Speech processing in radiology.

The goal of this study was to evaluate the recognition rate, learning potential and amount of time needed to complete a report with the Philips speech recognition system SP 6000 (Philips, Best, The Netherlands). Four radiologists dictated reports of interventional radiology, MRI examinations of the musculoskeletal system and CT examinations of the thorax and abdomen with the Philips system using the German language. The recognition rate of each report and improvement rate after each learning phase of the Philips system was assessed. The time needed to complete a report using the Philips system was then compared with the time needed to complete a report using the tape-based system via a time analysis. The average recognition rate for the four radiologists using the Philips system was 79.6 %, which improved to 92.5 % after the third adaptation. Initially, the average time demand to dictate and correct one report was approximately 16.8 min, but this time decreased to 8.1 min after the third adaptation. In contrast, only 3. 6 min were needed to dictate and correct one report using the tape-based system. However, with the speech recognition system, dictation, correction and transcription of the report can be completed within 15 min, whereas with the tape-based system, it takes nearly 1 day. With the Philips system, speech recognition can reach as high as 95 % since each adaptation of the system improves the recognition rate by approximately 5 %. While the Philips system is associated with longer dictation times than the tape-based system, turn-around time for a complete report is substantially shorter with the Philips system than the tape-based system.

A computer-based reporting system in radiology of the chest.

The aim of this study was to compare our computer-aided report writing system to standard techniques. A computer-aided reporting system for reporting on chest X-rays was developed and linked with a UNIX-based radiology information system. The reporting system consists of different text modules which can be composed to a complete radiological report. The quality of the report, the system's efficiency, flexibility and availability at the radiology information system (RIS), as well as its acceptance by the users, were criteria we took as a basis of evaluation. Acceptance and flexibility of the system were tested by assessing necessary changes and additions performed to text modules and by subjective evaluation. The time spent on working with the reporting system was evaluated by performing a time-analysis study comparing the new system to the two conventional methods, the tape system and handwriting. On average, the readers needed 22.6 text modules for each report. For the users the most important advantages of the new system are that primarily fewer changes to or additions to the text are necessary, and when they cannot be avoided they can be performed more easily. In comparison with the tape system and handwritten reports, it took on average two and a half to three times longer to report on a chest X-ray. The printed report had left the department within 6.4 h using the tape system within 0.4 h when handwritten and within 1.4 h when recorded by the reporting system. The completeness of the set of modules and the logical order were positively assessed by the users. The demand of time for reporting increases, but the final report is available sooner.

[Generalized gas gangrene infection with rhabdomyloysis following cholecystectomy]. / Generalisierte Gasbrand-infektion mit Rhabdomyolyse nach Cholezystektomie.

We report a rare case of spontaneously developing generalised gas gangrene with massive rhabdomyolysis after a cholecystectomy and drainage of a hepatic abscess. On preoperative physical examination the patient appeared severely ill and was icteric and oliguric. Laboratory evaluation showed signs of systemic inflammation, elevated lactate levels, evidence of disseminated intravascular coagulation (DIC), and increased levels of serum creatine kinase (CK) activity. Abdominal ultrasound and endoscopic retrograde cholangiography showed a gallbladder perforation and a hepatic abscess. Cholecystectomy and drainage of the abscess was performed immediately and without technical problems. After postoperative admission to the intensive care unit, the patient showed evidence of generalised myonecrosis with subcutaneous gas formation and acute renal failure. Initially, there were few other signs of systemic toxicity; the patient was not hypotensive and the pulmonary gas exchange was normal. Within hours diffuse swelling of his right leg developed with cutaneous gangrene and a compartment syndrome. After fasciectomy and extensive surgical debridement, uncontrollable bleeding due to DIC developed from the fasciectomy site, which finally required exarticulation of the leg at the hip joint. At this point, multiple organ failure including severe adult respiratory distress syndrome was present. Two days after cholecystectomy, the patient died from hypoxic cardiocirculatory failure. Clostridium perfringens was repeatedly isolated from the wounds. Besides gas gangrene, the differential diagnosis of such infections includes localised clostridial cellulitis, nonclostridial anaerobic cellulitis caused by mixed aerobes and anaerobes, and type I or type II necrotising fasciitis. Patients with systemic necrotising infections should be treated with broad-spectrum antimicrobial regimens (penicillin G, 3rd generation cephalosporins, clindamycin, and aminoglycosides). An otherwise unexplained elevation of serum CK activity in the presence of acute cholecystitis may suggest haematologic spread of an aggressive myolytic agent and the beginning of myonecrosis. This should prompt immediate surgical exploration after establishing broad-spectrum antibiotic coverage. The role of hyperbaric oxygen treatment in this situation remains to be established. If hyperbaric oxygen is to be employed, it should neither delay surgical exploration nor jeopardize the patient with the hazards of an interhospital transport.

Magnetic resonance imaging of the female pelvis. New circularly polarized body array coil versus standard body coil.

RATIONALE AND OBJECTIVES: The authors compare the value of a new circularly polarized body array coil (BAC) system with a standard body coil (BC) for high-resolution magnetic resonance imaging of the female pelvis. METHODS: Twenty patients with cervical cancer were examined with a BC and BAC. Imaging parameters were kept constant (sagittal T2-weighted turbo spin-echo: repetition time = 4000 mseconds; effective echo time = 99 mseconds; 160 x 160 mm field of view; 256 x 256 matrix; 0.63 x 0.63 mm pixel size; 4-mm slice thickness). Images were scored for lesion-to-organ delineation and overall image quality/ artifacts using a scale from 5 to 1 (excellent to poor). Signal-to-noise (S/N) ratios for different tissues (tumor, uterus, vagina, rectum, muscle, and fat) as well as contrast-to-noise (C/N) ratios between tumor and (1) uterus, (2) vagina, and (3) rectum were calculated. Magnetic resonance tumor staging was performed according to the International Federation of Gynecology and Obstetrics (FIGO) classification. RESULTS: Using the BAC, S/N and C/N ratios increased significantly compared with the BC (S/N: 2.7-3.4-fold increase for all organs evaluated, P < 0.001: C/N: tumor versus uterus 2.4-fold, P < 0.01; tumor versus vagina 6.1-fold, P < 0.001; tumor versus rectum 3.1-fold, P < 0.01). This resulted in an improved overall image quality (average ratings: BAC-4.3 points; BC-2.6 points; P < 0.001). Lesion-to-organ delineation (average ratings: BAC 4.3-4.1 points, BC 3.5-2.7 points for all organs evaluated; P < 0.001) was increased noticeably on BAC images. No significant difference was found for staging accuracy. CONCLUSIONS: Circularly polarized BAC provide superior S/N and C/N ratios and improve lesion conspicuity compared with standard BC.

Dynamic MR colpocystorectography assessing pelvic-floor descent.

Magnetic resonance colpocystorectography (MR-CCRG) is presented in the evaluation of patients with pelvic-floor disorders. Five healthy volunteers and 44 female patients with isolated or combined visceral descent underwent dynamic MRI and dynamic fluoroscopy (DF). MR-CCRG was performed with the patient in a supine position using a True FISP sequence (1 image/1.2 s; in-plane resolution 1.02 mm) during pelvic floor contraction, relaxation, and straining maneuvers. Relevant organs, such as urethra, bladder, vagina, and rectum, were opacified by using a saline solution, Magnevist (Schering AG, Berlin, Germany), and sonography gel, respectively. The clinical evaluation and the intraoperative results (30 cases) were used as reference. MR-CCRG and DF were non-diagnostic in 3 cases each. Most patients had a combined type of visceral prolapse, the most frequent combination being a vaginal vault prolapse and a cystocele. The points of reference were sufficiently outlined by DF and MR-CCRG. In comparison with the clinical and intraoperative results, MR-CCRG proved to be especially beneficial in the diagnosis of different types of enteroceles including a uterovaginal prolapse. MR-CCRG showed an equal or higher sensitivity and specificity for all individual sites when compared with DF. Also, predominant herniation obscuring other concomitant prolapse could be verified in 8 cases. MR-CCRG is superior to DF and accurately depicts pelvic-floor descent and prolapse in women. The possibility of dynamic presentation (see enclosed CD-ROM) allows for a better understanding of the organ movements within a given topographic reference setting.

[Differentiation of solitary pulmonary coin lesions by high-resolution computerized tomography]. / Differenzierung von solitären Lungenrundherden durch die hochauflösende Computertomographie.

PURPOSE: The aim of this prospective study was not to describe individual morphological findings in benign and malignant solitary intrapulmonary nodules; it was instead to examine in a critical manner the indications for differentiation found in the literature in order to facilitate safe differential diagnosis of benign and malignant nodules. PATIENTS AND METHODS: A total of 64 solitary pulmonary nodules were examined with high-resolution computed tomography and correlated with histological findings. Only lesions that had been removed by surgery were used. No lesion was excluded on the grounds of size. RESULTS: Useful characteristics for the differentiation of benign from malignant pulmonary nodules were: diameter and density of the lesion, air inclusion, unsharp and dystelectatic margin, the presence of spicules, length of spicules, spicules extending to the visceral pleura, pleural tail sign and cirumscribed pleural thickening. CONCLUSION: For the differentiation of benign and malignant solitary pulmonary nodules meticulous assessment of the margin of the nodule is necessary. Using the criteria mentioned, a sensitivity of 85% and a specifity of 78% can be achieved for the identification of malignant pulmonary nodules. Since it was not possible to differentiate between benign and malignant nodules with certainty using imaging methods, the chance of patient survival could only be promoted by early surgery.

Spirometrically controlled high resolution computed tomography - quantitative assessment of density distribution in patients with diffuse fibrosing alveolitis.

STUDY OBJECTIVE: Lung density assessed by high resolution computed tomography (HRCT) is sufficiently sensitive for the diagnosis of interstitial lung disease, but may be hampered by uneven disease distribution. We determined the mean and subpleural density values in patients with diffuse fibrosing alveolitis (FA) and evaluated the diagnostic accuracy of both parameters, expressed as post-test odds ratios. MATERIALS AND METHODS: Pulmonary HRCT was performed on 21 FA patients and compared to scans of 27 healthy volunteers. The HRCT procedure was standardized by taking 3 scans at the carina +/- 5 cm, and by defining inspiration levels at 50% vital capacity. Mean lung density (MLD) and subpleural lung density (SLD) were calculated for all participants. RESULTS: MLD and SLD values for healthy subjects were significantly higher compared with the patient group. Odds ratios were 7.8:1 and 3.9:1 for SLD and MLD, respectively, demonstrating a superior discrimination power of SLD in the diagnosis of FA. CONCLUSION: Diagnostic accuracy of quantitative HRCT measurements in FA was improved by the separate evaluation of subpleural lung density, which is a better indicator of the presence or absence of lung fibrosis than is mean lung density.

Time-dependent changes of insufficiency fractures of the sacrum: intraosseous vacuum phenomenon as an early sign.

Sacral insufficiency fractures develop over a period of time and show time-dependent changes. We report on 15 CT examinations of 5 patients with early-stage insufficiency fractures of the sacrum. In 4 patients only irregular sclerosis without distinct fracture lines was present in 7 of 8 fractures. Of these 4 patients; 3 exhibited intraosseous gas inclusions in a ventral part of a lateral mass; 5 of 8 fractures disclosed a ventral cortical break. When distinct fracture lines had developed in 1 patient, intraosseous vacuum phenomenon had disappeared. Fracture lines evolve over weeks to months and show central bone absorption. The fractures can heal as demonstrated in 4 of 6 fractures in 3 patients, can persist over 1 year without significant changes or can progress to pseudoarthrosis with bone destruction similar to neuropathic joint disease. Intraosseous vacuum phenomena can persist to this stage. Intraosseous vacuum phenomenon is recognized as a potential finding in the early stage of sacral insufficiency fracture, which also is true for irregular sclerosis and ventral cortical disruption.

[Quantitative computerized tomography of the lung--respiration controlled diagnosis of diffuse lung diseases]. / Quantitative Computertomographie der Lunge--Respiratorisch kontrollierte Diagnostik diffuser Lungenerkrankungen.

STUDY OBJECTIVE: Computed tomography provides measurements of lung attenuation which reflect changes in the air to tissue ratio and can thereby be employed for diagnosis of diffuse lung disease. In this prospective study, we quantitatively analyzed lung density by high resolution computed tomography (HRCT) in 26 healthy volunteers, 15 patients with chronic obstructive pulmonary disease (COPD), and 15 patients with idiopathic lung fibrosis (IPF). The procedure was standardized by examination of 3 scans at the carina +/- 5 cm and by defining inflation levels by %VC using an on-line hand held spirometer. RESULTS: Performance of HRCT at 50% VC provides not only significant and distinguishable group data, but is the easiest to carry out for dyspneic patients. The mean lung density at 50% VC for healthy subjects was -820 +/- 4.2 (mean +/- SEM) Hounsfield units (HU). It was significantly lower (p < 0.01) in COPD patients (-865 +/- 9.2 HU), and considerably higher (-697 +/- 17.8 HU, p < 0.001) in the IPF group. At an inflation level of 20% VC, mean lung density values were similarly distributed, at significantly lower values relative to those at 50% VC, but the procedure was more difficult to perform for patients with dyspnea. In contrast, at 80% VC, lung density values for the COPD and control groups were not significantly different (p = 0.08). The sensitivity to detect COPD was improved by selecting HRCT values lower than -900 HU, which represent the part of the lung with an increased air/tissue ratio. For IPF patients an increase of lung density values above -699 HU was characteristic, indicating a decrease of the air/tissue relationship. CONCLUSION: From our data we propose to perform quantitative HRCT measurements at 50% VC. Diagnosis of diffuse lung disease can be further improved by consideration of specific CT -value intervals. Spirometrically controlled quantitative HRCT is a clinically meaningful tool for the assessment of diffuse parenchymal lung disease.

Spirometrically controlled quantitative CT for assessing diffuse parenchymal lung disease.

OBJECTIVE: Assessment of lung attenuation by CT reflects changes in the air-to-tissue ratio of the lung. We have analyzed the interdependence of intrathoracic gas volume, lung morphology, and functional disorder by high resolution CT (HRCT) to assess quantitative disease threshold in obstructive and restrictive diffuse lung disease. MATERIALS AND METHODS: Pulmonary HRCT was performed on 24 healthy volunteers, 11 patients with chronic obstructive pulmonary disease (COPD), and 16 patients with idiopathic lung fibrosis (IPF). HRCT measurement was standardized by taking three scans at the carina +/- 5 cm and by defining inspiration levels by percent vital capacity (VC) via spirometrically gating to the scanner. RESULTS: The mean lung density at 50% VC (DL50) for healthy subjects was -819 +/- 3.8 (mean +/- SEM) HU. In contrast, COPD DL50 was lower, averaging -861 +/- 6.4 HU, and the IPF DL50 was considerably higher (-731 +/- 17.7 HU), both significantly different (p < 0.001) compared with the control group. The accuracy of quantitative HRCT at different inspiration levels was evaluated by scanning the basal layer at 20, 50, and 80% VC. The control values were -747 +/- 5.6, -816 +/- 3.6, and -855 +/- 3.0 HU, respectively, which were significantly higher (p < 0.001) than those seen in COPD patients at 20 and 50% VC. Again, the IPF patients exhibited increased lung density (p < 0.001) at all inspiratory levels. Discrimination power was best among all cohorts at 20 and 50% VC. Position-dependent artifacts on lung density were quantified by the anteroposterior density gradient (APG). Irrespective of the underlying disease, APG at 50 and 80% VC was similar, but was up to twofold higher at 20% VC, indicating that quantitative estimates near RV may misrepresent mean lung density. CONCLUSION: Our data indicate that quantitative HRCT measurements should be performed not near full inspiration or expiration, but at an intermediate degree of lung inflation, e.g., 50% VC, for reasons of accuracy, intra- and intersubjective comparability, and feasibility. We conclude quantitative HRCT to be a sensitive tool for the evaluation of diffuse parenchymal lung disease.

[The diagnostic value of digital and conventional imaging in intravenous urography]. / Diagnostische Wertigkeit digitaler und konventioneller Bildgebung bei intravenöser Urographie.

PURPOSE: To compare image quality of digital luminescence radiography with conventional film-screen techniques during excretion urography. Four field tests and ROC analysis for determining diagnostic value. MATERIAL AND METHOD: 135 patients were included in a prospective study. Three independent observers judged the five minute (59 cases) or ten minute (76 cases) films after contrast injection using digital images as well as corresponding conventional images (five minutes-76 cases, ten minutes-59 cases). RESULTS: The digital technique provided better information concerning the renal parenchyma, the soft tissues and bone structures. Contrast enhanced detail was demonstrated equally well by both systems. The two systems had similar sensitivity but digital radiography showed higher specificity.

Reproducibility of quantitative, spirometrically controlled CT.

Quantitative spirometrically controlled computed tomography (with 1-mm-thick sections) was performed twice (with a 5-minute break) in 24 adult patients with pulmonary disease to objectively evaluate parenchymal changes in the lung. Twelve measurements of attenuation were made on apical, carinal, and basal scans (right, left, total of each level, total right, total left, total of all three scans), obtained at 50% vital capacity. Since differences in measurements between the first and second examination were not significant, the method provides highly reproducible results.

[Chemoembolization in primary liver cell carcinoma. Results of a prospective study]. / Chemoembolisation beim primären Leberzellcarcinom (HCC). Ergebnisse einer prospektiven Studie.

A remarkable progress was made in the palliative treatment of unresectable hepatocellular carcinoma using transcatheter arterial chemoembolization (TAC). The combination of doxorubicin as cytotoxic drug and of Lipiodol as carrier, which is selectively accumulated within the tumors is an effective treatment. Prolonged survival has been demonstrated in several clinical studies. In a prospective trial the effect of regional TAC with temporary ischemia of the liver was evaluated concerning liver function, systemic reactions and tumor response. Temporary ischemia of the liver was well tolerated even in patients with liver cirrhosis. Revascularization of the liver after TAC was observed in all cases. Systemic side effects of the cytotoxic drug were mild. In patients with Child C cirrhosis or tumor volume of more than 60% of the liver no impact of the treatment on the survival time was observed. In the entire patient group a survival rate of 70% after 15 months was achieved.

[Ct-portography in diffuse liver steatosis. Potential for a false-negative assessment]. / CT-Portographie bei diffuser Leberverfettung. Möglichkeit der falsch-negativen Beurteilung.

CT portography is the most sensitive technique currently available for the preoperative diagnosis of liver metastases. We report on a patient with liver steatosis in whom ultrasound examination revealed two liver metastases in the follow up after resection of a papillary carcinoma. The liver metastases could be clearly identified both on plain CT and on enhanced CT with dynamic bolus contrast medium injection. Because of the small difference in attenuation values between liver parenchyma and metastases the two liver metastases had not been recognized on CT portography. When severe and diffuse liver steatosis is present CT portography may fail to detect metastases or small hepatocellular carcinoma.

[The technic and value of the 3-dimensional imaging of renal calyx staghorn calculi with spiral CT]. / Technik und Stellenwert der dreidimensionalen Darstellung von Nierenbeckenkelch-Ausgusssteinen mit Spiral-CT.

5 patients with staghorn calculi in the renal pelvis were examined by spiral CT. From the raw data three dimensional reconstructions of the stones were obtained. In all patients it was possible to compare the three dimensional model with the stone following performance of percutaneous litholapaxy and endoscopic removal of the fragments. In all cases the three dimensional reconstruction provided a realistic image of the stones and was of practical value for the urologist for preoperative diagnosis and intraoperative control.

[The results of a long-term follow-up of patients with a percutaneous cholecystostomy]. / Ergebnisse einer Langzeitkontrolle von Patienten mit perkutaner Cholezystostomie.

19 out of 37 patients with percutaneous cholecystostomy were followed up for assessment of gallbladder function after percutaneous drainage. 17 out of 19 of the patients remained free from symptoms of gallbladder disease during a mean follow-up period of 25.8 months. Contractility of the gallbladder calculated by measurement of the sonographic diameter of the gallbladder with provocation tests was 62%. One patient was operated upon for choledocholithiasis three years after percutaneous cholecystostomy. Histology showed signs of chronic cholecystitis. It can be concluded that cholecystectomy is not routinely necessary after percutaneous cholecystostomy provided biliary excretion is normal.

[The implantation of elastic metal endoprostheses in tracheal stenosis and tracheomalacia. The initial results with 4 patients]. / Implantation elastischer Metallendoprothesen bei Trachealstenosen und Tracheomalazie. Erste Ergebnisse bei 4 Patienten.

Narrowing of the trachea due to tracheomalacia or compression can lead to life-threatening asphyxia and may require tracheotomy with intubation or endoscopic introduction of a stent. The use of a self-expanding elastic metal prosthesis in 4 patients with airway obstruction has proved a satisfactory alternative to conventional plastic prostheses, both in the acute phase and over a long period of time. After 4 weeks total epithelium cover of the stent could be demonstrated; biopsies after 3 and 4 months showed differentiation into respiratory ciliated epithelium. Patient acceptance was excellent since there was no sensation of a foreign body, retention of secretions or cough. The physical properties of the wall stent made it a suitable mechanical replacement for an unstable or narrowed trachea during the period of observation.