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P Landwehr

Publications and source records attributed to P Landwehr.

At least 19 recordsLinked to original sources
PubMed2000

[Chronic recurrent parotitis in childhood in monozygotic twins. Magnetic resonance sialography].

Recurrent parotitis is rare in childhood. Its occurrence is characterized by recurrent episodes of swelling and pain in the parotid gland, which are usually accompanied by fever and malaise. Inflammation usually resolves spontaneously during adolescence. The disorder is a condition of unknown etiology. Sialectasis and stricturing occurs in the distal ducts, whereas inflammation of the gland and duct epithelium is probably caused by a low salivary flow rate. Which one can be considered the primary event or secondary change remains unknown. The main-stay of diagnosis is sialography, which depicts typical intraparotidal duct system lesions as strictures or ectasias and excludes sialolithiasis. We here report two 10-year-old male monovular twins who suffered from recurrent swelling and pain in only their left parotid glands. Symptoms were noted approximately every 6 weeks in both patients strictly. Characteristic sialectasis of the distal ducts was demonstrated by magnetic resonance-sialography. Our findings support the hypothesis that recurrent parotitis is caused by a congenital abnormality of the salivary gland ducts. Diagnostic imaging was performed by magnetic resonance imaging during the acute phase of the disease. This technique helps to make the diagnosis without retrograde application of a contrast agent.

Child↗
PubMed2000

[Magnetic resonance tomography in the diagnosis of intra-articular tibial plateau fractures: value of fracture classification and spectrum of fracture associated soft tissue injuries].

PURPOSE: To compare magnetic resonance imaging (MRI) and X-ray tomography in assessing the type of fracture, degree of comminution and amount of articular surface depression in acute tibial condylar fractures and to describe the associated soft tissue injuries diagnosed with MRI. METHOD: 27 patients with acute tibial plateau fractures were investigated using linear X-ray tomography and MRI employing T1-weighted and proton density turbo spin echo, STIR, and T2-weighted gradient echo images. Fractures were classified according to the AO classification system. The degrees of depression and comminution were measured and soft tissue injuries were recorded. RESULTS: Fractures were classified as type B1 in 7, as B2 in 6, and as B3 in 6 cases by MRI. More complex C-type fractures were diagnosed in 8 cases. MR and X-ray grading were consistent with the exception of two B3 fractures, which were graded as B1 by X-ray tomography. X-ray tomography under-estimated the degree of comminution 63% of the patients had either meniscal tears or complete ruptures of their cruciate or collateral ligaments. Ten meniscal tears were diagnosed in 9 of 27 patients. Complete tears of the anterior cruciate ligament were seen in 4, and avulsions of the posterior cruciate ligament in 2 patients. CONCLUSION: MRI allows a detailed assessment of acute tibial plateau fractures and can replace conventional X-ray tomography. The high rate of fracture-associated soft tissue lesions makes MRI an especially valuable tool.

Adult↗
PubMed2000

[MRI-controlled preoperative wire marking of uncertain breast lesions].

PURPOSE: Small suspicious breast lesions that are only visible at MR imaging were preoperatively marked with a hook wire under MR-guidance to allow the removal of the lesion with tissue-sparing surgery. METHOD: In all patients the suspicious lesions were marked preoperatively under MR guidance with a hook wire using a commercially available stereotactic device. Interventions were performed with MR guidance on a 1.0 T and on a 1.5 T system. RESULTS: In 19 patients 22 lesions were localized. One lesion was missed and removed in a second procedure. The mean duration for localization was 66 +/- 20 min (range 38-119 min). In two patients two lesions were localized. The mean deviation of the wire tip to the lesion was 2.0 +/- 2.6 mm. In this series, 6 of 22 lesions were malignant. The mean diameter of the lesion was 7.6 +/- 2.6 mm (range 3-14 mm). CONCLUSION: Suspicious breast lesions detectable only in MR imaging can be accurately localized with a hook wire preoperatively under MR control to remove the lesion with a tissue-saving surgery.

Adult↗
PubMed1999

[Thrombosis of the deep leg and pelvic veins in congenital agenesis of the vena cava inferior].

HISTORY AND ADMISSION FINDINGS: Severe pain and increasing swelling in the region of the right lower leg occurred after unaccustomed physical activity in a 29-year-old man. Physical examination showed painful swelling and livid discoloration of the right lower leg. INVESTIGATIONS: Laboratory tests were consistent with an acute inflammation. Colour Doppler duplex sonography of the leg and pelvic veins bilaterally revealed complete thrombosis of the deep leg and pelvic veins on the right. Spiral computed tomography of the abdomen confirmed deep pelvic vein thrombosis and also demonstrated complete agenesis of the inferior vena cava (IVC). TREATMENT AND COURSE: The patient was fully heparinized and compression bandage applied to the right leg, which was kept elevated, Ibuprofen, 3 x 400 mg daily, was given for pain relief. Anticoagulation treatment with phenprocoumon (Marcumar) was initiated. The patient was discharged much improved after ten days. Duplex sonography after 3 months demonstrated partial recanalization of the right pelvic and deep leg veins. CONCLUSION: Congenital malformations of the IVC are rare. Phlebothrombosis often results in affected patients. Treatment or prevention of thrombosis of the deep veins by anticoagulation is indicated. Additional risk factors for thrombosis--smoking, hormonal contraceptives, immobilization and unusual physical activity--should be strictly avoided.

Adult↗
PubMed1999

[Anisoperistaltic Roux-en-Y reconstruction: rare cause for recurrent cholangitis after hepatic jejunostomy].

Stenosis of the hepatico-intestinal anastomosis after hepaticojejunostomy is a common cause for recurrent cholangitis. In the following report a patient's history of recurrent cholangitis after hepaticojejunostomy performed because of bile duct injury is presented. Preoperative imaging revealed a stricture of the hepatico-intestinal anastomosis and a massive dilatation of the Roux-en-Y loop, so that a draining disorder was assumed. Laparotomy showed an anisoperistaltic Roux-en-Y loop. When assessing the differential diagnosis of recurrent cholangitis after hepaticojejunostomy, anisoperistaltic reconstruction should be considered.

Anastomosis, Roux-en-Y↗
PubMed1999

MR imaging of the chest: mediastinum and chest wall.

This review presents the options and limitations of MRI in non-vascular diseases of the mediastinum and the chest wall. In numerous thoracic pathologies, MRI is a useful supplement to spiral CT. This imaging procedure also allows a contrast-media-free differentiation of solid tumors and vascular lesions (e. g., aortic aneurysms). The advantages of MRI over CT are particularly useful when multiplanar tumor imaging is required prior to surgery to establish the exact spatial relationship between tumor and the other mediastinal structures. Primary indications for MRI in diseases of the mediastinum and chest wall are therefore: (a) tumors of the posterior mediastinum for determining their position in relation to the neural foramina and the spinal canal; (b) chest wall tumors; (c) preoperative multiplanar imaging of primary mediastinal tumors; and (d) contraindications against CT exams with iodine contrast media.

Contrast Media↗
PubMed1999

Spiral CT angiography of the abdominal aorta. Comparison of iodixanol and ioversol.

RATIONALE AND OBJECTIVES: Enhancement characteristics of a nonionic, dimeric, isotonic contrast medium (iodixanol [Visipaque]) were compared with a nonionic, monomeric contrast medium (ioversol [Optiray]) of the same iodine concentration in spiral computed tomography angiography (CTA) of the abdominal aorta. METHODS: Spiral CTA was performed in 78 patients referred for suspected renal artery stenosis (n = 35) and abdominal aortic aneurysm (n = 43). A test bolus was used to time the scan delay, and all patients were injected with 150 ml contrast medium (320 mgI/ml) of either iodixanol (n = 40) or ioversol (n = 38). Contrast enhancement was measured in the aorta, renal arteries, and renal parenchyma. RESULTS: All mean aortic enhancement was slightly higher with iodixanol than ioversol, measured at three different levels (celiac trunk 315 Hounsfield units [HU] versus 300 HU, renal arteries 325 HU versus 312 HU, aortic bifurcation 276 HU versus 266 HU). However, none of them were statistically significant (e.g., P = 0.26 at the celiac trunk level). Similar results were observed in renal artery and parenchyma enhancements. CONCLUSIONS: Iodixanol and ioversol had similar enhancement characteristics in the early arterial phase. Both substances were well tolerated and seem to be well suited for spiral CTA.

Adult↗
PubMed1999

[Performance of different CT angiography imaging modalities in detecting renal artery stenoses].

PURPOSE: Purpose of the study was to compare the sensitivity and specificity of various display modalities in the detection of renal artery stenosis. In particular, the difference between hard-copy reading and interactive analysis at the workstation was assessed. MATERIALS AND METHODS: Selected patients (n = 31) with expected suboptimal conditions for CT angiography due to long-standing hypertension and compromised renal function were included. Six radiologists evaluated independently a total of 77 renal arteries with 49 renal artery stenoses proven by angiography. Image analysis included: mode A: interactive display, analysis of multiplanar reformats and axial sections at the workstation, mode B: visualization of MIPs in the coronal and axial planes as hard copies only, mode C: visualization of MIPs and axial sections as hard copies only. RESULTS: The following sensitivities and specificities were found for internal readers and (readers from outside institutions): mode A: 94.8%, 87.9%, mode B: 97.7% (95.1%), 80.3% (75.4%); mode C: 97.0% (95.3%), 78.8% (76.6%). The differences were statistically not significant (p > 0.05). CONCLUSIONS: Standardized hard copies of MIPs plus axial CT provide sufficient accuracy to detect renal artery stenosis compared to interactive imaging even in this highly selected group of patients.

Adult↗
PubMed1998

The lateral calcaneal artery.

An anatomic study of the lateral extraosseous and intraosseous arterial supply of the calcaneus and the lateral soft tissue was carried out on 10 fresh lower adult cadaver legs using different anatomic and radiologic procedures (plastination, modified Spalteholz clearing technique, digital subtraction and rotational angiography and computed tomographic angiography). Consistent patterns of extraosseous and intraosseous lateral calcaneal vascular anatomy were demonstrated. The lateral calcaneal artery is a branch of the anterior tibial artery which crosses over the calcaneal tuberosity and forms a large lateral arch with the lateral tarsal artery which is a branch of the dorsalis pedis artery. The intraosseous circulation is supplied laterally by the lateral calcanear artery, medially via the short branches of the lateral plantar artery. Comparing magnet resonance images after fresh calcaneal fractures the lateral calcanear artery may be interrupted by the impacted lateral bulge, by the conventional lateral surgical approach, or by applying a lateral osteosynthesis plate. This may cause avascular bone necrosis. Furthermore the lateral calcanear artery can clinically serve as a vascular pedicle for a local rotational skin flap to cover soft tissue defects of the heel.

Adult↗
PubMed1998

Non-invasive vascular imaging of peripheral vessels.

The purpose of this review is to describe recent advances in non-invasive vascular imaging techniques and to discuss their current clinical applications for imaging of peripheral vessels. Principles for applying ultrasound, CT angiography (CTA), and magnetic resonance angiography (MRA) for non-invasive imaging of peripheral arteries and veins are presented. Clinical applications are reviewed for different vascular diseases, therapy planning, and follow-up studies. Conventional Doppler and color duplex sonography are the most cost-effective procedures to detect or rule out peripheral arterial occlusive disease (PAOD) and to provide specific recommendations for therapy. In the near future, contrast-enhanced MRA (CE MRA) with additional axial two-dimensional time-of-flight studies to search for non-anatomic runoff will replace diagnostic intra-arterial digital subtraction angiography (DSA) for planning of reconstructive surgery with acquisition slabs displaying projections similar to intra-arterial DSA. Color duplex sonography should also be the first non-invasive technique applied for the detection of peripheral aneurysms. Preoperative or preinterventional therapy planning of aneurysms may be performed by CTA or CE MRA. Compression ultrasound is the imaging procedure of choice in deep venous thrombosis (DVT). In the preoperative assessment of venous incompetence, color duplex sonography is the imaging technique which is sufficient in most cases.

Aneurysm↗
PubMed1998

Somatosensory evoked potentials: a simple neurophysiological monitoring technique in supra-aortal balloon test occlusions.

The aim of this study was to evaluate somatosensory evoked potentials (SEP) as a simple neurophysiological monitoring method in supra-aortal balloon test occlusions (BTO). The 13 patients examined had carcinoma of the larynx (n = 6), nasopharyngeal malignancy (n = 3), sphenoid meningioma (n = 2), mycotic aneurysm (n = 1), and a tumor of the carotid body (n = 1). Transfemoral balloon occlusion of the internal carotid artery was maintained for 30 min and monitored both clinically and by SEP. None of the 13 patients showed neurological deficits or pathological changes in the SEP. No thromboembolic complications occurred during BTO. In 11 cases the cervical vessels could be spared or reconstructed during surgery. No neurological symptoms occurred during the clinical follow-up. One patient died the day after BTO due to cardiac arrest. Neurophysiological monitoring of preoperative BTO using SEP is a technically simple method. A similar method has been shown to have a high sensitivity and reliability in carotid surgery.

Adolescent↗
PubMed1998

[Interventional palliative therapy].

From diagnostic procedures interventional radiology has developed a large number of therapeutic methods that have found a place in the treatment of palliative care patients. Minimal invasiveness and high efficiency characterise the implantation of metallic stents in the treatment of malignant biliary or esophageal obstruction and vena cava compression syndrome. Transcatheter arterial embolisation, chemoembolisation and chemoinfusion for palliative treatment of inoperable liver malignomas are performed at many centers. A specific concept and an accepted spectrum of indications have to be better defined by prospective trials. Therapeutic decisions in this patient group have to based on the individual case. The interventional radiologists is increasingly involved in the interdisciplinary decision making process.

Bile Duct Neoplasms↗
PubMed1996

Iodixanol vs iopamidol in intravenous DSA of the abdominal aorta and lower extremity arteries: a comparative phase-III trial.

Iodixanol (Visipaque, 320 mgI/ml) was compared with iopamidol (Solutrast, 370 mgI/ml) in a double-blind, randomized, parallel group, intravenous DSA phase-III trial for evaluation of safety and efficacy. A total of 117 patients received iodixanol (n = 60) or iopamidol (n = 57). Diagnostic efficacy was evaluated using categoric and visual analogue scales. Discomfort and adverse events were recorded. A total of 39 patients collected urine up to 72 h after the examination for analysis. Diagnostic efficacy and radiographic density were similar in both groups. Discomfort was milder with iodixanol. The difference between the frequency of adverse events between both groups (iodixanol = 7, iopamidol = 2) was without statistical significance. Creatinine clearance was slightly more affected by iodixanol, whereas the increase in renal excretion of N-acetyl-beta-glucosaminidase (NAG) in the first 24-h collection period after the examination was significantly higher (p < 0.01) with iopamidol. Iodixanol was of equal diagnostic efficacy compared with iopamidol despite its reduced iodine content. Both contrast media are well suited for IV DSA.

Acetylglucosaminidase↗
PubMed1996

[Contrast medium administration in spiral computed tomography: the results of a consensus conference. Institute for Radiodiagnosis, Regensburg].

The rapidity of spiral (helical-) computed tomography requires new protocols for i.v. contrast media administration. Flow rate, volume and delay are discussed controversially in the literature. Hence, a consensus meeting was initiated. In this meeting, problem related questions were designed, discussed and answered using a digital vote system. Spiral-CT-technology was found to be the ideal examination technique for thorax, liver, pancreas, kidney and the retroperitoneal space with an overall agreement between 89 and 97%. The exclusive use of nonionic contrast media and power injectors was recommended by 100% of the participants. More than 90% of the contributors did not accept native scans only for examinations of the neck, thorax, liver, pancreas, kidney and the retroperitoneal space. Regarding volume, flow rate, delay and physical CT-parameters the agreement laid between 50 and 100%. The meeting concluded that randomised controlled studies should be performed to evaluate detailed contrast media protocols for helical CT.

Berlin↗