Importance of measurement of spongious vertebral bone mineral density in the assessment of osteoporosis.

Quantitative computed tomography (QCT) measurements of bone mineral density, volume, and content were made of the spongious and compact portions of a vertebral body and of the total vertebral body in 19 osteoporotic patients (13 women and 6 men) and 20 normal (control) age- and sex-matched patients. Specifically, CT scans of 10mm thick transverse sections of L2 or L3 of each osteoporotic and control patient were subjected to QCT bone measurement with the use of K2HPO4 calibration for converting CT values into units (mg/ml) equivalent to bone mineral density. In every instance, a significant difference was found in the spongious vertebral bone mineral density (and content) between the osteoporotic and the paired normal groups. Even when the total vertebral bone mineral content was normal, the spongious vertebral bone mineral density was significantly less in the osteoporotic patients. Only in the osteoporotic men was a difference in compact bone density (and content) found; the osteoporotic men had a significantly lower compact bone mineral than did the normal male patients. This study shows that QCT can be applied to measurement of bone mineral density (and content) of both the anterior spongious and the more dense compact vertebral bone from a single section of a lumbar vertebra and that it is the anterior, spongious, vertebral bone rather than the compact vertebral bone that exhibits the more severe decrease in bone mineral density (and content) due to osteoporosis.

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 0.76) and dramatically increased after treatment (mean increase 16.4%; 7.7% with 95% confidence interval 2.2 to 12.2, excluding one patient whose spine BMD increased by 94.8%). In contrast, skeletal roentgenograms, computed tomographic scans, and magnetic resonance imaging did not reveal any significant improvement of patients' bone lesions. CONCLUSIONS: In patients with multiple myeloma, bone densitometry could be a useful way to assess the efficacy of treatment on bone status.

Effect of particle size on the tissue distribution of iodized emulsified fat following intravenous administration.

Three iodinated fat emulsions were tested by intravenous injection to rats: coarse with a mean size of particles of 7 micrometers, fine with a mean size of 1.3 micrometers, and ultrafine with a mean size of 0.7 micrometers. Iodine content analysis and scintigraphy of radioactive iodinated emulsions show important differences. Coarse emulsion is almost entirely fixed in the liver and the lungs; fine emulsion has a higher relative liver fixation; and ultrafine emulsion has a hepatosplenic fixation of short duration. Degradation of contrast medium is slow with coarse emulsion and very fast with ultrafine emulsion which is responsible for the rising iodine concentration in blood. Fine emulsion is a good compromise between excessive pulmonary fixation of coarse emulsion and high iodine peak in the blood after injections of ultrafine emulsion. The dose of 0.2 ml/kg of fine emulsion gives persistent enhancement of hepatic parenchyma without significant toxicity.

Changes in lipid and lipoprotein levels and Achilles tendon diameters and indices in familial hypercholesterolaemic patients with tendinous xanthomatosis treated by diet and bezafibrate for 2 years.

Thirteen young adult patients suffering from heterozygotic familial hypercholesterolaemia with tendinous xanthomatosis, previously treated with a suitable special diet, were studied to assess the effect of bezafibrate, given for 2 years at a dose of 800 mg/day, on plasma lipid and lipoprotein levels and on changes in size of the Achilles tendon xanthomas. Measurements were made before and at intervals during treatment, the tendinous xanthomas being measured by an echographic procedure to give data on antero-posterior and lateral diameters, thus enabling an Achilles tendon index to be defined. The results confirm the hypolipidaemic activity of bezafibrate, changes in the levels of total cholesterol, triglycerides, lipids and lipoproteins (LDL, VLDL and HDL) being similar in direction and magnitude to those reported previously. A significant regression in the size of the Achilles tendon xanthomas was observed in 11 of the 13 patients, and the regression in the Achilles tendon index correlated significantly with a favourable change in the ratio HDL/LDL + VLDL. It is suggested that, as a result of this objective observation, a favourable effect of bezafibrate treatment would possibly be seen on the anatomical atheromatous lesions which are usual in this type of hyperlipidaemia.

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. The lesions were multiple in four of the five patients and more numerous on MR images than on CT scans. The lesions (which demonstrate no parenchymal enhancement) are consistent with acute infarcts as confirmed at autopsy. In the large lesions, there is early intravascular and meningeal enhancement, as expected in acute infarcts involving an appreciable portion of the territory of a cerebral artery. CONCLUSION: The diagnosis of early cerebral infarction in a patient considered at risk for invasive aspergillosis, even without overt pulmonary disease, is an indication to institute aggressive antifungal therapy.

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. Six patients had primary tumours, of clinical stage T1 (n = 1) and T2 (n = 5). Three other patients had been previously treated and presented with a local recurrence of clinical stage T2. Surface-coil MRI was performed at 0.5 T with T1 weighted sequences before and after gadolinium-DOTA, and T2 weighted sequences. MRI results were compared with the clinical and surgical findings. T1 weighted sequences did not clearly demonstrate the margins of the tumours. T2 weighted sequences were the more useful in five patients, whereas contrast enhanced T1 weighted sequences allowed better delineation of the lesions in only three patients. Therefore, an imaging protocol should include spin echo T2 weighted sequences. Clinical examination correctly staged six of nine tumours; MRI, seven of nine tumours and the combination of both examinations, eight of nine tumours. MRI provided good evaluation of tumoral invasion into the penile shaft.

Observer variation in bone lesion detection in thoraco-abdominal visceral CT images.

This study measured missed bone diagnosis on CT performed for lymph nodes or visceral spread of cancers and lymphomas. A bone-expert reading was compared to that of visceral-cancer oriented observers. From 100 examinations, 65% of bone abnormalities were not described by current reporting of cancer cases. Changes in windowing and contrast of the image produced large variations in CT readings. A slow search with different windowing decreases the false-negative ratio. A fast reading with invariable viewing parameters increases false interpretations, even for experienced radiologists.

Radiation-induced lung injuries: a survey by computed tomography and pulmonary function tests in 18 cases of Hodgkin's disease.

Eighteen patients with Hodgkin's disease received chemotherapy and 40 Gy mantle-field irradiation. Radiation-induced lung injuries were studied 5 times during one year for each patient by chest x-ray, CT examination of the thorax and pulmonary function tests. Homogeneous and inhomogeneous densities developed within the radiations ports. They were more often and more easily detected by CT than by chest x-ray (39% vs 11% at the end of the irradiation). CT changes suggested that homogeneous lung density increase and lung nodules corresponded to the radiation pneumonitis phase, also that linear aspects and/or lung condensation aspects corresponded to irradiation-induced lung fibrosis. The displacement of the vessels and the fissures were seen more precisely by CT than by chest x-ray. There was a highly significant correlation between the number of modified areas and the increase in the coefficient of retraction (p less than 0.001).

New prospects in CT image processing via mathematical morphology.

New prospects are foreseen in CT image processing via mathematical morphology (M.M.). M.M. is a set theory based upon the concept of "structuring elements" and allows texture analysis and pattern recognition by performing sequences of neighborhood transformations. This results in a wide range of quantifications. Mathematical morphology applied to CT densitometry allows obtaining the mean density of an organ after its automatic extraction from the background. This operation eliminates the approximations due to the manual selection of the Region of Interest (ROI). Precision, reliability and reproducibility are therefore improved. In this study, we performed the automatic isolation of a sole vertebral body in thoracic or abdominal CT slices to quantify numerous parameters, among them, density of the vertebral trabecular and cortical bones. On scans of the second and third metacarpals, morphomathematical analysis allowed quantification of the parameters of bone evolution: mean cortical density, directional cortico-diaphyseal index, and medullar area. In a different connection, M.M. has allowed automatic segmentation of lung parenchyma, the measurement of its mean density and the determination of the relative importance of the vascular network.

Role of CT in the study of recurrences of Hodgkin's disease on the chest wall. Report on 12 cases.

Twelve cases of recurrences of Hodgkin's disease on the chest wall, associated with three breast lesions and three diaphragmatic lesions, were studied by computed tomography (CT). Although the chest radiographs of all the patients were abnormal, CT was more accurate than clinical and other radiological examinations in delineating the lesions of the chest wall and in studying the extension of the relapse. Muscle enlargement was present in all cases. In seven cases osseous lesions and in seven cases pleural effusion or subpleural plaques were found. Chest wall recurrences were associated with other thoracic or abdominal lesions in 75% of the cases. Recurrences to the chest wall occur late (mean 6.3 years) in the evolution of Hodgkin's disease. They developed during the first relapse in 67% of the cases and during the second to the fourth relapse in 33% of the cases. CT is useful for the screening of lesions for which the outcome is bad. Only in four cases patients were without any evidence of disease after treatment.

Experimental opacification of mediastinal lymph nodes by intraperitoneal injection of an iodinated fatty emulsion.

Absorption and lymphatic drainage of several lipiodol emulsions injected intraperitoneally have been studied in the rabbit and rat. Good opacification of the lymphatic channels and mediastinal lymph nodes is obtained in several hours with fine emulsions and in several days with coarse emulsions. The tolerance is related to dose, and the peritoneal reaction was moderate with the low doses, similar to that caused by the administration of physiologic saline alone. Computerized tomography in detecting low contrasts attained with small doses could render this method of indirect lymphography possible in man.

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). The efficiency of the proposed method is illustrated with the aid of both phantom and physical images. The impact of the inhomogeneity correction on brain tissue segmentation is studied in detail. The results show significant improvement of the tissue segmentation after inhomogeneity correction.

[NMR imaging of the normal wrist. Iconography]. / I.R.M. du poignet normal. Iconographie.

Results of NMR imaging of normal anatomy of wrist using a surface antenna are presented, this new technique providing serial sections, 5 mm thick, of the different carpal joints in 3 different planes. Quality of imaging of carpus showed NMR to be superior for exploration than standard radiography and even CT scan images. Investigation of tumors of wrist, osteonecrosis and compound fractures of this region (currently not simple) will be markedly facilitated by NMR imaging, allowing a precise diagnosis with complete details of possible extension to be established and appropriate therapy applied.

[Magnetic resonance imaging of the knee menisci. Normal aspects. Misleading images. Meniscus degeneration. Anatomic correlations]. / Imagerie par résonance magnétique des ménisques du genou. Aspects normaux. Images pièges. Dégénérescence méniscale. Corrélations anatomiques.

The authors report the result of a study on 5 knees of fresh corpses explored with magnetic resonance imaging, including 1 examined before and after intraarticular contrast injection, and on 15 asymptomatic subjects examined with the same procedure. A very thorough study of the menisci and of their attachment, ie. The tibial insertion of the menisceal horns, the transverse ligament, and the meniscofemoral ligament, is possible with T1-weighted MR sequences. The T2-weighted sequences, either following intraarticular contrast injection or in cases of articular effusion, allow analyzing the capsular attachments of the posterior horn of the lateral meniscus and its relationships with the tendon of the popliteal muscle. Five misleading images must be known for the exploration of the menisci, in order to avoid a number of interpretation problems. Images of type I and II initial meniscus degeneration are observed in 47% of all cases (control group). One case of menisceal cyst developing in the anterior horn of the lateral meniscus, with anatomical correlation, is also reported.

[Plate thermography in the evaluation of idiopathic carpal canal syndrome. Apropos of 32 cases]. / Apport de la thermographie en plaque dans l'évaluation du syndrome du canal carpien idiopathique. A propos de 32 observations.

During a period of eight months thirty-two cases (twenty-two unilateral and five bilateral) of idiopathic carpal tunnel syndrome were studied at the Saint-Louis Hospital, Paris, France. The patients were found to benefit from the use of the preoperative technique, thermography in addition to routine clinical exams and complementary exams such as radiographs and E.M.G. The period of intervention was from the fifteenth day through the second and thirds months. By comparing the clinical and functional results before and after surgical treatment through the use of images from patients in the same condition, it can be concluded that the use of this simple technique can provide valuable information and is harmless in the care of idiopathic carpal tunnel syndrome. It is demonstrated that thermography permits: the ability to foresee the action of treatment; the ability to survey the effects of treatment and therefore obtain a valuable prognosis; and finally, a method of deciding on other acrosyndromes.

[Recent modifications to remotely controlled tables employed in radiological diagnosis (author's transl)]. / L'évolution des tables télécommandées en radiodiagnostic.

Remotely controlled tables are still largely employed as diagnostic tools, but they have not evolved during the recent past when compared with computed tomography or ultrasonography. The most recent attempts at improvement have been the introduction of complex stands capable of numerous integrated movements, but very heavy and costly, and integrated development systems for the films. Current technological possibilities should permit very much greater progress. New high definition wide field amplifiers associated with high performance TV could suppress the directly exposed film and thus the selector. As with other systems employing a video image, a multi-image camera could be used. Acquisition of data in this way, combined with the use of visual treatment of this data, should considerably reduce patient irradiation. The introduction of the microcomputer and the lightening of stands (absence of the selector...) should simplify the obtaining of complex movements. These "revolutions" in the conception of remotely controlled tables are now possible, and all that remains is to evaluate possible improvements in diagnostic value and to assess the various economic implications.

[X-ray computed tomographic analysis of structural changes of the carpal bones, after section of the anterior annular ligament]. / Analyse tomodensitométrique des modifications structurales du carpe, après section du ligament annulaire antérieur.

Computed tomography analysis was conducted in 29 patients with 34 carpal canal syndromes to determine structural modifications of the wrist during the immediate preoperative period and two and three months after operation. The carpus was analyzed at 3 levels of the section: proximal at the entrance orifice of the canal, median and distal at the orifice of exit, with the wrist at rest and then in maximum active flexion and extension. Results showed that the increase of canal caliber (and therefore the decrease in local increase in pressure) continued during the second and third postoperative months, at rest as well as in flexion or extension. It appears, further, that opening of the canal does not alter structural organization of wrist bones or ligaments, the increases in caliber obtained varying in the same sense whatever the position of the wrist or the level of the section.

[Cystic lymphangioma of the abdomen in an adult. Contribution of echography and computed x-ray tomography. Apropos of a case]. / Lymphangiome kystique de l'abdomen chez un adulte. Apport de l'échographie et de la tomodensitométrie. A propos d'un cas.

Authors present a case of cystic lymphangioma of the abdomen in an adult patient. Pre-operative investigations are based on ultrasound and computed tomography since plain films, excretory urograms and barium enema are less helpful. Opportunity of such a diagnosis in adult is not frequent.

[Gas in a pyelic calculus (author's transl)]. / Présence de gaz dans un calcul pyélique.

An original case of a gas-containing pyelic calculus is described. This phenomenon in a radiolucent calculus spontaneously visible by computed tomography is attributed to the fissuration of a crystallin calculus. The hypothesis is emitted that, like gallstones, the apparition of gas is a fissuration that may precede the spontaneous disappearance of the calculus.