Hip fracture risk and proximal femur geometry from DXA scans.

In this retrospective study of hip fracture risk evaluation from hip dual-energy X-ray absorptiometry (DXA) scans, our objectives were to determine which part of the femoral neck length contributes most to the fracture risk and to define a geometric parameter better than hip axis length (HAL) for discriminating hip fracture patients. Forty-nine Caucasian women with a nontraumatic femoral neck fracture were matched on age to 49 normal women and on both age and femoral neck bone mineral density (BMD) to 49 unfractured women. In addition to BMD, geometric parameters including neck-shaft angle, neck width and several HAL segments were evaluated by discriminant analysis to determine which was the best hip fracture discriminator.

A method of radio-frequency inhomogeneity correction for brain tissue segmentation in MRI.

An automatic method of correcting radio-frequency (RF) inhomogeneity in magnetic resonance images is presented. The method considers that image intensity variation due to radio-frequency inhomogeneity contains not only low frequency components, but also high frequency components. The variation is regarded as a multiplication of low frequency (capacity variation of coil) and the frequency of object (true image).

[Digital radiography of the thorax].

Digital radiography of the thorax can, now be substituted to conventional chest radiography. Computed radiography with phosphor plates and the new selenium detector are emphasized. The major image processing are explained.

[Cervico-mediastinal recurrences of differentiated thyroid cancers: value of MRI].

Aim: The aim of this study was to evaluate the ability of MRI to detect recurrent differentiated thyroid carcinomas developed in the neck or the upper mediastinum.

Results: MRI was performed in 25 patients, and was compared in 5 cases with surgery. In 20 cases it was compared with I-131 scintigraphy (100 mCi in 14 cases and 5 mCi in 6 cases).

Evolution of bone densitometry in patients with myeloma treated with conventional or intensive therapy.

Background: Demineralization is a common hallmark of multiple myeloma (MM) that can be evaluated by dual-energy X-ray absorptiometry (DEXA). The evolution of lumbar and whole body bone density were investigated by DEXA in patients with MM treated by conventional or intensive therapy supported by autologous blood stem cell transplantation.

Methods: Sixty six patients younger than 66 years with MM were randomly assigned to either conventional (30 patients, Group A) or intensive therapy supported by autologous blood stem cell transplantation (36 patients, Group B).

Magnetic resonance imaging in patients with penile carcinoma.

The aim of the study was to determine the role of pre-operative magnetic resonance imaging (MRI), with and without contrast enhancement, in patients with penile carcinoma. Nine patients with a penile cancer were studied. The staging of the tumours was performed by clinical examination, MRI and surgery, according to the TNM classification.

Imaging of choroid plexus infection by Stomatococcus mucilaginosus in neutropenic patients.

We report two neutropenic patients with Stomatococcus mucilaginosus meningitis and choroid plexus involvement on neuroimaging studies. CT and MR showed abnormal enlargement of the choroid plexus in one lateral ventricle and intense enhancement. In one patient there was edema in the periventricular white matter adjacent to the involved choroid plexus; in both patients there was enhancement of the ependyma.

MR of cerebral aspergillosis in patients who have had bone marrow transplantation.

Purpose: To assess the CT and MR appearance of cerebral aspergillosis in patients who have undergone bone marrow transplantation.

Methods: The imaging and clinical data of five patients with cerebral aspergillosis were reviewed retrospectively and compared with autopsy findings.

Results: Lesions are often located in the basal ganglia and demonstrate an intermediate signal intensity within surrounding high-signal areas on long-repetition-time MR scans.

CT and MR patterns of spinal involvement in Richter syndrome.

Richter syndrome is the transformation of chronic lymphocytic leukemia (CLL) into large cell lymphoma. Besides the involvement of lymph nodes, liver, and spleen, bone lesions occur infrequently. We report one case of a patient with a paraspinous mass and destruction of the vertebra by large cell transformation of CLL seen on CT and MRI.

Dual-energy X-ray absorptiometry of the calcaneus: comparison with vertebral dual-energy X-ray absorptiometry and quantitative computed tomography.

The purpose of this study was to determine the efficacy of using bone mineral measurements of the calcaneus to evaluate osteoporosis. Dual energy X-ray absorptiometry (DXA) of the calcaneus was compared with posteroanterior lumbar absorptiometry (DXA) and vertebral quantitative computed tomography (QCT) measurements in 171 white women (78 normal and 93 osteoporotic). DXA measurement of os calcis mineralization decreased significantly in osteoporosis, but to a lesser extent than in vertebral sites.

[Radiological aspects of invasive aspergillosis].

Invasive aspergillosis is a life-threatening illness, whose diagnosis is difficult: clinical signs are indeed not specific, and biological and mycological exams are not always conclusive. Radiological exams are essential for the diagnosis of this disease allowing to start an early intensive appropriate therapy. According to the literature and to their own experience the authors report the main radiological patterns with emphasis on the pulmonary and cerebral affections.

Ultrasound attenuation imaging in the os calcis: an improved method.

A complete assessment of the broadband ultrasonic attenuation (BUA) distribution within the os calcis was made using an ultrasonic mechanical scanning device with focused transducers. Measurements were performed on 12 os calces removed from fresh female cadavers. We present the first images of BUA of the os calcis.

[Radiography of the thorax with phospholuminescent screens].

Image digitalization can be performed in several ways: equalization of the x-ray beam (Scanning Equalization Radiography and Advanced Multiple-Beam Equalization Radiography), digital fluorography, use of linear computed tomography detectors, digitalization of radiographic films and memory screens. Phospholuminescent screens use an x-ray receptor which is able to store the x-ray energy. This latent energy is then extracted and can be processed to obtain images with matrices ranging between 1,760 x 2,140 and 1,770 x 2,370.

[Contribution of medical imaging. What examinations for what indications?].

Osteoporosis is an obvious diagnosis in patients with fractures due to decreased bone mass. However, in many cases, major bone loss is infraclinical and requires quantification. Two methods are available to achieve this, i.

[Measurement of vertebral bone density. Quantitative tomodensitometry or dual-photon absorptiometry?].

We have compared vertebral bone density measurements (QCT and DXA) in women in the postmenopausal period who underwent both examinations. Our aim was to study the results and to define the respective indications of QCT and DXA in various clinical pictures of osteoporosis. The subjects of the study were distributed into various groups according to the presence or absence of vertebral collapse and/or peripheral fractures.

Bone densitometry in patients with multiple myeloma.

Purpose, Patients, And Methods: We performed dual-energy x-ray absorptiometry in 10 selected patients with aggressive multiple myeloma in whom substantial tumor mass reduction was achieved after high-dose chemoradiotherapy followed by autologous blood stem cell transplantation.

Results: In most cases, bone mineral density (BMD) of the spine was initially low (Mean Z score: -2.69, SEM 0.

CT image analysis of the vertebral trabecular network in vivo.

A method of computed tomography (CT) image analysis of lumbar vertebrae has been developed, providing a visualization of the trabecular network as it is represented in a 1.5 mm-thick CT image. We measured the length of the network and the number of discontinuities found in the image.

MR imaging of breast hemangioma in female infants.

Breast hemangioma in female infants is a rare benign lesion, prone to spontaneous regression. But when the lesion regresses there is a risk of breast atrophy if the breast bud is included in or very close to the hemangioma. A trial of corticosteroid therapy could be proposed to prevent this risk, but one must be sure that the breast bud is included in or very close to the hemangioma before treatment.

[Bone density in idiopathic hypercalciuria in men. Study by dual photon absorptiometry, X-ray computed tomography and histomorphometry].

Lumbar bone mineral density (BMD) of the L3 vertebra was evaluated by double photon absorptiometry or tomodensitometry (TDM) in 55 hypercalciuric individuals in two separate studies. In the first, in a department of nephrology, 29 lithiasis patients were studied by TDM of L3. By this technique, trabecular density was 75 +/- 23% of normal.