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Davis PC, Drayer BP, Anderson RE, Braffman B, Deck MD, Hasso AN, Johnson BA, Masaryk T, Pomeranz SJ, Seidenwurm D, Tanenbaum L, Masdeu JC. Head trauma. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000; 215 Suppl:507-24. [PMID: 11037462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Masdeu JC, Drayer BP, Anderson RE, Braffman B, Davis PC, Deck MD, Hasso AN, Johnson BA, Masaryk T, Pomeranz SJ, Seidenwurm D, Tanenbaum L. Multiple sclerosis--when and how to image. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000; 215 Suppl:547-62. [PMID: 11037465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Hasso AN. How to review and retrieve information from the AJNR; or, how to read the AJNR and still have time to ski. AJNR Am J Neuroradiol 1997; 18:1323-4. [PMID: 9282863 PMCID: PMC8338040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Perry JR, Hasso AN. Magnetic resonance imaging of cranial nerve VII. Top Magn Reson Imaging 1996; 8:155-63. [PMID: 8840470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Magnetic resonance imaging (MRI) is well suited for the evaluation of lesions of the seventh cranial (facial) nerve. The preferred MRI approach requires use of multiplanar thin sections of the full course of the nerve from the pons through to its terminal branches on the face. The use of paramagnetic contrast greatly increases the sensitivity of MRI and for the most part precludes the need to use computed tomography scans in conjunction with the MRI scans.
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Seynaeve P, Hasso AN, Thompson JR, Hinshaw DB. Basilar and distal vertebral artery occlusive disease: correlation of MR imaging and MR angiography. JOURNAL BELGE DE RADIOLOGIE 1996; 79:61-7. [PMID: 8767834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The purpose of this study is to evaluate the correlation of brain lesions seen on magnetic resonance imaging with vascular occlusive disease of the basilar and distal vertebral arteries as documented on MR angiography. The clinical findings are also correlated with the findings on MR imaging and MR angiography. The clinical records of twenty-one patients with proven occlusive disease of the distal vertebral and/or basilar arteries were retrospectively reviewed. All the patients were imaged utilizing either the Siemens Magnetom 1.5 T SP 4000 and the Siemens 1.0 T Impact systems. Dual MR angiographic techniques were employed including two-dimensional (2D) and three-dimensional time-of-flight. The 2D sequences utilized fast low angle shot gradient echo sequences. The 3D sequences utilized fast image steady-state precession gradient echo sequences. Gadolinium contrast was utilized for increased angiographic detail in one patient. Magnetization transfer contrast was used in three patients. The individual partitions as well as the maximum intensity pixel projection images were evaluated in each case. The most extensive brain lesions were seen in the group of patients with severe basilar and/or combined vertebrobasilar disease. One-half of these patients showed non-specific scattered foci of T2 lengthening similar to the findings found in a group of patients with noncritical stenosis. MR imaging invariably demonstrated more lesions than were clinically suspected. Even though the brain lesions tended to be more extensive in patients with severe vascular disease, the amount of brain tissue damage was not an adequate parameter to document the degree of vascular narrowing. The degree of vascular narrowing was useful in therapy planning. Such data was obtained by the MR angiograms, but not by MR imaging. MR angiography is a useful complementary examination when lesions in the basilar and distal vertebral vascular territories are diagnosed on MR imaging. MR angiography can differentiate critical from noncritical stenosis and can thus play a key role in the therapeutic decision making process.
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Hasso AN. Clinical reviews: the denouement of investigations in medicine. J Magn Reson Imaging 1995; 5:249. [PMID: 7633099 DOI: 10.1002/jmri.1880050302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Hasso AN, Stringer WA, Brown KD. Cerebral ischemia and infarction. Neuroimaging Clin N Am 1994; 4:733-52. [PMID: 7858918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cerebral infarction is most commonly related to atherosclerotic disease in the carotid and vertebrobasilar circulations. TIAs are manifestations of this same disease process and may occur before a complete infarction. The transformation of pale to hemorrhagic infarction may result from reperfusion of an infarct or from migration of an embolus. CT is often the primary imaging study to exclude frank hemorrhage. The use of MR is increasing, in both the acute and the subacute phases of stroke. The combination of MR imaging and MR angiography is gradually replacing CT, particularly in patients with TIAs. In addition, the depiction of minute alterations in contrast and subtle mass effect is visualized with MR more often than with CT. The precise localization of brain stem and posterior fossa infarctions is improved by the ability of MR to view complex structures in two or more orthogonal planes. Vascular structures are readily identified both on the spin echo images and with MR angiography. Slow or obstructed flow in the venous channels may be recognized, which makes MR the ideal examination for the evaluation of cerebral ischemia and infarction.
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Hoang TA, Hasso AN. Intracranial vascular malformations. Neuroimaging Clin N Am 1994; 4:823-47. [PMID: 7858922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance imaging is a useful process in the evaluation and follow-up examination of intracranial vascular malformations. Magnetic resonance imaging as related to the four subtypes of these malformations, arteriovenous malformations, venous angiomas, cavernous malformations, and capillary telangiectasis, is discussed.
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Hasso AN, Bell SA, Tadmor R. Intracranial vascular tumors. Neuroimaging Clin N Am 1994; 4:849-70. [PMID: 7858923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The study of intracranial vascular tumors is of significant importance because these tumors may stimulate vascular malformations, infarctions, or infections. This article describes vascular tumors and discusses their appearance on MR imaging studies. Choroid plexus neoplasms, primitive neuroectodermal tumors, hemangioblastoma and other disorders are discussed.
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Hasso AN. Imaging of pulsatile tinnitus: basic examination versus comprehensive examination package. AJNR Am J Neuroradiol 1994; 15:890-2. [PMID: 8059656 PMCID: PMC8332165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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McLachlan SJ, Francisco JC, Pernicone JR, Hasso AN. Efficacy evaluation of gadoteridol for MR angiography of intracranial vascular lesions. J Magn Reson Imaging 1994; 4:405-11. [PMID: 8061440 DOI: 10.1002/jmri.1880040328] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A phase III multicenter study was conducted in 89 patients with known intracranial vascular lesions to evaluate an extracellular gadolinium contrast agent, gadoteridol, for intracranial magnetic resonance (MR) angiography. The pre- and postcontrast MR angiograms of 82 patients were evaluated by the unblinded investigators and by two blinded readers (A and B) for visualization of lesions; arterial and venous anatomy; extent, size, and number of lesions; and disease classification. The unblinded readers indicated that lesions were visualized better on postcontrast images in the following categories: venous anatomy, 87 (81%) of 107 lesions; arterial anatomy, 43 lesions (40%); and extent or size of lesions, 38 lesions (36%). In 29 (35%) of 82 patients, the unblinded readers determined that enhanced MR angiography provided more diagnostic information than unenhanced MR angiography. The blinded readers determined that enhanced MR angiography provided more information for visualization of vascular anatomy in more than 60% of cases. The additional information provided with gadoteridol would have changed the diagnosis in nine (8%) of 107 lesions seen by the unblinded readers, 11 (12%) of 90 lesions seen by reader A, and three (3%) of 93 lesions seen by reader B. The results confirm that the use of gadoteridol improves the visualization of intracranial vascular lesions with MR angiography. The authors conclude that development of new postprocessing algorithms will improve the utility of contrast-enhanced MR angiography.
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Hasso AN, Lambert D. Magnetic resonance imaging of the paranasal sinuses and nasal cavities. Top Magn Reson Imaging 1994; 6:209-223. [PMID: 7803038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Magnetic resonance imaging has proven to be a useful tool for imaging the paranasal sinuses and nasal cavities. Of particular interest in this region is the ability to distinguish between lesions that are highly cellular with little free water (neoplasms) and lesions that have significant amounts of serous and mucinous secretions and thus contain predominantly free water (infections).
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Hasso AN, Nickmeyer CA. Magnetic resonance imaging of soft tissues of the neck. Top Magn Reson Imaging 1994; 6:254-274. [PMID: 7803041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Magnetic resonance imaging (MRI) has proven to be an ideal examination for evaluating a variety of soft tissue lesions in the extracranial head and neck. In this article we will describe the MRI characteristics of a variety of the soft tissue lesions found in the neck. Pathophysiology, clinical presentation, treatment, and prognosis are also discussed.
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Stringer WA, Hasso AN, Thompson JR, Hinshaw DB, Jordan KG. Hyperventilation-induced cerebral ischemia in patients with acute brain lesions: demonstration by xenon-enhanced CT. AJNR Am J Neuroradiol 1993; 14:475-84. [PMID: 8456732 PMCID: PMC8332972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE To examine the possibility that hyperventilation, commonly used to prevent or treat increased intracranial pressure in patients with acute brain lesions, may induce significant cerebral ischemia. METHODS Local cerebral blood flow and vascular reactivity were measured before and after hyperventilation using xenon-enhanced CT in 12 patients with acute brain lesions. RESULTS Five patients showed "paradoxical" reactivity (increased cerebral blood flow during hyperventilation) within the lesions. In five patients, hyperventilation induced ischemia in apparently normal regions of brain. In three patients, areas of luxury perfusion became ischemic during hyperventilation, while in three patients, lesions with moderate ischemia became more ischemic. Most patients showed more than one type of reactivity. CONCLUSIONS These findings document hyperventilation-induced ischemia in acute brain lesions, and demonstrate that this phenomenon affects both injured and apparently intact areas of the brain. Further studies are required to determine the clinical significance of these pathophysiologic changes.
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Hasso AN, Brown KD. Use of gadolinium chelates in MR imaging of lesions of the extracranial head and neck. J Magn Reson Imaging 1993; 3:247-63. [PMID: 8428093 DOI: 10.1002/jmri.1880030137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Tali ET, Yuh WT, Nguyen HD, Feng G, Koci TM, Jinkins JR, Robinson RA, Hasso AN. Cystic acoustic schwannomas: MR characteristics. AJNR Am J Neuroradiol 1993; 14:1241-7. [PMID: 8237710 PMCID: PMC8332755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE To evaluate the spectrum of MR characteristics of cystic acoustic schwannoma and to investigate its incidence. METHODS We retrospectively reviewed the MR findings and clinical records of 16 patients with cystic acoustic schwannomas. In addition, the MR examinations of 411 consecutive patients referred for clinical suspicion of acoustic schwannomas were reviewed retrospectively to assess the incidence of acoustic schwannomas with cystic lesions arising from the internal auditory canal. RESULTS Of the 16 acoustic schwannomas with MR evidence of intramural cysts, 11 tumors had single small cysts, and five had multiple intramural cysts of variable size. Intramural cysts in 11 of the 16 tumors exhibited higher signal intensity than that of cerebrospinal fluid; the remainder were isointense to cerebrospinal fluid on both T1- and T2-weighted images. All intramural cysts showed circumferential enhancement after contrast administration. Nine of the 16 cystic acoustic schwannomas also had MR evidence of extramural/arachnoid cysts. Six of the extramural/arachnoid cysts had epicenters away from the dural interface, and the other three cysts were broadly based against the dura. The incidence of cystic acoustic schwannomas was 11.3% and association with extramural/arachnoid cysts 7.5%. CONCLUSION Our series suggests that cystic changes in acoustic schwannomas and the association with extramural/arachnoid cysts are not as rare as previously reported by other diagnostic methods. The high signal intensity of intramural cysts is probably related to necrotic material, blood, or colloid-rich fluid. The difference in the MR characteristics of extramural/arachnoid cysts associated with acoustic schwannomas and those of typical arachnoid cysts not associated with neoplasia may be related to higher protein and/or colloid contents secreted by the tumor. Most extramural/arachnoid cysts had epicenters between the tumor and brain, suggesting that the most likely mechanism of formation is peritumoral adhesions. It creates a pseudo-duplication caused by the trapping of fluid between the leptomeninges and the mass, resulting in an acquired type of arachnoid cyst.
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Hasso AN. Adult extra-axial brain tumors. Top Magn Reson Imaging 1992; 4:41-63. [PMID: 1419033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Magnetic resonance imaging is the preferred cross-sectional imaging study for the evaluation of nearly all extra-axial brain tumors in adults. This article outlines the neoplasms by their pathology. The discussion covers the neoplasms originating from central neuroglial cells, meninges, and cranial nerves. In addition, developmental tumors and cysts and secondary extra-axial tumors are discussed.
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Tosk JM, Holshouser BA, Aloia RC, Hinshaw DB, Hasso AN, MacMurray JP, Will AD, Bozzetti LP. Effects of the interaction between ferric iron and L-dopa melanin on T1 and T2 relaxation times determined by magnetic resonance imaging. Magn Reson Med 1992; 26:40-5. [PMID: 1625565 DOI: 10.1002/mrm.1910260105] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
T1 and T2 relaxation times of agar phantoms containing L-dopa melanin and Fe3+ were measured under MRI conditions. Fe3+ shortened T1 and T2 relaxation times. Melanin influenced relaxation times only in the presence of Fe3+; thus, contrast in MR images of the basal ganglia may depend upon levels of both paramagnetic iron and neuromelanin.
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Witt PD, Hardesty RA, Zuppan C, Rouse G, Hasso AN, Boyne P. Fetal kleeblattschädel cranium: morphologic, radiographic, and histologic analysis. Cleft Palate Craniofac J 1992; 29:363-8. [PMID: 1643068 DOI: 10.1597/1545-1569_1992_029_0363_fkdcmr_2.3.co_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The kleeblattschädel deformity is a rare craniofacial condition typified by its trilobed, cloverleaf skull. The pathophysiology of this process is controversial. The morphologic, radiographic, and histologic abnormalities identified in the cranial base of an 18-gestational-week fetus with kleeblattschädel skull have not been described previously. Recently, the intrauterine diagnosis of kleeblattschädel was established by serial ultrasonography and, based on this evidence, the fetus was aborted. The fetus was studied extensively. Standard radiographs and high-resolution CT scans were obtained. Three-dimensional, reformatted contour surface images were constructed from the CT scan data. The cranial base was examined grossly, radiographically, and histologically. Histologic microanatomic study concentrated on structures of the mid-sagittal cranial base from the occiput to the mid maxilla. The distorted cranial architecture in kleeblattschädel deformity has, in the past, been attributed largely to the cranial base deformity which secondarily distorts the developing brain. Our study, however, suggests that the calvarium itself may be the primary focus of abnormal events leading to synostosis. The findings in this study seem to be inconsistent with earlier theories about the abnormal development of craniodysostoses.
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Hasso AN. Magnetic resonance angiography in the head and neck. West J Med 1992; 156:296-7. [PMID: 1595250 PMCID: PMC1003241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Hasso AN, Russell EJ. Tuesday morning grand ballroom E papers 225–232. Clinical imaging: Spine. J Magn Reson Imaging 1991. [DOI: 10.1002/jmri.1880010240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hasso AN. Gadolinium in magnetic resonance imaging of the central nervous system. West J Med 1990; 152:63-64. [PMID: 18750691 PMCID: PMC1002259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Hasso AN. My experience as a patient with subarachnoid hemorrhage. AJNR Am J Neuroradiol 1990; 11:229-30. [PMID: 2107705 PMCID: PMC8334690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Coates TL, Hinshaw DB, Peckman N, Thompson JR, Hasso AN, Holshouser BA, Knierim DS. Pediatric choroid plexus neoplasms: MR, CT, and pathologic correlation. Radiology 1989; 173:81-8. [PMID: 2781035 DOI: 10.1148/radiology.173.1.2781035] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Choroid plexus papillomas are rare, constituting approximately 0.5% of all intracranial neoplasms. Four benign choroid plexus papillomas and one choroid plexus carcinoma were retrospectively reviewed in patients aged 4-20 months who had been examined with magnetic resonance (MR) imaging with a field strength of 0.5 T or 1.0 T and with computed tomography (CT) before and after the administration of contrast material. In general, the tumors were of intermediate signal intensity on T1-weighted images and of either intermediate or increased signal intensity (T2 lengthening) with T2 weighting. All demonstrated variable areas of internal signal void interpreted as signifying regional blood flow, calcification, or old hemorrhage. CT findings included relatively uniform contrast enhancement. Microscopic pathologic changes of the benign lesions mimicked the appearance of normal choroid plexus and confirmed the highly vascular nature of these tumors. MR imaging, with its high-resolution multiplanar techniques, offers direct visualization of these lesions in relation to normal anatomy and better discrimination and confirmation of their intraventricular location, facilitating surgery and postoperative follow-up.
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