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Dorenbeck U, Butz B, Schlaier J, Bretschneider T, Schuierer G, Feuerbach S. Diffusion-Weighted Echo-Planar MRI of the Brain with Calculated ADCs: A Useful Tool in the Differential Diagnosis of Tumor Necrosis from Abscess? J Neuroimaging 2003. [DOI: 10.1111/j.1552-6569.2003.tb00200.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Abstract
Advances in neuroimaging provide unique opportunities to evaluate brain structure, biochemistry, and function. Although a number of imaging techniques have been used in newborns, cranial ultrasonography in premature infants and nuclear magnetic resonance modalities, including magnetic resonance imaging and diffusion-weighted imaging, in high-risk term infants are of foremost benefit. Interpretation is based on knowledge of characteristic imaging findings in specific childhood neurologic disorders and an understanding of differential diagnosis in cerebral palsy syndromes, such as spastic diplegia and various subtypes of extrapyramidal cerebral palsy. This review focuses on imaging studies that can be effectively used in at-risk infants and in children with spasticity and movement disorders to refine diagnosis and guide therapeutic interventions.
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Affiliation(s)
- Alexander H Hoon
- Johns Hopkins University School of Medicine, Division of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD 21205, USA.
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653
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Willinek WA, Gieseke J, von Falkenhausen M, Neuen B, Schild HH, Kuhl CK. Sensitivity encoding for fast MR imaging of the brain in patients with stroke. Radiology 2003; 228:669-75. [PMID: 12881577 DOI: 10.1148/radiol.2283020243] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE To evaluate sensitivity encoding (SENSE) technique in a clinical setting for magnetic resonance (MR) imaging in patients who are suspected of having infarction. MATERIALS AND METHODS This intraindividual comparative study included 62 patients suspected of having cerebral ischemia. Patients underwent T2-weighted fluid-attenuated inversion-recovery (FLAIR) (n = 62), T2-weighted turbo spin-echo (TSE) (n = 48), and single-shot echo-planar diffusion-weighted imaging (n = 27) with standard sequential and SENSE MR acquisitions with a 1.5-T magnet and phased-array coil. With SENSE, acquisition time was reduced from 1 minute 12 seconds to 35 seconds for FLAIR and from 1 minute 18 seconds to 39 seconds for T2-weighted TSE imaging. For diffusion-weighted imaging, echo train length was shortened (78 vs 71 msec) to reduce susceptibility effects while acquisition time was maintained. Two radiologists scored quality of standard and SENSE images with a five-point scale and assessed presence of artifacts (motion, susceptibility) and lesion conspicuity. To assess statistical significance, Wilcoxon signed rank and chi2 tests were used. RESULTS Statistical analysis revealed no significant difference in terms of image quality and presence of artifacts between standard and SENSE T2-weighted TSE (image quality, P =.724; presence of artifacts, P =.378) and FLAIR (image quality, P =.127; presence of artifacts, P =.275) images. Image quality at SENSE diffusion-weighted imaging was scored significantly higher compared with that at standard diffusion-weighted imaging (P =.002). Susceptibility artifacts were significantly reduced at SENSE diffusion-weighted imaging when compared with those at standard diffusion-weighted imaging (P <.001). Conspicuity of 84 lesions was rated equivalent with both standard and SENSE protocols. CONCLUSION SENSE allowed acquisition of T2-weighted TSE and FLAIR images with image quality and lesion conspicuity that did not differ from those of standard acquisition techniques but in only half the acquisition time. Use of SENSE with diffusion-weighted imaging significantly reduces susceptibility artifacts while lesion conspicuity is maintained.
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Affiliation(s)
- Winfried A Willinek
- Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany.
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654
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Chan I, Wells W, Mulkern RV, Haker S, Zhang J, Zou KH, Maier SE, Tempany CMC. Detection of prostate cancer by integration of line-scan diffusion, T2-mapping and T2-weighted magnetic resonance imaging; a multichannel statistical classifier. Med Phys 2003; 30:2390-8. [PMID: 14528961 DOI: 10.1118/1.1593633] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A multichannel statistical classifier for detecting prostate cancer was developed and validated by combining information from three different magnetic resonance (MR) methodologies: T2-weighted, T2-mapping, and line scan diffusion imaging (LSDI). From these MR sequences, four different sets of image intensities were obtained: T2-weighted (T2W) from T2-weighted imaging, Apparent Diffusion Coefficient (ADC) from LSDI, and proton density (PD) and T2 (T2 Map) from T2-mapping imaging. Manually segmented tumor labels from a radiologist, which were validated by biopsy results, served as tumor "ground truth." Textural features were extracted from the images using co-occurrence matrix (CM) and discrete cosine transform (DCT). Anatomical location of voxels was described by a cylindrical coordinate system. A statistical jack-knife approach was used to evaluate our classifiers. Single-channel maximum likelihood (ML) classifiers were based on 1 of the 4 basic image intensities. Our multichannel classifiers: support vector machine (SVM) and Fisher linear discriminant (FLD), utilized five different sets of derived features. Each classifier generated a summary statistical map that indicated tumor likelihood in the peripheral zone (PZ) of the prostate gland. To assess classifier accuracy, the average areas under the receiver operator characteristic (ROC) curves over all subjects were compared. Our best FLD classifier achieved an average ROC area of 0.839(+/-0.064), and our best SVM classifier achieved an average ROC area of 0.761(+/-0.043). The T2W ML classifier, our best single-channel classifier, only achieved an average ROC area of 0.599(+/-0.146). Compared to the best single-channel ML classifier, our best multichannel FLD and SVM classifiers have statistically superior ROC performance (P=0.0003 and 0.0017, respectively) from pairwise two-sided t-test. By integrating the information from multiple images and capturing the textural and anatomical features in tumor areas, summary statistical maps can potentially aid in image-guided prostate biopsy and assist in guiding and controlling delivery of localized therapy under image guidance.
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Affiliation(s)
- Ian Chan
- Surgical Planning Laboratory, Department of Radiology, Division of MRI, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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655
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Wenserski F, von Giesen HJ, Wittsack HJ, Aulich A, Arendt G. Human immunodeficiency virus 1-associated minor motor disorders: perfusion-weighted MR imaging and H MR spectroscopy. Radiology 2003; 228:185-92. [PMID: 12759468 DOI: 10.1148/radiol.2281010683] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE To investigate whether advanced magnetic resonance (MR) imaging techniques such as diffusion-weighted (DW) and perfusion-weighted (PW) MR imaging and hydrogen 1 (1H) MR spectroscopy can depict functional and pathophysiologic mechanisms in patients who have minor motor deficits (MMDs) associated with human immunodeficiency virus 1 (HIV-1). MATERIALS AND METHODS Thirty-two patients with results seropositive for HIV-1 and different degrees of HIV-1-related MMD underwent conventional brain MR imaging, as well as DW and PW MR imaging and 1H MR spectroscopy of the basal ganglia. PW MR imaging data were computed pixel by pixel for creation of time-to-peak, relative regional cerebral blood volume, and bolus amplitude parameter maps. In addition, quantitative regional cerebral blood flow (rCBF) maps were calculated with respect to the arterial input function by using the singular value decomposition algorithm. For 1H MR spectroscopy, a stimulated echo acquisition mode 20, or STEAM 20, sequence was used. Spectra were fit for determination of the signal intensities of the different metabolites. According to psychomotor testing results, patients were divided into three groups: group 1, 10 patients with normal motor function; group 2, eight patients with psychomotor slowing for the first time; and group 3, 14 patients who had had sustained pathologic psychomotor slowing for at least 6 months before the MR imaging examination. RESULTS No patients had an abnormality at either conventional or DW MR imaging. PW MR imaging depicted significantly elevated rCBF in group 2 patients (P =.039, analysis of variance [ANOVA]) and significantly elevated myo-inositol-to-creatine ratio levels in group 3 patients (P =.020, ANOVA). CONCLUSION Quantitative PW MR imaging and 1H MR spectroscopy can depict pathologic changes in patients who have HIV-1-related MMD but normal clinical examination and conventional MR imaging findings.
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Affiliation(s)
- Frank Wenserski
- Department of Diagnostic Radiology and Neurology, Heinrich-Heine-University, Moorenstr 5, 40225 Duesseldorf, Germany.
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656
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Lonergan GJ, Baker AM, Morey MK, Boos SC. From the archives of the AFIP. Child abuse: radiologic-pathologic correlation. Radiographics 2003; 23:811-45. [PMID: 12853657 DOI: 10.1148/rg.234035030] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In the United States, roughly one of every 100 children is subjected to some form of neglect or abuse; inflicted injury is responsible for approximately 1,200 deaths per year. Child physical abuse may manifest as virtually any injury pattern known to medicine. Some of the injuries observed in battered children are relatively unique to this population (especially when observed in infants) and therefore are highly suggestive of nonaccidental, or inflicted, injury. Worrisome injuries include rib fracture, metaphyseal fracture, interhemispheric extraaxial hemorrhage, shear-type brain injury, vertebral compression fracture, and small bowel hematoma and laceration. As noted, however, virtually any injury may be inflicted; therefore, careful consideration of the nature of the injury, the developmental capabilities of the child, and the given history are crucial to determine the likelihood that an injury was inflicted. The majority of these injuries are readily detectable at imaging, and radiologic examination forms the mainstay of evaluation of child physical abuse. Detection of metaphyseal fracture (regarded as the most specific radiographically detectable injury in abuse) depends on high-quality, small field-of-view radiographs. The injury manifests radiographically as a lucent area within the subphyseal metaphysis, extending completely or partially across the metaphysis, roughly perpendicular to the long axis of the bone. Acute rib fractures (which in infants are strongly correlated with abuse) appear as linear lucent areas. They may be difficult to discern when acute; thus, follow-up radiography increases detection of these fractures. For skull injuries, radiography is best for detecting fractures, but computed tomography and magnetic resonance imaging best depict intracranial injury.
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Affiliation(s)
- Gael J Lonergan
- Department of Radiologic Pathology, Armed Forces Institute of Pathology, 14th and Alaska Sts NW, Bldg 54, Rm M-121, Washington, DC 20306-6000, USA.
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657
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Aikele P, Kittner T, Offergeld C, Kaftan H, Hüttenbrink KB, Laniado M. Diffusion-weighted MR imaging of cholesteatoma in pediatric and adult patients who have undergone middle ear surgery. AJR Am J Roentgenol 2003; 181:261-5. [PMID: 12818870 DOI: 10.2214/ajr.181.1.1810261] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE The aim of this prospective study was to determine the role of diffusion-weighted MR imaging combined with conventional MR imaging for the detection of residual or recurrent cholesteatoma in patients who have undergone middle ear surgery. SUBJECTS AND METHODS Twenty-two patients who had undergone resection of cholesteatoma were referred for MR imaging. MR imaging (1.5 T) was performed using a diffusion-weighted single-shot spin-echo echoplanar sequence, a proton density and T2-weighted double-echo turbo spin-echo sequence, and T1-weighted spin-echo sequences before and after IV injection of gadopentetate dimeglumine (0.1 mmol/kg of body weight). An experienced reviewer evaluated the diffusion-weighted MR images for the presence of a high-signal-intensity cholesteatoma. Imaging findings were correlated with findings from surgery in 17 patients and with findings from clinical follow-up examination in five patients. RESULTS Diffusion-weighted MR imaging combined with conventional MR imaging depicted 10 of 13 cholesteatomas (sensitivity, 77%). The three lesions that were missed were smaller than 5 mm. All the MR images of patients without cholesteatoma were correctly interpreted as showing negative findings for cholesteatoma (specificity, 100%). The positive predictive value and negative predictive value were 100% and 75%, respectively. CONCLUSION Diffusion-weighted MR imaging combined with conventional MR imaging can confirm residual or recurrent cholesteatoma in patients who have undergone middle ear surgery by showing a high-signal-intensity lesion. Because tumors smaller than 5 mm may be missed, a diffusion-weighted MR imaging study with negative findings does not exclude small residual or recurrent cholesteatoma.
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Affiliation(s)
- P Aikele
- Department of Diagnostic Radiology, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
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658
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Oster J, Doherty C, Grant PE, Simon M, Cole AJ. Diffusion-weighted imaging abnormalities in the splenium after seizures. Epilepsia 2003; 44:852-4. [PMID: 12790901 DOI: 10.1046/j.1528-1157.2003.40902.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE Transient increased T2 signal in the splenium of the corpus callosum after seizures has been reported and sometimes attributed to a postulated toxicity of anticonvulsant medications (AEDs). METHODS We describe two patients with bitemporal epilepsy. RESULTS Transiently increased T2 signal (in one) and decreased apparent diffusion coefficient (ADC) (in both) in the splenium appeared to be related directly to acute seizures. CONCLUSIONS These cases illustrate an unusual acute postictal imaging finding, highlight involvement of an important commissural pathway, and suggest that seizures per se, and not their treatment, are the cause of transient white-matter abnormalities in these cases.
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Affiliation(s)
- Joel Oster
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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659
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Jaramillo D, Connolly SA, Vajapeyam S, Robertson RL, Dunning PS, Mulkern RV, Hayward A, Maier SE, Shapiro F. Normal and ischemic epiphysis of the femur: diffusion MR imaging study in piglets. Radiology 2003; 227:825-32. [PMID: 12773684 DOI: 10.1148/radiol.2273011673] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate normal diffusion characteristics in the femur in piglets and changes in diffusion with increasing duration of femoral head ischemia. MATERIALS AND METHODS Normal epiphyses, physes, and metaphyses of piglets were evaluated with line-scan diffusion imaging (n = 12) and diffusion-tensor imaging (n = 4). Apparent diffusion coefficient (ADC) differences between normal proximal and distal femoral structures, epiphyseal and physeal cartilage, and epiphyseal and metaphyseal marrow were compared (Mann-Whitney test). Short-term femoral ischemia was investigated after maximal abduction of the hips for 3 hours (n = 6); ADCs before and after abduction were compared (Wilcoxon signed rank test). Prolonged ischemia was investigated with placement of a ligature around the neck of a femur (n = 7); the ADC of the femur in this condition was compared (Wilcoxon signed rank test) with that of the normal contralateral femur. Changes in ADC ratios at three durations of ischemia (Kruskal-Wallis test) were compared. RESULTS ADC was greater in epiphyseal cartilage (mean +/- 1 SD, 1.62 x 10(-3) mm2/sec +/- 0.38) than it was in physeal cartilage (1.28 x 10(-3) mm2/sec +/- 0.31) (P <.007) and greater in epiphyseal marrow (1.26 x 10(-3) mm2/sec +/- 0.38) than it was in metaphyseal marrow (0.91 x 10(-3) mm2/sec +/- 0.35) (P <.001). There was columnar arrangement of tensors in the physis. ADC decreased 26% after 3 hours of maximal abduction. After femoral neck ligature, ADC increased a mean of 27% after 6 hours and a mean of 75% after 96 hours. CONCLUSION Normal line-scan diffusion imaging findings indicate relative restriction of diffusion in the metaphysis and parallel orientation of tensors in the physis. Diffusion is initially restricted with decreased blood flow but increases if ischemia lasts longer.
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Affiliation(s)
- Diego Jaramillo
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit St, Boston, MA 02114, USA.
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660
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Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study. Lancet 2003; 361:1241-6. [PMID: 12699950 DOI: 10.1016/s0140-6736(03)12978-9] [Citation(s) in RCA: 279] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND In most patients, severity of valvular aortic stenosis can be accurately assessed non-invasively by echocardiography. However, retrograde catheterisation of the aortic valve is often undertaken. This procedure has a potential risk of neurological complications, with an unknown incidence of clinically silent embolism. We aimed to establish the frequency of clinically apparent and silent cerebral embolism after this procedure. METHODS We prospectively randomised 152 consecutive patients with valvular aortic stenosis at a German university hospital to receive either cardiac catheterisation with (n=101) or without (n=51) passage through the aortic valve. Patients underwent cranial MRI and neurological assessment within 48 h before and after the procedure to assess cerebral embolism. Controls were 32 patients without valvular aortic stenosis who underwent coronary angiography and laevocardiography. FINDINGS 22 of 101 patients (22%) who underwent retrograde catheterisation of the aortic valve had focal diffusion-imaging abnormalities in a pattern consistent with acute cerebral embolic events after the procedure; three of these patients (3%) had clinically apparent neurological deficits. By contrast, none of the patients without passage of the valve, or any of the controls, had evidence of cerebral embolism as assessed by MRI. INTERPRETATION Patients with valvular aortic stenosis who undergo retrograde catheterisation of the aortic valve have a substantial risk of clinically apparent cerebral embolism, and frequently have silent ischaemic brain lesions. Patients should be informed about these risks, and this procedure should be used only in patients with unclear echocardiographical findings when additional information is necessary for clinical management.
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661
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Latchaw RE, Yonas H, Hunter GJ, Yuh WTC, Ueda T, Sorensen AG, Sunshine JL, Biller J, Wechsler L, Higashida R, Hademenos G. Guidelines and recommendations for perfusion imaging in cerebral ischemia: A scientific statement for healthcare professionals by the writing group on perfusion imaging, from the Council on Cardiovascular Radiology of the American Heart Association. Stroke 2003; 34:1084-104. [PMID: 12677088 DOI: 10.1161/01.str.0000064840.99271.9e] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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662
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Chung TI, Kim JS, Park SK, Kim BS, Ahn KJ, Yang DW. Diffusion weighted MR imaging of acute Wernicke's encephalopathy. Eur J Radiol 2003; 45:256-8. [PMID: 12595110 DOI: 10.1016/s0720-048x(02)00009-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We report a case of Wernicke's encephalopathy in which diffusion-weighted MR images demonstrated symmetrical hyperintense lesions in the paraventricular area of the third ventricles and medial thalami. Apparent diffusion coefficient mapping showed isointensity in the aforementioned areas. Diffusion-weighted MR images may provide evidence of vasogenic edema associated with thiamine deficiency, proven in the histopathology of experimental animals. In addition, diffusion-weighted MRI has many advantages over T2 or FLARE-weighted brain MRI in detecting structural and functional abnormalities in Wernicke's encephalopathy.
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Affiliation(s)
- Tae-Ick Chung
- Department of Neurology, College of Medicine, The Catholic University of Korea, Youido St Mary's Hospital, #62 Youido-dong, Youngdungpo-gu, Seoul 150-071, South Korea
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663
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664
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Coles JP, Steiner LA, Martin J, Donovan T, Hutchinson PJ, Carpenter TA, Menon DK. Assessment of the Ventrix parenchymal intracranial pressure monitoring probe (NL950-P) and Monitor (NL950-100) in a 3 Tesla magnetic resonance scanner. Anaesthesia 2003; 58:143-8. [PMID: 12562410 DOI: 10.1046/j.1365-2044.2003.02966.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Magnetic resonance (MR) imaging and spectroscopy provide important information in patients with acute head injury. However, optimal patient management requires intracranial pressure (ICP) monitoring. There are few reports on the use of ICP sensors in an MR environment. We tested the Ventrix parenchymal intracranial pressure monitoring probe and monitor (Integra Neurosciences, USA), modified by the use of a fibre-optic extension cable, within a 3 Tesla MR system. The device performed well in the MR environment, but one element within the fibre-optic extension was significantly ferromagnetic. The ICP probe produced a small susceptibility artefact on spin echo images, and a larger artefact on gradient echo images. The MR safety of the integrated system is probably acceptable, but could be easily improved with minor modifications. Although the system is MR compatible and produces generally acceptable imaging even at 3 Tesla, there is significant degradation of image quality during gradient echo sequences.
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Affiliation(s)
- J P Coles
- Department of Anaesthesia and Wolfson Brain Imaging Centre, Box 93, Addenbrookes Hospital, University of Cambridge, CB2 2QQ, UK
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665
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Taouli B, Vilgrain V, Dumont E, Daire JL, Fan B, Menu Y. Evaluation of liver diffusion isotropy and characterization of focal hepatic lesions with two single-shot echo-planar MR imaging sequences: prospective study in 66 patients. Radiology 2003; 226:71-8. [PMID: 12511671 DOI: 10.1148/radiol.2261011904] [Citation(s) in RCA: 439] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To (a) evaluate liver diffusion isotropy, (b) compare two diffusion-weighted magnetic resonance (MR) imaging sequences for the characterization of focal hepatic lesions by using two or four b values, and (c) determine an apparent diffusion coefficient (ADC) threshold value to differentiate benign from malignant lesions. MATERIALS AND METHODS Sixty-six patients were examined with two single-shot echo-planar diffusion-weighted MR sequences. In the first sequence, liver diffusion isotropy was evaluated by using diffusion gradients in three directions with two b values. In the second sequence, a unidirectional diffusion gradient was used with four b values. ADCs were measured in 43 patients with 52 focal hepatic lesions more than 1 cm in diameter and in 23 patients with 14 normal and nine cirrhotic livers and were compared by using nonparametric tests. RESULTS Diffusion in the liver parenchyma was isotropic. ADCs of focal hepatic lesions were significantly different between sequences (P <.01). The mean (+/- SD) ADCs in the first sequence were 0.94 x 10(-3) mm(2)/sec +/- 0.60 for metastases, 1.33 x 10(-3) mm(2)/sec +/- 0.13 for HCCs, 1.75 x 10(-3) mm(2)/sec +/- 0.46 for benign hepatocellular lesions, 2.95 x 10(-3) mm(2)/sec +/- 0.67 for hemangiomas, and 3.63 x 10(-3) mm(2)/sec +/- 0.56 for cysts. There was a significant difference between benign (2.45 x 10(-3) mm(2)/sec +/- 0.96, isotropic value) and malignant (1.08 x 10(-3) mm(2)/sec +/- 0.50) lesions (P <.01 for both sequences). CONCLUSION Diffusion-weighted MR imaging can help differentiate benign from malignant hepatic lesions. The use of two b values in one direction could be sufficient for the design of MR sequences in the liver.
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Affiliation(s)
- Bachir Taouli
- Department of Radiology, Hôpital Beaujon and Laboratoire d'Imagerie Médicale Paris-Nord, Faculté de Médecine Paris VII, Clichy, France.
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666
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Chapter 10 Magnetic Resonance Imaging and Spectroscopy: Insights into the Pathology and Pathophysiology of Multiple Sclerosis. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1877-3419(09)70039-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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667
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Pezzullo JA, Tung GA, Mudigonda S, Rogg JM. Diffusion-weighted MR imaging of pyogenic ventriculitis. AJR Am J Roentgenol 2003; 180:71-5. [PMID: 12490479 DOI: 10.2214/ajr.180.1.1800071] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to describe the features of pyogenic ventriculitis (ventricular empyema, pyocephalus) on diffusion-weighted MR imaging. CONCLUSION Markedly increased signal intensity of dependent intraventricular fluid on diffusion-weighted MR imaging and an apparent diffusion coefficient that is less than that of normal cerebral white matter indicate restricted water diffusion in purulent fluid and suggest the diagnosis of pyogenic ventriculitis.
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Affiliation(s)
- John A Pezzullo
- Department of Diagnostic Imaging, Brown University School of Medicine, Rhode Island Hospital, 593 Eddy St., Providence, RI 02903, USA
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668
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Stadnik TW, Demaerel P, Luypaert RR, Chaskis C, Van Rompaey KL, Michotte A, Osteaux MJ. Imaging tutorial: differential diagnosis of bright lesions on diffusion-weighted MR images. Radiographics 2003; 23:e7. [PMID: 12886888 DOI: 10.1148/rg.e7] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
High sensitivity (94%) and specificity (100%) have been reported in the diagnosis of acute cerebral infarction with diffusion-weighted magnetic resonance (MR) imaging. However, high signal intensity on diffusion-weighted MR images and low apparent diffusion coefficient values (similar to the findings in acute cerebral infarction) were reported in such diverse conditions as hemorrhage, abscess, lymphoma, and even Creutzfeldt-Jakob disease. The differential diagnosis of these conditions (eg, acute ischemic infarction and acute cerebral hemorrhage) is critical for the determination of appropriate treatment. The authors present a systematic review of bright lesions on diffusion-weighted MR images and their differential diagnosis, with emphasis on the practical and clinical approaches of differential diagnosis.
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Affiliation(s)
- Tadeusz W Stadnik
- Department of Radiology, Academisch Ziekenhuis AZ Vrije Universiteit, Laarbeeklaan 101, 1090 Brussels, Belgium.
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Wolf RL, Alsop DC, McGarvey ML, Maldjian JA, Wang J, Detre JA. Susceptibility Contrast and Arterial Spin Labeled Perfusion MRI in Cerebrovascular Disease. J Neuroimaging 2003. [DOI: 10.1111/j.1552-6569.2003.tb00152.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Huisman TAGM, Sorensen AG, Hergan K, Gonzalez RG, Schaefer PW. Diffusion-weighted imaging for the evaluation of diffuse axonal injury in closed head injury. J Comput Assist Tomogr 2003; 27:5-11. [PMID: 12544235 DOI: 10.1097/00004728-200301000-00002] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE The purpose of this work was to compare diffusion-weighted imaging (DWI) with conventional MRI in the detection of shearing injuries in acute closed head injuries. METHOD Twenty-five patients (19 male, 6 female) were examined within 48 h of trauma. Conventional MRI included T2-weighted fast spin echo, fluid-attenuated inversion recovery (FLAIR), and T2*-weighted gradient echo sequences. Full tensor DWI with calculation of apparent diffusion coefficient (ADC) maps was also performed. Lesions were identified and compared on all sequences. RESULTS Four hundred twenty-seven lesions were counted by the combined use of all sequences. DWI identified 70 lesions not seen on conventional MRI. DWI identified 310 shearing injuries, followed by T2/FLAIR (n = 248) and T2* (n = 202). The majority of DWI-positive lesions showed decreased diffusion (65%). CONCLUSION DWI is valuable in closed head injury because it identifies additional shearing injuries not visible on T2/FLAIR or T2* sequences. Furthermore, DWI/ADC maps differentiate between lesions with decreased or increased diffusion. DWI is less sensitive than T2* imaging for detecting hemorrhagic lesions.
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Affiliation(s)
- Thierry A G M Huisman
- Department of Radiology, Neuroradiology Section, and MGH-NMR Center, Massachusetts General Hospital, Harvard Medical School, Charlestown-Boston, USA.
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671
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Tha KK, Terae S, Sugiura M, Nishioka T, Oka M, Kudoh K, Kaneko K, Miyasaka K. Diffusion-weighted magnetic resonance imaging in early stage of 5-fluorouracil-induced leukoencephalopathy. Acta Neurol Scand 2002; 106:379-86. [PMID: 12460146 DOI: 10.1034/j.1600-0404.2002.01253.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We report a case of 5-fluorouracil (5-FU)-induced leukoencephalopathy in which magnetic resonance imaging (MRI) of the brain, including diffusion-weighted imaging (DWI), was performed serially. The initial T2-weighted and FLAIR images showed diffuse mild hyperintensity in bilateral deep cerebral white matter and corpus callosum, which on T1WI appeared as non-enhanced faint hypointensity. Isotropic DWI disclosed the abnormality as well-conspicuous diffuse hyperintensity with decreased ADC. Serial studies revealed that majority of the abnormal signal intensity on these sequences resolved, and the decreased ADC values approached normal. Some hyperintensity remained in the deep cerebral white matter and the splenium, but no further significant ADC change after normalization was noted. Measurement of ADC along the three orthogonal directions showed the presence of directional dependence of diffusion throughout the length of study. These findings suggest that early stage of 5-FU-induced leukoencephalopathy is associated with reversible restricted diffusion and preservation of anisotropy. Diffusion-weighted imaging may be useful for the diagnosis.
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Affiliation(s)
- K K Tha
- Department of Radiology, Hokkaido University School of Medicine, Kita-ku, Sapporo, Japan.
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672
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Sinha U, Bui A, Taira R, Dionisio J, Morioka C, Johnson D, Kangarloo H. A review of medical imaging informatics. Ann N Y Acad Sci 2002; 980:168-97. [PMID: 12594089 DOI: 10.1111/j.1749-6632.2002.tb04896.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This review of medical imaging informatics is a survey of current developments in an exciting field. The focus is on informatics issues rather than traditional data processing and information systems, such as picture archiving and communications systems (PACS) and image processing and analysis systems. In this review, we address imaging informatics issues within the requirements of an informatics system defined by the American Medical Informatics Association. With these requirements as a framework, we review, in four sections: (1) Methods to present imaging and associated data without causing an overload, including image study summarization, content-based medical image retrieval, and natural language processing of text data. (2) Data modeling techniques to represent clinical data with focus on an image data model, including general-purpose time-based multimedia data models, health-care-specific data models, knowledge models, and problem-centric data models. (3) Methods to integrate medical data information from heterogeneous clinical data sources. Advances in centralized databases and mediated architectures are reviewed along with a discussion on our efforts at data integration based on peer-to-peer networking and shared file systems. (4) Visualization schemas to present imaging and clinical data: the large volume of medical data presents a daunting challenge for an efficient visualization paradigm. In this section we review current multimedia visualization methods including temporal modeling, problem-specific data organization, including our problem-centric, context and user-specific visualization interface.
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Affiliation(s)
- Usha Sinha
- Telemedicine Division, Department of Radiological Sciences, University of California at Los Angeles, 90095-1721, USA.
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673
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Mori H, Abe O, Aoki S, Masumoto T, Yoshikawa T, Kunimatsu A, Hayashi N, Ohtomo K. Hemorrhagic brain metastases with high signal intensity on diffusion-weighted MR images. A case report. Acta Radiol 2002. [PMID: 12485251 DOI: 10.1034/j.1600-0455.2002.430604.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Diffusion-weighted MR imaging has been applicable to the differential diagnosis of abscesses and necrotic or cystic brain tumors. However, restricted water diffusion is not necessarily specific for brain abscess. We describe ring-enhancing metastases of lung carcinoma characterized by high signal intensity on diffusion-weighted MR images. The signal pattern probably reflected intralesional hemorrhage. The present report adds to the growing literature regarding the differential diagnosis of ring-enhancing brain lesions.
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Affiliation(s)
- H Mori
- Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
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674
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Cohen Y, Assaf Y. High b-value q-space analyzed diffusion-weighted MRS and MRI in neuronal tissues - a technical review. NMR IN BIOMEDICINE 2002; 15:516-542. [PMID: 12489099 DOI: 10.1002/nbm.778] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This review deals with high b-value q-space diffusion-weighted MRI (DW-MRI) of neuronal tissues. It is well documented that at sufficiently high b-values (and high q-values) neuronal water signal decay in diffusion experiments is not mono-exponential. This implies the existence of more than one apparent diffusing component or evidence for restriction. The assignment of the different apparent diffusing components to real physical entities is not straightforward. However, the apparent slow diffusing component that was found to be restricted to a compartment of a few microns, if originating mainly from a specific pool and if assigned correctly, may potentially be used to obtain more specific MR images with regard to specific pathologies of the CNS. This review examines the utility of analyzing high b-value diffusion MRS and MRI data using the q-space approach introduced by Callaghan and by Cory and Garroway. This approach provides displacement probability maps that emphasize, at long diffusion times, the characteristics of the apparent slow diffusing component. Examples from excised spinal cord, where the experimental conditions for which the q-space analysis of MR diffusion data was developed can be met or approached will be presented. Then examples from human MS patients, where q-space requirement for the short gradient pulse is clearly violated, are presented. In the excised spinal cord studies, this approach was used to study spinal cord maturation and trauma, and was found to be more sensitive than other conventional methods in following spinal cord degeneration in an experimental model of vascular dementia (VaD). High b-value q-space DWI was also recently used to study healthy and MS diseased human brains. This approach was found to be very sensitive to the disease load in MS, compared with other conventional MRI methods, especially in the normal appearing white matter (NAWM) of MS brains. Finally, the potential diagnostic capacity embedded in high b-value q-space analyzed diffusion MR images is discussed. The potentials and caveats of this approach are outlined and experimental data are presented that show the effect of violating the short gradient pulse (SGP) approximation on the extracted parameters from the q-space analysis.
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Affiliation(s)
- Yoram Cohen
- School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Israel.
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675
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Mullins ME, Schaefer PW, Sorensen AG, Halpern EF, Ay H, He J, Koroshetz WJ, Gonzalez RG. CT and conventional and diffusion-weighted MR imaging in acute stroke: study in 691 patients at presentation to the emergency department. Radiology 2002; 224:353-60. [PMID: 12147827 DOI: 10.1148/radiol.2242010873] [Citation(s) in RCA: 249] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance (MR) imaging in a consecutive series of patients at presentation to the emergency department with symptoms of acute stroke. MATERIALS AND METHODS Clinical data and images obtained in 691 consecutive patients with suspected acute stroke were examined. Results of first and second head CT and brain diffusion-weighted (DW) and conventional MR imaging were compared with each other and with the final neurologic discharge diagnosis. RESULTS Five hundred seventy-three patients underwent CT at presentation, with 42% sensitivity (95% CI: 37%, 46%) and 91% specificity (95% CI: 82%, 96%). A total of 173 patients underwent a second CT examination, with 77% sensitivity (95% CI: 70%, 84%) and 79% specificity (95% CI: 49%, 95%). Of 498 MR images, 411 were DW, with 94% sensitivity (95% CI: 1%, 96%) and 97% specificity (95% CI: 88%, 100%), and 87 were conventional, with 70% sensitivity (95% CI: 58%, 81%) and 94% specificity (95% CI: 70%, 100%). By using DW MR imaging in the early period (<6 hours after presentation to emergency department), a 97% sensitivity (95% CI: 92%, 100%) and a 100% specificity (95% CI: 69%, 100%) were achieved, compared with 58% (29%-84%) and 100% (16%-100%), respectively, with conventional MR imaging, and 40% (35%-45%) and 92% (84%-97%), respectively, with CT. Negative predictive value was higher with DW MR imaging (73%) than with conventional (42%) MR imaging or CT (24%). In studies conducted within 12 hours, DW MR imaging achieved substantially superior accuracy than did CT. After 12 hours, accuracy was equivalent. CONCLUSION In the diagnosis of stroke in the early period (<12 hours after presentation), DW MR imaging is superior to conventional MR imaging and CT.
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Affiliation(s)
- Mark E Mullins
- Neuroradiology Division, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, GRB285, Boston, MA 02114, USA
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676
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Rovira Cañellas A. [New diagnostic applications of magnetic resonance in neurology]. Med Clin (Barc) 2002; 118:741-4. [PMID: 12049707 DOI: 10.1016/s0025-7753(02)72516-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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677
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Marx JJ, Mika-Gruettner A, Thoemke F, Fitzek S, Fitzek C, Vucurevic G, Urban PP, Stoeter P, Hopf HC. Diffusion weighted magnetic resonance imaging in the diagnosis of reversible ischaemic deficits of the brainstem. J Neurol Neurosurg Psychiatry 2002; 72:572-5. [PMID: 11971039 PMCID: PMC1737856 DOI: 10.1136/jnnp.72.5.572] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To evaluate the sensitivity of diffusion weighted magnetic resonance imaging (MRI) for the diagnosis of clinically suspected reversible ischaemic deficits of the brainstem. METHODS A total of 158 consecutive patients presenting with acute signs of brainstem dysfunction were investigated using EPI diffusion weighted MRI within 24 hours of the onset of symptoms. High resolution T1 and T2 weighted imaging was performed as a follow up after a median of six days. RESULTS Fourteen of the 158 patients had a complete clinical recovery within 24 hours (transitory ischaemic attack (TIA)), and 19 patients recovered in less than one week (prolonged reversible neurological deficit (RIND)). Diffusion weighted MRI showed acute ischaemic deficits in 39% of patients with transient neurological deficits. The detection rate seemed to be higher in patients with longer lasting symptoms, but the difference between patients with TIA (29%) and RIND (47%) was not significant. CONCLUSIONS Diffusion weighted MRI is a sensitive indicator of acute ischaemic brainstem deficits even in patients with reversible neurological deficit. Early identification of patients with TIA and increased risk of stroke may influence acute management and improve patient outcome.
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Affiliation(s)
- J J Marx
- Department of Neurology, University of Mainz, Germany.
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678
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Sumi M, Takagi Y, Uetani M, Morikawa M, Hayashi K, Kabasawa H, Aikawa K, Nakamura T. Diffusion-weighted echoplanar MR imaging of the salivary glands. AJR Am J Roentgenol 2002; 178:959-65. [PMID: 11906883 DOI: 10.2214/ajr.178.4.1780959] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We determined the apparent diffusion coefficients of normal and dysfunctional salivary glands. SUBJECTS AND METHODS A diffusion-weighted single-shot spin-echo type of echoplanar MR imaging was performed on the parotid or submandibular glands, or both, in 36 healthy subjects, 20 patients with Sjögren's syndrome, and six patients with sialoadenitis. The apparent diffusion coefficient of the salivary gland was calculated using two b factors (b = 500 and 1,000 sec/mm(2)). RESULTS The apparent diffusion coefficient was lower in the parotid glands (0.28 x 10(-3) mm(2)/sec) than that of the submandibular glands (0.37 x 10(-3) mm(2)/sec). The apparent diffusion coefficient was increased in sialoadenitis, whereas it decreased with abscess formation. The apparent diffusion coefficients of the parotid glands in patients with Sjögren's syndrome correlated with the salivary flow rates but not with the sialographic gradings of the glands. We also found a correlation of the decreases in apparent diffusion coefficients with the severity of gland damage as assessed on T1-weighted MR images. CONCLUSION Diffusion-weighted echoplanar MR imaging may reveal diseased states of the salivary glands.
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Affiliation(s)
- Misa Sumi
- Department of Radiology and Cancer Biology, Nagasaki University School of Dentistry, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
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679
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Nossin-Manor R, Duvdevani R, Cohen Y. q-Space high b value diffusion MRI of hemi-crush in rat spinal cord: evidence for spontaneous regeneration. Magn Reson Imaging 2002; 20:231-41. [PMID: 12117605 DOI: 10.1016/s0730-725x(02)00470-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The development of the damage following hemi-crush trauma in rat spinal cord was studied ex vivo using high b value (bmax = 1 x 10(7) s cm(-2)) q-space diffusion weighted MRI (DWI) at five days, ten days and six weeks post-trauma. Rat spinal cord trauma, produced by hemi-crush of 15s and 60s duration, was studied. The water signal decay in these diffusion experiments was found to be non mono-exponential and was analyzed using the q-space approach. The q-space MRI parameters were compared with T1 and T2 MR images, behavioral tests and histopathological osmium staining. A very good anatomical correlation was found between the q-space MRI parameters and the osmium staining. Interestingly, we found that in the 15s hemi-crush model significant recovery was observed in both the q-space MR images and the osmium staining six weeks post-trauma. However, in the 60s hemi-crush trauma model very little recovery was observed. These results paralleled those obtained from behavioral tests demonstrating that partial spontaneous recovery seems to occur in the 15s hemi-crush spinal cord model, which should be taken in consideration when using it to evaluate new therapies.
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Affiliation(s)
- Revital Nossin-Manor
- School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
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680
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Weiss KL, Dong Q, Weadock WJ, Welsh RC, Shah GV. Multiparametric color-encoded brain MR imaging in Talairach space. Radiographics 2002; 22:e3. [PMID: 11896233 DOI: 10.1148/radiographics.22.2.g02mre1e3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Clinical magnetic resonance (MR) imaging of the brain is typically performed in the standard three orthogonal planes of the magnet, with little regard to head positioning. Multiple sequences with different imaging parameters are performed, and gray-scale images are obtained and displayed separately. The authors have implemented, and currently advocate, the routine acquisition of coregistered transverse images after roll, yaw, and pitch correction to Talairach space. Talairach, anterior commissure (AC)-posterior commissure (PC) referenced, stereotactic space has been widely embraced by the neuroscience community. This standardization should lead to more reproducible and readily interpretable MR examinations. A method is described to obtain direct AC-PC referenced (Talairach space) MR images. Sample protocols are provided. Coregistered T1-weighted, T1-weighted with contrast material administration, T2-weighted, fluid-attenuated inversion recovery (FLAIR), MR angiography, fractional anisotropy, and functional MR imaging sequences are presented, depicting a wide range of imaging parameters applied to normal brain anatomy in Talairach space. Illustrative examples of pathology are also provided. Color encoding is discussed and exploited to display and integrate multiparameter MR imaging contrast and white-matter-tract direction (anisotropy). The color composites may reduce the number of images needed for review by a factor of three or four and facilitate interpretation.
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Affiliation(s)
- Kenneth L Weiss
- Department of Radiology, University of Michigan, Ann Arbor, Mich, USA
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681
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Affiliation(s)
- Nathaniel A Chuang
- Division of Neuroradiology, Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
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682
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Bergui M, Bradic GB. Reversible parkinsonism and MRI diffusion abnormalities in cortical venous thrombosis. Neurology 2002; 58:332. [PMID: 11805278 DOI: 10.1212/wnl.58.2.332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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683
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Raffin LS, Bacheschi LA, Machado LR, Nóbrega JP, Coelho C, Leite CC. Diffusion-weighted MR imaging of cystic lesions of neurocysticercosis: a preliminary study. ARQUIVOS DE NEURO-PSIQUIATRIA 2001; 59:839-42. [PMID: 11733824 DOI: 10.1590/s0004-282x2001000600001] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neurocysticercosis is an endemic disease in some developing countries. It has pleomorfic clinical and imaging findings, which are variable from patient to patient. In this preliminary note, we studied the magnetic resonance (MR) diffusion-weighted images (DWI) of sixteen patients presenting with cystic lesions of this disease diagnosed by clinical and laboratorial findings. All the lesions had hypointense signal and the similar apparent diffusion coeficient (ADC) values as the cerebrospinal fluid (CSF).
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Affiliation(s)
- L S Raffin
- Neurology Department, Medical School, University of São Paulo
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684
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Huizinga TW, Steens SC, van Buchem MA. Imaging modalities in central nervous system systemic lupus erythematosus. Curr Opin Rheumatol 2001; 13:383-8. [PMID: 11604592 DOI: 10.1097/00002281-200109000-00007] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Within the past few years, a clearly defined case definition system for central nervous system systemic lupus erythematosus (CNS-SLE) has been established. This has allowed cross-study comparisons of patients fulfilling the specific case definitions. New imaging techniques used on the subgroup of CNS-SLE patients that did not have any evidence for infarctions suggest that in these patients symptoms are associated with a diffuse process in the brain. Most likely this process leads to axonal damage and demyelination, ultimately leading to cerebral atrophy. With respect to the diagnostic work-up of SLE patients with neuropsychiatric symptoms, it has become clear that cranial magnetic resonance imaging is the technique of choice. Preliminary studies using quantitative magnetic resonance imaging techniques suggest that patients with neuropsychiatric symptoms caused by active CNS-SLE can be differentiated from patients with the same symptoms caused by residual disease.
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Affiliation(s)
- T W Huizinga
- Department of Rheumatology and Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
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685
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Bangert BA. Magnetic resonance techniques in the evaluation of the fetal and neonatal brain. Semin Pediatr Neurol 2001; 8:74-88. [PMID: 11464960 DOI: 10.1053/spen.2001.24838] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Magnetic resonance imaging (MRI) has contributed dramatically to our understanding of the newborn with neurologic problems. Recently developed magnetic resonance techniques, such as fetal MRI and MR spectroscopy, offer additional insight into normal and pathologic processes affecting the fetal and neonatal CNS. This article examines developmental abnormalities as reflected in neuroimaging studies and discusses some of the newer MR modalities and their capabilities.
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Affiliation(s)
- B A Bangert
- Department of Radiology, University Hospitals of Cleveland, OH 44106, USA
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686
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Schwartz RB. Apparent diffusion coefficient mapping in patients with Alzheimer disease or mild cognitive impairment and in normally aging control subjects: present and future. Radiology 2001; 219:8-9. [PMID: 11274529 DOI: 10.1148/radiology.219.1.r01ap528] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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687
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Wennerberg AB, Jonsson T, Forssberg H, Li TQ. Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2001; 14:48-53. [PMID: 11252040 DOI: 10.1002/nbm.667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 9 sections: 1 Books, Reviews ' Symposia; 2 General; 3 Technology; 4 Brain and Nerves; 5 Neuropathology; 6 Cancer; 7 Cardiac, Vascular and Respiratory Systems; 8 Liver, Kidney and Other Organs; 9 Muscle and Orthopaedic. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
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Affiliation(s)
- A B Wennerberg
- Department of KARO, Division of Diagnostic Radiology, Karolinska Institutet, Huddinge University Hospital, SE-141 86 Stockholm, Sweden
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688
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Abstract
OBJECTIVE To document the signal characteristics of intracerebral hemorrhage (ICH) at evolving stages on diffusion-weighted images (DWI) by comparison with conventional MR images. MATERIALS AND METHODS In our retrospective study, 38 patients with ICH underwent a set of imaging sequences that included DWI, T1-and T2-weighted imaging, and fluid-attenuated inversion recovery (FLAIR). In 33 and 10 patients, respectively, conventional and echo-planar T2* gradient-echo images were also obtained. According to the time interval between symptom onset and initial MRI, five stages were categorized: hyperacute (n=6); acute (n=7); early subacute (n=7); late subacute (n=10); and chronic (n=8). We investigated the signal intensity and apparent diffusion coefficient (ADC) of ICH and compared the signal intensities of hematomas at DWI and on conventional MR images. RESULTS DWI showed that hematomas were hyperintense at the hyperacute and late subacute stages, and hypointense at the acute, early subacute and chronic stages. Invariably, focal hypointensity was observed within a hyperacute hematoma. At the hyperacute, acute and early subacute stages, hyperintense rims that corresponded with edema surrounding the hematoma were present. The mean ADC ratio was 0.73 at the hyperacute stage, 0.72 at the acute stage, 0.70 at the early subacute stage, 0.72 at the late subacute stage, and 2.56 at the chronic stage. CONCLUSION DWI showed that the signal intensity of an ICH may be related to both its ADC value and the magnetic susceptibility effect. In patients with acute stroke, an understanding of the characteristic features of ICH seen at DWI can be helpful in both the characterization of intracranial hemorrhagic lesions and the differentiation of hemorrhage from ischemia.
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Affiliation(s)
- Bo Kiung Kang
- Department of Diagnostic Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea
| | - Dong Gyu Na
- Department of Diagnostic Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea
| | - Jae Wook Ryoo
- Department of Diagnostic Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea
| | - Hong Sik Byun
- Department of Diagnostic Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea
| | - Hong Gee Roh
- Department of Diagnostic Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea
| | - Yong Seon Pyeun
- Department of Diagnostic Radiology, Masan Samsung Hospital, Sungkyunkwan University School of Medicine, Korea
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