Gd-BOPTA: "the MRA contrast agent of choice"?

Gd-BOPTA is a new positive MR contrast agent for intravenous application. In comparison to other gadolinium-chelates it has a nearly two-fold increased relaxivity due to weak protein binding with plasmatic macromolecules. In the papers published yet it has been evaluated to be useful for liver imaging. The purpose of this study was to evaluate, whether Gd-BOPTA is suited as an "magnetic resonance angiography (MRA) contrast agent". We examined four patients (aortic dissection, carotid artery stenosis, portal vein stenosis, exclusion of subclavian artery stenosis) with Gd-BOPTA with a dosage of 0.05 mmol/kg body weight. Furthermore, peripheral MRA of the pelvis and lower extremities was acquired in two healthy volunteers comparing 0.1 mmol Gd-DTPA/kg with 0.1 mmol Gd-BOPTA/kg. There was a delay of one week between the Gd-DTPA and the Gd-BOPTA examinations. In another volunteer Gd-BOPTA was reduced to 0.05 mmol/kg. The patient examinations revealed sufficient quality comparable with Gd-DTPA examinations despite of reduced dosage. In the volunteers Gd-BOPTA proved to be superior especially in the delineation of small pedal arteries which is important for surgical planning. These preliminary results demonstrate the potential of Gd-BOPTA to become a useful contrast agent for MRA. Its efficacy for this purpose has to be evaluated in future prospective studies.     

MRI of the kidney—state of the art

Ultrasound and computed tomography (CT) are modalities of first choice in renal imaging. Until now, magnetic resonance imaging (MRI) has mainly been used as a problem-solving technique. MRI has the advantage of superior soft-tissue contrast, which provides a powerful tool in the detection and characterization of renal lesions. The MRI features of common and less common renal lesions are discussed as well as the evaluation of the spread of malignant lesions and preoperative assessment. MR urography technique and applications are discussed as well as the role of MRI in the evaluation of potential kidney donors. Furthermore the advances in functional MRI of the kidney are highlighted.     

Monitoring of the medical radiological exposures of the population of the Emilia–Romagna Region

PURPOSE: The Italian Decree of Law 187/2000 provides for many fulfilments relevant to justification and optimisation of medical exposures that can complicate the daily work of radiology departments if considered as mere legal requirements. On the contrary, this law should be regarded as a good opportunity to analyse and optimise working practices. To this end, the Emilia- Romagna Region carried out an initial assessment of medical exposures to its population in 2001 followed by a second survey taking into account new dosimetric evaluations. This paper illustrates the results of this second survey and analyses the most significant parameters in comparison with similar studies reported in the literature. MATERIALS AND METHODS: We first determined the examinations to be considered: 12 easily identifiable examinations divided into macroaggregates were selected for conventional radiography and computed tomography (CT). Hospitals of the Emilia-Romagna Region were directly asked to provide the number of examinations performed subdivided by type and grouped by nomenclature code, some technical parameters related to both examination protocol and equipment and the value of dose quantities as measured by local medical physicists. RESULTS: Study of distribution of the entrance skin dose for different examinations in single hospitals showed no systematic differences in kilovoltage settings versus dose whereas the number of examinations tended to be inversely proportional to dose. These trends could be explained by the fact that in hospitals where many examinations of the same type are performed, operators, equipment and procedures are well integrated, leading to a level of specialisation that allows efficient interaction in order to deliver an "optimal dose". Analysis of the "entrance skin dosemax"/"entrance skin dosemin" ratios for various projections and comparison with literature data seem to show that a "scale factor" has a fundamental role in the variability of entrance skin dose values amongst hospitals and that "chest" examinations are the most critical, with the greatest differences in entrance skin doses. CONCLUSIONS: The evaluations performed in this study show that this type of analysis heavily relies not only on the cooperation of all professionals responsible for patient radiation protection but also on the experience gained during previous surveys because data collection is a very critical process that can invalidate, if not carefully performed, all subsequent processing.     

Assessment of the “functional length” of the three bundles of the anterior cruciate ligament

The objectives of the present study are to compare "functional length" between the three bundles of the anterior cruciate ligament (ACL) from extension to deep flexion and to perform a sensitivity study on the patterns of "functional length" change due to deviations in insertion site selection. Nine knees of healthy volunteers were examined using a horizontal open magnetic resonance apparatus with the knee at 0 degrees -150 degrees of flexion and created three-dimensional (3D) virtual models of the knee. The femoral and tibial attachment sites of the three ACL bundles were determined, and the distance between the attachment sites was automatically calculated as the "functional length" of each bundle in each position. After changing the attachment sites, computer simulation was performed to investigate in vivo "functional length" changes for the three bundles of the ACL in normal knee kinematics from extension to deep flexion. Three bundles statistically significantly changed in "functional length" during flexion/extension, while they were longest at full extension, and decreased with increasing knee flexion to 100 degrees . They were smallest at flexion of 100 degrees , with increase lengths with flexion deeper than 100 degrees . Deviation of 6 mm of insertion site beyond attachment area caused significant alteration in the pattern of "functional length" change of each bundle, while deviation of 3 mm within attachment area caused no significant difference. The "functional length" of the three ACL bundles was not isometric, not even the antero-medial bundle. The "functional length" might be of major importance in terms of the site of the ACL insertion. The "functional length" of multiple bundles of the ACL and the pattern of their changes are useful for not only graft choice and preparation but also knee angle and initial tension at graft fixation during multiple-bundle ACL reconstruction surgery.     

Determination of the Cause of Edema

Currently. neither external detection nor~1 dilution methods can differentiate among cardiac, overhydration (including renal failure) and capillary permeability edema. New techniques designed to detect 2~increased pem-     

American Burn Delegation Talking with the Officials of the Public Health Ministry of the People''''s Republic of China

(The officials from the Public Health Ministry who received the American Burn Delegation are:XiaoZiren.director of the Scientific and Technological Bureau of PHM;Oin Xinhua.deputy director of the Bu-reau;Li Fumin.deputy director of Medication Regulatory Bureau of PHM:Wang Xiufeng.chief ofAchievements Section of the Scientific and Technological Bureau and others)     

Influence of the Size of the Admixture of Irradiated Cells on the Révész Effect

Summary

The repair of sublethal and potentially lethal damage in stationary resting epidermal cells of Saintpaulia has been investigated. Fractionation experiments revealed an efficient repair of sublethal damage with a half-life of 1·9 hours. No repair of potentially lethal damage was noted when cultivation of the leaves was delayed for 24 hours after irradiation. At delay times of 2, 3 and 4 days some repair of potentially lethal damage has been found. A small pre-dose given 24 hours before a challenging dose improved the cells' chance to regenerate and the improvement has been shown to be compatible with an improved repair of potentially lethal damage induced by X-rays and fast neutrons. It has been shown that the stimulated repair process takes 12 to 24 hours to develop, is dependent on the size of the pre-dose, has single-hit dose kinetics, and an r.b.e. of 1 for neutrons. With delayed cultivation of 2 days the stimulated repair process leads to an alteration in the shape of the regeneration (survival)—dose relationship which increases the low dose r.b.e. for neutrons from 10 to 35.     

Lymphona of the Colon

Involvement of the large bowel by lymphosa?coma, reticulum cell sarcoma,and Hodgkin's disease is extremely rare. Symptoms are anorexia, fatigue, weightloss and fever. Generalized abdominal discomfort and alternating diarrhea and     

Sonography of injury of the ulnar collateral ligament of the elbow—initial experience

Objective The purpose of this study is to describe the sonographic appearance of injuries of the ulnar collateral ligament (UCL) of the elbow.Design and patients Eight non-professional male baseball pitchers, ages 13–35 years, with medial elbow pain and clinical suspicion of ulnar collateral ligament injury, were referred for imaging. All eight underwent sonography of the affected and contralateral asymptomatic elbow, and six also underwent MR imaging. Neither valgus stress nor power Doppler was used during the sonographic examinations. Time from onset of symptoms to imaging was 1.5 weeks to 6 months. Three patients had surgical confirmation of their injuries, with time from imaging to surgery of 2 days to 9 months.Results In four patients, the UCL was ruptured, manifest sonographically in three cases as discontinuity of the normally hyperechoic ligament with anechoic fluid in the gap and in one case as non-visualization of the ligament with heterogeneous echogenicity in the expected location of the ligament. Two adolescent patients had avulsions of the UCL from the medial epicondyle, with sonographic demonstration of the avulsed echogenic bony fragment in both cases. One patient had a mild sprain, manifest as mild thickening and decreased echogenicity of the ligament sonographically compared with the contralateral normal elbow, with mild surrounding hypoechoic edema. The eighth patient had a small partial tear of the deep surface of the distal aspect of the ligament, visualized as a hypoechoic focus between the deep surface of the ligament and its ulnar attachment.Conclusion Tears of the ulnar collateral ligament are manifested sonographically as non-visualization of the ligament or alteration of the normal morphology.     

Does the digital signature of the DICOM standard meet the requirements of German law?

The DICOM standard offers the possibilities to generate electronic signatures, valid according to German laws. This enhances the reliability of the correlation between image and patient data. However, only so called qualified electronic signatures--conveniently issued by an accredited supplier--are permissible and not rejectable as evidence in German jurisdiction and are completely equivalent to the handwritten signatures. These qualified electronic signatures can be executed only by individuals, whereas the former are not applicable to technical apparatus like image generating modalities. In consequence, a modality is able to provide its pictures with a "common or advanced signature" solely. This limits the use of the digital signature of the DICOM standard for further applications, e.g. the verifiability within the teleradiology.     

"Whatever happened to the class of 2000?" An outcome survey of potential interventional radiologists

OBJECTIVES: To find out what final career choices were made by trainee doctors who had indicated a strong interest in pursuing a career in interventional radiology and to establish the reasons behind their final career choice. METHODS: Eighty-eight doctors who attended a meeting in 2000 designed to promote interventional radiology as a career were questioned as to whether the meeting influenced their potential career choices and then further surveyed via postal questionnaire 5 years later to find out their eventual career choices. Of the 88 doctors who attended, 56 were radiology trainees and 32 were training in either medical or surgical specialties. There were 25 women and 63 men. RESULTS: Five years after the meeting, six are now interventional radiologists (6.8%) though four of these are still in a 6th year interventional radiology fellowship. A further 12 (13.6%) are systems based, predominantly diagnostic radiologists with an interest in intervention. Thirty-two (43.2%) are diagnostic radiologists who undertake little or no therapeutic intervention. Of the 32 non-radiologists who attended the meeting only three entered radiology and are still in training. CONCLUSIONS: Interventional radiology is a popular initial career choice amongst trainee doctors. However, only a small number eventually pursue the specialty. If the manpower shortage of interventional radiologists is to be addressed, there needs to be improvements in training, accreditation, career opportunities and working conditions.