Arrhythmogenic right ventricular dysplasia: MR features

Arrhythmogenic right ventricular dysplasia (ARVD) is a heart disease characterized by a total or partial fat replacement of the myocardium. A total of 30 patients were studied with a suspected diagnosis of ARVD. Clinical criteria used for evaluation of ARVD were: (a) ventricular origin arrhythmias with a left bundle branch block configuration, (b) T-wave inversion in the anterior precordial leads, (c) ventricular kinetic alterations observed using echocardiography and angiography and (d) cardiac failure when there are no pathologies attributable to other heart diseases. All patients had serial EKG and echocardiography tests. One third of patients underwent angiocardiography; 7 of 30 had Holter; 7 of 30 had exercise test just to evaluate the effectiveness of the anti-arrhythmic therapy. All patients underwent MRI examination. The following MRI criteria were used: (a) high-intensity areas indicating the fatty substitution of the myocardium, (b) ectasia of the right ventricular outflow tract, (c) dyskinetic bulges, (d) dilation of the right ventricle and (e) enlargement of the right atrium. The diagnosis of ARVD was classified as highly probable for patients manifesting at least three positive criteria, probable with two positive criteria, dubious with one and negative in the absence of all criteria. Highly probable diagnosis of ARVD was made in 8 patients, probable in 4, dubious in 7 and negative in 11. The MRI technique is very effective in the assessment of ARVD. The MRI criteria may be helpful in the diagnosis of this condition.

[Introduction to the study of the Willis circle with transcranial color Doppler: methodological notes and preliminary experience]

To date, adult intracranial circulation has been studied only with pulsed-wave Doppler US, which is a useful diagnostic tool even though several technical and practical limitations are related to the difficult location of intracranial vessels. Recently, dedicated color-Doppler transducers have been proposed, which can pass through the skull which makes a physiologic barrier for the US beam: this technique has been called transcranial color-Doppler (TCD). We report on our personal experience with TCD in 30 healthy volunteers (12 men and 18 women, age range: 17-75 years) submitted to TCD for Willis circle imaging. We used an ATL Ultramark 9HDI unit with a phased array transducer (3.5 MHz) and 2 MHz Doppler frequency; the PRF was 3000 Hz, with 80% color gain. 100 Hz wall filters were used. The middle cerebral artery was always shown correctly in all subjects, while the posterior one was depicted only in 7 cases (23.3%); in contrast, the anterior cerebral artery was demonstrated in 3 cases only (10%). Nowadays, TCD is mostly applied to normal intracranial circle studies, to assess normal blood speed values more accurately. To this purpose, both the direct visualization of blood vessels and the flowmetric values obtained measuring the incidence angle are useful pieces of information. TCD permits a more accurate study of intracranial local blood flow in the Willis circle and of its changes in pathologic conditions. In contrast, TCD yield is poor in characterizing intracranial tumor tissue.

[A computer system for the systematization of MR findings in knee joint diseases]

An inexpensive, easy-access computer-based system is proposed, which was developed for the systematization of the clinical series of knee joint disorders studied with Magnetic Resonance Imaging (MRI). The system is based upon the integration of multimedia technology and Data Base Management Systems (DBMS). The hardware configuration for this project included an Apple Macintosh workstation based on a Motorola 68040 microprocessor and a customized application developed by the authors with the 4th Dimension software. The MR images available only on film were digitized off-line with a solid-state Charge Coupled Device (CCD) scanner with back-light cover for transparency. Otherwise, MR images were acquired on-line through an Ethernet-based local area network from the MR unit or from a SparcStation-Advantage Windows workstation connected with the MR unit. Image post-processing was performed with the Adobe PhotoShop software. The system was devoted to the systematization and analysis of a clinical series of 800 MR studies of the knee. A mean of 10 significant MR images were stored for each examination with a standard image compression algorithm--the Joint Photographic Experts Group (JPEG). This permitted us to save the system's storage space and at the same time to preserve image quality for consultation and teaching purposes, not for diagnosis which is made on the backboard or on the MR unit's or Advantage Window's monitor. Finally, MR findings were indexed with a customized check-list specific for knee joint disorders. On the basis of stored and selected information, it was thus possible to carry out a statistical analysis and to make detailed reports which are useful for scientific purposes, such as the preparation of lectures and papers. Moreover, the system was very useful for patients' follow-up and for the preparation of hypermedia teaching applications on knee joint disorders which are available on the Internet at our World-Wide Web server (URL: http://mbox.unipa.it/radpa/radpa ++ +.html). In conclusion, the system is a cost-effective and user-friendly solution for the multipurpose management of radiologic series.