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Biomedical subjects

M Forsting

Publications and source records attributed to M Forsting.

At least 37 records · Page 2Linked to original sources
PubMed2005

[MR-guided vacuum assisted breast biopsy].

OBJECTIVE: This prospective study was undertaken to determine the feasibility of MR-guided vacuum assisted breast biopsy with the Vacora-vacuum-biopsy system for histological evaluation of suspicious lesions in MR-mammography. MATERIAL AND METHODS: During 3 months MR-guided vacuum assisted breast biopsy was indicated in 12 patients with suspicious lesions in MR-mammography. RESULTS: MR-guided vacuum assisted breast biopsy with the Vacora-vacuum-biopsy system could be performed in 9 of 12 patients. In 2 patients the lesions could not be identified at the time of the intervention. In one patient the intervention could not be performed due to obesity. Histopathology revealed benign lesions in 8 patients and malignancy in one patient. In one of the cases with benign histology, the biopsy specimen was not representative for the lesion. CONCLUSIONS: MR-guided vacuum assisted breast biopsy with Vacora-vacuum-biopsy is technical feasible can be performed with a low complication rate.

Adult↗
PubMed2005

[MR imaging of the pelvis in characterization of adnexal masses].

MRI has proved beneficial in characterizing ovarian masses that are indeterminate by sonographic criteria. MRI can distinguish between benign and malignant ovarian tumors with high sensitivity and specificity and is capable of characterizing many adnexal masses. MRI should be therefore included in the preoperative diagnostic of adnexal masses.

Adnexal Diseases↗
PubMed2005

Treatment of wide-necked intracranial aneurysms with a self-expanding stent: mid-term results.

PURPOSE: To evaluate mid-term clinical and angiographic results after using a self-expanding neurovascular stent and coils for the management of broad-based intracranial aneurysms. METHODS: During the period from August 2001 to October 2004 we treated a total of 42 patients with 44 aneurysms using a self-expandable stent. To date we have data on more than 6 months of follow-up in 25 patients with 26 aneurysms. Aneurysm occlusion was divided into the following categories: 100 % (complete), 95-99 % (subtotal), and < 95 % (incomplete). RESULTS: In 15 aneurysms complete occlusion, in 11 aneurysms subtotal occlusion was initially achieved. Control DSA showed progressive thrombosis in seven aneurysms leading to total occlusion in another 4 aneurysms. Three recanalizations were observed in one large and two giant ICA aneurysms. No vessel occlusion occurred. One vessel stenosis of the stented segment was noted, but it was not clinically relevant. One patient experienced a small embolic infarction after stopping antiplatelet medication. No persistent deterioration of the clinical status occurred. CONCLUSION: Combining a stent with coils seems to be an acceptable treatment option for broad-based intracranial aneurysms. As this special subgroup of treated aneurysms includes only those with an unfavourable geometry, the results are extremely promising.

Aneurysm, Ruptured↗
PubMed2005

[Stenting plus coiling: dangerous or helpful?].

PURPOSE: The purpose of this study was to evaluate the procedural risk of treating acute ruptured aneurysms with a stent-coil combination. MATERIAL AND METHODS: Between August 2001 and January 2004 we treated nine acute subarachnoid hemorrhage (SAH) patients with a combination of stents and platinum coils. RESULTS: Six aneurysms were 100% eliminated; the residual three aneurysms had a 95% to 99% occlusion. A transient thrombosis in the stent in one patient could be recanalized by intravenous application of ReoPro. In another patient an occlusive vasospasm at the distal end of the stent was successfully treated with intraarterial Nimotop. Neurological complications occurred in none of the patients. CONCLUSION: In broad-based aneurysms which cannot be clipped or in which any neurosurgical treatment presents an unacceptably high risk (posterior circulation and paraophthalmic aneurysms), treatment using a combination of stent and platinum coils might be an option even in the acute phase of an SAH. Platelet aggregation can be treated with Aspirin and Plavix after placement of the first coil, vasospasms with intraarterial Nimotop, and acute stent thrombosis with GP IIa/IIIb-antagonists.

Acute Disease↗
PubMed2005

[Infectious diseases of brain parenchyma in adults: imaging and differential diagnosis aspects].

Infectious diseases of the central nervous system have often to be considered in differential diagnosis, particularly in immunocompromised persons. Neuroimaging, specifically advanced techniques such as diffusion-weighted MRI and perfusion MRI contribute much to the differentiation of various brain infections and to delineation of brain infections from other, for instance, neoplastic diseases. In this review we present the imaging criteria for the most important brain infections in adults and discuss in detail differential diagnostic aspects.

Adult↗
PubMed2004

Amplitude changes of unconditioned eyeblink responses in patients with cerebellar lesions.

Timing and amplitude parameters of unconditioned eyeblink responses were investigated in 24 patients with unilateral cerebellar lesions following infarcts within the territory of the superior cerebellar artery (SCA, n=12) and of the posterior inferior cerebellar artery (PICA, n=12). The extent of cortical cerebellar lesions, i.e., which lobules were affected and possible involvement of cerebellar nuclei, was determined by three-dimensional magnetic resonance imaging (3D MRI). Amplitude parameters of eyeblink responses were normalized and expressed as percentage of the unaffected side in patients and the second tested side in age-matched controls. Normalized peak amplitudes, burst area and burst duration were significantly increased in SCA patients with lesions restricted to cortical areas. Burst onset and time to peak were not significantly different compared with controls. Temporal and amplitude parameters of eyeblink responses were unchanged in SCA patients with additional involvement of cerebellar nuclei and in patients with lesions of the PICA territory. Consistent with animal lesion and recording studies and a recent human functional magnetic resonance imaging (fMRI) study, the present data suggest that cortical areas of the superior cerebellum are of importance in eyeblink control in humans. These areas partly overlap with areas known to be critical in eyeblink conditioning.

Adult↗
PubMed2004

[Cardiovascular whole-body MRI: possibilities and limitations in prevention].

Cardiovascular disease is a major challenge to the healthcare with increasing prevalence in western societies. Hence, early detection of cardiovascular pathologies and preventative strategies will experience growing relevance in the future. Magnetic resonance imaging (MRI) nowadays allows a comprehensive analysis of the cardiovascular system. By combining separate examinations of brain, arterial vasculature, and heart the technique permits early detection of pathological changes with high diagnostic accuracy void of adverse events. Such a protocol has been proven feasible and technically robust and can be performed within 45 min. Inherent limitations are low spatial resolution of whole-body MR angiography and lack of functional stress testing of the heart. However, while being suitable as a fast and comprehensive imaging technique for cardiovascular screening purposes, medical consequences and socioeconomic relevance must further be elucidated.

Adult↗
PubMed2004

[New techniques in computed tomography. Significance for urology].

Computed tomographic (CT) imaging has become the modality of choice for the assessment of patients with urological malignancies. Recently, multi-slice CT imaging was introduced, providing faster acquisition times and higher resolution leading to improved image quality. Several studies show that thin-slice, high-resolution acquisition strategies lead to an improved accuracy for T-staging, especially of renal cell carcinomas. Three-dimensional post-processing techniques for the visualization of the vascular supply as well as the ureter (CT-angiography and CT-urography) are helpful for surgical planning. Compared to conventional imaging strategies unenhanced CT images render higher sensitivities and specificities for detecting stone disease in patients with acute flank pain. In the USA unenhanced CT imaging has almost replaced conventional urography, as no contrast agent is administered and the examination time is shorter. PET/CT examinations provide information on the morphology and function of tumors in one examination. However, there are only few data available for the assessment of urologic tumors.

Algorithms↗
PubMed2004

Does intraoperative aneurysm rupture influence outcome? Analysis of 169 patients.

OBJECTIVES: The aim of this study was to evaluate the prognostic value of intraoperative aneurysm rupture (IAR) in patients with subarachnoid hemorrhage (SAH) undergoing surgery for cerebral aneurysms. PATIENTS AND METHODS: Between July 1997 and April 2000, 292 consecutive patients were admitted to our institution with SAH due to ruptured intracranial aneurysms. Of these, 169 patients were treated surgically according to standard microsurgical procedures and were included in this study. Mean age was 47 years. Initial clinical state was graded according to the classification of Hunt and Hess (HH). Outcome was classified according to the Glasgow Outcome Scale as favorable (grades IV and V) and unfavorable (grades I-III). Outcome of patients with intraoperative ruptured and non-ruptured aneurysms was analyzed in correlation to the preoperative clinical state and with respect to the time of surgery and to aneurysm localization. RESULTS: Different rupture rates were observed with respect to the localization of the aneurysm: anterior circulation (n=69) 39.1%, middle cerebral artery (n=46) 34.8%, internal carotid artery (n=48) 31.2%, and posterior circulation (n=6) 16.7%. Patients with HH-grades I-III showed a favorable outcome in 72.2% (61 of 84 patients) without intraoperative rupture and in 71.7% (33 of 46 patients) with intraoperative aneurysm rupture. The corresponding values for patients with HH-grades IV/V were: favorable outcome in 34.6% (9 of 26 patients) and 23.1% (3 of 13 patients), respectively. Poor initial clinical condition (HH IV and V) as well as the initial Fisher grades III and IV were strongly associated with poor clinical outcome. CONCLUSIONS: Intraoperative aneurysm rupture has no impact on the outcome, neither in patients with good initial condition nor for poor grades patients.

Adolescent↗
PubMed2004

Multimodal imaging in the elastase-induced aneurysm model in rabbits: a comparative study using serial DSA, MRA and CTA.

BACKGROUND AND PURPOSE: The elastase-induced aneurysm model in rabbits has proved to be suitable for testing new endovascular occlusion devices. The purpose of this study was to evaluate different imaging modalities for the depiction of anatomy and size of elastase-induced aneurysms and for serial follow-up imaging. MATERIALS AND METHODS: Elastase-induced aneurysms were created in eight Chinchilla bastard rabbits by endoluminal incubation of porcine elastase. Serial imaging was performed using intravenous DSA (IVDSA), contrast-enhanced MRA (CEMRA), and time-of-flight MRA (TOF) 14 days, 4 weeks and 3 months after aneurysm creation. Intraarterial DSA (IADSA) and CT angiography (CTA) were performed after 3 months. Aneurysm size and geometry (height H, width W, neck width N) were compared. RESULTS: On IVDSA after two weeks mean aneurysm height was 6.2 mm (range 2.8 - 11.0 mm), mean aneurysm width was 2.8 mm (range 2.0 - 4.2 mm) and mean aneurysm neck width was 2.7 mm (range 2.0 - 4.2 mm). We did not observed any statistically significant change in aneurysm dimensions during follow-up at 4 weeks (CEMRA: H: 5.4, W: 2.4, N: 2.4; TOF: H: 5.7, W: 2.4, N: 2.7) and 3 months (CEMRA: H: 5.8, W: 2.6, N: 2.6; TOF: H: 6.9, W: 2.8, N: 3.0). Aneurysm dimensions could be best seen on IADSA (H: 6.2, W: 3.0, N: 2.7) with good correlation to CTA (r = 0.94; H: 6.1, W: 2.8, N: 2.6), CE-MRA (r = 0.92), and TOF (r = 0.97). TOF was superior to CEMRA in delineating the aneurysm wall. CONCLUSIONS: Serial imaging using MRA, CTA or intravenous and intraarterial angiography is feasible in the elastase-induced aneurysm model. Contrast-enhanced MRA, TOF-MRA and CTA showed good correlation to IADSA and are all suitable for non-invasive pretherapeutic measurement of aneurysm size.

Angiography↗
PubMed2004

[Value of pelvic MRI in the preoperative diagnosis of endometriosis].

PURPOSE: To determine the value of magnetic resonance imaging (MRI) of the pelvis in the preoperative diagnosis of endometriosis. MATERIALS AND METHODS: Over a period of 8 months, preoperative MRI of the pelvis were obtained in 13 patients with suspected endometriosis (mean patient age 34.6 years; range 25 - 47 years). RESULTS: In 9 of 13 patients (69 %), the diagnosis of endometriosis was made by MRI and confirmed by laparoscopy in 8 cases. In 2 of 13 patients, endometriotic lesions were detectable by laparoscopy only. In the remaining 2 patients, no endometriosis was visible on MRI or by laparoscopy. MRI was able to visualize a total of 19 endometriotic lesions, with 14 (74 %) confirmed by histopathologic examination following laparoscopy. Five of these 19 lesions (26 %) visible on MRI were not seen by laparoscopy. Using laparoscopy and subsequent histopathologic examination, 27 endometriotic lesions were diagnosed, with 13 (48 %) not seen on the preoperative MRI. CONCLUSION: MRI and laparoscopy are complementary diagnostic tools that will best document the full extent of endometriosis when combined. MRI can visualize additional lesions inaccessible to laparoscopy. Thus, MRI of the pelvis should used preoperatively for surgical treatment planning.

Adult↗
PubMed2003

Multilocal magnetic resonance perfusion mapping comparing the cerebral hemodynamic effects of decompressive craniectomy versus reperfusion in experimental acute hemispheric stroke in rats.

This study examined the hemodynamic effects of craniectomy compared to reperfusion on the temporal evolution of cerebral perfusion in different brain regions in a rat model of focal cerebral ischemia. Three groups were investigated: no treatment, reperfusion or craniectomy at 1 h. Perfusion-weighted magnetic resonance imaging (PWI) was performed serially from 0.5 to 6 h. Relative regional cerebral blood flow was calculated for different regions and infarct volume was assessed by histology at 24 h. As conclusion, both, craniectomy and reperfusion increased cerebral perfusion in the acute phase of cerebral ischemia. While reperfusion resulted in a homogeneous improvement of perfusion in the cortex and basal ganglia, craniectomy improved only cortical perfusion in areas directly under the craniectomy site. PWI is well suited to non-invasively monitor perfusion alterations after aggressive therapeutical approaches in stroke.

Acute Disease↗
PubMed2003

Cerebellar responses evoked by nociceptive leg withdrawal reflex as revealed by event-related FMRI.

The aim of the present study was to examine nociceptive leg withdrawal reflex-related areas in the human cerebellum using event-related functional brain imaging (fMRI). Knowledge about cerebellar areas involved in unconditioned limb withdrawal reflex control has some relevance in understanding data of limb withdrawal reflex conditioning studies. Sixteen healthy adult subjects participated. Nociceptive leg withdrawal reflexes were evoked by electrical stimulation of the left tibial nerve behind the medial malleolus. An event-related fMRI paradigm was applied with a total of 30 stimuli being delivered pseudorandomly during 500 consecutive MR scans. Surface electromyographic (EMG) recordings were performed from the left anterior tibial muscle. Only trials with significant reflex EMG activity were used as active events in fMRI statistical analysis. The specified contrasts compared the active event condition with rest. Leg withdrawal reflex-related areas were located within the vermis, paravermis, and lateral posterior cerebellar hemispheres bilaterally. Vermal and paravermal areas in lobules III/IV in the anterior lobe and in lobule VIII in the posterior lobe agree with the cerebellar representation of climbing and mossy fiber hindlimb afferents and voluntary leg movements. They are likely related to efferent modulation of the leg withdrawal reflex and/or sensory processing of afferent inputs from the reflex and/or the noxious stimulus. Additional activation within vermal lobule VI and hemispheral lobules VI/Crus I may be related to other pain-related processes (e.g., facial grimacing, fear, and startlelike reactions).

Adult↗
PubMed2003

Cross-modal plasticity for sensory and motor activation patterns in blind subjects.

Experimental data on cortical reorganization in blind subjects using H(2)(15)O positron emission tomography and functional magnetic resonance imaging (fMRI) showed activation of the visual cortex related to Braille reading and tactile discrimination tasks in congenitally and early blind subjects. The purpose of our study was to differentiate whether occipital activation of blind subjects during Braille reading is task specific or only triggered by sensory or motor area activation. Twelve congenitally and early-onset blind subjects were studied with fMRI during Braille reading, discriminating nonsense dots, sensory stimulation with electromagnetic pulses, and finger tapping. All experiments were performed utilizing a block design with 6 active epochs alternating with 6 rest conditions lasting 34 s each. Echo-planar imaging sequences with 34 transversal slices were performed on a 1.5-T MR scanner. All blind individuals reading Braille and discriminating nonsense dots showed robust activation of the primary, secondary, and higher visual cortex. Application of peripheral electrical stimuli to the reading hand revealed expected sensory activation of the primary somatosensory cortex, but no activation in the visual cortex. Pure motor activation during finger tapping with the reading hand showed expected precentral activation and no activation of visual cortex. In conclusion, occipital activation during Braille reading and discrimination tasks is not due to plasticity of sensory or motor function; pure motor or sensory tasks do not lead to an activation of striate cortex. The brain learns to differentiate between "finger touching" and "finger reading." Our results suggest that activation of the visual cortex in blind subjects is related to higher and more complex brain functions.

Adult↗
PubMed2003

[Dural arteriovenous fistulas with intracranial hemorrhage: diagnostic and therapeutic aspects].

Seven patients presented with intracranial hemorrhage due to arteriovenous dural fistula. Six patients showed intracerebral hemorrhage combined with subdural hematoma and intraventricular hemorrhage in one case respectively, and one patient had infratentorial subarachnoid hemorrhage. Location of the fistulae was frontobasal (n=2), tentorium (n=2), transverse sinus (n=2), and superior sagittal sinus (n=1). Angiography revealed reflux into cortical veins in all cases. Therapy was surgery in both cases with fistula of the anterior cranial fossa with good results. An endovascular intraarterial therapy was performed in a case with circumscribed fistula of the superior sagittal sinus, this patient developed a second dural fistula during follow-up. Two patients with tentorial fistulae had primary endovascular treatment complicated by infarction of both thalami in one case and a recurrence of the fistula in the other. In the last case the fistula was closed by surgery. Out of two patients with widespread fistulae of the transverse sinus one made a good clinical recovery and the other remained unchanged. In the first case definite closure of a remnant of the fistula was refused, in the second no further therapy was recommended.

Aged↗