Evaluation of marrow perfusion in the femoral head by dynamic magnetic resonance imaging. Effect of venous occlusion in a dog model.

RATIONALE AND OBJECTIVES. There is a continuing need for a greater sensitivity of magnetic resonance imaging (MRI) in the diagnosis of avascular necrosis (AVN). Previously, it was demonstrated that a dynamic MRI method, with gadolinium-DTPA (Gd-DTPA) enhancement, can detect acute changes not seen on spin-echo images after arterial occlusion in a dog model. Because venous congestion appears to be a more directly relevant hemodynamic abnormality in a majority of clinical AVN cases, the authors extended the dynamic MRI technique to study changes in venous occlusion. METHODS. Dynamic MRI of the proximal femur was performed in five adult dogs before and after unilateral ligation of common iliac and lateral circumflex veins. Sixteen sequential gradient-recalled pulse sequence (GRASS) images (time resolution = 45 mseconds, echo time = 9 mseconds, flip angle = 65 degrees) were obtained immediately after a bolus intravenous injection of 0.2 mmol/kg of Gd-DTPA. Simultaneous measurements of regional blood flow were made using the radioactive microsphere method. RESULTS. After venous ligation, there was a 25% to 45% decrease in the degree of enhancement compared with preligation values on the ligated side. The decrease in cumulative enhancement (integrated over the entire time course) was statistically significant. The occlusion technique was verified by confirming a statistically significant decrease in blood flow determined by the microsphere method. CONCLUSIONS. Dynamic Gd-DTPA-enhanced fast MRI technique can detect acute changes in bone marrow perfusion due to venous occlusion. This technique may have applications in the early detection of nontraumatic AVN.     

Centro-somatic staged tuberculous vertebral osteitis: a case report

Centro-somatic tuberculous vertebral osteitis is defined as tuberculous infection of the vertebral body with preserved integrity of the adjacent intervertabral disk. Other types of vertebral tuberculosis include Pott's spondylodiscitis and exceptional lesions of the posterior arch. We report a case of centro-somatic tuberculous vertebral osteitis in a 14-year-old boy who developed staged lesions of the L2 to S1 bodies, associated with a posterior epidural collection but without any deterioration of the intervertebral disk on plain x-rays and computed tomography. This atypical aspect of the lesions required a surgical biopsy which yielded a yellow-whitish fibro-oleagenous, friable product more suggestive of neoplasm than infection, but histology rectified the diagnosis, showing typical caseo-follicular tuberculosis. A 6-month anti-tuberculosis regimen was rapidly followed by symptom improvement. We emphasize the importance of modern imaging techniques for the diagnosis of vertebral lesions and for guided biopsy or drainage.     

Three-dimensional systolic strain patterns in the normal human left ventricle: characterization with tagged MR imaging

PURPOSE: To present a database of systolic three-dimensional (3D) strain evolution throughout the normal left ventricle (LV) in humans. MATERIALS AND METHODS: In 31 healthy volunteers, magnetic resonance (MR) tissue tagging and breath-hold MR imaging were used to generate and then detect the motion of transient fiducial markers (ie, tags) in the heart every 32 msec. Strain and motion were calculated from a 3D displacement field that was fit to the tag data. Special indexes of contraction and thickening that were based on multiple strain components also were evaluated. RESULTS: The temporal evolution of local strains was linear during the first half of systole. The peak shortening and thickening strain components were typically greatest in the anterolateral wall, increased toward the apex, and increased toward the endocardium. Shears and displacements were more spatially variable. The two specialized indexes of contraction and thickening had higher measurement precision and tighter normal ranges than did the traditional strain components. CONCLUSION: In this study, the authors noninvasively characterized the normal systolic ranges of 3D displacement and strain evolution throughout the human LV. Comparison against this multidimensional database may permit sensitive detection of systolic LV dysfunction.     

Abdominopelvic computed tomography in the preoperative evaluation of early cervical cancer

The efficacy of abdorainopelvic computed tomography (CT) in determining the extent of disease in the patient with early cervical cancer was evaluated in 24 patients (FIGO Stage Ia-1, Ib-18, IIa-5). The CT stage was compared to both the clinical and surgical pathological staging, CT was accurate only in 58% of the cases in determining parametrial extension. It was unable to detect any of the 6 cases of histologically documented lymph node metastases. CT appears to have limited use in the patient with early cervical carcinoma because with parametrial thickening it lacks sufficient specificity to differentiate between malignant and nonmalignant tissues and there is not sufficient sensitivity to detect early nodal involvement.     

Patient information and the cardiologist

AIM OF THE STUDY: The patient's information prior to paraclinical testings is a part of the medical deontology and takes on increasing legal importance since new laws. METHODS: From December 2001 to January 2002, we administered to cardiologists through the website of the French Society of Cardiology a questionnaire in order to determine the way the information is dispensed to patients and to compare the results to the survey performed in 2000. RESULTS: Among the 293 answers obtained, 243 were utilizable. The answers were obtained from cardiologists working on private medicine (27.5%), public medicine (52.8%) or mixed (19.7%). Information was more frequently dispensed for invasive procedures: coronary angiography (92.2%), cardiac pacing (76.8%) than non invasive assessments: transesophageal echocardiography (47.6%) and treadmill test (44.7%). The most frequent information document given to patients was the one edited by the French Society of Cardiology (71.6%). In the great majority of cases, there is the prescribing cardiologist (35.9%) and/or the one performing the assessment who dispenses the information, generally the day prior the examination (73.5%) with additive explanations (91.4%). Few patients refuse the examination after information. The situation where the assessment is performed on a patient without the faculty of understanding modalities and the necessity of that examination is in emergency (45%). In 63.4% of cases, the cardiologist requires the patients signature on the information document. CONCLUSION: Information dispensation prior to an examination is generally well done by cardiologists. The evidence of the information's dispensation is not at ease and most of cardiologists require written document from their patients, which is not legally necessary.     

Prenatal screening of kidney pelvis ectasia,frequently caused by vesico-ureteral reflux detected after birth. Analysis of a series of 159 cases in 4 years at a maternal-child unit

To describe the pre- and post-natal management of vesico-ureteric reflux in a prospective study of babies presenting with vesico-ureteric reflux suspected from pre-natal ultrasonography in a tertiary paediatric center. PATIENTS AND METHODS: Between 1997 and 2001, 35 children (25 boys and 10 girls) with were vesico-ureteric reflux followed for 12 to 36 months after the pre-natal detection of urinary tract anomalies. Ultrasound examination was realized at the 5th of life, retrograde cystography at the 15th if the renal pelvic dilatation measured at least 10 mm of diameter. In 11 the reflux was bilateral and 46 refluxing units were reviewed. RESULTS: According to the international classification of, 7% vesico-ureteric reflux were grade I, 20.5% were grade II, 32% were grade III, 18% were grade IV, 22.5% were grade V. Fourteen patients (17 refluxing units) underwent ureteric-reimplantation. Four total and two partial nephrectomics were carried out in patients < 2 years old; in 8 patients the VUR resolved spontaneously. Of the latter, 7 patients (ten refluxing grade III-IV units) are still being followed and awaiting a decision on treatment. CONCLUSION: This study confirms the predominance of boys in those with antenatally suspected vesico-ureteric reflux. The spontaneous resolution or improvement during the first 3 years of life was apparent in most cases, even in those with severe reflux (grade III-V).     

Patient information. First evaluation

The recent harmonisation of the jurisprudence between the Court of Appeal and State Council has affected medical responsibility because it is now the physician's obligation to prove that the information to the patient has been properly given: it is, therefore, a current issue. A first evaluation was undertaken to determine the modalities of patient information in cardiology by an enquiry of cardiologists working in the public and private sectors. The results show that information to patients was given concerning complementary investigations such as exercise stress testing, transoesophageal echocardiography, coronary angiography and cardiac pacing; the information was more often given for invasive procedures. In the great majority of cases (92%), it is the prescribing or operating physician who gives this information, usually the day before the procedure, with complementary oral explanations in about 90% of cases. Patient information, therefore, seems to be well done by cardiologists. However, the proof of information is not always easy, written consent, signed by the patient, not being compulsory at present.     

Endobronchial tuberculosis. Report of 21 cases

Since the advent of antituberculosis drugs, endobronchial tuberculosis has become an exceptional finding, often in a misleading context. Cases reported generally occur in patients with immune deficit. We report 21 cases of endobronchial tuberculosis in immunocompetent patients (mean age 37 years). Clinical and radiological signs were not specific. Bronchial fibroscopy was essential for certain diagnosis, particularly in budding forms. Early treatment reduced the risk of complications. Based on our experience with these 21 cases, we propose a discussion of the pathogenic mechanisms involved and the diagnostic difficulties encountered as well as the disease course and risk of complications that can be expected.     

Volumetric rendering techniques: applications for three-dimensional imaging of the hip

Volumetric rendering is a new approach to three-dimensional (3D) imaging that overcomes many of the drawbacks of currently available surface-rendering systems. Its application on the Pixar Imaging System in two cases of acetabular fracture was assessed to illustrate the features of the technique. The fast-computing architecture and large memory of this system allow rapid generation of a series of high-quality 3D images in each plane of rotation (x or spinal axis, z or somersaulting axis) that can be viewed as independent static images or as an animated real-time video loop. Editing to remove the normal contralateral hemipelvis enhances appreciation of acetabular abnormalities. Every pixel of computed tomographic data is preserved, allowing representation of both soft tissue and bone as translucent overlap. The presentation of data also allows detection of subtle abnormalities and features and minimizes the artifact generation common in surface-rendered images.