Edith Eisenhuber

Improved outcome prediction in unconscious cardiac arrest survivors with sensory evoked potentials compared with clinical assessment

Objective: To compare the prognostic ability of sensory evoked potentials in cardiac arrest survivors with the outcome predicted by a panel of experienced emergency physicians based on detailed prehospital, clinical, and laboratory data. Design: Inception cohort study. Setting: Medical intensive care unit and department of emergency medicine at a university hospital. Patients: A total of 162 unconscious, mechanically ventilated patients who survived ≥24 hrs after resuscitation from cardiac arrest. Interventions: Recording of sensory evoked potentials and outcome prediction after review of detailed clinical and laboratory data by emergency physicians within 24 hrs after cardiac arrest. Measurements and Main Results: At 6 months, the outcome of 36 patients was classified as favorable and 126 patients were rated as poor. After review of prehospital data, emergency physicians predicted favorable vs. poor outcome with a sensitivity of 70% and a specificity of 65%. After additional assessment of data 1 hr after cardiac arrest, the sensitivity of emergency physician predictions increased to 80%, whereas the specificity decreased to 48%. Outcome prediction by emergency physicians was most accurate after obtaining detailed patient data 24 hrs after cardiac arrest (sensitivity, 81%; specificity, 58%). In 35 of 36 patients with favorable outcomes, the cortical evoked potential N70 peak was detected between 72 and 128 msec. Of 113 patients with an N70 peak latency > 130 msec or an absent N70 peak, all except one had a poor outcome. By using a cutoff of 130 msec, the N70 peak latency alone had a sensitivity of 94% and a specificity of 97%. The predictive accuracy of the N70 peak latency was significantly higher than the clinical assessment 24 hrs after cardiac arrest (91% vs. 76%, p = .0003). Conclusion: In unconscious cardiac arrest survivors, a recording of long‐latency sensory evoked potentials is more accurate in predicting individual outcome than an emergency physician review of clinical data.

Cyclosporine May Affect Improvement of Cognitive Brain Function After Successful Cardiac Transplantation

BACKGROUND The effects of cardiac transplantation on cognitive brain function are uncertain. METHODS AND RESULTS We measured cognitive brain function and quality of life in out-of-hospital cardiac transplant candidates (n = 55; ejection fraction, 19.9%; age, 54.8 years [means]). After transplantation, the patients were serially reevaluated at 4 months (n = 25) and at 12 months (n = 19). Brain function was measured objectively by cognitive P300 evoked potentials. Additionally, standard psychometric tests (Trail Making Test A, Mini-Mental State Examination, and Profile of Mood State test) were performed. Cognitive P300 evoked potentials were impaired in cardiac transplant candidates (359 ms, recorded at vertex) compared with 55 age- and sex-matched healthy subjects (345 ms, P < .01). Trail Making Test A was also abnormal (45 versus 31 seconds in 55 healthy subjects, P < .01). After transplantation, P300 measures were normalized at 4 months (345 ms, P < .05 versus before transplantation) but declined again at 12 months (352 ms, P = NS versus before transplantation). Stepwise multiple regression analysis revealed that cumulative cyclosporine dosage was the only predictor of individual cognitive brain function 4 months (753 mg/kg body wt, P < .05) and 12 months (2006 mg/kg body wt, P < .01) after transplantation, respectively. CONCLUSIONS Objective cognitive P300 auditory evoked potential measurements indicate that cognitive brain function is significantly impaired in patients suffering from stable end-stage heart failure. Successful cardiac transplantation is effective to fully normalize impaired brain function. Subsequent relative long-term decline of cognitive brain function after successful cardiac transplantation is strongly suggested to be related to cumulative cyclosporine neurotoxicity.

Imaging of chest trauma: radiological patterns of injury and diagnostic algorithms

In patients after chest trauma, imaging plays a key role for both, the primary diagnostic work-up, and the secondary assessment of potential treatment. Despite its well-known limitations, the anteroposterior chest radiograph remains the starting point of the imaging work-up. Adjunctive imaging with computed tomography, that recently is increasingly often performed on multidetector computed tomography units, adds essential information not readily available on the conventional radiograph. This allows better definition of trauma-associated thoracic injuries not only in acute traumatic aortic injury, but also in pulmonary, tracheobronchial, cardiac, diaphragmal, and thoracic skeletal injuries. This article reviews common radiographic findings in patients after chest trauma, shows typical imaging features resulting from thoracic injury, presents imaging algorithms, and recalls to the reader less common but clinically relevant entities encountered in patients after thoracic trauma.

Digital radiography of the chest: detector techniques and performance parameters.

Substantial advances in detector technology characterize digital chest radiography. This article compares the various systems from a radiologists point of view. Computed radiography (CR) is a well-established system that is robust, has good reproducibility, and is relatively inexpensive. Image quality has been continuously improved in recent years while the physical size of the readout units has been reduced and the throughput increased. CR is the only digital system that can be used for bedside chest radiographs. Improved detector properties and dual reading have made it a dose-efficient system. Although now widely available, a 4K image matrix does not appear to offer a general diagnostic improvement for imaging the chest. New developments with respect to detector composition and readout process can be expected in the future. Direct radiography (DR) is the common name for different technologies that are characterized by a direct readout matrix that covers the whole exposure area. Conversion of x-ray intensity into electric signals can either be direct (selenium-based systems) or indirect (scintillator/photodiode systems). Advantages of DR systems are a high image quality and the potential for dose reduction. The role of selenium radiography (Thoravision) has decreased after the advent of DR systems although this dedicated chest unit offers high image quality at 400 speed acquisition dose. Especially in a PACS environment, CR and DR systems will increasingly substitute for conventional radiography with advantages for CR for bedside chest radiographs and for DR for high-end chest stands.

CT fluoroscopy-guided vs. multislice CT biopsy mode-guided lung biopsies: Accuracy, complications and radiation dose

BACKGROUND The aim of this retrospective study was to compare the diagnostic accuracy, the frequency of complications, the duration of the interventions and the radiation doses of CT fluoroscopy (CTF) guided biopsies of lung lesions with those of multislice CT (MS-CT) biopsy mode-guided biopsies. METHODS Data and images from 124 consecutive patients undergoing CTF-guided lung biopsy (group A) and 132 MS-CT-biopsy mode-guided lung biopsy (group B) were reviewed. CTF-guided biopsies were performed on a Siemens Emotion 6 CT scanner with intermittent or continuous CT-fluoroscopy, MS-CT biopsy mode-guided biopsies were performed on a Siemens Emotion 16 CT scanner. All biopsies were performed with a coaxial needle technique. RESULTS The two groups (A vs. B) did not differ significantly regarding sensitivity (95.5% vs. 95.9%), specificity (96.7% vs. 95.5%), negative predictive value (87.9% vs. 84%) or positive predictive value (98.8% vs. 98.9%). Pneumothorax was observed in 30.0% and 32.5% of the patients, respectively. Chest tube placement was necessary in 4% (group A) and 13% (group B) of the patients. The duration of the intervention was significantly longer in group A (median 37 min vs. 32 min, p=0.04). The mean CT dose index (CTDI) was 422 in group A and 36.3 in group B (p<0.001). CONCLUSION Compared to CTF-guided biopsies, chest biopsies using the MS-CT biopsy mode show dramatically lower CTDI levels. Although the diagnostic yield of the procedures do not differ significantly, biopsies using the MS-CT-biopsy mode have a three-fold higher rate of chest tube placement.

Quantitative and O2 Enhanced MRI of the Pathologic Lung: Findings in Emphysema, Fibrosis, and Cystic Fibrosis

Purpose: beyond the pure morphological visual representation, MR imaging offers the possibility to quantify parameters in the healthy, as well as, in pathologic lung parenchyma. Gas exchange is the primary function of the lung and the transport of oxygen plays a key role in pulmonary physiology and pathophysiology. The purpose of this review is to present a short overview of the relaxation mechanisms of the lung and the current technical concepts of T1 mapping and methods of oxygen enhanced MR imaging. Material and Methods: molecular oxygen has weak paramagnetic properties so that an increase in oxygen concentration results in shortening of the T1 relaxation time and thus to an increase of the signal intensity in T1 weighted images. A possible way to gain deeper insights into the relaxation mechanisms of the lung is the calculation of parameter Maps. T1 Maps based on a snapshot FLASH sequence obtained during the inhalation of various oxygen concentrations provide data for the creation of the so-called oxygen transfer function (OTF), assigning a measurement for local oxygen transfer. T1 weighted single shot TSE sequences also permit expression of the signal changing effects associated with the inhalation of pure oxygen. Results: the average of the mean T1 values over the entire lung in inspiration amounts to 1199 +/− 117 milliseconds, the average of the mean T1 values in expiration was 1333 +/− 167 milliseconds. T1 Maps of patients with emphysema and lung fibrosis show fundamentally different behavior patterns. Oxygen enhanced MRT is able to demonstrate reduced diffusion capacity and diminished oxygen transport in patients with emphysema and cystic fibrosis. Discussion: results published in literature indicate that T1 mapping and oxygen enhanced MR imaging are promising new methods in functional imaging of the lung and when evaluated in conjunction with the pure morphological images can provide additional valuable information.

Computed radiography and direct radiography: influence of acquisition dose on the detection of simulated lung lesions.

Purpose:We sought to evaluate the performance of dual-readout and single-readout computed radiography compared with direct radiography for detecting subtle lung abnormalities with a standard and a low-dose technique. Materials and Methods:Posteroanterior radiographs of an anthropomorphic chest phantom were obtained with a single-readout storage phosphor radiography system (CRS, pixel size 200 &mgr;m), a dual-readout storage phosphor radiography system (CRD, pixel size 100 &mgr;m), and a direct detector (DR, pixel size 143 &mgr;m) at dose levels of 400 and 800 speed. Ten templates were superimposed to project 4 types of lesions over low- and high-attenuation areas, simulating nodules, micronodules, lines, and patchy opacities. Six radiologists evaluated 60 hard-copy images for the presence or absence of lesions. Statistical significance of differences was evaluated using receiver operating characteristic analysis and analysis of variance. Results:For both low- and high-attenuation areas, CRD (Az = 0.85 and 0.66) was superior to CRS (Az = 0.75 and 0.58) for overall performance and all lesion subtypes (P < 0.05). DR (Az = 0.87 and 0.67) performed slightly better than CRD, being significant only for the detection of micronodules. Acquisition dose significantly affected only the detection of lines and micronodules, whereas the detection of nodules and patchy opacities was not significantly different with reduced exposure, regardless of the system used. Conclusion:The dual-readout CR system significantly outperformed the single-readout CR and almost equaled the performance of DR. Dose reduction was more critical for small-sized lesions (micronodules, lines) than for nodular or patchy opacifications and affected mainly the lesions in high attenuation areas.

Bedside Chest Radiography

The bedside chest x-ray (CXR) is an indispensible diagnostic tool for monitoring seriously ill patients in the intensive care unit. The CXR often reveals abnormalities that may not be detected clinically. In addition, bedside CXRs are an irreplaceable tool with which to detect the malposition of tubes and lines and to identify associated complications. Although the image quality is often limited, bedside CXRs still provide valuable diagnostic information. The interpretation of the bedside CXRs is often challenging, and requires extensive radiologic experience to avoid misinterpretation of the wide spectrum of pleural and pulmonary disease. The clinical information is of substantial value for the interpretation of the frequently nonspecific findings.

Radiologic diagnosis of lung tuberculosis

ZusammenfassungDas Kennen und Erkennen charakteristischer Tuberkulose-assoziierter Lungenveränderungen stellt einen Grundpfeiler in der Diagnostik der Tuberkulose dar. Neben dem Thoraxröntgen spielt die Computertomographie bei der Lungentuberkulose eine zunehmend wichtigere Rolle, da sie wesentlich sensitiver beim Nachweis von Kavernen, einer hilären und mediastinalen Lymphadenopathie, von Streuherden und Komplikationen der Tuberkulose ist. Die Computertomographie erlaubt die Beurteilung einer Aktivität speziell bei negativem Nachweis der Mykobakterien im Sputum und bei multiresistenter Tuberkulose. Die Tuberkulose kann in Abhängigkeit von der Immunlage des Patienten ein sehr unterschiedliches Erscheinungsbild haben. Die frühzeitige Diagnose und Therapie sind entscheidend, um eine weitere Ausbreitung zu verhindern. AbstractThe radiologic knowledge of tuberculosis-associated lung disease is an essential tool in the clinical diagnosis of tuberculosis. Chest radiography is the primary imaging method, but the importance of CT is still increasing, as CT is more sensitive in the detection of cavitation, of hilar and mediastinal lymphadenopathie, of endobronchial spread and of complications in the course of the disease. In addition, CT has been proven as a valuable technique in the assessment of tuberculosis activity, especially in patients where M. tuberculosis has not been detected in the sputum or in patients with multidrug-resistant tuberculosis. Depending on the immune status of the patient, the morphologic spectrum of tuberculosis is quite variable. Early diagnosis of tuberculosis is essential to prevent further spread of the disease.

Radiologische Diagnostik der Lungentuberkulose

ZusammenfassungDas Kennen und Erkennen charakteristischer Tuberkulose-assoziierter Lungenveränderungen stellt einen Grundpfeiler in der Diagnostik der Tuberkulose dar. Neben dem Thoraxröntgen spielt die Computertomographie bei der Lungentuberkulose eine zunehmend wichtigere Rolle, da sie wesentlich sensitiver beim Nachweis von Kavernen, einer hilären und mediastinalen Lymphadenopathie, von Streuherden und Komplikationen der Tuberkulose ist. Die Computertomographie erlaubt die Beurteilung einer Aktivität speziell bei negativem Nachweis der Mykobakterien im Sputum und bei multiresistenter Tuberkulose. Die Tuberkulose kann in Abhängigkeit von der Immunlage des Patienten ein sehr unterschiedliches Erscheinungsbild haben. Die frühzeitige Diagnose und Therapie sind entscheidend, um eine weitere Ausbreitung zu verhindern. AbstractThe radiologic knowledge of tuberculosis-associated lung disease is an essential tool in the clinical diagnosis of tuberculosis. Chest radiography is the primary imaging method, but the importance of CT is still increasing, as CT is more sensitive in the detection of cavitation, of hilar and mediastinal lymphadenopathie, of endobronchial spread and of complications in the course of the disease. In addition, CT has been proven as a valuable technique in the assessment of tuberculosis activity, especially in patients where M. tuberculosis has not been detected in the sputum or in patients with multidrug-resistant tuberculosis. Depending on the immune status of the patient, the morphologic spectrum of tuberculosis is quite variable. Early diagnosis of tuberculosis is essential to prevent further spread of the disease.