Browse Health
Radiologist
22 years of experience
Accepting new patients

Education ?

Medical School Score
Wayne State University (1988)
  • Currently 1 of 4 apples

Awards & Distinctions ?

Associations
American Board of Radiology

Affiliations ?

Dr. Hoeffner is affiliated with 3 hospitals.

Hospital Affilations

Score

Rankings

  • University of Michigan Hospitals & Health Centers
    1500 E Medical Center Dr, Ann Arbor, MI 48109
    • Currently 4 of 4 crosses
    Top 25%
  • University of Michigan Health System
  • Ann Arbor Veterans Affairs Medical Center
    2215 Fuller Rd, Ann Arbor, MI 48105
  • Publications & Research

    Dr. Hoeffner has contributed to 12 publications.
    Title Cerebral Blood Flow Alterations in Pain-processing Regions of Patients with Fibromyalgia Using Perfusion Mr Imaging.
    Date March 2012
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    Widespread pain sensitivity in patients with FM suggests a CNS processing problem. The purpose of this study was to assess alterations in perfusion as measured by DSC in a number of brain regions implicated in pain processing between patients with FM and healthy controls.

    Title Safety of Intravenous Thrombolytic Use in Four Emergency Departments Without Acute Stroke Teams.
    Date February 2011
    Journal Academic Emergency Medicine : Official Journal of the Society for Academic Emergency Medicine
    Excerpt

    The objective was to evaluate safety of intravenous (IV) tissue plasminogen activator (tPA) delivered without dedicated thrombolytic stroke teams.

    Title Cerebral Perfusion Imaging.
    Date March 2006
    Journal Journal of Neuro-ophthalmology : the Official Journal of the North American Neuro-ophthalmology Society
    Excerpt

    There are multiple imaging techniques available to assess cerebral perfusion, including positron emission tomography (PET), xenon computed tomography (XeCT), single photon emission computed tomography (SPECT), perfusion-weighted MRI (PWI), and perfusion computed tomography (PCT). Current interest has focused mainly on their use in the setting of acute brain ischemia. Perfusion imaging may be able to distinguish infarcted from salvageable ischemic tissue as a guide to treatment. Perfusion techniques may also be helpful in cases of chronic ischemia, post-subarachnoid hemorrhage vasospasm, trauma, and contemplated therapeutic carotid artery occlusion.

    Title Delineation of Lateral Tentorial Sinus with Contrast-enhanced Mr Imaging and Its Surgical Implications.
    Date September 2004
    Journal Ajnr. American Journal of Neuroradiology
    Excerpt

    BACKGROUND AND PURPOSE: The lateral tentorial sinus (LTS) has not been well described in the imaging literature. The aim of this study was to investigate the value of MR imaging in assessing the LTS, which may provide guidance for preoperative planning. METHODS: Fifty-five adult patients underwent MR imaging of the brain. Four neuroradiologists evaluated the studies for delineation of the LTS and its branches. Presence of arachnoid granulation and dominance of the venous drainage also were reported. RESULTS: An LTS was detected in 104 of 110 lobes. The LTS in each lobe was classified as type I (candelabra) in 30 (28.8%), type II (independent veins) in 22 (21.1%), and type III (venous lakes) in 37 (35.5%); in 15 (14.4%) of the lobes, the LTS was indeterminate. LTS branches were inconsistently detected, with the exception of the vein of Labbé (VL). Five of eight branches were seen in approximately half of the cases. The VL was identified in 94 (85.4%) lobes. Among these, 53 (56.4%) were draining into the LTS and 22 (23.4%) into the transverse sinus; in 19 (20.2%) cases, the terminal portion was not visualized. The right transverse sinus was dominant in 19 (34.5%) patients and the left in 18 (32.7%); codomination was present in 18 (32.7%) cases. At least one arachnoid granulation was seen in the transverse sinus in 27 (49.1%) patients. CONCLUSION: In many instances, the LTS and VL drainage patterns were well delineated on routine MR images. For selected cases, this information may be crucial during lateral skull base surgery to avoid venous infarct.

    Title Cerebral Perfusion Ct: Technique and Clinical Applications.
    Date June 2004
    Journal Radiology
    Excerpt

    Perfusion computed tomography (CT) is a relatively new technique that allows rapid qualitative and quantitative evaluation of cerebral perfusion by generating maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). The technique is based on the central volume principle (CBF = CBV/MTT) and requires the use of commercially available software employing complex deconvolution algorithms to produce the perfusion maps. Some controversies exist regarding this technique, including which artery to use as input vessel, the accuracy of quantitative results, and the reproducibility of results. Despite these controversies, perfusion CT has been found to be useful for noninvasive diagnosis of cerebral ischemia and infarction and for evaluation of vasospasm after subarachnoid hemorrhage. Perfusion CT has also been used for assessment of cerebrovascular reserve by using acetazolamide challenge in patients with intracranial vascular stenoses who are potential candidates for bypass surgery or neuroendovascular treatment, for the evaluation of patients undergoing temporary balloon occlusion to assess collateral flow and cerebrovascular reserve, and for the assessment of microvascular permeability in patients with intracranial neoplasms. This article is a review of the technique, clinical applications, and controversies surrounding perfusion CT.

    Title Carotid Perfusion Ct with Balloon Occlusion and Acetazolamide Challenge Test: Feasibility.
    Date June 2004
    Journal Radiology
    Excerpt

    Carotid balloon test occlusion (BTO) is used to assess the collateral circulation and cerebrovascular reserve in patients in whom carotid artery occlusion is contemplated. Eight patients in whom the test was successful were evaluated with perfusion computed tomography (CT) in the resting state and after acetazolamide challenge. Three of the patients showed symmetric blood flow and normal response to acetazolamide. One of them underwent permanent carotid occlusion and did not develop any delayed ischemic stroke. The remaining five patients showed asymmetric blood flow. One of them had markedly low blood flow and abnormal response to acetazolamide. The patient developed ipsilateral hemispheric stroke following permanent carotid occlusion after the superficial temporal artery to middle cerebral artery bypass graft occluded. In the other four patients, the steal phenomenon was seen in ipsilateral and contralateral hemispheres. Although definitive quantitative values for perfusion CT are not yet standardized, it may be feasible to predict that the patients with symmetric blood flow and normal acetazolamide-enhanced challenge test results will do well after permanent carotid occlusion. Patients with asymmetric blood flow and abnormal response to the acetazolamide challenge test may require a revascularization procedure to protect them from delayed ischemic stroke.

    Title Computed Tomography Perfusion of Squamous Cell Carcinoma of the Upper Aerodigestive Tract. Initial Results.
    Date October 2003
    Journal Journal of Computer Assisted Tomography
    Excerpt

    OBJECTIVE: To define the computed tomography (CT) perfusion characteristics of head and neck squamous cell carcinoma. METHODS: Fourteen consecutive patients with untreated squamous cell cancers of head and neck underwent CT of the head and neck along with CT perfusion imaging through the primary site. For the perfusion studies, CT density changes in blood and tissues were kinetically analyzed using the commercially available CT Perfusion 2 software (General Electric Medical Systems. Milwaukee, WI) on a GE Advantage Windows workstation. This yielded parameter maps of fractional tissue blood volume (mL/100 g), blood flow (mL x 100 g(-1) x min(-1)), mean transit time (s), and microvascular permeability surface area product (mL x 100 g(-1) x min(-1)). One head and neck radiologist analyzed perfusion data. Regions of interest (ROI) were placed over the primary tumor site, tongue base, and adjacent muscle groups. The average values of tissue blood volume (BV), blood flow (BF), mean transit time (MTT), and capillary permeability surface area product (CP) were then calculated for the tumor and compared with the average values for the tongue base and adjacent musculature. To determine a statistically significant difference between the tumor and muscle parameters, the Wilcoxon sign test, a nonparametric test for paired data, was employed. RESULTS: The average values of CP, BF, and BV were higher in primary tumor (41.9, 132.9, 6.2, respectively) than in tongue base or adjacent muscular structures. The MTT was reduced in primary tumors (4.0) compared with adjacent normal structures. The above differences were statistically significant (P<0.05). CONCLUSIONS: We obtained baseline perfusion data for head and neck squamous cell cancers and compared it with adjacent normal structures. Our initial results suggest that CT perfusion parameters (CP, BF, BV, and MTT) can be used to help differentiate head and neck squamous cell carcinoma (SCCA) from adjacent normal tissue.

    Title Development of a Protocol for Coronal Reconstruction of the Maxillofacial Region from Axial Helical Ct Data.
    Date June 2001
    Journal The British Journal of Radiology
    Excerpt

    Using a fresh frozen cadaver head, a series of axial helical CT scans were obtained using varying imaging parameters both before and after traumatizing the head. The appearance of reformatted coronal images was optimized for the lowest radiation dose. A protocol for imaging the maxillofacial region was developed that produced diagnostic coronal reconstructed images from the axial helical CT data.

    Title Mra in Cerebrovascular Disease.
    Date July 1997
    Journal Clinical Neuroscience (new York, N.y.)
    Excerpt

    Stroke is a major cause of disability and death each year in the United States. Most cases result from atherosclerotic disease at the carotid bifurcations. The risk of such events can be reduced by carotid endarterectomy in both symptomatic and asymptomatic patients with severe occlusive disease documented by imaging studies. A noninvasive means of determining the degree of stenosis is desirable due to morbidity, mortality, and cost associated with catheter angiography. At the present time the main role of MRA is as a screening test to determine who should undergo catheter angiography.

    Title Magnetic Resonance Imaging of Massive Bone Allografts with Histologic Correlation.
    Date October 1996
    Journal Skeletal Radiology
    Excerpt

    OBJECTIVE. The objective of this study was to better understand the MRI appearance of massive bone allografts. DESIGN. The MRI findings of three massive bone allografts imaged in vivo were correlated with the histologic findings following removal of the allografts. A fourth allograft, never implanted, was imaged and evaluated histologically. PATIENTS. Allografts were placed for the treatment of primary or recurrent osteosarcoma. RESULTS AND CONCLUSIONS. The in-vivo allografts have a heterogeneous appearance on MRI which we attribute to the revascularization process. Fibrovascular connective tissue grows into the graft in a patchy, focal fashion, down the medullary canal from the graft-host junction and adjacent of the periosteum. The marrow spacers are initially devoid of normal cellular elements and occupied by fat and gelatinous material. This normal postoperative appearance of massive bone allografts must be interpreted as recurrent neoplasm or infection in the allograft. Recognition of these complications rests on features outside the marrow.

    Title Mr Imaging Appearance of Intraperitoneal Gelatin Sponge in Mice.
    Date August 1992
    Journal Journal of Magnetic Resonance Imaging : Jmri
    Excerpt

    Intraperitoneal gelatin sponge can mimic a mass lesion on magnetic resonance (MR) images. To determine the MR imaging characteristics of gelatin sponge over time, a 15 x 10 x 4-mm piece of gelatin sponge soaked in saline was surgically implanted in the peritoneal cavity of 14 mice. Two mice underwent a sham operation. Contiguous axial spin-echo images of the abdomen were obtained with T1-weighted, spin-density, and T2-weighted sequences preoperatively and over a 6-week period postoperatively. Gelatin sponge initially appears as a heterogeneous mass of low signal intensity on T1-weighted images and increasing intensity on spin-density and T2-weighted images, containing multiple round foci of very low signal intensity, attributable to air, at all sequences. Over time, signal intensity further increases and becomes more homogeneous on spin-density and T2-weighted images, although foci of air persist to 3 weeks. By 2-4 weeks, the mass is no longer discrete. Foci of air should help differentiate gelatin sponge from tumor and add gelatin sponge to the differential diagnosis of abscess.

    Title Gelatin Sponge Mimicking a Pelvic Neoplasm on Mr Imaging.
    Date December 1991
    Journal Ajr. American Journal of Roentgenology

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