Role of computerized tomography in the diagnosis of bone disease in multiple myeloma

PURPOSE: To assess the role of CT in the diagnosis and management of multiple myeloma (MM) and to investigate if CT findings can influence the clinical approach, prognosis and treatment. STUDY DESIGN AND PATIENTS: We reviewed the findings relative to 273 MM patients submitted to CT June, 1994, to December, 1996. The patients were 143 men and 130 women (mean age: 65 years): 143 were stage I, 38 stage II and 92 stage III according to Durie and Salmon's clinical classification. All patients were submitted to blood tests, spinal radiography and CT, the latter with serial 5-mm scans on several vertebral bodies. The CT unit was a Philips Tomoscan SR 7000. RESULTS: CT showed lysis foci in some vertebral bodies (4 cases) where conventional radiography had shown only aspecific osteopenia. CT also depicted vertebral arch and process involvement in 3 cases with the vertebral pedicle sign. Moreover, CT proved superior to radiography in showing the spread of myelomatous masses into the soft tissues in a case with solitary permeative lesion in the left pubic bone, which facilitated subsequent biopsy. As for extraosseous localizations, CT demonstrated thoracic soft tissue (1 woman) and pelvic (1 man) involvement by myelomatous masses penetrating into surrounding tissues. In our series, only a case of osteosclerotic bone myeloma was observed in the pelvis, associated with lytic abnormalities. DISCUSSION AND CONCLUSIONS: The role of CT in the diagnosis and management of MM has not been assessed, because this technique demonstrates tumor extent more accurately than radiography but CT findings do not seem to improve the clinical approach and therapeutic management of the disease. Nevertheless, we recommend CT for some myelomatous conditions, namely: a) in the patients with focal bone pain but normal skeletal radiographs; b) in the patients with M protein, bone marrow plasmocytosis and back pain, but with an inconclusive MM diagnosis; c) to assess bone spread in the regions which are anatomically complex or difficult to study with radiography and to depict soft tissue involvement; d) for bone biopsy.     

Electroencephalography and computerized transaxial tomography in epilepsy diagnosis

Over a 6-month period 89 patients with epileptic seizures were systematically examined by EEGs and CT. Forty-two percent of all cases showed pathological findings in CT compared to 89% with abnormal EEGs. CT is very useful in identifying organic lesions in the epileptic patient. CT identified 11 cases of supratentorial tumour which were correctly localized by EEG. In patients with seizures after trauma or encephalitis the EEG abnormalities were more than could be detected by CT. The EEG and CT findings in cerebrovascular disorders, alcoholism and other diseases are discussed. A remarkable result is the relatively high percentage of hydrocephalus (23%) in the group of cryptogenic epilepsy. Positive EEG findings as to epilepsy could be seen in 62% of the cases.     

Relationship of computerized axial tomography in the diagnosis and staging of bladder tumors

The authors report four observations of actinomycotic brain abcess. One patient with multiple hemispheric abcesses and with stomatologic and pulmonary lesions, one with seemingly primary cerebellar abcess, one with associated hemispheric abcess associated with pneumopathy. About these four cases, they discuss the role of actinomycosis in infectious diseases of the central nervous system, and the elements necessary for the diagnosis. The neurological syndrom is not specific, but the discovery of visceral lesions is an excellent argument. From the histological point of view, the discovery of "granules" containing the bacteria conforms the diagnosis by special colorations. From the bacteriological point of view, the isolation of the germ is easy but its specific identification necessitates special techniques. The diagnosis of actinomycosis is indispensible to begin a correct treatment. For the authors, this treatment must associate surgical excision of the most extensive lesions and adapted antibiotherapy for more than four months.     

Optimization and diagnostic accuracy of computerized tomography with tridimensional spiral technique in the study of craniostenosis

INTRODUCTION: Conventional Computed Tomography (CT) with three-dimensional (3D) reconstructions is considered the most complete and accurate imaging modality to diagnose craniosynostosis. However, the introduction of Spiral CT (SCT) opened new possibilities for 3D studies of the skull in pediatric patients with craniosynostosis. The purpose of our study is two fold: first, to optimize the scanning and imaging parameters to obtain diagnostic images in a single spiral scan; second, to assess the diagnostic accuracy of such images in the identification of normal and abnormal cranial vault sutures. MATERIAL AND METHODS: Seventy-eight pediatric patients (age range: 1-35 months; mean: 11.8 months) with craniosynostosis were submitted to SCT of the head. The images were acquired with the following parameters: 3- and 5-mm nominal slice thickness, 5-6 mm/s table feed (pitch 1-2), 165 mAs and 120 kV. Two different algorithms and increases were used for image reconstructions. A first set of images was reconstructed with 2-mm increases and a soft tissue algorithm: these images were used for brain studies and for 3D reconstructions. A second set of slices was reconstructed with 5-mm increases and a bone algorithm to visualize the sutures of the axial plane. The 3D images were processed with the Shaded Surface Display software with threshold values ranging 120-150 HU. All images were acquired with a single spiral scan lasting less than 30 seconds. Two blinded radiologists analyzed the 3D and the planar images independently to evaluate the course and depth of each cranial suture. The sensitivity, specificity and diagnostic accuracy of both 3D and planar SCT images were evaluated. The frequency of artifacts (the Lego effect, boiled egg, pseudoforamina, movement, and chainsaw artifacts) and their influence on the final diagnosis were studied on 3D SCT images. RESULTS: The diagnostic accuracy rates of 3D SCT images, by suture, were: sagittal 90.7%, metopic 100%, left lamboid 90.9%, right lamboid 93.9%, left coronal 85.7%, right coronal 91.1%. The diagnostic accuracy rates of the axial images, by suture, were: sagittal 90.7%, metopic 95.5%, left lamboid 86.4%, right lamboid 90.9%, left coronal 83.7%, right coronal 91.1%. The interobserver agreement on 3D images was: sagittal 91.1%, metopic 100%, left lamboid 88.9%, right lamboid 91.1%, left coronal 88.9%, right coronal 84.4%. The Lego effect artifact was the most frequent one (82%) and affected image evaluation in 6.3% of cases. CONCLUSIONS: Our results prove that 3D SCT is a very accurate technique for identifying normal and abnormal sutures and presents many advantages over conventional 3D CT in the examination of pediatric patients with craniosynostosis. The quality of 3D SCT images was adequate and the artifacts did not affect the final diagnostic yield significantly.     

Acromio-humeral distance and acromial shape in 3-dimensional computerized tomography reconstruction. Side comparison in supraspinatus outlet syndrome

Mechanical irritations of the supraspinatus tendon due to a reduction of the subacromial space are considered to be a potential cause of supraspinatus outlet syndrome. The aim of the current study was, therefore, to provide a method of improved measurement of the acromiohumeral distance and the evaluation of the acromial shape. In seven patients aged 50-60 years with unilateral supraspinatus outlet syndrome, imaging with standardized, high-resolution computed tomography (CT) was performed in order to demonstrate the acromion and the subacromial space three-dimensionally. The acromiohumeral distance was measured in three reconstructed frontal sections, and the two sides of each patient were directly compared. The acromial shape was compared with the classification of Bigliani as derived from conventional radiography. Whereas the Constant Score was found to be significantly reduced in the diseased shoulders (p < 0.01), the acromiohumeral distance was not significantly lower in three standardized frontal sections. In five cases the classification of the acromial form from the conventional radiograph was confirmed by 3D CT, whereas in two cases it was shown to be different. Our results suggest that primary or secondary changes of the acromial form can be more accurately evaluated with 3D CT than with conventional radiography. A direct comparison of the two sides in patients with supraspinatus syndrome does not suggest a reduction of acromiohumeral distance in the diseased shoulder.     

Dynamic computerized tomography of the bone marrow of normal and pathologic vertebrae]

We have analyzed 59 unrelated Mexican Duchenne/Becker muscular dystrophy patients (DMD/BMD) using PCR analysis of the 2 prone deletion regions in the DMD gene. Thirty one (52%) of the patients had a deletion of one or several of the exons. Most of the alterations (87%) were clustered in exons 44-52, this being the highest percentage reported until now. In order to improve the molecular diagnosis in the Mexican population, we designed a new multiplex assay to PCR amplify exons 44-52. This assay allowed for the identification of a greater number of deletions in this region compared with the 9 and 5-plex assays previously described and to determine most of the deletion end boundaries. This is a reliable alternative for the initial screening of the DMD patients in the Mexican population.     

Usefulness of computerized tomography in the study of pleural effusion with no presumed diagnosis

To establish the diagnostic yield of computerized tomography (CT) in pleural effusions with no presumed diagnosis arising from standard clinical examination. A prospective protocol study enrolling all cases of effusion admitted to our hospital between January 1994 through July 1995 without a presumed diagnosis after initial testing that included thoracocentesis. Twenty-two patients were enrolled. All were given a CT scan as well as other complementary examinations considered appropriate and were referred to our outpatient clinic for follow-up. The CT images were read by an expert radiologist and their contribution was classified as "diagnostic", "suggestive" or "nil". A definitive etiologic diagnosis was achieved in 14 cases (8 neoplasms, 4 benign due to asbestos, 1 tuberculosis and 1 pulmonary embolism). The CT contribution was nil in 13 cases (59%), "diagnostic" in 6 (2 mesotheliomas, 1 hypernephroma, 1 lymphoma, 1 adenocarcinoma of the colon and another of the ovary) and "suggestive" in 3 (2 benign due to asbestos and 1 lymphoma). Positive information was obtained in 9 cases (41%). CT gives good yield in the investigation of pleural effusions with no presumed diagnosis and should be made available to this group of patients before other more invasive procedures are resorted to. It is especially useful for detecting neoplastic disease of the upper abdomen, mesothelioma and sings of unsuspected exposure to asbestos.     

Value of B-image ultrasound in diagnosis of paranasal sinus diseases in comparison with computerized tomography

BACKGROUND: In diagnostic imaging of the paranasal sinuses, the A-mode technique is increasingly being substituted by B-mode ultrasonography. To assess the value of B-mode sonography we compared in a double-blind study computed tomography with our ultrasound findings. PATIENTS AND METHODS: Seventy-eight patients were examined by CT and subsequently by ultrasound, two-thirds before endonasal surgery and one-third for diagnosis of serious facial pain and swelling. RESULTS: Among 114 pathological maxillary sinus tomograms, 83 findings could also be diagnosed by ultrasound (sensitivity 72.8%). In the frontal sinuses only 12 of 52 of pathological findings could be detected (23.1%) and only 9 of 80 in the frontal ethmoid (11.3%). Except for circumscribed polyps and moderate general swelling of the mucosa, the detection rate by sonography was 97.4% for the maxillary sinuses, 31.5% for the frontal and 18% for the ethmoid sinuses. CONCLUSIONS: Ultrasound usually only demonstrates the presence of absence or unspecific findings. Differential diagnosis between tumors and sinusitis is generally difficult. The healthy individual is correctly assessed as healthy due to the total reflection of the air-filled healthy sinus. According to our findings ultrasound has a certain value in the diagnosis of maxillary sinuses. It can be used to obtain a preliminary diagnosis and as a screening method although a negative result never excludes a disease of the sinuses. As it does not involve radiation exposure, ultrasonography can be recommended as first step in diagnosis for children, pregnant women, and young women especially in acute sinusitis, because in acute sinusitis the maxillary sinuses are generally affected.     

Role of computerized axial tomography in diagnosis and treatment of common neurosurgical problems of infancy and childhood

Computerized axial tomography (CAT) is a new, highly accurate technique for studying the skull and intracranial contents. It is rapid enough to be utilized in acute emergencies and safe enough to be utilized for routine serial followups and evaluation of outpatients with equivocal findings. Because CAT can delineate the ventricular system without need for contrast agent, can distinguish clearly between hematoma and edema and can differentiate cystic from solid tumors, it finds wide application in the evaluation of neurological disease.     

A data reduction scheme for improving the accuracy of oxygen saturation calculations from spectrometric in vivo measurements

A developing tool in ophthalmological research and practice is the study of the oxygen saturation in retinal vessels because this measurement contains important diagnostic information about the metabolism at the human ocular fundus. Imaging spectrometry enables locally resolved measurements of the oxygen saturation simultaneously in arteries and veins. The vessel reflex, imaging errors of the detection system and the noise of the signal result in substantial uncertainties in the calculated data. We present a data processing method for the improvement of the primary information leading to a reduction of the uncertainties of the derived oxygen saturation.     

Diagnostic imaging of Tietze's syndrome. Comparison of computerized tomography and ultrasonography

Tietze's syndrome is an uncommon disease characterized by the absence of any systemic symptom; imaging techniques play a major role in the diagnosis of this condition. A control group including 10 normal subjects and 4 patients with clinical evidence of Tietze's syndrome were submitted to US; 3/4 patients underwent CT too. In the lesion site, US demonstrated thickened cartilage and inhomogeneously increased echogenicity in 4 patients, blurred outline in 3 patients and a hypoechoic halo in 1 patient. CT showed thickened cartilage and blurred outline in 3 patients and hypodense cartilage in 1 patient. Both methods were very useful to diagnose the disease in all cases. The authors conclude that US plays a major role in the diagnosis of Tietze's syndrome thanks to its harmlessness, repeatability and cost-effectiveness.     

Structural brain changes in the computerized tomography of schizophrenic patients

VBR was higher and the cortical atrophy more frequent in the schizophrenic patients as compared to the control group. VBR correlated negatively with SANS and PANSS (negative) scores, especially with alogia and inattention, it also correlated positively with female sex. Positive intercorrelations were found between VBR and other ratios concerning lateral ventricles and no correlations were found between them and cortical atrophy.     

Precision and accuracy of total body bone mass and body composition measurements in the rat using x-ray-based dual photon absorptiometry

Lean body mass (LBM), total body bone mineral mass (BMC), total body bone areal density (BMD), and body fat mass (FM) were measured in rats by dual photon absorptiometry (DXA), using two different instruments. The coefficients of variation for repeated measurements of LBM and FM were about 0.4 and 2.5%, respectively, over an animal body weight range of 150 to 600 g. For BMC and BMD, the coefficients of variation were less than 2%. The correlation coefficients for LBM, FM, BMC, and BMD measured on the two densitometers were all greater than 0.94. The slope of the regression line relating LBM measured by DXA and LBM measured by carcass analysis was 0.999, and the correlation coefficient was 0.99. For FM the slope was 1.05, and the correlation coefficient was 0.98. BMC measures by DXA were falsely low in small animals. For larger animals, the correlation between BMC and ash weight was 0.93, but the slope of the regression line was 0.78. DXA measures of LBM and FM were accurate and reproducible for rats weighing between 150 and 600 g. There was a size-dependent error in BMC, which will be significant in longitudinal measurements of bone mass.     

Accuracy of cortical and trabecular bone measurements with peripheral quantitative computed tomography (pQCT)

In order to assess the accuracy of peripheral QCT (Stratec XCT 960) we analysed scans of the European Forearm Phantom and another phantom consisting of K2HPO4 encased in aluminium tubes to simulate cortical walls. Additionally 14 cadaveric forearm specimen scans were compared to CT scans acquired on a GE9800Q. The accuracy for density assessment of the European Forearm Phantom was better than 3%. A small increase in density was observed with increasing thickness of the aluminium wall (10% for each mm). Density measurements within the wall were confounded by limited spatial resolution. For a thickness of less than 4 mm, the density within the wall was underestimated by up to 40%. The measurement of mineral content was not influenced by this effect and showed an accuracy error of less than 6%. The agreement of density measurements on the different CT systems was very strong (R2 > 0.96; RMSE < 6.2%). Our findings suggest that the Stratec pQCT scanner very accurately measures volumetric trabecular and total bone mineral densities at the distal radius while the assessment of cortical density is associated with considerable inaccuracies due to limited spatial resolution.     

Peritoneal splenosis. Apropos of a case: contribution of ultrasonography and computerized tomography

The authors report a case of peritoneal splenosis: the initial diagnosis was established at ultrasound examination and CT scan. This unusual lesion must be suggested when the past history is significant, as asymptomatic should not be removed.     

The significance of computerized tomography in the conservative treatment of liver injuries

Increasing experience with early radiological evaluation by ultrasound (US) and computed tomography (CT) of patients with abdominal trauma is leading to more frequent use of conservative treatment in patients with severe liver injuries. In a retrospective study with predominant use of peritoneal lavage only 3 out of 100 patients with liver injuries were treated non-surgically. In a consecutive prospectively evaluated series of 75 patients with early use of US and CT, 30 patients in stable circulatory conditions were treated non-surgically. With increasing experience a higher percentage of patients, even with severe liver injuries, could be treated non-operatively. 17 patients with minor injuries (grade I and II, modified according to Moore) and 13 patients with severe injuries (grade III and IV) could be treated non-surgically. 2 patients with grade IV injury developed an arterial/portal-venous fistula and an arterial aneurysm which necessitated radiological embolizations. All conservatively treated patients have been followed up for a mean period of 18 months without complications. Although a precise anatomical classification of the liver injury degree seems difficult, the predictive value of computed tomography for non-surgical treatment was good. Use of i.v.-contrast is mandatory. We conclude that in experienced hands computed tomography allows precise evaluation of liver injuries for adequate treatment, provided careful follow-up (intensive care unit, CT, angiography) ensues to avoid complications.     

Comparisons of pulmonary and sinonasal lesions in patients with cystic fibrosis. Evaluation using computerized tomography

INTRODUCTION: Cystic fibrosis is a recessive genetic systemic exocrinopathy caused by a variety of mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). The disease is characterized by alterations of the secretions, which become thickened and viscous. Both the paranasal sinuses and the lung parenchyma are involved in all cases. The aim of this study was to assess a correlation between the rhinosinusal and lung parenchyma changes in cystic fibrosis patients. MATERIAL AND METHODS: Eighteen patients (11 men and 7 women, age range: 8 to 22 years) were examined with chest HRCT and sinonasal low dose CT. Lung symptoms were found in all patients; 13 of them, also affected with rhinosinusal symptoms, had been examined with ENT and nasal endoscopy. The other 5 patients, without rhinosinusal symptoms and previously examined with ENT, were evaluated as control group. Chest CT was performed with the high-resolution technique, 2 mm slice thickness and 10 mm table feed. Rhinosinusal CT was performed with the low dose technique, acquiring contiguous 2-4 mm thickness coronal sections. The CT patterns were analyzed by two radiologists and scored as slight, medium and diffuse involvement of both districts. RESULTS: No statistically significant correlation between lung and sinonasal damage was found in our study. Parenchymal lung involvement appeared more severe than sinonasal involvement in 14/18 patients. The retention of secretions in the paranasal sinuses, even if limited, was demonstrated in all symptomatic and asymptomatic patients. CONCLUSIONS: The absence of correlation between pulmonary and sinonasal damage and more generally, the different severity of cystic fibrosis can be caused by different allele mutations of the cystic fibrosis transmembrane conductance regulator gene, the most frequent of which is Delta F-508.     

Usefulness of ultrasonography and computerized tomography in predicting resectability of pancreatic carcinoma

BACKGROUND: Surgical resection is the only curative treatment of pancreatic carcinoma (PC). An accurate assessment of the extension of PC is mandatory to select appropriate patients to this therapeutic option. This study was aimed at assessing the usefulness of abdominal ultrasonography (US) and computed tomography (CT) to establish tumoral staging and to predict tumor resectability. PATIENTS AND METHODS: Between January 1990 and December 1995, 84 PC patients were submitted to surgical procedures (potentially curative resection in 30%, biliodigestive anastomosis in 51% and exploratory laparotomy in 13%). Preoperative staging was carried out by means of abdominal US and/or CT. Definitive staging was established according to surgical findings, using the TNM classification. RESULTS: Accuracy of preoperative evaluation with regard to tumoral staging was 65%, being underestimated in 29 (35%) patients. This underestimation was mainly due to lesions in stage I. In addition, preoperative staging predicted tumor unresectability with a 50% sensitivity and a 83% specificity. CONCLUSIONS: US and CT have a good specificity in the staging and unresectability prediction of pancreatic cancer. However, their usefulness is limited by their low sensitivity.     

Measurement of the absorbed dose to the patient by computerized whole-body x-ray tomography with the aid of thermoluminescence dosimeters in an Alderson-phantom (author's transl)

Radiation dosis for brain, lung, liver, and kidney examinations which were performed with computerized wholebody scanner (Ohio-Nuclear, 120 KV, 30 mA) was measured by LiF-TLD in the Alderson-Phantom. The absorbed skin dosis to the trunk by a single scan (filtration 6 mm A1) was found to be 1.2 rd at the entrance and 90 mrd at the exit. Patient investigations were simulated with a series of 5 scans. Under those conditions the maximum abdominal entrance dosis is 1.8 rd, at the body axis 700 mrd and near the exit 250 mrd. In this example the dosis to the gonads is less than 2 and 4 mrd, if the distance is more than 15 cm between the last scan and the gonads. Scattered radiation in the Delta-Scan room during an investigation is 1.5 mR/scan and 0.3 mR/scan for a distance of 1 m and 2 m from the irradiated volume.