[Liver cirrhosis as sequela of selective hepatic radio-embolization with Yttrium (Y-90) microspheres].
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Angiography↗
Biomedical subjects
P Haage
Publications and source records attributed to P Haage.
Radiological intervention to maintain vascular access.
Stenoses and thromboses of dialysis grafts and fistulae are common problems in patients with end stage renal disease (ESRD). Timely recognition and treatment of access-related complications are essential to achieve long-term access function. Minimally invasive percutaneous interventions are techniques of growing importance for the interventional community. While stenoses can typically be treated by balloon angioplasty (PTA), thrombotic lesions may necessitate the combination of mechanical devices and/or thrombolytic agents with ancillary PTA. In this article, interventional treatments for the failing arteriovenous (AV) access are presented and reviewed.
Angioplasty, Balloon↗
Phase-inversion tissue harmonic imaging compared to fundamental B-mode ultrasound in the evaluation of the pathology of large and small bowel.
Our purpose was to compare phase-inversion harmonic imaging (PIHI) with conventional B-mode ultrasound (US) regarding image quality in the evaluation of bowel pathology. Forty-one patients prospectively underwent intestinal ultrasound scans with US and PIHI in randomly chosen order. Crucial technical parameters were standardized. Bowel morphology as well as perienteric pathology and complications were documented. In 24 cases, the ultrasound results were compared to those of other imaging modalities. Three radiologists evaluated (1) overall image quality, (2) lesion conspicuity and diagnostic confidence, and (3) detection of free fluid on hardcopy films. The ratings for image quality were compared using the two-sample paired t test for means and Bowker's test for symmetry (p=0.05). Compared to US, PIHI provided significantly better overall image quality, lesion conspicuity and diagnostic confidence, as well as better detection of free fluid (p< 0.05). Bowel wall pathology, detected by both modalities, showed good correlation to additional imaging modalities. In 12 patients (29.3%), a gain of crucial diagnostic information was observed with PIHI when compared to US. PIHI significantly enhances sonography of the intestine by offering better overall image quality, better visualization of bowel pathology and associated changes. Additionally, PIHI adds crucial diagnostic information in several patients.
Adolescent↗
[Iliofemoral and iliocaval interventions in deep venous thrombosis].
Significant spontaneous thrombus disintegration in deep venous thrombosis (DVT) occurs very infrequently. On the contrary, these thrombi are prone to appositional growth and migration into the pulmonary arteries. The development of chronic venous insufficiency due to postthrombotic syndrome is a frequent consequence of DVT. Therapeutic options in DVT include anticoagulation and recanalising procedures such as thrombolysis and thrombectomy. After appropriate indication assessment, the interventional radiologist can offer an efficacy-proven minimally-invasive vessel restitution approach by performing locoregional thrombolysis, pharmacomechanical therapy or, particularly in iliocaval thrombosis, mechanical thrombectomy. These methods not only serve to restitute of vessel patency, but also allow preserving venous valve function. In DVT with recurrent pulmonary embolism, retrievable filters with extended implantation duration can be deployed. In chronic proximal venous flow obstruction or in case of significant residual stenosis after thrombolysis, balloon angioplasty with stent implantation is the treatment modality of choice. Consequently, the radiologist can adopt an important role in the treatment of extensive venous disease. In this article, the treatment modalities concerning iliofemoral and iliocaval thrombosis are demonstrated and illustrated.
Blood Vessel Prosthesis↗
[Diagnostic evaluation of chronic inflammatory intestinal diseases in children and adolescents: MRI with true-FISP as new gold standard?].
PURPOSE: To evaluate the impact of magnetic resonance imaging (MRI) with use of True-FISP sequences in the evaluation of inflammatory bowel-wall changes in children and adolescents with Crohn's disease. Furthermore, the diagnostic procedure in children and adolescents with chronic inflammatory bowel disease (IBD) will be discussed in light of the relevant literature. MATERIAL AND METHODS: Twenty-four children and adolescents aged between 7 and 21 years with suspected or known IBD underwent MRI on a 1.5 T-scanner (Philips ACS-NT, Best, Netherlands). One hour after 1 l of a 2.5 % mannitol solution was given orally, MR imaging was performed using coronal HASTE-M2D, coronal fat-suppressed T2-TSE, axial dynamic T1-weighted GE-sequences before and after i. v.-contrast material injection (0.1 mmol/kg Gd-DTPA) and using a 2D-balanced-FFE-sequence (True-FISP) before and after i. v.-contrast material injection in coronal and axial planes. The MR-images were correlated with endoscopy and the clinical findings. In 14 patients, a recently performed conventional radiographic enteroclysis was available. Each performed MRI sequence was evaluated by three experienced radiologists regarding the sensitivity and specificity of each sequence in the detection of inflammatory bowel wall changes. In addition, the image quality was assessed regarding the different tissue contrasts and the susceptibility to artifacts. The distension of the bowel wall and the patients' acceptance of the MRI examination were recorded. RESULTS: With a sensitivity in detecting inflammatory small bowel changes of 93.3 % (axial pre-contrast, coronal post-contrast) and 100 % (axial post-contrast, coronal pre-contrast), the True-FISP outnumbers the other performed sequences (T1 = 80 %, HASTE = 13.3 % and T2-TSE = 53.3 %). The difference between True-FISP and contrast-enhanced T1 was not statistically significant, whereas the difference between True-FISP and HASTE and T2-TSE, respectively, was statistically significant. The True-FISP sequences revealed a statistically significant superiority regarding the soft-tissue differentiation in comparison to all other performed MR-sequences. The distension of the bowel wall was good in all patients. The patients' acceptance of the MRI examination was excellent. CONCLUSION: The described small bowel MRI examination is appropriate for children and adolescents. With the use of True-FISP sequences, it is a convincing method with an outstanding sensitivity in the diagnosis of IBD. Not least because of the lack of radiation exposure, small bowel MRI ought to replace conventional enteroclysis as a gold standard for IBD diagnosis in children and adolescents.
Adolescent↗
Heart and muscle involvement by extra-medullary myeloid leukemia: a case report and review of the literature.
Extra-medullary myeloid tumours (EMT) have been described after curative treatment for acute myeloid leukaemia (AML) in increasing numbers after allogeneic stem cell transplantation. The sites of manifestations are ubiquitous and the discovery is most frequently guided by symptoms reported by the patient or by findings on clinical examination. This study reports a case of EMT in muscles and the heart 1.5 years after allogeneic transplantation for an AML with t(8;21)(q22;23) who achieved a complete remission by use of an idarubicine-based combination chemotherapy. Pathological and imaging findings are presented and treatment options are discussed.
Adult↗
Semicircular canal dehiscence: comparison of T2-weighted turbo spin-echo MRI and CT.
We assessed the value of MRI for delineation of dehiscence of the superior or posterior semicircular canal, as compared with CT, the current standard study for this entity. We reviewed heavily T2-weighted fast spin-echo images and high-resolution CT of the temporal bones of 185 patients independently semicircular canal dehiscence and its extent. In 30 patients (19 men, 11 women) we identified dehiscence of the bone over the superior and/or posterior semicircular canal on MRI. In 27 of these cases CT also showed circumscribed bone defects. In one patient dehiscence of the superior semicircular canal was initially overlooked on MRI, but seen on CT. MRI imaging thus had a sensitivity of 96% and specificity of 98%. Knowledge of the appearances of this entity on MRI may contribute to early diagnosis in patients with vertigo due to semicircular canal dehiscence.
Adult↗
Posterior semicircular canal dehiscence: a morphologic cause of vertigo similar to superior semicircular canal dehiscence.
The aim of this study was to assess imaging findings of posterior semicircular dehiscence on computed tomography and to evaluate incidence of posterior and superior semicircular canal dehiscence in patients presenting with vertigo, sensorineuronal hearing loss or in a control group without symptoms related to the inner ear. Computed tomography was performed in 507 patients presenting either with vertigo ( n=128; 23 of these patients suffered also from sensorineuronal hearing loss), other symptoms related to the inner ear, such as hearing loss or tinnitus ( n=183) or symptoms unrelated to the labyrinth ( n=196). All images were reviewed for presence of dehiscence of the bone, overlying the semicircular canals. Twenty-nine patients had superior semicircular canal dehiscence. Of these patients, 83% presented with vertigo, 10% with hearing loss or tinnitus and the remaining 7% with symptoms unrelated to the inner ear. In 23 patients dehiscence of the posterior semicircular canal was encountered. Of these patients, 86% presented with vertigo, 9% with hearing loss or tinnitus and 5% with symptoms unrelated to the inner ear. Defects of the bony overly are found at the posterior semicircular canal, in addition to the recently introduced superior canal dehiscence syndrome. Significant prevalence of vertigo in these patients suggests that posterior semicircular canal dehiscence can cause vertigo, similar to superior semicircular canal dehiscence.
Case-Control Studies↗
[MR imaging of lung ventilation with aerosolized gadolinium-chelates].
PURPOSE: To evaluate the feasibility of magnetic resonance assessment of human lung ventilation with aerosolized Gd-chelates in healthy volunteers. MATERIALS AND METHODS: Five healthy adults (mean age 37 years) were studied with a 1.5 T unit. The volunteers were instructed to inhale the aerosol through an airtight facial mask for 10 minutes. The aerosol was generated with a jet-type small particle nebulizer with attached heater. Ventilation imaging was performed using a respiration-gated dynamic T1-weighted turbo spin echo sequence (T(R) = 199 ms, T(E) = 8.5 ms, 12 signal averages, slice thickness 10 mm). Pulmonary signal intensity changes were calculated before and after nebulization. RESULTS: The investigation was successfully carried out in all volunteers. An acute or delayed allergic reaction to the aerosolized contrast medium was not observed. In 4 of 5 experiments (80 %), a homogeneous signal intensity increase was readily visualized with an average signal increase of 35 % after 10 minutes; in one experiment, the aerosol distribution was slightly heterogeneous. CONCLUSION: The results of the presented phase I clinical study demonstrate the feasibility of human ventilation imaging with aerosolized Gd-chelates for the first time. More trials with a larger number of healthy subjects and patients are needed before the clinical introduction of Gd-based ventilation MR imaging of the lungs.
Adult↗
[Can that be really true?].
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Journal Article↗
Aneurysmal bone cyst: value of MR imaging and conventional radiography.
Our objective was to investigate the accuracy and the diagnostic value of different imaging features of primary aneurysmal bone cysts (ABC) in conventional radiographs and MRI. Conventional radiographs and MR images of 34 patients with a suspected aneurysmal bone cyst were reevaluated by six independent radiologists in a blinded fashion. Morphological features, MR signal characteristics, and contrast enhancement patterns were assessed. Diagnoses were correlated with histology. Sensitivity and specificity of the different imaging findings for each imaging technique were calculated. In 24 patients ABC was histologically proven. In 10 cases diagnoses other than ABC were established. Conventional radiography and MRI each demonstrated a sensitivity of 76.4 and 77.8% with a specificity of 55.0 and 66.7%, respectively. With combined use of both imaging modalities sensitivity and specificity increased to 82.6 and 70%, respectively. The ABC was significantly more often seen as circumscribed lesion with bone expansion, lobulation, septa, and pathological cortical bone reaction than those cases with different diagnoses. Septal contrast enhancement proved to be a useful MR imaging finding in suspected ABC. The combined use of conventional radiographs and MRI revealed the highest sensitivity in the diagnosis of ABC in relation to histology. Magnetic resonance imaging provides improved diagnostic specificity and valuable information on soft tissue changes.
Adolescent↗
Virtual endoscopy combined with intraoperative neuronavigation for planning of endoscopic surgery in patients with occlusive hydrocephalus and intracranial cysts.
We assessed the clinical value of MR ventriculoscopy (virtual endoscopy, VE) combined with image-guided frameless stereotaxy for endoscopic surgery of occlusive hydrocephalus and intracranial cysts. VE was obtained in 20 patients with hydrocephalus and three with intracranial cysts. All surgical operations were endoscopic. The path of the rigid endoscope to the target point was planned using neuronavigation. VE was carried out along the same trajectory retrospectively in 20 cases and prospectively in three. The results were analysed for demonstration of anatomical landmarks and structures at risk. VE was successful in all patients. Possible obstacles to endoscopic access to the lamina terminalis and the basal cisterns and structures at risk, such as the basilar artery, were clearly shown in relation to the direction of the endoscope. However, the floor of the third ventricle and septum pellucidum were not clearly seen and possible abnormalities could therefore not be appreciated. VE can provide realistic simulation of endoscopic third ventriculostomy and cystostomy. The appropriate trepanation point and trajectory of the endoscope can be assessed with regard to the size of the foramen of Monro and the position of vulnerable structures. This simulated trajectory can be adapted to the field of operation by image-guided neuronavigation. This regime may potentially reduce the risk of damage to intracranial structures.
Adolescent↗
[A differentiated approach to the diagnosis of pulmonary embolism and deep venous thrombosis using multi-slice CT].
PURPOSE: To establish a differentiated protocol for multi-slice CT (MSCT) examinations in cases of clinically suspected pulmonary embolism (PE) using pulmonary CT-angiography (CTA) and indirect CT-phlebography (CTP). MATERIALS AND METHODS: 161 patients with suspected PE were examined using an MSCT (SOMATOM Volume Zoom; Siemens, Forchheim, Germany). After intravenous administration of 120 ml of contrast material, a thin collimation chest-CT scan was performed (120 kV, 100 mAs, collimation: 4 x 1 mm). If PE was present, or previous examinations and clinical signs suggested deep venous thrombosis (DVT), a CTP was subsequently completed. CTPs were performed using a 4 x 5 mm protocol (120 kV, 170 mAs). Venous phase scanning, starting from the pelvic crest, was completed in the popliteal fossa three minutes after contrast material injection. In 73 extremities, CTP were compared to the results of ultrasound, phlebography and autopsy. Scan ranges were documented in all patients. Cumulative doses were calculated for male and female subgroups. RESULTS: 62 patients in our series suffered from PE and in 47 of these patients deep venous thrombosis was seen additionally. Of the 99 patients without PE, 47 also received indirect CTP. CTP confirmed the suspicion and extent of DVT in 8 patients. Only in 2 of 39 patients (5.1 %) was previously unknown DVT found, despite the exclusion of PE. Regarding DVT, sensitivity was 94.3 % and specificity was 92.1 % for indirect CTP. Cumulative chest CT doses averaged 3.3 mSv for males and 4.2 mSv for females, the calculated CTP dosage was 9.3 mSv (according to ICRP 60). CONCLUSIONS: The examination protocol presented is suitable for clinical usage in patients with suspected PE. If PE is confirmed, indirect CTP is justified, so that detailed information of the venous system can be obtained. However, the relatively high radiation dosage of an additional CTP requires a strict indication regiment in patients with a negative CTA.
Adult↗
MR-guided percutaneous cryotherapy of the liver: in vivo evaluation with histologic correlation in an animal model.
The purpose of this study was to evaluate the feasibility of MR-guided percutaneous cryotherapy of the porcine liver and to correlate the resulting tissue necrosis with MR imaging and histology. Using an MR-compatible, argon-based cryotherapy system (CryoHit; Galil Medical Ltd., Israel) with 2- and 3-mm diameter tapered cryotherapy probes, MR-guided percutaneous cryotherapy was performed in seven pigs (mean body weight, 40 kg) under general anesthesia in a short-bore magnet (1.5 T ACS NT; Philips, The Netherlands) using an ultrafast T2-weighted single-shot LoLo TSE sequence and a T1-weighted gradient-echo sequence. The frozen liver tissue was depicted accurately on fast T2- and T1-weighted sequences, providing precise delineation of the ablated tissue volume. On follow-up postcontrast MR controls, the cryolesions appeared avascular. They decreased in size compared with the initially frozen volume down to 70% at a 2-week follow-up. Histologically, a coagulation necrosis with a close correlation to the MR follow-up examinations was objectified. No cryotherapy-related complications occurred. J. Magn. Reson. Imaging 2001;13:50-56.
Animals↗
Comparison of aerosolized gadoteridol and gadopentetate dimeglumine for magnetic resonance ventilation imaging of the lung.
The purpose of this study was to compare aerosolized gadoteridol and gadopentetate dimeglumine in regard to homogeneity of aerosol distribution and relative pulmonary signal intensity (SI) changes after a 10-min mechanical ventilation period. Twenty experimental procedures were performed in 10 intubated domestic pigs that were mechanically aerosolized with the nebulized contrast medium. Images were obtained by using a respiratory-gated T(1)-weighted TSE sequence. Pulmonary SI increase for the right and left lung was 26% +/- 25% and 25% +/- 12%, respectively, for gadopentetate dimeglumine, and 45% +/- 12% and 43% +/- 10%, respectively, for gadoteridol. Aerosol distribution was rated homogeneous in all cases by two readers. It is concluded that both contrast agents in aerosolized form are capable of depicting pulmonary ventilation in healthy animals with lung capacities comparable to those of humans. SI differences between gadoteridol and gadopentetate dimeglumine are explained by their considerable difference in viscosity.
Aerosols↗
[MRI-controlled percutaneous cryotherapy of liver metastases].
The prognosis for patients with liver metastases depends on the therapeutic options regarding the treatment of the primary tumor, co-existing extrahepatic metastases and the extent and treatment possibilities of the hepatic metastases themselves. Numerous curative or palliative oncological therapeutic concepts have been introduced in case of non-resectable liver metastases to prolong survival while maintaining a highest possible quality of life. Cryotherapy, which can be performed percutaneously and under magnetic resonance guidance, is one of these manifold therapeutic modalities, combining the inherent advantages of MRI with minimal invasiveness. Excellent visualization of the frozen liver tissue, precise tumor ablation, as well as an almost painless intervention due to the analgetic effect of the ice are implicating percutaneous cryotherapy as an attractive alternative to other ablation techniques. First clinical results are promising. However, meticulous and extensive long-term evaluation on a broad clinical scale is required.
Animals↗
Diuretic-enhanced gadolinium excretory MR urography: comparison of conventional gradient-echo sequences and echo-planar imaging.
The aim of this study was to investigate the utility of different gadolinium-enhanced T1-weighted gradient-echo techniques in excretory MR urography. In 74 urologic patients, excretory MR urography was performed using various T1-weighted gradient-echo (GRE) sequences after injection of gadolinium-DTPA and low-dose furosemide. The examinations included conventional GRE sequences and echo-planar imaging (GRE EPI), both obtained with 3D data sets and 2D projection images. Breath-hold acquisition was used primarily. In 20 of 74 examinations, we compared breath-hold imaging with respiratory gating. Breath-hold imaging was significantly superior to respiratory gating for the visualization of pelvicaliceal systems, but not for the ureters. Complete MR urograms were obtained within 14-20 s using 3D GRE EPI sequences and in 20-30 s with conventional 3D GRE sequences. Ghost artefacts caused by ureteral peristalsis often occurred with conventional 3D GRE imaging and were almost completely suppressed in EPI sequences (p < 0.0001). Susceptibility effects were more pronounced on GRE EPI MR urograms and calculi measured 0.8-21.7% greater in diameter compared with conventional GRE sequences. Increased spatial resolution degraded the image quality only in GRE-EPI urograms. In projection MR urography, the entire pelvicaliceal system was imaged by acquisition of a fast single-slice sequence and the conventional 2D GRE technique provided superior morphological accuracy than 2D GRE EPI projection images (p < 0.0003). Fast 3D GRE EPI sequences improve the clinical practicability of excretory MR urography especially in old or critically ill patients unable to suspend breathing for more than 20 s. Conventional GRE sequences are superior to EPI in high-resolution detail MR urograms and in projection imaging.
Adult↗
Magnetic resonance urography in children: evaluation of suspected ureteral ectopia in duplex systems.
PURPOSE: We evaluate the diagnostic accuracy of magnetic resonance urography in children with suspected ectopic ureters and ureteroceles in duplex systems. MATERIALS AND METHODS: A total of 14 children 4 weeks to 8 years old with a total of 18 duplex systems underwent magnetic resonance urography using a 1.5 tesla scanner. After injection of low dose furosemide, half-Fourier rapid acquisition with relaxation enhancement images were obtained for T2-weighted static fluid magnetic resonance urography. Respiratory gated 3-dimensional gradient echo images were acquired for T1-weighted excretory magnetic resonance urography 5 to 30 minutes after intravenously administered gadolinium. RESULTS: All magnetic resonance examinations were successfully performed without sedation. The diagnostic accuracy of T1-weighted excretory magnetic resonance urography depended on the renal function. Twelve duplex systems with a normal excretory function, including 6 bifid ureters and 6 upper moieties with inferomedial ectopic ureters, were analyzed correctly with the exception of a 6 mm. ureterocele in 1 case. In 6 duplex systems with poor or nonfunctioning upper moieties ectopic ureters were only demonstrated on T2-weighted magnetic resonance urograms. CONCLUSIONS: Respiratory gated excretory and static fluid magnetic resonance urography complement each other in the evaluation of duplex systems in children and provide high accuracy in the evaluation of suspected ectopic ureters and ureteroceles.
Child↗