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Biomedical subjects

R Sokiranski

Publications and source records attributed to R Sokiranski.

At least 37 records · Page 2Linked to original sources
PubMed1998

Comparison of virtual and fiberoptic bronchoscopy.

Preoperative diagnostic procedures in the treatment of non-small-cell lung carcinoma (NSCLC) include fiberbronchoscopy (FBS) and CT scanning of the thorax and abdomen. The introduction of double-detector helical computed tomography has led to improved image resolution which allows three-dimensional reconstruction of the bronchial tree. A special computer simulation provides a virtual endoscopic view into the inner surface of the bronchial system. In order to determine whether the so-called virtual bronchoscopy (VBS) accurately reflects the anatomic situation of the bronchial tree, neoplastic lesion, and postoperative control of sleeve resections, we performed a virtual bronchoscopy in 24 patients with NSCLC and in 6 patients following sleeve resections and compared the results with the findings of fiberoptic bronchoscopy. An anatomic computer simulation of the bronchial tree was created in 100% of the investigated patients. Central tumor stenosis or occlusion was visualized by VBS as well as by FBS. In peripheral tumorous lesions VBS revealed the correct diagnosis in only 75%. VBS, however, enables viewing beyond the stenosis. FBS remains the gold standard in the endoscopic diagnostic procedures, showing not only airway patency but also mucosal changes in the vicinity of the tumorous lesion. VBS, however, gives further information about the poststenotic area in occlusive main bronchus stenosis. Furthermore, adequate control investigation of airway patency in patients following sleeve resections or stent implantation can be performed by VBS.

Bronchoscopy↗
PubMed1998

[Dosimetry in conventional and spiral CT in 8 spiral CT scanners of the latest generation].

PURPOSE: Measurement of scanner-dependent differences in PCTDI for conventional and spiral CT and evaluation of PCTDI/100 mAs in eight spiral CT scanners of the latest generation. METHODS: Central PCTDI was evaluated in a PMMA phantom for different scan lengths of conventional and spiral CT in four scanners. Central and peripheral PCTDI/100 mAs, average dose and the quotient between peripheral and central PCTDI/100 mAs were measured with a dedicated 10 cm ionisation chamber positioned within a PMMA phantom using the parameters of a standardised liver protocol and a high-resolution inner ear protocol for eight spiral CT scanners. RESULTS: Depending on scanner type and scan length PCTDI for the spiral mode is in a range between 11.3% higher and 4.3% lower than that for the conventional mode. PCTDI/100 mAs varies considerably between different CT scanners. For the standardised liver protocol PCTDI/100 mAs varies up to a factor of 2, for the inner ear protocol up to a factor of 4. CONCLUSION: Even in comparable modern CT scanners there are considerable protocol and scanner-dependent differences in PCTDI/100 mAs. The values for his own scanner should be known to each CT user so that he can develop a dose-optimised, patient and problem-orientated examination strategy.

Ear, Inner↗
PubMed1998

Diagnostic value of spiral-CT angiography in comparison with digital subtraction angiography before and after peripheral vascular intervention.

To evaluate spiral-computed tomography (CT) angiography in primary diagnosis and/or in noninvasive follow-up after vascular intervention, we compared spiral-CT angiography and conventional angiography before and after vascular intervention. Helical-CT examinations before and after percutaneous transluminal angioplasty (PTA) or stent implantation were performed in 10 patients (mean age 63 years) with symptomatic peripheral arteriosclerotic disease. Stenoses were located in the iliac, femoral, or popliteal artery. CT examinations were done with a spiral-CT in double detector technique (CT Twin, Elscint). The parameters were as follows: slice thickness: 5.5 mm, increment: 2.7 mm, pitch: 1.5, contrast medium: 150 mL, flow rate: 2.5 mL/second, delay: 30 seconds. For evaluation, transverse planes as well as maximum intensity projections and 3-D reconstructions were used. The possible scan length reached from the aortic bifurcation down to about 10 cm below the ankle trifurcation. Preinterventional digital subtraction angiography (DSA) was superior to CT angiography (CTA: 94%, maximum intensity projection [MIP] alone: 65%), although high-grade stenoses were detected by both methods. After intervention, a resolved stenosis and improved peripheral flow could be detected by helical-CT as well as by intraarterial angiography in every patient (100%). In the primary diagnosis of vascular changes, intraarterial DSA remains the method of choice. Nevertheless, spiral-CT angiography shows comparable results after percutaneous intervention and becomes a noninvasive alternative in the postinterventional follow-up.

Angiography↗
PubMed1998

Emergent endoluminal repair of delayed abdominal aortic rupture after blunt trauma.

PURPOSE: To report the emergency repair of a traumatic abdominal aortic rupture using endoluminal techniques. METHODS AND RESULTS: A 25-year-old female sustained multiple head, chest, and abdominal injuries in a motorcycle accident. Six days after emergency treatment (including splenectomy and repair of a superficial hepatic rupture and lacerations to the stomach, small bowel, and colon), she became hemodynamically unstable. A massive retroperitoneal hematoma had evolved from a distal aortic rupture. Owing to a hostile abdomen and possibility of bacterial contamination, a self-expanding stent-graft was inserted transfemorally to repair the aortic injury. The patient recovered uneventfully and continues in good health with a patent endograft repair 2 years after treatment. CONCLUSIONS: This experience would support the efficacy of endograft implantation for emergent repair of trauma aortic injuries; however, proper facilities, an experienced interventional team, and an assortment of endografts and stents must be available.

Adult↗
PubMed1998

Virtual cystoscopy based on helical CT scan datasets: perspectives and limitations.

The purpose of the study was to simulate cystoscopy based on three-dimensional helical CT scan datasets in real-time in patients with tumours of the urinary bladder. A helical CT scan with double detector technology was carried out pre-operatively in 11 patients with histologically confirmed carcinoma of the urinary bladder and one patient with chronic cystitis. A non-enhanced scan was first performed, followed by an examination in the early phase of contrast medium enhancement. Further images were acquired after adequate filling of the bladder with contrast medium, approximately 30 min after injection. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and histopathological findings. All tumours of the urinary bladder identified at fibreoptic cystoscopy were shown on virtual cystoscopy. The best reconstruction results were obtained from data acquired 30 min after injection of contrast medium. The ureteric orifices were not visualized at virtual cystoscopy. These data lead us to conclude that, at present, virtual cystoscopy has not reached the quality of fibreoptic examination and remains restricted to use in specific cases, for example patients with urethral strictures.

Aged↗
PubMed1998

Mechanical thrombolysis of acute occlusion of both the superficial and the deep femoral arteries using a thrombectomy device.

OBJECTIVE: Our objective was to evaluate the efficacy of the Amplatz thrombectomy device for recanalization of acute occlusions of both the superficial and the deep femoral arteries. MATERIALS AND METHODS: Eighteen patients with acute occlusions of the femoral arteries (eight male, 10 female; 10-87 years old) were treated using the Amplatz thrombectomy clot macerator. The duration of occlusion was 16 +/- 8 hr. Eighteen patients underwent treatment of the deep femoral artery, and 16 patients had additional involvement of the superficial femoral artery. After primary recanalization of the deep femoral artery, the superficial femoral artery was also recanalized using the Amplatz thrombectomy device. Nine patients required additional aspiration thrombectomy of the tibial arteries, five patients required additional aspiration thrombectomy of side branches of the deep femoral artery, and 12 patients required additional local thrombolysis with urokinase. RESULTS: In 14 (78%) of 18 patients, recanalization of the deep femoral artery was complete without demonstrable residual thrombi. Arterial spasms were observed in five patients (28%). The rate of limb salvage was 94% at a mean follow-up interval of 8.9 +/- 4.1 months. In the 18 patients, the ankle-brachial pressure index went from a median value of 0.56 before therapy to a median value of 0.91 after therapy. No severe complications occurred. CONCLUSION: Mechanical thrombolysis in the deep femoral artery with the Amplatz thrombectomy device is an effective, rapid method of treatment and is rarely associated with complications. In cases of concomitant occlusion of the tibial arteries, recanalization should always be attempted because the deep femoral artery may provide a functionally decisive collateral artery between the iliac and tibial vasculature.

Adolescent↗
PubMed1997

[Interventional treatment of hemobilia].

PURPOSE: Aim of the study was to assess the use of embolisation in cases of iatrogenic haemobilia. METHOD: In 18 patients with severe haemobilia after percutaneous biliary system drainage or stent implantation, an embolisation with minicoils (17 x) or gelfoam particles, was performed. To achieve a sufficient vascular obstruction, Histoacryl (4 x) or Ethibloc (1 x) were additionally used in five cases. A transarterial approach was used in 17 cases. In one patient, an approach through the biliary system was possible. RESULTS: In all cases, the bleeding source was identified (5 false aneurysms, three biliary leaks, 9 irregularities at the junction of the artery and drainage catheter, 1 multiple collaterals at the proximal end of the stent). In 17 out of 18 cases, haemorrhage ceased definitely. In one case of a patient with pancreas carcinoma and obstruction of the portal vein as well as a simultaneous high grade stenosis of the hepatic artery propria, it was only possible to embolise small collaterals to avoid liver necrosis. This resulted in an incomplete bleeding of control. An infected haematoma was the only complication. It was treated by drainage over 10 days. During an observation period ranging approximately 7.6 months, 10 of the patients died due to their basic illness. CONCLUSION: Embolisation is an effective procedure in the treatment of haemobilia, with a low complication rate.

Aged↗
PubMed1997

[A new method in the determination of individual delay time in bolus application in spiral CT].

Helical-CT examinations, particularly CT angiography, require precise timing between the examination procedure and the individual dynamics of contrast medium distribution in the arteriovenous system of the patient. The necessary delay between contrast medium injection and onset of has usually been either estimated or determined by means of an additional helical CT examination. The present paper introduces a new technique which allows bolus analysis without an additional scan. Prior to a CT angiography with 10 patients, two techniques for bolus analysis (BA) were compared. Prior to diagnostic contrast medium enhanced examination, a native (BA I) and a dynamic (BA II) examination were performed. Ten seconds prior to the start of each examination, a 10 ml test bolus was applied with an injection flow rate of 3 ml/s. Both examinations lasted for 30 s. During BA I, increase in attenuation in the aorta was compared at different sites, during BA II consistently at the same site. Comparison of the individual peak times yielded a coefficient of correlation of r = 0.926. The median value for BA I was 18.4 +/- 5.4 s and 19.2 +/- 4.5 s for BA II. The difference between measurement of peak time was 1.2 +/- 1.16 s. This modified technique for bolus analysis during the primary native scan of the upper abdominal organs permits calculation of the required individual delay time between contrast medium application and scan start: no additional examination is required and the method can be performed with any helical CT unit.

Adult↗
PubMed1997

[Mechanically detachable minicoils attached to a wire for superselective embolization].

PURPOSE: Evaluation of clinical usability and effectivity of newly developed, mechanically applicable minicoils attached to a wire for super-selective embolisation. MATERIAL AND METHODS: The new embolisation coils have been used in 16 patients aged between 28 and 90 years for the following indications: 4 haemorrhages in cases of advanced carcinoma of the cervix, one false aneurysm, 7 traumatic lesions and 4 arteriovenous fistulas. The minicoils are made of platinum and are attached to a guide wire with a connecting hook. Application is via a microcatheter in coaxial technique. RESULTS: Percutaneous embolisation has been successful in patients. Additional surgery has not been required in any of them. Manipulation of the system is relatively easy and embolisation is made possible under controlled circumstances. In one case a minicoil disappeared into a peripheral vessel, but could be recovered percutaneously. CONCLUSION: The minicoils allow super-selective embolisation but, for reasons of cost, should be reserved to such vascular regions where the risk of misplacing must be kept at a minimum. Basic experience with embolisation techniques is indispensable for the application of this method.

Adult↗
PubMed1997

[Diagnosis of pleural effusion in intensive care patients with supine digital thoracic imaging. A study of CT validated cases].

PURPOSE: The significance of the recumbent chest x-ray using digital luminescence radiography was to be assessed in respect of diagnosis of pleural effusions. MATERIAL AND METHODS: Three experienced radiologists evaluated 32 digital recumbent chest x-rays of 32 intensive-care patients. The radiologists were asked to estimate the effusion volume and to assess whether typical x-ray signs of pleural effusions were seen. These evaluations were compared with one another and with the simultaneously produced CTs. RESULTS: Diagnostic accuracy of the digital recumbent chest x-ray is of medium quality in respect of diagnosis of pleural effusions (sensitivity: 69%, specificity: 54%, positive predictive value: 81%, negative predictive value: 34%, rate of accuracy: 65%). Diagnostic safety is the same for right-sided or left-sided pleural effusions, and increases with increasing effusion volume. The ratings by the radiologists are statistically not significantly different, but are significantly different from the CT measurements (Wilcoxon test, p < 0.05). Correlations of the assessments and the measurements were weakly positive (r = 0.24, r = 0.36, r = 0.47). The pleural effusions were on the average underestimated by the radiologists. The median predictive error was 203 ml. CONCLUSIONS: Recumbent chest x-ray with digital luminescence radiography is an imaging method of limited accuracy in respect of diagnosis of pleural effusions. Supplementary diagnostic methods are recommended, as the present results show, especially in such cases where the recumbent chest x-ray does not reveal an effusion or if the volume must be determined accurately. Digital recumbent chest x-ray ranks equal with conventional x-ray in the diagnosis of pleural effusions.

Adolescent↗
PubMed1997

Mechanical thrombectomy of embolic occlusion in both the profunda femoris and superficial femoral arteries in critical limb ischaemia.

We report our preliminary experience using the Amplatz device for percutaneous thromboembolectomy in acute occlusion in both the profunda femoris artery (PFA) and superficial femoral artery (SFA) in four patients (mean age 78.5 years). All patients suffered from acute lower limb ischaemia, Fontaine Grade 3, due to cardiac embolization. Estimated occlusion times range from 3 h to 3 days. All four patients were treated successfully. Device activation time for both the PFA and the SFA was 85 s +/- 15 s. Total procedure time was 25 min +/- 10 min. There was no need for adjunctive procedures or intensive care monitoring. We conclude that the Amplatz device is a very effective and safe procedure for the quick restoration of vascular patency in cases of simultaneous embolically occluded PFA and SFA.

Acute Disease↗
PubMed1997

Sensitivity of computed tomography in detecting local recurrence of prostatic carcinoma following radical prostatectomy.

The aim of this study was to evaluate CT imaging in the post-operative follow-up and in the detection of recurrence after radical prostatectomy in cases of prostatic carcinoma. In over 500 patients undergoing radical prostatectomy for prostatic carcinoma, 22 cases with local recurrence were found. CT examinations of the pelvis were retrospectively evaluated in these patients. Local recurrence was detected by PSA uptake and confirmed by transrectal ultrasound (TRUS) in combination with guided biopsy. In 22 cases of confirmed local recurrence, positive results on CT were found in eight patients (36%) and negative results in nine patients (41%). In the remaining five cases (23%), no distinction could be made between scar and local recurrence. All cases definitively classified as recurrent tumour disease showed a soft tissue mass of 2 cm or more. CT sensitivity in local recurrence of prostatic carcinoma after surgery is low. Even in a very careful follow-up, the understaging would be up to 41%. In comparison, PSA, TRUS and needle biopsy are the methods of choice and are superior to CT imaging. Based on these results, there would be no reason for including pelvic CT examinations in the follow-up of prostatic carcinoma after radical prostatectomy.

Follow-Up Studies↗
PubMed1997

Musculoskeletal involvement in cystic echinococcosis: report of eight cases and review of the literature.

OBJECTIVE: Our purpose was to describe the morphologic appearance of musculoskeletal lesions in patients with cystic echinococcosis shown by CT and MR imaging. CONCLUSION: Patients with musculoskeletal lesions of cystic echinococcosis typically have cystic structures in adjacent soft tissues. These cysts morphologically resemble abscesses, with peripheral uptake of contrast medium and variable signal intensities on T1-weighted MR images. The absence of calcifications or endovesicular daughter cysts does not exclude the diagnosis of cystic echinococcosis.

Adult↗
PubMed1997

Displaced metallic biliary stents: technique and rationale for interventional radiologic retrieval.

OBJECTIVE: We investigated the spontaneous course and the possibility of transhepatic removal of displaced biliary stents. MATERIALS AND METHODS: Displaced biliary stents were observed in 11 patients (13-75 years old) between October 1988 and August 1996. Stent types included the Palmaz stent (n = 3), Wallstent (n = 3), and the Strecker stent (n = 5). Reasons for stent displacement included primary misplacement (n = 4), dislocation due to transhepatic endoscopy with biopsy (n = 2), dislocation resulting from a recanalization maneuver in stent occlusion (n = 3), and unknown causes (n = 2). In three cases, the stent was displaced into the proximal bile duct system. Seven patients had primary malignancy. RESULTS: Eight of 11 displaced biliary stents were removed transhepatically. Extraction was performed using either a wire loop (n = 4) or forceps (n = 4). No complications occurred. In the remaining three patients, whose stents were displaced into the intestine, no invasive action was taken. In one of these patients, a Palmaz stent was passed spontaneously after 1 week. In the second of these patients, a 6 cm Wallstent remained innocuously at a position in the right lower abdomen, and the patient died as a result of malignancy. In the third patient, who had a 10-cm Wallstent, an abscess developed in the stent region 4 months after displacement and resulted in formation of an ileocutaneous fistula. CONCLUSION: Transhepatic extraction of displaced biliary stents is technically possible, even in the case of rigid stents such as the Palmaz stent. Because of the risk of intestinal perforation, displaced stents should be removed.

Adolescent↗
PubMed1997

Comparison of real-time virtual and fiberoptic bronchoscopy in patients with bronchial carcinoma: opportunities and limitations.

OBJECTIVE: Both helical CT and fiberoptic bronchoscopy are used in the staging of pulmonary tumors for therapeutic decision making. The improved resolution offered by helical CT has led to the clinical use of three-dimensional reconstruction techniques such as virtual bronchoscopy. We tested this new simulated endoscopic view of inner organ surfaces and compared it with corresponding fiberoptic examinations of the tracheobronchial system. SUBJECTS AND METHODS: Twenty patients with malignancies of the lung and mediastinum were examined with both virtual bronchoscopy and fiberoptic bronchoscopy. Both examinations were reviewed by radiologists and surgeons familiar with fiberoptic bronchoscopy. Virtual bronchoscopy was calculated and reconstructed from the cross-sectional images on a separate workstation. Stenoses and tumor infiltration were classified from the fiberoptic examination. These results were compared with the virtual bronchoscopy findings. RESULTS: Virtual bronchoscopy of diagnostic quality was achieved in 19 of 20 patients. High-grade stenoses were revealed equally well with virtual and fiberoptic techniques. Virtual bronchoscopy offered the advantage of being able to visualize areas beyond even high-grade stenoses. However, on virtual bronchoscopy discrete infiltration or extraluminal impression was not visible in five patients. In another patient, strong heart pulsation produced motion artifacts that prevented evaluation of the reconstruction. CONCLUSION: Virtual bronchoscopy represents a new noninvasive method for evaluating helical CT findings. In comparison with fiberoptic bronchoscopy, virtual bronchoscopy offers the advantage of being able to visualize areas beyond even high-grade stenoses. In addition to the limited view of fiberoptic bronchoscopy, extraluminal causes of lumen compressions can be analyzed in the cross-sectional images and evaluated together with the virtual representation. However, it was not possible to detect small infiltrations with virtual bronchoscopy. This new representation of helical CT data might be helpful for postoperative follow-up examinations, such as after stent implantation, and can be carried out without additional risk to the patient. Radiologists do need special fiberoptic bronchoscopy knowledge and experience with three-dimensional-reconstructions to differentiate between real stenoses and artificial stenoses that might be caused by pulsation artifacts.

Artifacts↗