Biomedical subjects

U Mödder

Publications and source records attributed to U Mödder.

At least 19 recordsLinked to original sources

PubMed1992

[Renal stent implantation. The current indications, 2-year results and the possibilities for percutaneous stent recovery].

Use of the Strecker flexible balloon-expandable tantalum stent for treatment of renal artery stenosis after failed angioplasty or transaortic thrombendarterectomy was evaluated in 18 patients (17 hypertensive, 1 normotensive). Right (n = 10) and left (n = 6) renal arteries were involved; in 2 patients renal artery stenosis had developed after kidney transplantation. Indications for stent placement were inadequate immediate postangioplasty response (n = 16), and obstructing intimal flaps following transaortic endarterectomy (n = 2). Stent placement was technically successful (less than 20% residual stenosis) and patency was preserved in 14 patients. Mid-term results (mean, 12-13 months) of 11 patients showed restenoses (greater than 50%) in 2 patients, and improvement of hypertension in 8 patients. The Strecker stent may be helpful in treating residual stenosis after failed revascularization procedures of the renal arteries, although long-term efficacy of stent placement will not be known until trials with more subjects and longer follow-up periods are completed.

Adult↗

PubMed1992

[Color-coded duplex sonography (angiodynography)].

Colour-coded duplex sonography is a relatively new method of diagnostic imaging. Compared with conventional duplex sonography it has advantages in respect of simplicity and speed in several applications. The main application of colour-coded duplex sonography is for the detailed demonstration of a limited area. A comprehensive demonstration of blood vessels remains the province of angiography. Clinical applications include vessels in the neck, lateral soft tissue anatomy of the neck, arteries and veins in the extremities, haemodialysis shunts, transplanted kidneys and acute abnormalities in the scrotum. In the abdomen the method is of only limited application.

Abdomen↗

PubMed1992

[The value of 2- and 3-dimensional computed tomography in the diagnosis and classification of midfacial and orbital fractures].

The value of 2D- and 3D-computed assisted tomography in detecting and classifying midfacial fractures and craniofacial deformities acquired by gunshot injuries was assessed in 123 resp. 26 patients and compared with the postoperative results. In a comparative study 37 patients were prospectively examined by pluridirectional tomography. Examinations of a macerated skull were performed to optimize 3D investigation technique. High resolution CT proved to be the most reliable technique in detecting midfacial fractures and associated soft tissue injuries. 3D-imaging of bony surfaces allowed clear demonstration of fraction extent and fragment displacement without offering additional detail information. 3D-based computer-assisted manufacturing of individual models facilitated surgical planning of complex midfacial injuries.

Adolescent↗

PubMed1991

Renal artery stenosis: preliminary results of treatment with the Strecker stent.

Use of the Strecker flexible balloon-expandable tantalum stent for treatment of renal artery stenosis after failed angioplasty or transaortic thromboendarterectomy was evaluated in 10 patients (nine hypertensive, one normotensive). Left (n = 3) and right (n = 5) renal arteries were involved; renal artery stenosis in two patients had developed after kidney transplantation. Indications for stent placement were inadequate immediate postangioplasty response (n = 7), development of considerable restenosis after angioplasty (n = 1), and obstructing intimal flaps following transaortic endarterectomy (n = 2). Stent placement was technically successful (less than 20% residual stenosis) and patency was preserved in eight patients. Of the seven hypertensive patients with successful implantation, two were cured, three had improvement, and two had no change at latest follow-up evaluation (mean, 10.6 months; range, 6-12 months). The Strecker stent may be helpful in treating restenosis after failed revascularization procedures, although the precise indication, true safety, and long-term efficacy of stent placement in renal arteries will not be known until trials with more subjects and longer follow-up periods are completed.

Adult↗

PubMed1991

Color coded duplex sonography in the diagnosis of peripheral vascular disease--applications in the evaluation of peripheral aneurysms, follow-up after arterial graft surgery and deep venous thrombosis.

Color coded duplex sonography has definitive advantages over conventional duplex sonography for investigation of lower limb vessels. It contributes significantly to the non-invasive evaluation of peripheral aneurysms and complications associated with arterial puncture. After arterial graft surgery it is an effective imaging method to check bypass patency and evaluate suspected complications. Furthermore, color coded duplex sonography is sufficiently accurate to definitely diagnose lower extremity DVT, when not technically compromised. Postthrombotic vascular changes and clot alteration under anticoagulant treatment can be demonstrated with high sensitivity.

Anastomosis, Surgical↗

PubMed1991

[Radiologic diagnosis in hyperparathyroidism].

The most important radiologically detectable effects of the primary and secondary hyperparathyroidism of the skeletal system and the periarticular soft tissue structures are presented. In the following sensitivity and specificity of radiological imaging--sonography, scintigraphy, computed tomography, magnetic resonance imaging, arteriography and selective venous sampling--in the preoperative diagnostic of the parathyroid adenomas are discussed. Therefore, radiological imaging can be omitted before primary surgery. It was only in secondary surgery that radiological process proved useful and a guide during surgical intervention.

Bone Diseases↗

PubMed1991

[MRT in syringomyelia--follow-up control after syringo-arachnoid shunt surgery with clinical correlation].

In 8 patients with syringomyelia, MR long-term follow-ups (observation period 25-46 months) were done after syringosubarachnoidal shunt operations. MR showed directly after surgery in 6 cases an extensive collapse of the syringomyelias and in 2 cases a lesser reduction of the diameter of the syrinx. During the subsequent course the size of the cavities increased again in 3 cases. The size of the syrinx visualised by MR did not correlate with the clinical status during the follow-up studies. This seems to point to an insufficient representation of the disease process by the morphological visualisation of the size of the syrinx.

Adult↗

PubMed1991

[Color-coded duplex sonography].

Color Coded Duplex-Sonography (CCD) is the latest development in ultrasound equipment for non-invasive evaluation of the vascular system. Compared to conventional Duplex-Sonography the advantage of CCD is the ease of handling and quicker diagnosis, although there in no significant increase in information with CCD. The main indications for CCD are superficially located circumscribed vascular lesions as in carotid artery stenosis, tumors in the neck, disturbed renal transplant perfusion, hemodialysis vascular access shunts, deep vein thrombosis, testicular torsion and complications following vascular surgery of the extremities. The abdominal applications are limited.

Humans↗

PubMed1990

[Color-coded Doppler sonography--possibilities for application in the neck area, the abdomen and the extremities].

Colour coded Duplex sonography has definite advantages over duplex sonography for the investigation of neck and limb vessels. Diagnosis of arterial stenoses, occlusions and aneurysms can be readily made. The method also allows to follow the evolution after vascular surgery and percutaneous transluminal angioplasty. Deep venous thromboses can be reliably detected without the use of contrast media. Application for abdominal vascular diagnosis is still limited.

Abdomen↗

PubMed1990

[The diagnosis of deep venous thromboses of the leg. Color-Doppler sonography versus phlebography].

Angiodynography of the pelvic and deep leg veins was compared with ascending phlebography in a prospective study, comprising 102 examinations. Improved detection of flow following the introduction of the so-called "slow flow technique" permitted direct visualisation of the tibio-fibular veins in the second stage of this study (26 examinations). Demonstration or exclusion of femoro-popliteal thrombosis achieved a sensitivity of 95% and 90% respectively and a specificity of 99% and 97%. During the first part of this study, demonstration of calf vein thrombosis had a low sensitivity of 72%. This was improved by the introduction of a new high-pass filter resulting in the detection of all occlusions (nine). The sonographic signs of acute and chronic occlusions overlap somewhat. Colour demonstration showed eccentric, non-linear channels in two out of three cases and was able to exclude thrombus, although the veins could not be compressed.

Adult↗

PubMed1990

[Color-coded Doppler sonography of deep venous thrombosis--possibilities and limitations in the area of the veins of the pelvis and the lower leg including postthrombotic changes].

A comparative angiodynographic and phlebographic examination of 150 extremities in a total of 119 patients was performed in respect of the visualisation of the veins of the pelvis and lower leg. Controls regarding the course of disease with conservative treatment of a thrombotic occlusion were carried out between the 2nd and 6th weeks after the acute incident. Despite restricted examination conditions in the pelvic region, the examination yields satisfactory proof of the presence or non-existence of an iliac vein thrombosis. Improved flow detection enables the visualisation of the veins of the lower leg and the diagnosis even of incomplete thromboses of the veins of the lower leg. Colour-coded Doppler sonography is highly sensitive in detecting postthrombotic vascular changes, and hence angiodynography is a non-invasive method that is useful in checking on the success of conservative therapy subsequent to the treatment. This method is an essential improvement compared with conventional sonography in respect of the difficult differentiation between fresh venous thromboses and late postthrombotic changes.

Adolescent↗

PubMed1990

[Radiologic diagnosis of anal incontinence].

Defaecography was performed in 47 consecutive patients with faecal incontinence. A gap in the anal canal with spontaneous leakage of contrast medium was observed in 19 patients and demonstrated a severe disturbance of sphincteric function. In 13 cases, an anorectal angle of more than 120 degrees that did not change during voluntary sphincter contraction and the missing dorsal impression of the anorectal junction indicated a damage of the puborectalis muscle. A rectocele was detected in 18 patients, an intussusception in 14 patients, and a complete rectal prolapse in 3 patients. Thus, mechanisms of faecal incontinence can be elucidated radiologically in more than one half of the patients examined. However, the high prevalence of a rectocele or an intussusception in patients with faecal incontinence causes doubt whether these alterations of rectal morphology are functionally relevant in the majority of patients with faecal incontinence.

Adult↗

PubMed1989

[NMR tomography with gadolinium-DTPA of the trunk in pediatric oncology].

The results of enhanced MR imaging for staging, follow-up and diagnosis of recurrence are presented in 24 children with thoracic, abdominal and pelvic masses. The use of gadolinium-DTPA usually leads to better definition of the tumour and of its relation to neighbouring organs, thereby making it easier to determine whether the tumour is resectable. The place of MR imaging in the diagnostic work-up of paediatric tumours is discussed.

Abdominal Neoplasms↗

PubMed1989

[Space-occupying lesions in the pineal region--MRT using Gd-DTPA].

The results obtained from contrast-enhanced MRI in 21 patients with masses in the pineal region are reported. The use of gadolinium-DTPA results in intensive contrast uptake by the tumour; this produces better definition of the tumour and more exact delineation from neighbouring structures. This is of importance in judging resectability and in choosing the operative approach. During chemotherapy or radiotherapy, it provides reliable demonstration of the success of treatment and accurately demonstrates the size of the tumour and the presence of necrosis. On the other hand, histologic classification of pineal tumours is possible only occasionally.

Adolescent↗

PubMed1989

[Contrast medium enhanced MRT of tumors of the posterior fossa in children and adolescents].

The results of contrast-enhanced MR in 24 children and adolescents with tumours of the posterior cranial fossa are presented. During initial diagnosis, the majority of tumours showed intensive enhancement with improved demarcation from neighbouring structures. The solid component of a cystic tumour, even when small and not visible on the original scan, could be demonstrated in all cases by means of gadolinium-DTPA. Post-operatively, T2-weighted scans regularly showed areas of high signal strength at the margin of the resection; in the absence of a mass or demonstrable progression, the significance of this is uncertain. In these cases gadolinium-DTPA, because of the function of the blood-brain barrier, greatly increases accuracy in demonstrating residual or recurrent tumours.

Adolescent↗

PubMed1989

[MRT using gadolinium-DTPA in spinal intradural space-occupying lesions].

The results of contrast enhanced MRI in 36 patients with suspected spinal intradural tumours are described. All intramedullary tumors showed distinctive enhancement and solid tumors could be delineated clearly, even if they were not clearly visible on unenhanced scans. The differentiation between neoplasm and non-neoplastic syrinx was markedly improved. The sensitivity of MRI for demonstrating intradural extramedullary tumours was greatly improved by gadolinium DTPA and even small lesions or flat meningeal infiltrates could be visualised. In addition, gadolinium DTPA improved the delineation and localisation of larger lesions, even if they had already been seen on unenhanced images.

Adolescent↗

PubMed1989

[Diagnostic imaging following reconstructive surgery of the arteries of the legs. Angiodynography versus digital subtraction angiography].

Fifty-three patients were examined by angio-dynography and angiography in a prospective study following vascular surgery of the lower extremities. The question of patency was correctly solved in all cases. A-V communications could be localised in eight out of nine cases. Evaluation of anastomoses is equally accurate by both methods; all angiographically demonstrated stenoses were also visible on sonography. Aneurysms at the anastomoses and peri-vascular fluid collections were better shown by angio-dynography, as might have been expected. The demonstration of the distal run-off, following femoro-crural bypass, presented a problem; in eight cases this could not be achieved because of technical difficulties. Surprisingly, angio-dynography proved superior in demonstrating large distal A-V shunts. Our experience so far indicates that angio-dynography may be used as an alternative to angiography for certain specific indications (bypass patency, large A-V shunts and complications around the anastomosis). Demonstration of vessels, and particularly of distal femoral bypasses can be improved by using the "slow-flow technique".

Adolescent↗

PubMed1989

Prostatic carcinoma and benign prostatic hyperplasia: MR imaging with histopathologic correlation.

Twenty-eight patients with prostatic carcinoma who underwent magnetic resonance (MR) imaging and subsequent radical prostatectomy were studied. The resected prostates were sectioned axially, and the whole-mount prostatic specimen was compared with the corresponding MR images. The carcinoma could be identified in 20 cases (71%), but the tumor volume was underestimated in 12 patients (43%). In 19 of 20 visualized cases (95%), the carcinoma was seen as an area of low signal intensity within the peripheral zone on T2-weighted images. However, in one case the signal intensity of the carcinoma was higher than that of the remainder of the peripheral zone. All carcinomas were located within the peripheral zone. The accuracy of MR imaging in the prediction of extraglandular tumor spread was 82%, with a sensitivity of 37.5% and a specificity of 100%. Nineteen patients (67%) exhibited histologically benign hyperplasia, which could be identified on MR images in 10 cases (53%). The signal intensities of the nodules varied. All areas of benign hyperplasia were located within the central zone. The location of the pathologic changes must therefore be considered in differential diagnosis.

Adenocarcinoma↗