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

Current Role of Emergency US in Patients with Major Trauma.

In patients with major trauma, focused abdominal ultrasonography (US) often is the initial imaging examination. US is readily available, requires minimal preparation time, and may be performed with mobile equipment that allows greater flexibility in patient positioning than is possible with other modalities. It also is effective in depicting abnormally large intraperitoneal collections of free fluid, which are indirect evidence of a solid organ injury that requires immediate surgery. However, because US has poor sensitivity for the detection of most solid organ injuries, an initial survey with US often is followed by a more thorough examination with multidetector computed tomography (CT). The initial US examination is generally performed with a FAST (focused assessment with sonography in trauma) protocol. Speed is important because if intraabdominal bleeding is present, the probability of death increases by about 1% for every 3 minutes that elapses before intervention. Typical sites of fluid accumulation in the presence of a solid organ injury are the Morison pouch (liver laceration), the pouch of Douglas (intraperitoneal rupture of the urinary bladder), and the splenorenal fossa (splenic and renal injuries). FAST may be used also to exclude injuries to the heart and pericardium but not those to the bowel, mesentery, and urinary bladder, a purpose for which multidetector CT is better suited. If there is time after the initial FAST survey, the US examination may be extended to extra-abdominal regions to rule out pneumothorax or to guide endotracheal intubation, vascular puncture, or other interventional procedures.

Advances in digital radiography: physical principles and system overview.

During the past two decades, digital radiography has supplanted screen-film radiography in many radiology departments. Today, manufacturers provide a variety of digital imaging solutions based on various detector and readout technologies. Digital detectors allow implementation of a fully digital picture archiving and communication system, in which images are stored digitally and are available anytime. Image distribution in hospitals can now be achieved electronically by means of web-based technology with no risk of losing images. Other advantages of digital radiography include higher patient throughput, increased dose efficiency, and the greater dynamic range of digital detectors with possible reduction of radiation exposure to the patient. The future of radiography will be digital, and it behooves radiologists to be familiar with the technical principles, image quality criteria, and radiation exposure issues associated with the various digital radiography systems that are currently available.

Emergency chest tube placement in trauma care - which approach is preferable?

BACKGROUND: Pneumothorax is present in about 20% of blunt major trauma cases. Insertion of an intercostal tube drainage is one effective treatment, however it is unclear whether the thoracostomy has more advantages if placed in the ventral (2.-3. intercostal space) or lateral (4.-6. intercostal space) approach. The aim of this study was to determine, whether there are any differences between the two approaches in respect of malposition and complications. MATERIAL AND METHODS: The data from 851 consecutive patients, admitted to our trauma centre from January 2000 to June 2004, was collected and analysed prospectively. The inclusion criteria were: ISS > or = 16, insertion of an intercostal tube and subsequent thoracic computed tomography. Epidemiological and physiological data were analysed together with the location of the tube (ventral or lateral). The attending physician was free to choose the location of insertion. Chest tubes placed both on-scene and in-hospital chest tubes were investigated. Malpositions, defined as extrathoracic, abdominal, parenchymal or interlobal positions, were analysed by reviewing the computed tomography of the thorax (CT). Complications, like injuries to vessels or organs, infection or empyaema were analysed using our standardised prospective trauma protocol. Furthermore, the rate of clinically relevant malfunctions due to malposition was investigated as well as the number of chest tubes that had to be replaced. RESULTS: One hundred and one chest tubes were inserted in 68 patients with multiple trauma (mean age 40.7, ISS=38.1, AIS thorax=3.9). In 21 cases a ventral approach was chosen (20.8%) and in 80 a lateral approach (79.2%). CT revealed malposition in two of the ventrally placed tubes (9.5%) and in 20 of the laterally placed tubes (25%) (p=0.15, Fisher's exact test). One tube was identified in a subcutaneous location 17 chest tubes, after ventral approach all of them as a result of lateral approaches, were placed in the interlobe. No interlobal positions were observed in the ventral group. The interlobal position was found to be significantly higher in the lateral approach (p=0.013, Fisher's exact test). Clinically relevant malfunction was diagnosed in 6 of the 22 malpositioned chest tubes (5.9%). These tubes had to be repositioned, one was placed ventrally, the other five were placed laterally. CONCLUSIONS: In our setting physicians preferred the lateral approach on-scene as well as in-hospital. In every fifth patient malpositioning of the tube was observed, mostly interlobal after lateral chest tube, however only few were associated with relevant clinical malfunctions. The probability of interlobal malpositioning is significantly higher when using the lateral approach as opposed to the ventral approach. Correction of malpositioned and ineffective chest tubes was necessary in every 17th case. No statistically significant difference between the two approaches for functional malposition was observed. Hence both approaches for emergency chest tube insertion seem to be equally justified.

Depiction of low-contrast detail in digital radiography: comparison of powder- and needle-structured storage phosphor systems.

PURPOSE: We sought to evaluate the low-contrast performance of a newly developed needle image plate/line scanner (NIP) computed radiography system in comparison with a standard powder image plate/flying-spot scanner (PIP) system. MATERIALS AND METHODS: A total of 36 images of a CDRAD phantom, simulating low-contrast structures with different drill holes of different diameters, were obtained with both imaging systems using 9 different exposure variables. All images had window and level set to generate consistent density and contrast. In addition, multiscale contrast-dependent contrast amplification was applied to some of the images. All images obtained were printed and presented to a total of 10 observers (5 radiologists, 5 engineers/physicists), who were blinded to both the image plate and parameter setting used. The smallest detectable drill hole depth (= contrast) correctly identified was recorded for each diameter. The median values observed were calculated and tested for statistical differences between PIP and NIP using Student t test for matched pairs (level of significance P < or = 0.05). RESULTS: At all but 2 settings of the variables, NIP images depicted significantly lower contrast levels (= lower depth of drill holes) compared with PIP images. The 2 settings also showed a trend towards better low contrast depiction with NIP. In no case was low contrast performance better using PIP images. CONCLUSION: Images obtained with needle image plate/line scanner provide superior low contrast performance compared with the images obtained with powder image plate/flying-spot scanner.

Comparison of different patient positioning strategies to minimize shoulder girdle artifacts in head and neck CT.

The purpose of this study was to analyze different patient positioning strategies for minimizing artifacts of the shoulder girdle in head and neck CT. Standardized CT examinations of three positioning groups were compared (P: patients pushed their shoulders downwards; D: similar optimization by a pulling device; N: no particular positioning optimization). Parameters analyzed were the length of the cervical spine not being superimposed by the shoulder girdle as well as noise in the supraclavicular space. In groups P and D, the portion of the cervical spine not superimposed was significantly larger than in group N (P: 10.4 cm; D: 10.6 cm; N: 8.5 cm). At the supraclavicular space, noise decreased significantly (P: 12.5 HU; D: 12.1 HU; N: 17.7 HU). No significant differences between the two position-optimized groups (P and D) were detected. Optimized shoulder positioning by the patient increases image quality in CT head and neck imaging. The use of a pulling device offers no additional advantages.

Treatment of benign and malignant tracheobronchial obstruction with metal wire stents: experience with a balloon-expandable and a self-expandable stent type.

Over the last few years various types of metal wire stents have been increasingly employed in the treatment of both malignant and benign tracheobronchial obstruction. To date, however, few studies have investigated the in vivo properties of different stent types. We implanted 26 balloon-expandable tantalum Strecker stents (18 patients) and 18 self-expandable Wallstents (16 patients) into the tracheobronchial system of 30 patients with combined stenting in 4 patients. Mean age was 51 years (range: 0.5-79 years). Malignant disease was present in 23 patients, benign disease in seven patients. Both patients and individual stents were monitored clinically and radiographically. The probability of stents remaining within the tracheobronchial system, and of their remaining undislocated and uncompressed was calculated using Kaplan-Meier analysis for both stent types. Average stent follow-up time was 112 days until explantation and 115 days until patients' death or discharge. Kaplan-Meier analysis revealed a higher probability for the Wallstent to remain within the tracheobronchial system. Dislocation and compression occurred more rarely. Explantation, however, if desired, was more difficult compared to the Strecker stent. The Wallstent also led to the formation of granulation tissue, especially at the proximal stent end, frequently requiring reintervention. Both stent types proved to be effective therapeutic options in the management of obstructive tracheobronchial disease. The mechanical properties of the Strecker stent seem to be less favorable compared to the Wallstent but removal is easy. For benign disease, however, the Wallstent reveals limitations due to significant side effects.

3D imaging with an isocentric mobile C-arm comparison of image quality with spiral CT.

The purpose of this study was to evaluate the image quality of the new 3D imaging system (ISO-C-3D) for osteosyntheses of tibial condylar fractures in comparison with spiral CT (CT). Sixteen human cadaveric knees were examined with a C-arm 3D imaging system and spiral computed tomography. Various screws and plates of steel and titanium were used for osteosynthesis in these specimens. Image quality and clinical value of multiplanar (MP) reformatting of both methods were analyzed. In addition, five patients with tibial condylar fractures were examined for diagnosis and intra-operative control. The image quality of the C-arm 3D imaging system in the cadaveric study was rated as significantly worse than that of spiral CT with and without prostheses. After implantation of prostheses an increased incidence of artifacts was observed, but the diagnostic accuracy was not affected. Titanium implants caused the smallest number of artifacts. The image quality of ISO-C is inferior to CT, and metal artifacts were more prominent, but the clinical value was equal. ISO-C-3D can be useful in planning operative reconstructions and can verify the reconstruction of articular surfaces and the position of implants with diagnostic image quality.

C-arm-based mobile computed tomography: a comparison with established imaging on the basis of simulated treatments of talus neck fractures in a cadaveric study.

OBJECTIVE: To analyse the image quality and diagnostic effectiveness of a new C-arm-based 3D imaging method (C-arm-CT) for intraoperative evaluation of screw osteosyntheses adjacent to a peripheral joint. MATERIALS AND METHODS: Insertion of screws into four cadaveric specimens simulated the surgical treatment of talus neck fractures. Ten orthopedic surgeons and 10 radiologists evaluated X-ray, C-arm fluoroscopy, C-arm-CT and CT images. RESULTS: The best image quality was obtained with X-rays (p < 0.001), followed by C-arm fluoroscopy (2D) and CT, with the C-arm-CT (3D) being rated lowest (p < 0.001). The most correct diagnoses were obtained with CT and C-arm-CT (with no statistical difference between them), while C-arm-fluoroscopy was inferior (p < 0.001) and X-rays were the worst (p < 0.05). CONCLUSIONS: Even if the image quality of C-arm-CT is definitely inferior to that of CT, screw misplacements can be reliably detected using C-arm-CT. As compared to the current standard procedures (intraoperative fluoroscopy and postoperative radiography), C-arm-CT performed better. C-arm-CT is ideally suited to the intraoperative diagnosis of high-contrast inquiries like bone fragments and OS material, especially at the extremities. Coupling of the new 3D imaging to existing navigation systems is possible. C-arm-CT will support the further development and implementation of open and minimally invasive surgical procedures.

Classification of calcaneal fractures by spiral computed tomography: implications for surgical treatment.

The purpose of this study was to evaluate spiral computed tomography and multislice CT (SCT/MSCT) with multiplanar reconstructions (MPR) in the classification of calcaneal fractures according to a modified CT classification and to quantify fragment displacement to guide surgical treatment. Forty-eight calcaneal fractures were examined by spiral CT (1- to 2-mm slice thickness, pitch=1.5) with multiplanar reconstructions (MPR). Fractures were grouped according to a modified Munich classification scheme, differentiating six categories of fractures by joint involvement, number of fragments in the posterior facet, and the presence and extent of displacement. A qualitative and quantitative statement was made for the presence of clinical relevant displacement of the posterior articular facet (A: >2 mm), widening of the heel (B: crossing fibular reference line), reduction in calcaneal height (C: >10%), and axis shift of the calcaneocuboid angle (D: >10 degrees ). Treatment recommendations resulting from the CT classification were retrospectively compared with the treatment given by examining the patients' files. There were 10 extra-articular and 38 intra-articular fractures; 8 were in class I (extra-articular, nondisplaced), 2 in class II (extra-articular, displaced), 1 in class III (intra-articular, nondisplaced), 20 in class IV (two fragments), 9 in class V (three fragments), and 8 in class VI (>4 fragments), one of the latter being uncertain; 34 showed displacement of the articular facet, 35 widening of the heel, 35 reduction in calcaneal height, and 20 a shift of the axis. In 94% of the cases the procedure recommended by the Munich system of classification was followed; there was disagreement in 1 case in class I and 1 in class IV. Spiral CT allowed fracture classification and quantification of relevant displacement of fragments by radiologists. The implemented recommendations for treatment were adopted by surgeons in most cases.

A case of an upper gastrointestinal bleeding due to a ruptured dissection of a right aortic arch.

We report a case of severe upper gastrointestinal hemorrhage with a rare underlying cause. The patient was unconscious when he was admitted to the hospital. No chest radiogram was performed. Routine diagnostic measures, including endoscopy, failed to reveal the origin of the bleeding, which was believed to originate from the esophagus secondary to a peptic ulcer or varices. Exploratory laparotomy added no further information, but contrast-enhanced multislice computed tomography (MSCT) of the chest showed dextroposition of the widened aortic arch with a ruptured type-B dissection and a consecutive aorto-esophageal fistula (AEF). The patient died on the day of admission. Noninvasive MSCT angiography gives rapid diagnostic information on patients with occult upper gastrointestinal bleeding and should be considered before more invasive conventional angiography or surgery.

Whole-body computed tomography in polytrauma: techniques and management.

An interdisciplinary team should be involved in the diagnosis and management of severely injured patients. The adoption of criteria for starting treatment for multiple trauma avoids underestimation of seriousness of injury. These criteria are established by the circumstances of the accident, the patterns of trauma, and the vital findings. Basic diagnosis comprises a limited number of plain films in the trauma room, including supine chest, lateral cervical spine, and pelvis, and ultrasound of abdomen, pleura, and pericardium. Organ diagnosis using CT is complementary and depends on the clinical findings and findings from the basic investigations. We recommend spiral CT (skull base 2/2/4 mm, cerebrum 8/8/8 mm native) and after intravenous contrast medium thoracic (5/7.5/5 mm) and abdominal CT (8/12/8 mm). Image reconstruction of bony structures can be added. The CT and the trauma center should be in close proximity; time-consuming transfers must be avoided. If this is not possible, a CT can be integrated in the trauma room. Our hospital trauma registry contains over 2200 entries. A quality committee has been established and external quality control is implemented.

Three-dimensional CT with a modified C-arm image intensifier: feasibility.

A portable C arm was modified for cone-beam computed tomography (CT). This three-dimensional (3D) CT imaging system facilitated the acquisition of fluoroscopic images during a 190 degrees rotation and computed a 3D data cube (matrix, 256 x 256 x 256; scanning time, 100 seconds) with multiplanar image reformation. The high-contrast resolution, 0.9 line pairs per millimeter, was comparable; the low-contrast resolution, minimal; and the radiation dose, 60%-80% lower, as compared with these parameters at spiral CT. The normal anatomy of small joints could be depicted, and the osteosynthesis screws in the talus were correctly identified.

Gadolinium as an alternative contrast agent for diagnostic and interventional angiographic procedures in patients with impaired renal function.

BACKGROUND: The study was designed to investigate the safety and feasibility of gadopentetate dimeglumine, a gadolinium-based contrast medium, as an alternative angiographic contrast agent in patients with impaired renal function and high risk for iodinated contrast-induced nephropathy. METHODS: Gadopentetate dimeglumine was used as the radiographic contrast agent in 32 diagnostic or interventional angiographic procedures in 29 patients (59% diabetics) with severe renal insufficiency (average serum creatinine of 3.6+/-1.4 mg/dl). The average dose of gadopentetate dimeglumine was 0.34+/-0.06 mmol/kg body weight. Gadopentetate dimeglumine was used either alone (n=20) or in conjunction with carbon dioxide (n=12). RESULTS: Thirty-two angiographic procedures (24 diagnostic angiographies and 8 interventional procedures) were performed in 29 patients. For diagnostic purposes, eleven selective renal arteriographies, six angiographies of the iliac arteries and lower extremities, and seven venous angiographies of the upper extremity and central veins were performed. Interventional procedures consisted of two percutaneous transluminal renal angioplasties with stenting, four percutaneous peripheral vascular interventions, and two balloon angioplasties of a dialysis fistula. None of the patients, except one, had evidence of post-procedure contrast material-induced renal failure (increase in serum creatinine >0.5 mg/dl within 72 h) or other complications. This patient had a clinically important increase in serum creatinine level after percutaneous transluminal renal angioplasty and stenting, probably due to cholesterol embolism. Gadopentetate dimeglumine had sufficient radiographic density to allow adequate diagnostic visualization with digital subtraction equipment in all cases. CONCLUSIONS: Gadopentetate dimeglumine is an alternative and safe radiographic contrast agent for angiography and interventional procedures in patients with severe pre-existing renal impairment. In this population with high risk for contrast-induced acute renal failure, it is obviously less nephrotoxic than iodinated contrast media.