Spiral (helical) computer tomography

The introduction of spiral (helical) computed tomography (CT) has revolutionized the way established body CT examination are performed and has created new examinations as CT angiography. The production of overlapping images from single short X-ray exposure, the minimization of motion artefact and the suppression of respiratory misregistration have all improved performance of routine CT examinations. These same technical advantages have also led to the development of new applications. With advanced 3-D postprocessing applications, simulated endoscopy is made possible permitting the radiologist the view anatomy from within any lumen or anatomic space within the body.     

High-resolution computer tomography of diffuse infiltrative lung diseases

During a period of 17 months, a total of 101 patients were examined by high resolution computed tomography (HRCT) whose minor focal changes revealed by chest X-ray raised the suspicion of diffuse infiltrative pulmonary disease. The disease of the interstitium was primarily caused by idiopathic pulmonary fibrosis (19%), autoimmune disease (18%), Boeck sarcoidosis (18%) as well as by specific (16%) and aspecific inflammation (12%). HRCT disclosed reticular (61%), nodular (55%), ground-glass opacity-like (48%), emphysematous (33%) and ring-like changes (17%). Also transbronchial excision was performed in 51 patients the results of which were compared to the changes observed during HRCT. Concerning fibrosis and inflammation, HRCT and histological analysis showed identical results in 70%. According to the authors observations, this technique is suitable for detection of fairly fine fibrotic, empysematous and inflammatory signs and for defining the activity of the individual disease as also for the selection of the optimal site of transbronchial excision. HRCT is a useful investigative method both for diagnosing diffuse infiltrative pulmonary disease as well as in following up the effectiveness of treatment.     

Single-photon emission-computed tomography in the diagnosis of cerebrovascular diseases

BACKGROUND: SPECT-HM-PAO allows to detect the regional cerebral blood flow and total diminution of the brain perfusion still before morphological substrate evolution in CT scan, without invasive technologies. SEARCH GOAL: The authors have analyzed data obtained by SPECT-99mTc HM-PAO in the group of 46 patients suffering from cerebrovascular disorders and they have compared them with results aimed by CT scans. Both, the SPECT-99mTc HM-PAO and CT scan were performed within 48 hours or later after the onset of the stroke; some of CT scans were repeatedly performed. RESULTS: They discovered 40 positive and 6 negative SPECT-HM-PAO findings, 26 positive and 20 negative CT scans. SPECT investigation more frequently discovers circulatory failures in the clinically altered hemisphere than the CT scan does in a substrate; SPECT discloses hypoperfusion of the clinically unaltered hemisphere if silent hypoperfusion is present. The ipsilateral foci of CT substrates were significantly less frequently observed (p < 0.001) than some ipsilateral regional hypoperfusions. Not only the number, but also size and extent of hypoperfusional foci searched by SPECT are significantly higher and wider than the numbers and dimensions of substrates observed by CT (p < 0.001). CONCLUSION: CT scan diagnostic possibilities are restricted by the time factor (CT examinations performed within 48 hours since the onset of the stroke are significantly less frequently positive than those performed later-p < 0.001). SPECT examination has not such a limiting time factor (p > 0.05). MEANING: Hence SPECT-HM-PAO renders early, long lasting and wide information on the restriction of the overall and regional perfusion, independently of the fact as to whether the reduction of cerebral perfusion is, or is not going to result in ischemic necrosis and/or ischemic sclerosis. SPECT renders correlation of the perfusion disorder earlier, wider in space, and more frequently than the CT scan, and therefore it is a prerequisite to the disclosure of the mentioned silent focal blood flow reductions. (Graph 12, Fig. 3, Ref. 4.)     

Radioisotope diagnosis in lung diseases]

Following immunization against sheep erythrozytes, it is possible to induce a double-peaked antibody response curve in the serum of experimental animals (rats) by using vincristine sulfate (Vi). Immunosuppression is enhanced in thymectomised and sensitised animals during rechallenge following Vi/Cy, as compared to animals treated with cyclophosphamide (Cy) alone, and an attentuated anamnestic reaction is subsequently observed. Survival time of allogeneic skin grafts in colony bred and inbred rat strains could not be prolonged by using Vi/Cy, as compared to animals treated with Cy alone.     

Radiation diagnosis of spleen diseases]

The paper discusses the present-day radiation diagnosis of renal bulky formations: tumors and cysts. Based on the study of a great body of clinical data on 708 patients, the authors showed the potentialities of routine X-ray and currently available radiation techniques in the diagnosis of benign and malignant tumors and cysts of the kidney. Based on the data available in the literature and their own findings, the authors concluded that at the earliest stages of their preclinical development, tumors can be today diagnosed by a complete package of up-to-date diagnostic tools. Ultrasonic and computerized tomographies are of the highest informative value in diagnosing tumors and cystic formations. However, in some cases, a diagnosis is made via a routine excretory urography, angiography and needle biopsy. Excretory urography is of limited value for the diagnosis of renal bulky formations and it is used as an auxiliary mainly when a pathological process takes place in the renal hilus area. Angiography retains its significance as a supplementary technique. In the vast majority of cases, an accurate nosological diagnosis can be made on the basis of evaluation of the pattern of blood supply (the presence of abnormal vessels and their topographic features). The paper details the semiotics of a wide range of renal bulky processes by applying all currently available techniques of radiation diagnosis.     

Magnetic resonance tomography in diagnosis of cardiac space-occupying lesions]

The ability to assess viability of tissues by monitoring changes in oxygenation and perfusion during harvesting and following transfer of free and pedicled flaps is potentially important in reconstructive surgery. Rapid detection of a critical change in tissue oxygenation could enable earlier and more successful surgical intervention when such problems arise. In this study near infra-red spectroscopy (NIRS) was used to assess changes in tissue oxygenation, haemoglobin oxygenation and blood volume in a porcine prefabricated myocutaneous flap model in response to pedicle manipulations. As far as we are aware this is the first usage of a NIRS instrument to assess changes in oxygenation in a flap model which closely simulates the clinical situation. A myocutaneous flap was raised (n = 9 pigs), tubed and the flap circulation allowed to readjust for periods between 7 and 9 days. The pedicle vessels were then subjected to arterial (n = 9), venous (n = 12) and total occlusion (n = 6). Repeatable and reproducible patterns of change were measured in each case. Comparison of mean values indicated that the differences between arterial and venous, and venous and total occlusions were significant for all NIRS parameters. The monitor was easily able to detect two additional features: (i) the presence of venous congestion indicated by raised levels of deoxygenated haemoglobin and an increase in blood volume; and (ii) the presence and magnitude of reactive hyperaemia. In two flaps release of arterial or total occlusion did not result in the expected reactive hyperaemia associated with an increase in blood volume (oxygenated haemoglobin) suggestive of possible damage to the vascular bed. NIRS proved able to detect and distinguish between microcirculatory changes occurring as a result of arterial, venous or total vascular occlusion. We believe that NIRS provides a sensitive and reliable postoperative monitor of tissue viability following transfer of free and pedicled flaps. It can accurately identify different types of problems with the pedicle vessels. In addition its predictive capabilities would allow assessment of flaps buried deep to the skin. This monitor is excellent for surgical and intensive care unit monitoring since it is unaffected by light, portable and is extremely easy to use.     

Molecular biology in the diagnosis of cardiovascular diseases]

Genes shown to affect risk factors or protective factors with respect to coronary heart disease (CHD) have been identified at the APOB, APOAI, LPA, LDLR, APOE and CETP loci. Rare mutations (e.g., in the LDLR and APOE genes) may have a major effect, whereas genes belonging to normal polymorphism have only a moderate effect. Even genes with only a slight effect can be clinically important in combination with other genes or life-style factors. There is gene to gene interaction between LDLR and APOE genes. Important risk factors determined by genes as well as by environmental factors are homocystein and fibrinogen. In addition to traditional lipid and apoprotein measurements, the levels of Lp(a) lipoprotein, fibrinogen and homocystein should be examined in connection with diagnosing CHD cases. DNA analyses are appropriate when familial hypercholesterolemia is suspected, and it is likely that the importance of mutation analyses will increase significantly in the near future.     

The significance of sIL-2R detection in various hepatic diseases]

A patient with an idiopathic bilateral vestibulopathy described two types of oscillopsia, one induced by head movement, the other induced by changing pressure in the right external auditory canal. This is the first report of both types of oscillopsia occurring in the same individual and illustrates their different mechanisms and symptomatology.     

The value of computer tomography, orbital venography and carotid angiography in the diagnosis of exophthalmos

On the bases of 25 patients examined by orbital venography, computer tomography, (CT scanning) and sometimes carotid angiography, the diagnostic value of each of these methods is evaluated. The data obtained are compared with the corresponding information from the literature. In view of the findings it can be stated that CT scanning can be regarded as the primary neuroradiological examination in cases of exophthalmos. Orbital venography gives supplementary information in cases of varices and venous malformations. Angiography is the method which supplies the maximum of information when cavernous sinus fistulae are clinically suspected. With reference to 3 patients it is explained that in such selective angiography of the internal and external carotid and the vertebral artery is indicated.     

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.     

High-resolution computer tomography of the lungs

High-resolution CT (HRCT) is a technique developed over the last decade. It optimises spatial resolution and provides details similar to those obtainable from gross pathologic specimens. HRCT of the lungs provides an accurate assessment of the pattern and distribution of many disease processes that in the conventional chest radiograph are occult or non-specific. HRCT is an established technique and the method of choice for evaluating a variety of pulmonary diseases. In this review we describe the modifications in CT technique that are instrumental in obtaining HRCT, and we also give examples of normal and pathologic findings in general.     

Spiral computed tomography for bilioenteric anastomotic stricture

Spiral computed tomography scanning after intravenous cholangiography (IVC-SCT) was used to assess the anatomy of the biliary tree and anastomosis in a 7-year-old girl with recurrent cholangitis 5 years after surgical excision of a choledochal cyst. The technique clearly visualized the stenosis of the hepaticojejunostomy and hepatic duct and the dilated intrahepatic ducts. IVC-SCT provides a precise, prompt, and accurate image with minimal invasiveness and is especially suitable for the preoperative evaluation of pediatric patients.     

Measurement of allergen-specific IGG for diagnosis of atopic diseases in children]

The concentrations of allergen-specific IgE were measured in 146 children with respiratory, skin, and mixed forms of allergic diseases. The spectrum of the allergens was determined and specific features for each of the studied patient populations defined.     

The role of nuclear magnetic resonance in the diagnosis of pericardial diseases]

The hypothesis that due to the high prevalence of solitary adenoma and the accuracy of modern imaging techniques it should be possible to cure a considerable number of patients by direct adenomectomy through a minimally invasive approach was tested in a consecutive series of 66 patients with primary hyperparathyroidism. Preoperative parathyroid imaging consisted of a combination of (Doppler) ultrasound and spiral computed tomography with cine-loop reconstruction potentiality. If only one parathyroid adenoma was identified preoperatively, a minimally invasive approach was advised. If more than one adenoma was located, or when the imaging results were equivocal, the patient was advised to undergo a conventional bilateral neck exploration. Sixty-six patients (54 female, 12 male) with a median age of 60 years and a median serum calcium of 2.90 mmol L(-1) were studied. Fifty-one of these patients underwent minimally invasive surgery, which was successful in 49 patients, while conversion to conventional neck exploration was necessary in two patients. Conventional neck exploration was chosen for the other 15 patients. Six of these proved to have multiglandular disease or a retro-sternal adenoma, while in nine patients only one parathyroid adenoma was found. All patients became normocalcaemic postoperatively. Morbidity consisted of a transient unilateral vocal cord paralysis in one patient. These results support the original hypothesis: successful minimally invasive surgery was possible in 74% (49 of 66) of patients, thus avoiding conventional neck exploration. This strategy further simplifies the operative treatment of primary hyperparathyroidism without loss of efficiency.     

The role of dynamic contrast magnetic resonance tomography in the complex radiation diagnosis of focal hepatic lesions

The results of complex radiation study of 269 patients with various focal hepatic diseases were analyzed. Present day methods of radiation study were used. Dynamic contrast magnetic resonance imaging (DCMRI) was made in 62 patients. It is concluded that DCMRI is higher sensitive in detecting focal hepatic diseases than other techniques. The time course of changes in signal intensity in different abnormalities greatly differs in quantitative and qualitative parameters, which differentiates the nosological nature of the revealed changes to a high accuracy.     

Comparative evaluation of visual function computer examining methods for early diagnosis of glaucoma]

The statistical uncertainty caused by speckle noise artifacts is the reason for the great importance of the problem which is the optimum choice between the medical diagnostic systems resolution and the statistical accuracy of histological tissue identification. The way of speckle noise suppression, which is closely associated with the well-known idea of adaptive filtration and based on the physical analysis of the origin of true and false signals, is very promising. The testing results of the nonlinear real-time adaptive filter which has been designed for a TI628A echotomoscope are presented. The filter has been shown to have a rather high contrast and space resolution and reduces the speckle noise and other artifacts of the images.