APPC--a new standardised coding system for trans-organisational PACS retrieval.

OBJECTIVES: As part of a general strategy to integrate the health care enterprise, Austria plans to connect the Picture Archiving and Communication Systems (PACS) of all radiological institutions into a nationwide network. To facilitate the search for relevant correlative imaging data in the PACS of different organisations, a coding system was compiled for all radiological procedures and necessary anatomical details. RESULTS: This code, called the Austrian PACS Procedure Code (APPC), was granted the status of a standard under HL7. Examples are provided of effective coding and filtering when searching for relevant imaging material using the APPC, as well as the planned process for future adjustments of the APPC. DISCUSSION: The implementation and how the APPC will fit into the future electronic environment, which will include an electronic health act for all citizens in Austria, are discussed. A comparison to other nationwide electronic health record projects and coding systems is given. Limitations and possible use in physical storage media are contemplated.

MRI of the knee: how do field strength and radiologist's experience influence diagnostic accuracy and interobserver correlation in assessing chondral and meniscal lesions and the integrity of the anterior cruciate ligament?

Accuracy of MRI reports is taken for granted. In this paper the inter-observer reliability in the interpretation of meniscal lesions, degree of chondropathy, and integrity of the ACL was analyzed while taking the radiologist's experience and field strength into account. Fifty-two MRI studies of knees were interpreted by 11 radiologists independently. Twenty-two were acquired on 1.0-T, 20 on 1.5-T, and 10 on 3.0-T systems. Four of the radiologists had more than 5 years and seven had 3 to 5 years of experience in interpreting MRI studies. The findings were compared with the intra-operative findings. Inter-observer variance, specificity, and sensitivity were evaluated for each field strength. Inter-observer correlation ranged between 0.370 for cartilage lesions and 0.597 for meniscal tears. Correlation values did not increase with experience or field strength. The number of false reports was dependent on the observer, but not on field strength. The rate of false interpretations was significantly higher for most criteria in the less experienced group. In conclusion, inter-observer correlation was low, although the diagnostic criteria were defined. The use of the classification scheme should be standardized by uniform training. Radiologist experience seems to be more important than field strength.

VITA study: white matter hyperintensities of vascular and degenerative origin in the elderly.

The etiology of white matter hyperintensities (WMH) seen on T2-weighted cranial magnetic resonance images is a matter of debate. We investigated deep and periventricular WMH in the brains of a community-based cohort of 532 subjects aged 75-76 years. The objective of this study was to determine whether WMH at age of 75 years were associated rather with vascular factors than with degenerative factors. Arterial hypertension treated with antihypertensive drugs favored WMH, and WMH were found more frequently in subjects with focal vascular lesions. Additionally, we found significant associations between both, deep white matter and periventricular hyperintensities, and focal atrophy of medial temporal lobe structures. The odds ratio for deep WMH in subjects with more severe medial temporal atrophy was 4.4 (95%-CI: 1.9-9.8) that for periventricular hyperintensities was 3.9 (95%-CI: 1.7-8.8). These findings might indicate that not only vascular factors alone but also degenerative factors favor the occurrence of WMH after the age of 75 years.

Improving the safety of laparoscopic cholecystectomy: the routine use of preoperative magnetic resonance cholangiography.

BACKGROUND: The aim of this study was to determine the value of routinely performed preoperative magnetic resonance cholangiography (MRC) in detecting common bile duct (CBD) stones in patients stated to undergo elective laparoscopic cholecystectomy. In addition, we used MRC to investigate possible variants of the cystic duct. METHODS: Magnetic resonance cholangiography was performed preoperatively in 773 patients (311 male and 462 female; median age 55 years, range 16-91) who had no clinical signs of cholestasis prior to undergoing elective laparoscopic cholecystectomy. In cases where the MRC was positive for CBD stones, endoscopic retrograde cholangiopancreatiography (ERCP) was then performed. A total of 532 patients were available for continuous postoperatively follow-up (median 54 months, range 36-85). In 462 patients (247 female, and 215 male), MR images were also reviewed for variants of the cystic duct. RESULTS: In 705 patients (91%), MRC was negative for CBD stones. In 64 patients (9%) MRC was positive. Of these patients, 47 (6%) had CBD stones on ERCP. In 12 patients (2%), MRC was false positive. In five cases (0.6%), ERCP had an inconclusive result postoperative follow-up (532 patients, or 69%) revealed evidence of CBD stones in three patients (10.4%) despite a preoperative negative MRC result. Anatomical variants in the course of the cystic duct and its confluence with the common bile duct were found in 27 of 462 patients (6%). CONCLUSIONS: Magnetic resonance cholangiography proved to be a reliable screening technique in the preoperative evaluation of patients with silent CBD stones. Imaging of the course of the cystic duct is possible in a high percentage of cases. Therefore, MRC can be recommended as a screening technique before laparoscopic cholecystectomy.

Integration of ultrasound in a fully digital radiology department.

OBJECTIVES: The authors' experiences concerning the use of video-framegrabbers for the integration of ultrasound devices into a fully digital imaging environment are presented. METHODS: Video acquisition workstations (VAW) (Siemens, Gammasonics Inc., Hoffman Estates, IL) are used in our department to link ultrasound devices to the picture archiving and communication system (PACS). A study was carried out concerning the impact of this integration on throughput by comparing the average times for image acquisition and storage in this digital system with the times found in a conventional archive, which is still used for some ultrasound units. The annual costs for the two kinds of archives were compared. RESULTS AND CONCLUSION: Video acquisition is a feasible way of integrating ultrasound in a digital environment. No impact on throughput has been found for the radiologist carrying out the examination, but for the assisting technologist, the times for image retrieval and archiving could be reduced from 3 minutes and 8 seconds to 24 seconds per patient. The instant availability of previous studies could be increased from 93.5% to almost 100%. Archive costs could be reduced by 28%, with further reductions to be expected using different archive configurations.

Conventional film-screen versus computed storage phosphor radiography. Simulated miliary lung disease in an anthropomorphic phantom.

RATIONALE AND OBJECTIVES: In this experimental study, the authors examined whether laser printed hardcopies from digital storage phosphor radiographs yield diagnostic performance equal to conventional film-screen radiographs in the detection of simulated miliary disease, using a standardized object. METHODS: A commercially available anthropomorphic chest phantom was used for radiographic evaluation. Miliary disease was simulated by superimposing one to four sheets of millet seeds on the lungs, resembling a miliary disease pattern with varying degrees of detectability. An observer study (receiver-operating characteristic) with eight radiologists was conducted to compare the reader performance using hardcopies of computed storage phosphor radiography versus the conventional film-screen system, optimized for chest x-rays. The digitally generated images were presented as a double-image hardcopy, with a conventionally adopted version and an edge enhanced image version. RESULTS: When analyzed separately, one out of the eight observers performed slightly better using the conventional films. When treated as a group, analysis of the areas under the receiver-operating characteristic curves demonstrated no significant difference in reader performance for each of the systems under investigation (t = 0.286). The Wilcoxon test could not prove a statistical difference. CONCLUSION: Storage phosphor technology is a method that yields equal diagnostic performance as conventional film in evaluating miliary disease of the chest.

The Vienna SMZO-PACS-project: the totally digital hospital.

This paper gives an overview of the SMZO-PACS-Project in the form of a rough specification of the system architecture and the functional parameters related to it. The PACS architecture, determined by the large amount of data volume produced in the SMZO Hospital is outlined. In both radiology and trauma departments high technical requirements concerning data throughout and fault tolerance are demanded. Therefore these PACS modules are designed to minimize the workload of the network so that the performance is not degraded in the case of fault of a single component. A PACS module includes image acquisition devices of a certain modality with related reporting workstations and a distributed electronic archive. The functionality of the modules is described, special interest is posed on the integration of the different information management systems PACS, RIS and HIS, to achieve a complete record of data input and throughput in the hospital.

Integration of radiology and hospital information systems (RIS, HIS) with PACS: requirements of the radiologist.

PACS development has now reached a stage where it can clearly be stated that the technology for storage, networking and display in a fully digital environment is available. This is reflected by an already large and rapidly increasing number of PACS installations in USA, Western Europe and Japan. Such installations consist of a great variety of information systems, more or less interconnected, like PACS, HIS, RIS and other departmental systems, differing in both hardware and software. Various data - even if they only concern one person - are stored in different systems distributed in the hospital. The integration of all digital systems into a functional unit is determined by the radiologist's need of quick access to all relevant information regardless where it is stored. The interconnection and functional integration of all digital systems in the hospital determine the clinical benefits of PACS. This paper (1) describes the radiologist's requirements concerning this integration, and (2) presents some realistic solutions such as the Siemens ISI (Information System Interface), and a mobile viewing station for the wards (visitBox).

[Comparison of ultrasonic and CT diagnosis of solid liver tumors]. / Vergleich zwischen Ultraschall- und CT-Diagnostik solider Lebertumoren.

A prospective study compares the results of ultrasound and CT diagnostics in 323 patients with liver tumours. The accuracy of both methods is high: the sensitivity of ultrasound comes up to 90.4%, of CT to 96.1%. The important role of the comparatively economic ultrasound in specific tumour diagnosis is eg shown by the fact that if lesions of high and low echogenicity were found in one patient, or if there were found calcifications, the tumour was always a malignoma. This specificity was missing in the cost intensive CT which is also more time consuming and needs i.v. contrast.

[The renal pelvic tumor in the sonogram]. / Der Nierenbeckentumor im Sonogramm.

A prospective study evaluates screening investigations of the kidneys of 2350 patients. Sonographic criteria of the renal pelvic tumour are established. So-called "indirect signs" are only recognized by the compound scanner. By these ultrasonic symptoms a pelvic tumor could be detected with 15 patients which is a frequency of 6,5%. Part of the patients were preselected. The possibility of false-negative findings remains unconsidered. The study proves the great relevancy of ultrasonography in this disease. When operations of renal pelvic carcinomas were retrospectively checked our diagnostic results were underlined.

[Liver hemangioma--an angiographic contribution to the differential diagnosis of sonographic lesions (author's transl)]. / Leberhämangiom--ein angiographischer Beitrag zur Differentialdiagnose sonographischer Läsionen.

Small liver hemangiomas are displayed as echogenic as well as sonolucent patterns on ultrasonic scans. Differentiation from malignomas is difficult and responsible, hepatomas and solitary metastases being possible. By partial liver resection the malignant diseases can be treated successfully. Therefore an accurate diagnosis is to be aimed at. Of all the methods only angiography can ensure a certain amount of clarity. This is possible under the following circumstances: The cavernomas must be of a certain size. They must not withdraw from evidence due to large avascular areas which can result from thrombosis, fibrosis or necrosis. Moreover a superselective filling of the hepatic artery is claimed but not always possible. If the portal vein is opacified it conceals the radiologically typical image of the cavernoma. Under these circumstances only few moments of the late arterial and the hepatovenous phases remain to detect the hemangioma in the seriogram.

[Sonography of the lungs and pleura]. / Die Sonographie der Lunge und Pleura.

Diagnoses were made by ultrasound in 73 out of 80 cases with unclear thorax x-ray. One case was misinterpreted, no diagnoses were possible in 6 cases. Pleural effusion or opacities reaching the pleura are necessary to perform ultrasound examination. Sonographic findings in pleural or pulmonary changes are discussed and correlated with pathological anatomical findings. Additional information can be obtained by sonography in pleural lesions and in pulmonary lesions masked by pleural effusion. Atelectases can be differentiated from pneumonia, and tumours can be identified in peritumorous pneumonia or atelectases.

[Radiofrequency-thermoablation in malignant liver disease]. / Radiofrequenz-Thermoablation maligner Raumforderungen der Leber.

The clinical application of radiofrequency tumor ablation in primary liver tumors and metastatic liver disease is rapidly growing because this technique has proven to be simple, safe, and effective in first clinical studies. Most of the patients with malignant liver disease are not candidates for surgical resection due to localisation or comorbidity, so radiofrequency therapy offers a good alternative for inoperable patients. With this method, high frequency alternating current is delivered to tissue via a needle electrode, the produced heat leads to coagulation necrosis. The largest focus of necrosis that can be induced with the currently available systems is approximately 4 - 5 cm with a single application. The radiofrequency needle is usually placed with US or CT guidance. For follow up examinations CT and MRI can be used, they proved to be equally accurate in the assessment of treatment response.

[Pre- and postoperative diagnosis of an aortic aneurysm by dynamic computed tomography with omission of angiography]. / Prä- und postoperative Diagnostik des Aortenaneurysmas mittels dynamischer Computertomographie unter Verzicht auf die Angiographie.

A study which was prospective with regard to the method, showed 41 cases of aortic aneurysms in a collective of 3597 body-CT-examinations (1.14%). By means of CT and its possibility of reconstruction all morphological details of an aneurysm become visible. The course of the vessels to the bowel and to the kidneys are shown with the same excellence as in angiography. However, additional information which angiography cannot supply, is also given, like non-perfused lumen, changed wall structure and perivascular changes. Measurement of flow can be performed in the vessel and in the organ, the arterial supply of which is involved in aneurysmatic disease. The method is non-invasive. This is important for control after operation. Morphological changes of the vessel prosthesis are detected, as well as bleeding and infection. Functional parameters are determined semiquantitatively.

[Strut fractures in the long-term follow-up of Günther cava filters--the results after 64 filter implantations]. / Strebenbrüche bei der Langzeitkontrolle von Günther-Kavafiltern--Ergebnisse nach 64 Filterimplantationen.

Follow-up of patients with inferior vena cava filters was performed every 3 months with clinical controls, plain radiographs and duplex sonography. Whereas the clinical results were excellent (no recurrence of pulmonary embolism), radiological controls showed broken anchoring legs in 14 cases and a broken filter basket in one patient. In two cases, the broken anchoring prongs had perforated the inferior vena cava wall. All patients with broken filters were clinically asymptomatic. CT showed no morphological changes in these cases. As experience proves, strict follow-up of caval filters for early detection of complications is mandatory even with well-established filter types.

[Cerebral blood flow measurement by dynamic computed tomography before and after reconstructive vascular surgery]. / Durchblutungsmessung des Gehirns mit dynamischer Computertomographie vor und nach rekonstruktiver Gefässoperation.

Sequential changes of cerebral regional blood flow and parenchymal perfusion were examined with dynamic CT in 12 patients with arteriosclerotic occlusive disease before and after vascular reconstructive surgery. ROI density values were recorded bilaterally in corresponding regions of the brain tissue and vessels. Interpretation is based on transient time of the bolus (timing of peak), delay of the peak and amplitude of the change of density-time curve. Differences of hemodynamics before and after surgery are demonstrated, a practical technique for measuring the relative perfusion.

[Laryngeal and hypopharyngeal carcinoma--the limits and advantages of sonography]. / Das Larynx- und Hypopharynxkarzinom--Grenzen und Vorteile der Sonographie.

29 patients with carcinoma of the larynx and the hypopharynx were evaluated not only for staging cervical lymph nodes but also for classification of the primary tumour. With appropriate technique it is possible to assess tumour infiltration (T4) of surrounding tissue of the larynx at all levels. Tumour classification T1 to T3 is possible in patients with tumour of the epiglottis (regio supraglottis, UICC). The endolaryngeal tumour T1 to T3 (regio glottis and subglottis, UICC) still remains the domain of the microlaryngoscopy. The limits of the method are apparent in hypopharynx carcinomas where in only 50% of the patients the tumour could be assessed.

[The value of barium double-contrast study in the aftercare of gastrectomy patients (Roux-Y)]. / Stellenwert der Barium-Doppelkontrast-Untersuchung in der Nachsorge von Gastrektomierten (Roux-Y).

We evaluated 32 patients who had undergone jejuno-oesophagostomy for gastric carcinoma. Double contrast radiography was performed 3 to 36 months after gastrectomy, 3 to 14 days prior to routine endoscopy. Endoscopy is superior to double contrast radiography in detecting tumour recurrence, particularly in small tumours, due to the possibility of biopsy. Double contrast radiography is excellent in demonstrating the afferent loop. We found a high number of jejuno-oesophageal reflux and very different small intestine transit times without correlation to clinical signs and symptoms.

[Findings of digital intensive or bed lung radiographs at the monitor vs. hard copy: a clinical ROC study]. / Befundung von digitalen Intensiv- bzw. Bettlungenaufnahmen am Monitor vs. Hardcopy: eine klinische ROC-Studie.

45 bedside chest examinations acquired with storage phosphorus radiography, were displayed on a viewing box as single-format hard copies and at a high-performance digital reporting console. 6 observers performed an ROC study. For the pathologies under question, significantly better results were shown in monitor reporting due to pneumonic infiltration whereas no significant differences were found for pulmonary or mediastinal masses, or for pneumothoraces.

[Lumbar meningeal enhancement after surgery in the posterior cranial fossa: a normal finding in children?]. / Lumbales meningeales Enhancement in der KM-MRT.

PURPOSE: Spinal meningeal Gd-DTPA enhancement after cranial surgery is a known observation of a not well understood underlying mechanism. This paper demonstrates that this MRI finding is a normal meningeal reaction to subarachnoid hemorrhage, which should not be mistaken for metastatic spread. MATERIAL AND METHODS: Three pediatric patients were examined by MRI for metastatic spread of malignant infratentorial tumors along the spinal canal two to nine days after the removal of the primary cerebral lesion. The findings were compared with a control group that underwent cranial surgery (cyst resection or fenestration of the posterior cranial fossa) without major bleeding into the subarachnoid space. Unenhanced and enhanced sequences were obtained to prove that the high signal within the CSF is caused by an abnormal Gd-DTPA uptake and not by methemoglobin. RESULTS: Meningeal enhancement was observed in all patients with intraoperative bleeding resembling subarachnoid masses on enhanced T 1 -weighted images. This was not present in any patient of the control group. This finding lasts for approximately two weeks. CONCLUSION: The meningeal enhancement renders immediate postoperative studies inconclusive for the detection of metastatic spread. Consequently, the obligatory tumor staging along the spinal canal should ideally be done prior to the resection of a cerebral tumor.