Guy Marchal

Localized 1H NMR spectroscopy in fifty cases of newly diagnosed intracranial tumors

Fifty patients with newly diagnosed, untreated intracranial tumors were examined with 1H nuclear magnetic resonance single-volume spectroscopy (MRS) using a 1.5 T whole-body MR system. Prior to the MRS, contrast enhanced MR and/or CT imaging studies were carried out. Histological verification was obtained in all patients except one. All tumor spectra revealed distinct abnormalities as compared with the normal brain spectra. Although most meningiomas showed a rather characteristic spectral pattern, generally features specific for the various tumor types were not observed. For instance, though a strong lactic acid signal was seen in most malignant tumors, this signal was also evident in five benign neoplasms.

Evaluation of the diagnostic value of a computed radiography system by comparison of digital hard copy images with screen–film mammography: results of a prospective clinical trial

The purpose of the study was to determine prospectively the diagnostic value of a computed radiography (CR) system by comparing mammographic hard copy images with screen–film mammography (SFM). A series of 100 patients, who came for diagnostic investigation, underwent two-view SFM (Lorad M-IV Platinum) and digital mammography with a CR system (AGFA CR system). The images were obtained by double exposure, i.e. same view without removing compression of the corresponding breast. The CR images were processed with dedicated processing for mammography. Six radiologists read sets of SFM and CR images. The primary efficacy parameter was the overall diagnostic value. The secondary efficacy parameters were lesion conspicuity and lesion details (for masses and micro-calcifications), tissue visibility at chest wall and at skin line, axillary details, overall density and sharpness impression and the overall noise impression. These parameters were scored by a 7-point scoring system. “CR non-inferior to SFM” was concluded if the lower confidence interval bound exceeded 80%. The confidence interval for the overall diagnostic value was between 96.4% and 100%. Pooled analysis of the ten features for image quality comparison demonstrated for all but one feature (lesion details of the calcifications) CR non-inferiority to SFM.

Using WWW and JAVA for image access and interactive viewing in an integrated PACS

We start from the observations that (1) potential benefits from PACS can only be realized if PACS and HIS are integrated into a multimedia medical information system, and (2) that this also requires integration at the level of the user interface. The user interface should allow integrated interaction with information from different subsystems, of which PACS is one. However, in the real world, different information systems are constructed using different technologies. Moreover, radiological image viewing is a highly interactive task that puts a particular burden on the graphical user interface. We describe our experiences in applying technology emerging around the World Wide Web (WWW) for interactive access to an integrated PACS/HIS. We illustrate the use of Web browsers to access new medical services, touch technologies for interactive access to HIS-PACS information, and emphasize the potential of JAVA applets. We argue that JAVA may become an important tool for providing highly interactive user interfaces to larger multimedia information systems. We discuss Web technology in the general context of HIS/PACS integration.

Magnetic Resonance Angiography: Techniques, Prospects, and Limitations

Vascular flow is characterized by its velocity, velocity spectrum, and pulsatility. The flow in the veins is slow, more or less regular, and mainly modulated by respiration and atrial contraction (Fig. 1a, b). On the contrary, the shape of arterial flow varies according to the vascular resistance. At rest, the extremities have a high resistance vascular system, with only flow during systole and some reversed or no flow during diastole (Fig. 1c). On the other hand, the arterial system of the vital organs like kidneys or brain is characterized by a low resistance, with flow during both the arterial and the venous phases (Fig. 1d).

Design for user efficiency in a dedicated ICU viewing station

The intensive care unit (ICU) is one application where significant benefit is expected from the use of digital technology in the acquisition, management and presentation of images. However, the potential benefits should not be outweighed by disadvantages of current digital technology. One of the bottlenecks is the efficiency of image viewing using a workstation, especially if this viewing station is implemented using affordable commonly available hardware. In this paper we describe the design concepts of a relatively low-cost but efficient viewing station for chest images, and discuss clinical experience with this system at an ICU ward. The user interface has been optimized towards the specific patterns of ICU image viewing. By anticipating user requests and preparing images during idle times of the computer, the mean image access time could be reduced by a factor of 4, while most images could be presented instantaneously. Information from the hospital information system (HIS) is exploited in the user interface, and a simplified PAC-HIS coupling has been implemented for the simultaneous presentation of images and reports.

Practical aspects of HIS/PACS integration with emphasis on radiological workflow

Abstract In the PACS that is now being installed for the University Hospitals Leuven, there is a strong emphasis on integration into the overall hospital-wide information system and on supporting interdepartmental workflow. In this paper, we focus on operations within the Radiology Department. We (1) motivate our emphasis on integration, (2) briefly describe our approach to integrating a commercial PACS, (3) situate some of the challenges we were faced with so far, and (4) report on initial experiences. We discuss integration into the overall workflow from the perspective of a changing emphasis in PACS.

Magnetic Resonance Imaging in Soft Tissue Tumours

Soft tissue tumours are common. Malignant soft tissue masses are twice as frequent as malignant primary bone tumours, whereas benign soft tissue tumours occur about 100 times as often as malignant soft tissue lesions [1].

Magnetic Resonance Imaging of the Pathological Female Pelvis: Assessment of 24 Patients with High-Field Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) has proven to be a very promising method in evaluating the normal and pathological female pelvis [1–5]. The present study was undertaken to determine the importance of MRI in the evaluation of primary tumours in the genital tract with respect to location, size and extent of the tumour. A total of 24 patients were imaged and the tumour identified histologically, MRI is valuable because it can demonstrate tumour location and size without administering contrast medium and with multiplanar images. Enhancement of the intestine by oral administration of Gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) was demonstrated in one patient.

Magnetic Resonance Imaging of Primary Bone Tumours

In the surgical treatment of malignant bone tumours local en bloc resection has been used widely during the last decade. To restore function this is frequently followed by reconstructive surgery [1].