addition to abdominal distension. RESULTS: Between January 2005 and October 2010 eleven patients with iatrogenic bowel perforation were admitted to our surgical department. The mean time between perforation and admission was 36 ± 14 hrs (range 30 min - 130 hrs), between ER admission and begin of the operation 3 hrs and 15 min ± 47 min (range 60 min - 9 hrs). Three out of eleven patients had clinical signs of tension pneumoperitoneum. In those patients emergency percutaneous needle decompression was performed with a 16G venous catheter. This improved significantly the patients' condition (stabilization of vital signs, reducing jugular vein congestion), bridging the time to the start of the operation. CONCLUSIONS: Hemodynamical and respiratory compromise in addition to abdominal distension shortly after endoscopy are strongly suggestive of tension pneumoperitoneum due to iatrogenic bowel perforation. This is a rare but life threatening condition and it can be managed in a preclinical and clinical setting with emergency percutaneous needle decompression like tension pneumothorax. Emergency percutaneous decompression is no definitive treatment, only a method to bridge the time gap to definitive surgical repair.

Traumatic dissection of a coronary artery: detection by multislice computed tomography and use of tirofiban as a reversible platelet inhibitor.

We report on a trauma victim without history of or risk factors for cardiac disease, who suffered coronary artery dissection caused by blunt chest injury (BCI). Myocardial ischaemia was detected by multislice computed tomography (MSCT) promptly after trauma centre admission and managed by immediate revascularisation. Thoracic trauma may cause myocardial ischaemia in the absence of a specific risk profile. MSCT, as part of initial work-up in severely injured patients, may support differential diagnosis after BCI. Tirofiban and unfractionated heparin as short-acting anticoagulants warrant stent patency and concurrently offer the possibility of quick recovery of haemostasis in case of haemorrhage.

Analysis of responses of radiology personnel to a simulated mass casualty incident after the implementation of an automated alarm system in hospital emergency planning.

The purpose of this study was to evaluate the response to an automated alarm system of a radiology department during a mass casualty incident simulation. An automated alarm system provided by an external telecommunications provider handling up to 480 ISDN lines was used at a level I trauma center. During the exercise, accessibility, availability, and estimated time of arrival (ETA) of the called in staff were recorded. Descriptive methods were used for the statistical analysis. Of the 49 employees, 29 (59%) were accessible, of which 23 (79%) persons declared to be available to come to the department. The ETA was at an average 29 min (SD ±23). Radiologists and residents reported an ETA to their workplace almost two times shorter compared with technicians (19 ± 16 and 22 ± 16 vs. 40 ± 27 min, p > 0.05). Additional staff reserve is crucial for handling mass casualty incidents. An automated alarm procedure might be helpful. However, the real availability of the employees could not be exactly determined because of unpredictable parameters. But our results allow estimation of the manpower reserve and calculation of maximum radiology service capacities.

Monoaxial versus polyaxial screw insertion in angular stable plate fixation of proximal humeral fractures: radiographic analysis of a prospective randomized study.

BACKGROUND: Monoaxial and polyaxial screw insertion are used in angular stable plating of displaced proximal humeral fractures. Aim of the study was to compare both fixation techniques by radiographic evaluation. METHODS: Prospective randomized treatment with monoaxial or polyaxial screw insertion in angular stable anatomic preshaped plates of displaced proximal humeral fractures. Analysis of standardized true anterior-posterior (true a.p.) and outlet-view radiographs at 1 day, 6 weeks, 3 months, and 6 months after surgery by two radiologists with respect to radiographic evidence of secondary varus displacement, cut out of screws, osteonecrosis, and hardware failure. Secondary varus displacement was defined as a varus decrease of the humeral head-shaft angle of > 10 degree in true a.p. radiographs. RESULTS: Sixty-six consecutive patients (48 women, [72.7%]; 18 men, [27.3%]; mean age 67.7 years [95% CI, 63.9-71.6]) with displaced proximal humeral fractures were evaluated in this study. Nineteen patients (29%) showed secondary varus displacement of > 10-degree angle. In 6 cases (9%), intra-articular cut out of screws was found. Furthermore, 1 case (2%) of nonunion was observed. No relationship between monoaxial and polyaxial screw insertion was found regarding occurrence of secondary varus displacement (monoaxial, 11/polyaxial, 8; p = 0.91) or screw cut out (monoaxial, 4/polyaxial, 2; p = 0.64). Prevalence of secondary varus displacement and hardware cut out was related to patients age (p = 0.02) and fracture pattern, according to Neer- and AO/OTA-classification (p < 0.001). The average immediate postoperative head-shaft angle was 135.2 degrees (CI, 132.3-138.1) in the group without radiographic complication, compared with 126.7-degree angle (CI, 123.6-129.7) among those with secondary varus displacement of > 10-degree angle and screw cut out (p < 0.001). Furthermore, in cases of an immediate postoperative head-shaft angle of < 130 degrees, there was a 48% incidence of secondary varus dislocation (n = 13) versus 15% in cases with a head-shaft angle > 130 degrees (n = 6, p = 0.004). CONCLUSION: Monoaxial and polyaxial screw insertion allow for mechanical stabilization in angular stable plating of unstable proximal humerus fractures. Radiographic evidence of secondary varus displacement of > 10-degree angle and screw cut out was seen similarly often in both fixation techniques. To avoid secondary varus displacement and screw cut out, restoration of a humeral head-shaft angle of > 130 degrees seems to be important in monoaxial and polyaxial fixation of proximal humeral fractures.

Computed tomography during cardiopulmonary resuscitation using automated chest compression devices--an initial study.

The purpose of the study was to evaluate both CT image quality in a phantom study and feasibility in an initial case series using automated chest compression (A-CC) devices for cardiopulmonary resuscitation (CPR). Multidetector CT (MDCT) of a chest/heart phantom (Thorax-CCI, QRM, Germany) was performed with identical protocols of the phantom alone (S), the phantom together with two different A-CC devices (A: AutoPulse, Zoll, Germany; L: LUCAS, Jolife, Sweden), and the phantom with a LUCAS baseplate, but without the compression unit (L-bp). Nine radiologists evaluated image noise quantitatively (n = 244 regions, Student's t-test) and also rated image quality subjectively (1-excellent to 6-inadequate, Mann-Whitney U-test). Additionally, three patients during prolonged CPR underwent CT with A-CC devices. Mean image noise of S was increased by 1.21 using L-bp, by 3.62 using A, and by 5.94 using L (p < 0.01 each). Image quality was identical using S and L-bp (1.64 each), slightly worse with A (1.83), and significantly worse with L (2.97, p < 0.001). In all patient cases the main lesions were identified, which led to clinical key decisions. Image quality was excellent with L-bp and good with A. Under CPR conditions initial cases indicate that MDCT diagnostics supports either focused treatment or the decision to terminate efforts.

Evaluation of a CT triage protocol for mass casualty incidents: results from two large-scale exercises.

The purpose of this study was to evaluate the feasibility, stability, and reproducibility of a dedicated CT protocol for the triage of patients in two separate large-scale exercises that simulated a mass casualty incident (MCI). In both exercises, a bomb explosion at the local soccer stadium that had caused about 100 casualties was simulated. Seven casualties who were rated "critical" by on-site field triage were admitted to the emergency department and underwent whole-body CT. The CT workflow was simulated with phantoms. The history of the casualties was matched to existing CT examinations that were used for evaluation of image reading under MCI conditions. The times needed for transfer and preparation of patients, examination, image reconstruction, total time in the CT examination room, image transfer to PACS, and image reading were recorded, and mean capacities were calculated and compared using the Mann-Whitney U test. We found no significant time differences in transfer and preparation of patients, duration of CT data acquisition, image reconstruction, total time in the CT room, and reading of the images. The calculated capacities per hour were 9.4 vs. 9.8 for examinations completed, and 8.2 vs. 7.2 for reports completed. In conclusion, CT triage is feasible and produced constant results with this dedicated and fast protocol.

Effect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study.

BACKGROUND: The number of trauma centres using whole-body CT for early assessment of primary trauma is increasing. There is no evidence to suggest that use of whole-body CT has any effect on the outcome of patients with major trauma. We therefore compared the probability of survival in patients with blunt trauma who had whole-body CT during resuscitation with those who had not. METHODS: In a retrospective, multicentre study, we used the data recorded in the trauma registry of the German Trauma Society to calculate the probability of survival according to the trauma and injury severity score (TRISS), revised injury severity classification (RISC) score, and standardised mortality ratio (SMR, ratio of recorded to expected mortality) for 4621 patients with blunt trauma given whole-body or non-whole-body CT. FINDINGS: 1494 (32%) of 4621 patients were given whole-body CT. Mean age was 42.6 years (SD 20.7), 3364 (73%) were men, and mean injury-severity score was 29.7 (13.0). SMR based on TRISS was 0.745 (95% CI 0.633-0.859) for patients given whole-body CT versus 1.023 (0.909-1.137) for those given non-whole-body CT (p<0.001). SMR based on the RISC score was 0.865 (0.774-0.956) for patients given whole-body CT versus 1.034 (0.959-1.109) for those given non-whole-body CT (p=0.017). The relative reduction in mortality based on TRISS was 25% (14-37) versus 13% (4-23) based on RISC score. Multivariate adjustment for hospital level, year of trauma, and potential centre effects confirmed that whole-body CT is an independent predictor for survival (p

Assessment of renal vasoconstriction in vivo after intra-arterial administration of the isosmotic contrast medium iodixanol compared to the low-osmotic contrast medium iopamidol.

BACKGROUND: Low-osmotic contrast media (LOCM) such as iopamidol are known to increase the renal resistance index (RRI). The aim of our study was to evaluate in vivo the different effects of intra-arterial administration of LOCM in comparison to isosmotic contrast medium (IOCM) such as iodixanol on the human RRI. METHODS: Twenty patients (16 males, 4 females; 66 years on average) with normal renal function (mean creatinine 1.0 mg/dl) had digital subtraction angiography (DSA) of the abdominal and lower-limb arteries. Ten patients received LOCM, and 10 patients IOCM (150 ml on average, 20 ml/s). The RRI was assessed by an experienced nephrologist with duplex ultrasound from 15 min before until 30 min after the first injection with delays of 1-5 min. The basic value of the RRI and differential RRI were calculated. RESULTS: The basic value of the RRI was 0.69 in the LOCM group and 0.71 in the IOCM group. After LOCM a significant increase of the RRI to 0.73 on average (P < or = 0.001) 2 min after the first injection was found, whereas IOCM did not result in a significant change of the RRI (RRI remained 0.71 on average, P > or = 0.1). In the LOCM group, the RRI returned to the basic value after 30 min (+/-2.3 min). CONCLUSIONS: Intra-arterial administration of IOCM had no influence on renal vascular resistance as expressed by the RRI, unlike LOCM, which induced a highly significant increase of the RRI for up to 30 min.

Assessment of the vessel lumen diameter and degree of stenosis in the superficial femoral artery before intervention: comparison of different algorithms.

PURPOSE: To determine which angiography-based algorithm delivers the most precise results in comparison with direct measurements at intravascular ultrasonography (US) and evaluate their influence on the resulting balloon size for treatment. MATERIALS AND METHODS: Thirty patients with untreated superficial femoral artery stenosis underwent digital subtraction angiography (DSA) and intravascular US before intervention. Two experienced radiologists measured twice the native vessel lumen diameter and the degree of stenosis with all algorithms and modalities in a predefined vessel segment that was perceived to be unaffected. On the basis of the measurements of the vessel lumen diameter, a suitable balloon size for treatment of the lesion was calculated. RESULTS: The mean vessel diameter was 5.7 mm for intravascular US, 6.6 mm for caliper calibration, 6.0 mm for calibration of the catheter tip, and 4.7 mm for visual estimation. Selected balloon sizes were 6.0 mm, 7.0 mm, 6.0 mm, and 5.0 mm, respectively. The mean percentage of stenosis was 78.8% for intravascular US, 81.6% for caliper calibration, 79.7% for catheter calibration, and 88.8% for visual estimation. Intermethod correlation was best for intravascular US and calibration of a catheter tip (0.881, P < .0001). CONCLUSIONS: Measurements on DSA equipment calibrated to a catheter tip correlate best with direct intravascular measurements. Visual estimation can lead to underestimation of the true vessel size and overestimation of stenosis.

Imaging performance with different doses in skeletal radiography: comparison of a needle-structured and a conventional storage phosphor system with a flat-panel detector.

PURPOSE: To evaluate possible radiation dose reduction in the extremities with use of digital radiography and a needle-structured image plate (NIP) by comparing this technique with digital radiography performed with a powder-structured image plate (PIP) and a flat-panel detector (FPD). MATERIALS AND METHODS: This study was approved by the local review board. A total of 72 plain radiographs of the feet of six human cadavers were obtained with four surface entrance doses (65, 43, 20, and 10 micro Gy) by using three systems. The reference image of each specimen was obtained with an 85-micro Gy dose and with use of a PIP. Five independent blinded radiologists evaluated the images. The noise level and the depiction of the cortical bone, trabecular bone, and soft tissue were rated and compared with those of the reference image by using a five-point scale. An overall image score was developed for these four criteria by calculating the unweighted mean. The Wilcoxon test was used to assess differences between overall image scores. RESULTS: For each dose, NIP images were significantly superior (P < .001), whereas FPD images and PIP images were significantly inferior (P < .01). NIP images obtained with 65-, 43-, and 20-micro Gy doses were significantly superior to reference images and to FPD and PIP images obtained with a 65-micro Gy dose. There were no significant differences between reference images and FPD images obtained with 65- and 43-micro Gy doses. CONCLUSION: Radiation dose can be reduced by 75% in clinical skeletal imaging of peripheral extremities by using NIP, with no significant loss of information. For FPD images, this might be possible with a dose reduction of 50%.

Diagnosis and classification of pancreatic and duodenal injuries in emergency radiology.

Pancreatic and duodenal injuries after blunt abdominal trauma are rare; however, delays in diagnosis and treatment can significantly increase morbidity and mortality. Multidetector computed tomography (CT) has a major role in early diagnosis of pancreatic and duodenal injuries. Detecting the often subtle signs of injury with whole-body CT can be difficult because this technique usually does not include a dedicated protocol for scanning the pancreas. Specific injury patterns in the pancreas and duodenum often have variable expression at early posttraumatic multidetector CT: They may be hardly visible, or there may be considerable exudate, hematomas, organ ruptures, or active bleeding. An accurate multidetector CT technique allows optimized detection of subtle abnormalities. In duodenal injuries, differentiation between a contusion of the duodenal wall or mural hematoma and a duodenal perforation is vital. In pancreatic injuries, determination of involvement of the pancreatic duct is essential. The latter conditions require immediate surgical intervention. Use of organ injury scales and a surgical classification adapted for multidetector CT enables classification of organ injuries for trauma scoring, treatment planning, and outcome control. In addition, multidetector CT reliably demonstrates potential complications of duodenal and pancreatic injuries, such as posttraumatic pancreatitis, pseudocysts, fistulas, exudates, and abscesses.

The fulcrum axis: a new method for determining glenoid version.

Previously applied methods for the evaluation of glenoid version did not use body-surface landmarks; therefore, it is not possible to get information about glenoid version from the outside. The tip of the coracoid and the posterolateral corner of the acromion can easily be found on the body surface. These 2 landmarks were connected by a line called the fulcrum axis. After using an experimental x-ray technique in 143 human cadaver scapulae, 5 independent observers identified the fulcrum axis and the glenoid fossa twice. The resulting overall angle between the fulcrum axis and the glenoid fossa was 1.8 degrees (SD 4.5). The fulcrum axis may be used for the preoperative planning and the intraoperative evaluation of glenoid version while performing total shoulder arthroplasties. As the fulcrum axis and the plane of the glenoid fossa are approximately parallel, the fulcrum axis can be used to position patients for performing a true antero-posterior x-ray.