Hartmut Becker

Hannover Medical School, Hannover, Lower Saxony, Germany

Are you Hartmut Becker?

Claim your profile

Publications (35)60.71 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A 49-year-old female with diabetes and chronic low back pain was treated with computed tomography-guided injections after years of unsuccessful pain management. Magnetic resonance imaging (MRI) demonstrated degenerative changes of the lumbar spine with disk herniation, facet joint degeneration, and instability of the presacral segment. Following epidural steroid injection, local infection and sepsis occurred and, finally, tetraparesis developed. A cervical epidural abscess was demonstrated on follow-up MRI and evacuation was performed. The patient survived severely handicapped. Legal proceedings were initiated against the radiologists. They were accused of causing damage to the patient. The plaint was defeated with special reference to the report and expertise of the neuroradiologic evidence.
    Clinical Neuroradiology 09/2009; 19(3):220-6. · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 43-year-old male subject without neurological deficits presented left eye ptosis and diplopia caused by subcutaneous emphysema after high-pressure (2.2 MPa) air injury. Ophthalmologic examination disclosed bilateral subconjunctival air, with no visible conjunctival lacerations. The computed tomography presented an orbital emphysema, a fracture of the orbital floor and intracranial air particularly periclival and pre-chiasmal. Visus stayed at a constant good level. After 36 hours, both intracranial air and intraorbital emphysema were markedly reduced without surgical intervention. However, detailed ophthalmological examination showed binasal deficit in the visual field. Orbital emphysema due to high-pressure air injury has rarely been reported in literature.
    07/2009; 30(5):133-136.
  • Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 11/2008; 29(7):1037-8. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of our study was to evaluate the safety and efficacy of intra-arterial (IA) thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute stroke due to occlusion in the anterior or posterior circulation. We retrospectively analyzed the clinical and radiological data of 88 consecutive patients with acute ischemic stroke who underwent emergency cerebral angiography for the purpose of subsequent IA thrombolysis. The neurological deficit on admission and discharge was graded using the National Institutes of Health Stroke Scale (NIHSS) score. Baseline computer tomography (CT) scans were examined for any signs indicative of cerebral ischemia. The angiographic findings were classified according to the Thrombolysis in Myocardial Infarction (TIMI) score for myocardial infarction. Follow-up CT scans were examined for hemorrhagic complication. Of the 88 patients who underwent IA thrombolysis, 63 presented with complete or partial arterial occlusion in the suspected perfusion area. In these 63 patients, the median NIHSS score dropped from 15 points on admission to 10 points at discharge. The recanalization rate was 52.6% for partial and complete reperfusion. In-hospital mortality was 20.6% (9.1% for carotid, 44.4% for basilar territory occlusion). Intracerebral bleeding (ICB) occurred in 38.6% of the patients with occlusion in the anterior circulation, resulting in these patients presenting a worse clinical outcome than those without ICB. Only minor extracranial bleedings occurred in 20.6% of patients. Patients with ICB had a significantly higher frequency of ischemic signs on the baseline CT scan. Occlusion of a cerebral artery is present in about 75% of the patients eligible for thrombolytic therapy. Intra-arterial thrombolysis using rt-PA in patients with acute ischemic stroke can achieve re-vascularization, although ICB remains the major risk factor affecting its efficacy.
    Neuroradiology 02/2008; 50(1):75-83. · 2.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study examined the explanatory power of 3-dimensional visualization of middle ear prostheses and to introduce this method as a supplementary diagnostic tool. Various prostheses were examined in vitro. Surface rendering and perspective volume-rendering techniques were compared with axial, curviplanar, and maximum intensity projection images. One hundred three patients with hearing difficulty underwent high-resolution computed tomography scanning. The 3-dimensional images of 41 patients after nonspecific middle ear surgery were compared with the tympanoscopic findings. The PVR technique allowed the depiction of the smallest individual substructures of the prostheses. The evaluation of the prostheses' localization using PVR was significantly better than using maximum intensity projection (P < 0.001). Surface rendering showed no advantages over 2-dimensional imaging. Diagnostic findings of high-resolution computed tomography were comparable to tympanoscopy (specificity 100%, sensitivity 95.1%). The 3D depiction facilitates the evaluation of middle ear prostheses fitting.
    Journal of Computer Assisted Tomography 01/2008; 32(2):304-12. · 1.58 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The increasing incidence of central nervous system (CNS) lymphoma in the general population, especially in young adults with AIDS, should alert the otolaryngologist that in future there will be an even greater incidence of this rare disease. It may be responsible for hearing loss accompanied by other neurological deficits. CNS lymphoma often has a rapidly progressive course. Early diagnosis and rapid therapy are crucial for a better prognosis. We report a case of primary CNS lymphoma involving both internal auditory canals that presented with sudden deafness and disequilibrium accompanied by facial and abducens nerve palsy.
    Skull Base Surgery 12/2007; 17(6):409-12. · 0.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Schimke-immuno-osseous dysplasia is an autosomal-recessive multisystem disorder with the prominent clinical features disproportionate growth failure, progressive renal failure, and T-cell immunodeficiency. Neurological symptoms caused by transient ischemic attacks (TIAs) and strokes are a typical clinical finding in severe SIOD. Cerebral ischemia and white matter changes, moyamoya phenomena and absence of a cerebellar hemisphere and partial absence of the cerebellar vermis have been described in patients with severe SIOD. We present three SIOD patients with atrophy of the caudal parts of the cerebellar vermis (posterior lobule) and of the cerebellar hemispheres. We hypothesize that these cerebellar abnormalities are a continuum of the ongoing vascular disease in severe SIOD.
    American Journal of Medical Genetics Part A 10/2007; 143A(17):2040-5. · 2.30 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hemangiomas rarely occur in the internal auditory canal. These tumors originate from the capillary bed of the epineurium surrounding the nerve and can either compress or infiltrate the nerve. Depending on location and the nerve of origin, these lesions can cause severe and progressive sensorineural hearing loss, tinnitus, facial nerve palsy, or vertigo even when they are relatively small. The presence of a small contrast-enhancing tumor in the internal auditory canal accompanied by severe sensorineural hearing loss and facial nerve palsy, should raise the suspicion of a hemangioma. Early recognition and surgical intervention in these benign tumors may improve the chance of preserving the functional integrity of the facial nerve and provides better results after nerve reconstruction. Due to their relative small size, the temporal bone CT-scan may show no evidence of pathological widening of the internal auditory canal or the typical intralesional calcifications at the time of presentation. MRI with Gadolinium is the imaging method of choice and a high index of clinical suspicion is necessary for the diagnosis of these tumors. In this paper we report about a 51-year-old male presented with right-sided sensory-neural deafness and facial nerve palsy, accompanied by severe tinnitus and ipsilateral loss of vestibular function due to a cavernous hemangioma in the internal auditory canal.
    Archiv für Klinische und Experimentelle Ohren- Nasen- und Kehlkopfheilkunde 06/2007; 264(5):569-71. · 1.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We sought to evaluate the accuracy of the perfusion computed tomography (PCT) deconvolution-based brain perfusion measurements and the lesions' (infarct and penumbra) volumetric with regard to arterial input function (AIF) selection in patients with acute stroke. Eighteen consecutive patients with symptoms of acute stroke underwent PCT at admission. Follow-up magnetic resonance imaging was obtained in all patients after 3.6 +/- 1.7 days (range, 1.5-6 days). PCT maps were generated focusing on the anterior cerebral artery (ACA) and branches of the middle cerebral artery (MCA) ipsilateral and contralateral to the ischemic lesion as AIFs. Infarct, penumbra, and total ischemic lesion were delineated on cerebral blood flow (CBF) maps. CBF, cerebral blood volume (CBV), and mean transit time (MTT) were calculated in the ischemic regions as provided by the 3 different AIFs, the normality test was applied for the obtained parameters, and the values were correlated (Pearson's correlation coefficient). Volumes of the ischemic regions (as obtained by the different AIFs) also were correlated and compared (paired t test) to the follow-up infarct volume. The CBF and CBV values obtained by the different AIFs in the infarct, penumbra, and total ischemic lesion were significantly correlated (r=0.94-0.96, P<or=0.01). Only in the infarct region calculated MTT values were correlated (r=0.88-0.91, P<0.05) between the different AIFs groups. High correlation coefficients (r=0.79-0.91, P<0.001) were observed between the admission PCT infarct and total ischemic volume and the MRI follow-up infarct volume. ACA as AIF provided the best correlations (r=0.91, P=0.0002) with the follow-up measurements. No statistically significant difference was found between the 3 different AIF-estimated admission total ischemic volumes and the follow-up infarct volume. The AIF selection in the ACA as well as in the ipsilateral (to the hypoperfused area) or contralateral branches of the MCA has no statistically significant impact on the calculation of the CBF, CBV values, and the volume estimation of the ischemic region in the acute stroke patients.
    Investigative Radiology 04/2007; 42(3):147-56. · 5.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report a case of synchronous olfactory bulb meningioma and undifferentiated carcinoma of the nose and paranasal sinuses that involved and destroyed the anterior skull base and mimicked intracranial invasion by a carcinoma. The heterogeneity of tissue types in the skull base gives rise to a diverse variety of benign and malignant neoplasms which have totally different prognoses. Synchronous development of benign and malignant primary tumors both originating from and involving the skull base at the same location is very rare and may cause confusion for both the skull base surgeon and neuroradiologist.
    Skull Base Surgery 04/2007; 17(2):153-6. · 0.72 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: High-resolution imaging, as provided by flat-panel-based volume computed tomography (fpVCT), could increase navigation accuracy and could therefore improve image-guided procedures or make novel navigated surgery concepts possible. Intraoperative navigation is an accepted tool in head and neck surgery. However, its use is limited in the lateral cranial base because of its low surgical accuracy. Surgical accuracy is substantially influenced by the resolution of the underlying data set. The fpVCT offers a resolution of nearly two times higher than multislice computed tomography (MSCT). Target registration error (TRE), as a measurement for surgical navigation accuracy, should decrease when navigation is based on fpVCT data sets. An acrylic glass phantom with 37 fiducial points was scanned in a current MSCT and in an experimental fpVCT. Both data sets were imported in an optical navigation system. Five fiducial points were used for registration, and seven points were used for measuring TRE. The distance between the indicated pointer tip and the corresponding fiducial point in data set was measured as TRE. Registration and TRE measurement were repeated five times for each computed tomographic data set. Average TREs were calculated, and results were compared using t-test. The average TRE using MSCT (0.82 mm [standard deviation, 0.35 mm]) was significantly higher than that using fpVCT (0.46 mm [standard deviation, 0.22 mm]) (p < 0.01). Submillimeter surgical navigation accuracy is possible using high-resolution fpVCT. This could be highly beneficial in cranial base surgery navigation.
    Ontology & Neurotology 02/2007; 28(1):129-34. · 2.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [(15)O]H(2)O PET using multilinear least-squares minimization procedure based on the one-compartment model. In corresponding transaxial PET scans, CBF values were extracted using standardized ROIs. The baseline perfusion CT-CBF values were lower in perfusion CT than in PET (P>0.05). CBF values obtained by perfusion CT were significantly correlated with those measured by PET before (P<0.05) and after (P<0.01) acetazolamide challenge. Nevertheless, the cerebrovascular reserve capacity was overestimated (P=0.05) using perfusion CT measurements. The AIF selection relative to the side of carotid stenosis did not significantly affect calculated perfusion CT-CBF values. In conclusion, the perfusion CT-CBF measurements correlate significantly with the PET-CBF measurements in chronic carotid stenotic disease and contribute useful information to the evaluation of the altered cerebral hemodynamics.
    European Radiology 11/2006; 16(10):2220-8. · 4.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report a case of fractured occipital condyle caused by minor trauma accompanied by light pain on palpation at the lateral cervical trigonum. A 15-year-old boy complained of nuchal pain, particularly pain on palpation at the left lateral cervical trigonum in the absence of neurologic deficits after head deceleration trauma. Computed tomography demonstrated a unilateral nonluxated fracture of the occipital condyle. Owing to consequent immobilization by means of cervical orthosis, pain disappeared after the first 48 hours. Follow-up examination 4 weeks later showed no neurologic deficits. The boy had no severe impairment of movements at the cervical spine.
    Journal of Pediatric Surgery 11/2006; 41(10):1774-6. · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Flat-panel based volume computed tomography could improve cochlear implant electrode evaluation in comparison with multislice computed tomography. Flat-panel based volume computed tomography offers higher spatial resolution and less metal artifacts than multislice computed tomography. Both characteristics could improve the evaluation of challenging but important questions in cochlear implantation assessment, such as an exact imaging of cochlea, osseous spiral lamina, electrode array position, and single electrode contacts. These questions are not currently fully answered by multislice computed tomography. Four isolated temporal bone specimens were scanned in a current multislice computed tomography scanner and in two experimental flat-panel based volume computed tomography scanners before and after cochlea implantation. To compare flat-panel based volume computed tomography and multislice computed tomography, four features were rated according to the following criteria: 1) visibility of the cochlea; 2) visibility of the osseous spiral lamina; 3) discernibility of individual electrode contacts; and 4) the ability to determine the electrode array position relative to scala tympani and scala vestibuli. Layer-by-layer microgrinding pictures were used as the ground truth for verification of imaging findings. Flat-panel based volume computed tomography was superior to multislice computed tomography in all four features rated. The cochlea and facial nerve canal were much better delineated in flat-panel based volume computed tomography. The osseous spiral lamina and single electrode contacts were only visible in flat-panel based volume computed tomography. Assessment of implant position with regard to the cochlear spaces was considerably improved by flat-panel based volume computed tomography. Cochlear implantation assessment could be improved by flat-panel based volume computed tomography and, therefore, would be highly beneficial for cochlea implantation research and for clinical evaluation. However, these first results were shown by scanning isolated temporal bone specimens; scanning whole human skull bases might be more challenging.
    Ontology & Neurotology 07/2006; 27(4):491-8. · 2.01 Impact Factor
  • Hartmut Becker, Friedrich Götz
    [Show abstract] [Hide abstract]
    ABSTRACT: Bericht über eine präoperative Embolisation eines parietalen Falxmeningeoms mit 50-µ-Partikeln. Es kam zu einem Visusverlust des rechten Auges. Ursache war eine nicht erkannte Anastomose zwischen der A. meningea media und der A. ophthalmica. Die Komplikation hatte einen Rechtsstreit zur Folge. Das Gericht verurteilte die beklagte Klinik zur Zahlung eines Schmerzensgeldes in Höhe von 25 000 Euro. Report of a preoperative embolization of a parietal meningioma of the falx with 50-µ particles. During the procedure, it came to a visual loss of the right eye. The cause was a nondiagnosed anastomosis between the middle meningeal artery and the ophthalmic artery. The complication was followed by a lawsuit. The court condemned the accused hospital to pay a compensation of 25,000 Euros.
    Clinical Neuroradiology 02/2006; 16(1):59-62. · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study is to investigate the inner ear malformations in patients with Goldenhar syndrome and to hypothesize the potential embryopathogenesis of these malformations. Retrospective case review. Tertiary referral center. Fourteen patients with Goldenhar syndrome. Each patient underwent hearing tests and high-resolution computed tomography (CT) of the temporal bone. In six patients, magnetic resonance imaging of the temporal bone also was performed. Among the 14 patients with Goldenhar syndrome, 13 had outer and middle ear anomalies and 5 (36%) had inner ear malformations, including one case of common cavity. Our observations regarding inner ear anomalies in Goldenhar syndrome correlate with the reported cases in the literature and may help to hypothesize the embryological origin of these malformations, which can caused by an early developmental arrest in the fourth gestational week. Specialists evaluating patients with Goldenhar syndrome should be aware of the possibility of inner ear malformations, which could be diagnosed earlier with appropriate imaging studies.
    Ontology & Neurotology 06/2005; 26(3):398-404. · 2.01 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To present and evaluate a registration method to fuse complementary information of CT and MRI of the temporal bone. CT and MRI of the temporal bone of 26 patients were independently registered 4 times. A manual, iterative, intrinsic, rigid, and retrospective registration method was used. Mean CREm (consistency registration error) was calculated as a reproducibility measurement. CREm was 0.6 mm (95% CI = 0.52-0.68 mm). T-test revealed no difference between pathologic and normal cases (t[102] = -1.71; P = 0.09). Time needed: 13 minutes. In the registered and fused datasets, important bony surgical landmarks (eg, facial nerve canal, inner ear) could be assessed in 3 dimensions relatively to tumor tissue (eg, acoustic schwannoma). Fluid distribution within partially obliterated cochleae could be assigned to either scalae. An accurate, reproducible registration and fusion method that improves tumor surgery and cochlea implantation planning with only minor changes to the clinical workflow was presented and described. We suggest this method in selected cases.
    Journal of Computer Assisted Tomography 04/2005; 29(3):305-10. · 1.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this 4-part series is to demonstrate the high-resolution axial and coronal anatomy of temporal bone from a flat-panel detector-based volume computed tomography (CT) scanner (parts I and II); these imaging planes are then used to outline the effect of different surgical procedures commonly applied to the temporal bone (parts III and IV). The structures that are removed and/or altered in 11 different surgical procedures are color coded and inscribed in axial and coronal sections. Clinically important imaging features and complications after these operations are also discussed. In these high-resolution images, many structures that are below the resolution limit of conventional CT can be seen and localized. It is hoped that this exposition enables one to visualize these structures and surgeries in the mind's eye, even when they fall below the resolution limit using a conventional CT scanner. This article (part II) focuses on the preoperative coronal anatomy.
    Journal of Computer Assisted Tomography 01/2005; 29(4):566-9. · 1.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this four-part series is to show the high-resolution axial and coronal anatomy of the temporal bone from a flat-panel detector-based volume CT (parts 1 and 2); these imaging planes are then used to outline the effect of different surgical procedures commonly applied to the temporal bone (parts 3 and 4). The structures that are removed or altered in 11 different surgical procedures are color-coded and inscribed in axial and coronal sections. Clinically important imaging features and complications following these surgeries will also be discussed. In these high-resolution images, many structures that are below the resolution limit of conventional CT can be seen and localized. It is hoped that one would be able to picture these structures and surgeries, in the mind's eye, even when they fall below the resolution limit using a conventional CT scanner. This article (part 1) focuses on the preoperative axial anatomy.
    Journal of Computer Assisted Tomography 01/2005; 29(3):420-3. · 1.58 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was to determine how well a prototypical volume CT (VCT) scanner with a flat-panel detector system defines fine structures in temporal bone. Four partially manipulated temporal-bone specimens were imaged by use of a prototypical cone-beam VCT scanner with a flat-panel detector system at an isometric resolution of 150 microm at the isocenter. These specimens were also depicted by state-of-the-art multisection CT (MSCT). Forty-two structures imaged by both scanners were qualitatively assessed and rated, and scores assigned to VCT findings were compared with those of MSCT. Qualitative assessment of anatomic structures, lesions, cochlear implants, and middle-ear hearing aids indicated that image quality was significantly better with VCT (P < .001). Structures near the spatial-resolution limit of MSCT (e.g., bony covering of the tympanic segment of the facial canal, the incudo-stapedial joint, the proximal vestibular aqueduct, the interscalar septum, and the modiolus) had higher contrast and less partial-volume effect with VCT. The flat-panel prototype provides better definition of fine osseous structures of temporal bone than that of currently available MSCT scanners. This study provides impetus for further research in increasing spatial resolution beyond that offered by the current state-of-the-art scanners.
    American Journal of Neuroradiology 09/2004; 25(8):1417-24. · 3.17 Impact Factor