Search PubMed⌕ Search

Biomedical subjects

M Pocek

Publications and source records attributed to M Pocek.

33 records · Page 2Linked to original sources
PubMed1991

[Interventional radiology of the digestive system].

The authors report on the use of interventional radiology modalities in the treatment of some gastrointestinal diseases (intussusception, stenosis, hemorrhage, etc). The results are compared with literature data relative to both interventional radiology and conventional therapeutic procedures. In our series, hydrostatic reduction of ileocolic intussusception was successful in 60% of cases. Transluminal dilatation with a balloon catheter was attempted in 108 patients with alimentary tract stenosis and was successful in 93. Hemorrhage and ischemia can be treated by means of transcatheter therapy (vasopressin, embolization) and percutaneous angioplasty. Percutaneous gastrostomy appears to be an effective alternative to surgical gastrostomy. Tapeworm infections can be cured by intraduodenal injection of "Gastrografin" (Schering). The success achieved in the different applications is such as to suggest a wider use of interventional radiology procedures, for they offer a more favorable cost/benefit ratio and often yield better results than conventional techniques.

Digestive System↗
PubMed1990

Optimal branching of human arterial bifurcations.

The area ratio, defined as the combined cross-sectional areas of the daughter branches divided by that of the parent artery, is an important indicator of "expansion" or "narrowing" in an arterial tree. In 120 morphologically normal human arterial bifurcations, angiographically studied, we measured branch artery diameters at and away from the bifurcation point to obtain "beta" and "D" ratios, respectively. These results were compared with optimal curves. Area ratio D values showed better agreement than area ratio beta with theoretical curves; for area ratio D, the positive regression line showed the same trend as expected from theory (y = 1.26 + 0.153x); for area ratio beta, the regression line was negative, showing a trend opposite to theory (y = 0.962 - 0.191x). Area ratio beta showed a significant correlation coefficient (r = 0.194; P less than 0.05) associated with aging, while for area ratio D it was not the same (r = 0.023; P less than 0.05). A significant correlation coefficient was also found between both of the area ratios and total branching angle. The new area ratio D, reflecting the branching geometry nearer to the bifurcation, is more promising than area ratio beta in the evaluation of optimal arterial bifurcation.

Adolescent↗
PubMed1988

The vascular geometry of human arterial bifurcations.

We used angiography to evaluate the branching characteristics of 69 morphologically normal human arterial bifurcations. Each angiographic picture was enlarged photographically and traced on paper. The diameter of the parent vessel (d0), the diameters of the two daughter vessels (d1 and d2-d1 denote the larger vessel), and the angles at which the two branches arise from the parent vessel (teta 1 and teta 2) were measured on each bifurcation. Because theoretically there are optimal values for angles and diameters that render an arterial bifurcation more efficient physiologically, the measured data were compared with predicted values. Branch diameters correlated better with predicted values than did branching angles. Twenty-six per cent of teta 1 and only 7.2% of teta 2 angles were within the optimal range; 68.2% of teta 1 and 79.7% of teta 2 were within 2% of optimal values in terms of physiologic efficiency. On the average, teta 1 angles were smaller than teta 2 angles (17.0 degrees vs. 29.5 degrees). Morphologic and hemodynamic pecularities of vessels and errors in the measuring technique must be considered in analyzing the data obtained. Moreover, branching angle measurements changed slightly with age: teta 1 became larger and teta 2 narrower. In the cardiovascular system branching angles and branch diameters follow, to some degree, the principles predicted by theory. Branching angles diverging considerably from those principles may indicate the presence of vascular disease although a direct connection has not been established.

Adolescent↗
PubMed1987

[Use of digital subtraction angiography in the study of thoracic outlet syndrome].

Thoracic outlet syndrome (TOS) is characterized by neural and vascular symptoms of the upper extremity, caused by abnormal compression on the brachial plexus, subclavian-axillary artery and/or vein, when the patient makes some movements. Compression can occur on various anatomic levels: interscalene triangle, costoclavicular passage, pectoralis minor tendon. The authors describe the various stress position to point out the place of compression, etiology and the most common methods of study. They refer also their experience about TOS obtained using selective digital subtraction angiography (DSA) of both subclavian arteries in 6 patients. Thanks to DSA, that allows the dilution of contrast medium, it is possible to carry out all the stress maneuvers using a little amount of contrast medium.

Adolescent↗
PubMed1986

[Role and possibility of intravenous digital substraction angiography in problems of renal transplantation].

Intravenous Digital Subtraction Angiography (IVDSA) was used to evaluate 6 renal allograft recipients and 3 potential renal donors. In 4 potential renal donors and in 2 allograft recipients, angiographic data were confirmed by surgery. IVDSA is a safe, accurate, easily performed, outpatient procedure; in our opinion DSA should became the procedure of choice to study vascular anatomy in renal transplant evaluation.

Angiography↗
PubMed1984

[Morphological lesions of the choledochus studied with combined percutaneous transhepatic cholangiography and hypotonic duodenography].

Twenty two patients obstructive jaundice were investigated by combined fine needle percutaneous cholangiography and hypotonic duodenography. The association of the two techniques enables prompt localization of the site of obstruction and definition of the nature of the lesion. It proves to be of particular use in the differential diagnosis of carcinoma of the head of the pancreas, carcinoma of the distal choledochus and carcinoma of the socalled choledochoduodenal junction.

Bile Duct Neoplasms↗
PubMedDate not supplied

[Non-invasive assessment of epiaortic vessels. Comparison of magnetic resonance angiography with gadolinium, spiral computerized tomography angiography, and digital angiography].

PURPOSE: The aim of the study was to compare gadolinium-enhanced MRA (Gd-MRA), Computed Tomography angiography (CTA) and digital subtraction angiography (DSA) in the evaluation of carotid stenosis. MATERIAL AND METHODS: Thirty patients with US-proven internal carotid artery stenosis over 50%, underwent Gd-MRA, CTA and DSA. Gd-MRA was acquired using the keyhole technique. RESULTS: The overall agreement was 90% for Gd-MRA and 93% for CTA. Gd-MRA and CTA overestimated 5 and 4 cases of mild stenosis and 1 case each of moderate stenosis, respectively. Gd-MRA better delineated ulcerated plaques, tandem lesions and pseudo-occlusions. DISCUSSION AND CONCLUSIONS: Because of the high speed acquisition breath-hold is no longer necessary for Gd-MRA and more delayed phases were analysed when necessary. The main limitation of Gd-MRA was represented by insufficient volume coverage that allowed the visualisation of supraaortic vessels from the arch only in 57% of the cases. Calcified plaques were very well detected by CTA and not by Gd-MRA. In our experience Gd-MRA represents the second step non invasive tool in patients with US-proven carotid stenosis. This leads to avoid conventional angiography in most cases.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Multidetector row CT coronary angiography: technique and preliminary experience.

PURPOSE: To report our preliminary experience with multi-slice spiral CT coronary angiography of the coronary arteries. MATERIALS AND METHODS: 50 volunteers (mean age 61 years, range 45-72) with baseline heart rates below 70 bpm underwent multi-detector row CT coronary angiography (GE Light Speed Plus, 140 kVp, 270 mA, 1.25-mm collimation, 0.5-second rotation time, high quality pitch) with retrospective ECG gating after receiving 140-150 ml of iodinated contrast medium (Iopamiro 300 mg-dl, Bracco, Italy) at a flow rate of 4 ml/sec. Three of the 50 patients had previously undergone coronary procedures (1 anterior descending artery stent, 1 left circumflex artery stent and 1 anterior descending artery percutaneous angioplasty) and three were undergoing follow-up examinations after by-pass surgery. The remaining 44 patients were asymptomatic and had no history of coronary artery disease. All CT angiograms were back-reconstructed from 20 to 80% of the diastolic cycle with 10% increments to establish the phase with fewer "stair-step" motion artefacts for each artery. Patients with heart rates above 70 bpm were administered beta-blockers during the five days preceding the examination in doses appropriate for the patient's clinical characteristics. RESULTS: The CT room occupation time ranged from 25 to 35 minutes (mean time 27') and the post-processing time from 30 to 60 minutes (mean time 40'). The left anterior descending artery was best visualised in middle diastole (70% of cardiac cycle), the circumflex artery at 60% of the cardiac cycle, and the right coronary artery at 40%. Out of 132 arteries, 19 (14.4%) were considered non-assessable due to "stair-step" motion artefacts, whereas 2 (1.5%) were only partially visualised owing to the presence of extensive wall calcifications. Among the 113 assessable arteries, we observed: 72 normal coronary arteries without stenosis or wall calcifications (54.5%); 28 arteries with minimal wall irregularities and stenoses below 50% (21.2%); 7 stenoses >50% involving the right coronary artery (no. 2), the anterior descending arteries (no. 4) and the left circumflex artery (no. 1) (5.3%). In the remaining 6 patients, optimal visualisation of the stents and venous and arterial surgical by-passes was obtained. CONCLUSIONS: Although further larger-scale studies are required to compare MSCT coronary angiography with CT coronary angiography, the application of MSCT technology to the study of the coronary arteries is a promising technique with a good potential for use in routine clinical practice. In selected patients (with baseline heart rates <70 bpm, or after beta-blocker therapy) it is able to provide very interesting results and could be used as a method of choice for following patients after interventional procedures or as a mass-screening tool to select patients to be referred for coronary angiography.

Aged↗
PubMedDate not supplied

Computed tomography detection of gastrointestinal neoplasms.

Gastrointestinal (GI) tract neoplasms can be detected, evaluated and staged by computed tomography (CT), especially from high-resolution examinations, but routine CT scanning may occasionally discover GI neoplasms in patients with non-specific symptoms. We therefore evaluated the sensitivity and main signs of CT examinations resulting from routine sessions. In 46 out of 1560 patients who underwent abdominal CT, it was possible to obtain a diagnosis of primitive gastric or colo-rectal tumour by means of barium X-ray and/or endoscopy. The sensitivity rate of CT obtained from the present study was 86% in gastric tumours and 87% in colonic tumours. In gastric lymphoma, infiltrating carcinoma of stomach and rectal carcinoma, the sensitivity rate was 100%. The CT diagnosis of GI neoplasms was based on diffuse or local thickening of the gut on a solid dishomogenous mass showing contrast enhancement. The prevalence of various patterns depends on site of origin and on macroscopic features of the neoplasia. In conclusion the results suggest that abdominal CT, even if performed with a method not specifically devoted to GI tract, has high sensitivity rates and then a high probability of detecting GI neoplasms when unsuspected at time of the examination. In our series 11% of GI neoplasms were initially diagnosed by routine CT examination.

Adult↗
PubMedDate not supplied

[Use of coronal sections in computerized tomography].

The authors emphasize the use of coronal cut in CT in sellar and parasellar lesions; in tumors involving the tentorium; in differential diagnosis between meningiomas of falx and parasagittal ones and in those lesions with extension into paranasal sinus and face. The purpose of this method is to evaluate the exact relationship of these type of lesions with adjacent structures in a tridimensional view.

Adenoma↗
PubMedDate not supplied

[Diagnostic imaging and interventional therapy in hepatocarcinoma. Multicenter study of 290 cases].

We report the results of a multicenter study on the diagnosis and interventional therapy of hepatocellular carcinoma (HCC). The first aim--diagnosis--was to evaluate the sensitivity of 4 imaging techniques, namely ultrasonography (US), Computed Tomography (CT), digital arteriography (DSA) and Lipiodol CT (LCT), in HCC detection. The accuracy of these techniques was also investigated in tumor staging, which is important for treatment planning. Two hundred ninety patients underwent this imaging protocol. The patients were classified by tumor spread into three groups, namely group 1 (single HCCs < 5 cm), group 2 (multifocal HCCs with max. 3 nodules or tumor volume < 80 cc), group 3 (multifocal HCCs with more than 3 nodules and/or tumor volume > 80 cc). US and CT diagnosed more cases as group 1 and fewer cases as group 3 than DSA and LCT; the latter two techniques gave a similar classification. With LCT as the gold standard, US and CT understaged 27.9% and 26.5% of cases, respectively. Even though LCT is known to have 53% sensitivity, it is currently the most sensitive preoperative investigation and therefore the best tool for treatment planning. In surgical patients, however, intraoperative US, with its nearly 100% sensitivity, is suggested. The second aim--treatment--consisted in assessing the therapeutic efficacy of intraarterial chemoembolization (CEAT) versus percutaneous ethanol injection (PEI) in non advanced HCC and of CEAT versus no treatment (NT) in advanced HCC. Treatment efficacy was evaluated with the following randomized protocols: PEI versus CEAT in group 1, PEI versus CEAT in group 2 and CEAT versus NT in group 3. The data were analyzed relative to 215 patients for 6 to 30 months. The Kaplan-Meier method was used to calculate survival rates, which were, at 24 and 30 months, 72% and 72% for PEI and 72% and 52% for CEAT in group 1, 52% and 28% for PEI and 70% and 50% for CEAT in group 2 and finally 30% and 20% for NT and 45% and 30% for CEAT in group 3. In group 1, PEI appeared markedly superior to CEAT. In group 2, the difference between PEI and CEAT was not statistically significant; the results in this group indicate that CEAT should be considered when three nodules are present because of PEI invasiveness in these cases. In group 3, CEAT results were definitely better in the first two years, but there was no difference with NT patients at the end of the third year. Therefore, CEAT is indicated in advanced HCC because it improves the survival rate in the first 24 months. After this period, the survival time is not modified by treatment.

Antineoplastic Agents, Hormonal↗