BJR
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
British Journal of Radiology (2004) 77, 183-188
© 2004 British Institute of Radiology
doi: 10.1259/bjr/62546157
This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Saleh, A
Right arrow Articles by Mödder, U
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Saleh, A
Right arrow Articles by Mödder, U

Full Paper

Exclusion of brain lesions: is MR contrast medium required after a negative fluid-attenuated inversion recovery sequence?

A Saleh, MD1, F Wenserski, MD1, M Cohnen, MD1, G Fürst, MD1, E Godehardt, PhD2 and U Mödder, MD1

1 Institute of Diagnostic Radiology and 2 Biometric Research Group, Clinic of Thoracic and Cardiovascular Surgery, University Hospital Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany


   Abstract
Top
 Abstract
Introduction
 Materials and methods
 Results
 Discussion
 References
 
We hypothesized that in patients with negative fluid-attenuated inversion recovery (FLAIR) images T2 weighted fast spin-echo (FSE) images and T1 weighted spin-echo (SE) images before and after intravenous administration of gadolinium-based contrast medium display no pathology either. Thus, we assessed the negative predictive value of FLAIR images to rule out MR-detectable brain lesions. 1026 consecutive cranial MR examinations were reviewed. Routine MRI of the brain included T1 weighted coronal imaging before and after administration of gadopentetate dimeglumine, axial T2 weighted FSE and fast-FLAIR imaging. The FLAIR images were rated by two radiologists into categories of 0 (without pathologic changes) and 1 (with pathologic changes). Two other radiologists analysed the complete examination. In 284 MR examinations of the brain no abnormalities were found (28%). FLAIR-ratings were false-negative in four cases and false-positive in 30 cases. Sensitivity and specificity of the FLAIR sequence for MR-detectable brain lesions were 99.5% and 89.4%. The unselective application of gadolinium avoided one false-negative MR-reading and improved the sensitivity of the MR-examination from 99.5% to 99.6%. Positive and negative predictive values were 96.1% and 98.4%, respectively. The interobserver reliability was {kappa}=0.93 for the FLAIR-readers and 0.89 for the readers who rated the complete examination. In conclusion, negative FLAIR images provide a high negative predictive value for MR-detectable brain lesions. Thus, in patients with negative FLAIR images the unselective application of gadolinium seems to be unnecessary.


   Introduction
Top
 Abstract
 Introduction
Materials and methods
 Results
 Discussion
 References
 
In the fluid-attenuated inversion recovery (FLAIR) sequence the signal from the cerebrospinal fluid (CSF) can be nulled by applying a 180-degree pulse and an appropriate inversion time (TI). Setting the signal for CSF as a baseline (zero), it is possible to use a long echo time and develop heavily T2 weighted contrast without problems from CSF partial volume effects. Due to improved sensitivity in demonstrating T2 prolongation, most parenchymal lesions become more conspicuous in the FLAIR sequence. The nulling of the CSF maximizes the sensitivity of the sequence to changes in the T1 relaxation time of CSF. Many reports confirm the superiority of the FLAIR sequence over conventional spin-echo (SE) sequences with respect to disease in the subarachnoid space and parenchyma [1–17]. It has been suggested that FLAIR images may eliminate the need for gadolinium enhanced T1 weighted images in the diagnosis of leptomeningeal disease [18] and in the detection, but not characterization of, intracranial tumours [19, 20], intracranial infections [21], multiple sclerotic lesions [22], and others [1].

Thus, we hypothesized that a negative FLAIR sequence is able to rule out MR-detectable brain lesions. The purpose of our study was to retrospectively assess the rate of false-negative diagnoses under the assumption that an MR examination of the brain would have been terminated upon negative FLAIR sequencing and, to calculate the negative predictive value of FLAIR imaging in ruling out MR-detectable brain lesions.


   Materials and methods
Top
 Abstract
 Introduction
 Materials and methods
Results
 Discussion
 References
 
Patients
The routine use of FLAIR sequences in brain imaging at our institution began in December 1995. Between 1995 and March 1999, 1026 MR examinations of the brain, including technically satisfactory FLAIR images, were performed in 926 patients (450 female, 476 male; average age, 47 years; age range, 2 days–89 years). Due to motion artefact, the images of 11 patients were judged to be inadequate and the subjects were excluded from evaluation. Paediatric patients were studied after informed consent was obtained from a parent or guardian. Patients were outpatients referred from internal medicine, paediatrics, neurology, otolaryngology and dermatology. Inpatients were referred from all departments of our university hospital. Indications for imaging are shown in Table 1Go.


View this table:
[in this window]
[in a new window]
  		Table 1. Indications for brain imaging

 
MR imaging
All imaging was performed on a commercially available superconducting 1.0 T system (Gyroscan T10-NT; Philips Medical Systems, Best, The Netherlands). We included only examinations from one of three (different) MR devices of our institution for standardization. MR images of the brain were obtained with a standard quadrature head coil operating in the receive mode. Routine MRI of the brain included T1 weighted SE coronal imaging before and after administration of gadolinium, axial T2 weighted TSE and axial fast-FLAIR (IR-TSE) imaging. In 26 examinations no contrast material was administered.

Parameters for the FLAIR sequence were 5000/100/1900 (repetition time [TR] ms/echo time [TE] ms/inversion time ms), an echo train length of 25, generation of 20 5-mm thick sections (0.5 mm interslice gap) in 1:50 min. A 157 x 256 matrix was acquired over a 230 mm field of view (FOV). The T1 weighted sequences were performed with a 179 x 256 matrix over a 230 mm FOV with 24 6 mm sections and a 0.6 mm gap. Acquisition time was 2:26 min. Sequence parameters were 575/13 (TR ms/TE ms). Contrast-enhanced MR imaging was performed immediately after a bolus injection of a standard dose gadolinium diethylenetriaminepentaacetic acid (0.1 mmol Gd-DTPA/kilogram of body weight). The parameters of the T2 weighted sequence were 2229/110 (TR ms/TE ms), an echo train length of 29, generation of 20 6 mm sections (0.6 mm interslice gap) in 1:11 min. A 182 x 256 matrix was acquired over a 230 mm FOV.

Image analysis
In all patients FLAIR images were read separately by a neuroradiologist (FW) and a radiologist with 4 years experience in neuroradiology (AS). They independently evaluated the FLAIR images with knowledge of the patient's clinical diagnosis as provided by the clinician. The readers had to classify the images as normal (absence of brain lesions) or abnormal mass lesion or abnormal signal intensity. Alterations of signal intensity or structure were classified as normal if the readers assigned no pathological relevance to it, e.g. small punctate white matter lesions in elderly patients.

Two other readers, one neuroradiologist (UM) and a radiologist with 5 years experience in neuroradiology (MC) reviewed the complete MR examination of the brain with knowledge of the patient's clinical diagnosis as provided by the clinician. As it was not our goal to compare FLAIR images with non-FLAIR images, but to compare a limited with an extended examination protocol, they reviewed all sequences, including FLAIR images and additional sequences, if available. They were blinded to the results of the FLAIR reading and evaluated the examination for presence or absence of intracranial lesions using the same definition as the FLAIR readers.

Statistical analysis
Interobserver reliability between readers was based on kappa-statistics. Descriptive statistical analysis was performed using cross-tables. For the calculation of the negative predictive value, disagreements were resolved by consensus. All calculations were carried out with the SPSS statistical package version 9.0.1 (SPSS, Chicago, IL).


   Results
Top
 Abstract
 Introduction
 Materials and methods
 Results
Discussion
 References
 
In 284 MR examinations of the brain, no abnormalities were found (28%). Table 2Go shows the results of FLAIR- and control-readings. FLAIR-ratings were false-negative in four cases. Sensitivity and specificity of the FLAIR sequence for a MR-morphologically detectable cerebral pathology were 99.5% and 89.4%. Positive and negative predictive values were 96.1% and 98.4%, respectively. The interobserver reliability was {kappa}=0.93 for the FLAIR-readers and 0.89 for the readers who rated the complete examination.


View this table:
[in this window]
[in a new window]
  		Table 2. Results of fluid-attenuated inversion recovery (FLAIR) reading and control reading

 
Three of four false-negative cases are displayed in Figures 1–3GoGoGo. The first case (not shown) involves a 52-year-old woman receiving high dose chemotherapy for breast cancer and suspected acromegaly. FLAIR-readers recognized a slightly enlarged pituitary gland but assigned no pathological relevance to it. Thin section images demonstrated mild enlargement of the pituitary gland. However, before and after intravenous administration of gadolinium, no focal mass lesion was obvious. The second case was a 16-year-old woman suffering from hemichorea of her left side. T2 weighted TSE images clearly depicted one lacunar lesion of each caudate nucleus head. The left one is displayed in Figure 1bGo. The corresponding FLAIR image (Figure 1aGo) is negative. In the third case, hypoxic brain damage was suspected after cardiopulmonary resuscitation in a 50-year-old patient. Even in retrospect, FLAIR images are normal (Figure 2aGo). After intravenous administration of gadolinium, disturbance of the blood–brain barrier was obvious in the region of the basal ganglia (Figure 2bGo) and occipital lobes (not shown). In the fourth case, a 44-year-old patient with HIV-1 associated psychomotor inhibition revealed a hyperintense pons lesion which is visible on FLAIR images, in retrospect (Figure 3aGo), but was missed by the FLAIR readers. The lesion can be depicted much more easily in T2 weighted TSE images (Figure 3bGo).



View larger version (95K):
[in this window]
[in a new window]
  		Figure 1. Lacunar lesions of the caudate nucleus. (a) Axial fluid attenuated inversion recovery image (IR-TSE 5000/100/1900) demonstrates no abnormalities. (b) The corresponding T2 weighted image (TSE 2229/110) clearly depicts a hyperintense lesion in the left head of the caudate nucleus.

 


View larger version (85K):
[in this window]
[in a new window]
  		Figure 2. Disturbed blood–brain barrier. (a) Axial fluid attenuated inversion recovery image (IR-TSE 5000/100/1900) demonstrates no abnormalities. (b) Corresponding post-contrast T1 weighted image (TSE 480/15) shows bilateral enhancement in the region of the basal ganglia.

 


View larger version (92K):
[in this window]
[in a new window]
  		Figure 3. Hyperintense brainstem lesion. (a) Axial fluid attenuated inversion recovery image (IR-TSE 5000/100/1900) shows only faint hyperintensity in the left pons. (b) The corresponding T2 weighted image (TSE 2229/110) reveals a better lesion/parenchyma contrast.

 
In 30 cases the FLAIR-readers judged the examination to be abnormal, whereas the two other readers who rated the complete examination, including FLAIR images, judged the exam to be normal. Thus, formally, there were 30 false-positive FLAIR examinations. The study lacks a gold standard concerning brain pathology, therefore it is not possible to decide, whether the FLAIR images are false positive or the non-FLAIR images are false negative. Since the aim of our study was to assess the consequences of a limited examination protocol, and since false positive FLAIR images would lead to a "normal" extended examination, we did not analyse these 30 cases in further detail.


   Discussion
Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
References
 
MRI in neurologic patients covers a wide spectrum of disease. In view of specific and specialized clinical problems, "standard" MRI may not be adequate. Therefore, it can be helpful to start an MR-examination of the brain with a sequence that combines an excellent lesion/parenchyma contrast with an adequate delineation of anatomic details. As most brain lesions give long T2 values, FLAIR images depict these lesions with high contrast when long echo times are used. CSF shows signal loss improving the analysis of parenchyma in the direct vicinity of the CSF. Additionally, the nulling of the highest signal (fluid) improves the apparent contrast between white matter, grey matter, and lesions due to a better use of the dynamics (highest signal intensity minus lowest signal intensity) during acquisition. Thus, FLAIR imaging has been found to be more sensitive than other sequences in the evaluation of cerebral pathology [1–12]. After FLAIR images give an overview of the pathology, the further examination can be adapted accordingly.

In contrast, in our study we focused on those FLAIR images that displayed no pathology. We hypothesized that patients with negative FLAIR images would also not display any pathology in T2 weighted SE images, and in T1 weighted images before and after intravenous administration of gadolinium. As negative cranial MRI does not exclude brain disease, we could only demonstrate the predictive value of FLAIR-images to exclude MR-detectable brain lesions and not to exclude intracranial pathology in general.

Our results show that in a quarter of all cranial MR-examinations, no pathological finding could be observed based on FLAIR images. A nearly perfect interobserver reliability indicates, that the criteria used for normal or abnormal can be applied with good stability. In four of a total of 1026 MR-examinations, and out of 258 MR-examinations with "normal" rated FLAIR images, we found pathological changes in other sequences. The small number of false negative results of FLAIR images in this study did not allow statistical analysis of indications or pathology, which frequently leads to false-negative results in FLAIR imaging. However, an analysis of the four false-negative cases may merit further discussion.

In the first case, the readers of the FLAIR images noticed a slight enlargement of the pituitary gland which was confirmed by a thin slice examination of the sella region. In general, an accurate diagnostic depiction of organs and their pathology usually requires thin slices and cannot be achieved with 6 mm-slices, independent from the sequence protocol and the TR/TE applied. Clinical findings suggesting pathology involving the pituitary gland or the cerebellopontine angle need thin section imaging, so that we perhaps did not miss more relevant findings in these regions only by chance.

The second case was rated false-negative because a lacunar lesion in the head of the caudate nucleus was not seen as a consequence of the diminished contrast of the small lesion in respect to the adjacent cerebral parenchyma. The detection rate of small lesions with CSF-like high signal is decreased due to the suppression of CSF-signal by the inversion pulse. However, clinical significance of such lesions without parenchymal gliosis may be argued as physiologic perivascular spaces ("Virchow–Robin spaces"), which have a similar appearance.

It is known that FLAIR images suffer from a diminished contrast of lesions in the posterior fossa [23–25]. Accordingly, the improved contrast of the brain stem lesion in conventional T2 weighted TSE-images causes better conspicuity leading to a false-negative rating of the FLAIR images in case four. Although no definite cause has been found to explain the decreased FLAIR image quality in the posterior fossa, most authors feel that CSF-pulsation artefacts impair lesion detection [23–25]. Furthermore, there is increasing evidence, that demyelinating lesions in the posterior fossa give T2 values that differ from those obtained in supratentorial lesions [26]. Thus, a single demyelinating lesion in the posterior fossa may be missed by the FLAIR sequence. As these lesions are highly specific for the diagnosis of multiple sclerosis, a FLAIR sequence should be accompanied by T2 weighted SE images in these instances.

The third false-negative case forms part of a well-known group of patients in which contrast-enhanced series show a higher sensitivity than FLAIR sequences. Apart from a disruption of the blood–brain barrier in hypoxic-ischaemic brain damage as in our study, cerebral metastases and pathologies of the subarachnoid space, including tumorous and granulomatous disease, may benefit from contrast application [20, 27]. However, data concerning the sensitivity of FLAIR images regarding the subarachnoid space are inconsistent. One study reports the superiority of FLAIR images over contrast-enhanced T1 weighted images [18]. A more recent report found the contrast-enhanced T1 images to be better than FLAIR imaging for detection of leptomeningeal metastases [27]. In our study population we had no case of false-negative subarachnoid space rating regarding the FLAIR images.

Many previous studies have compared the FLAIR imaging with other pulse sequences [1–25]. However, to the best of our knowledge, no systematic analysis of FLAIR sequences has been performed in comparison with contrast-enhanced sequences in a large series of unselected patients. Although the use of Gd-DTPA can increase diagnostic accuracy in selected patients, it remains a point of debate whether all patients should receive contrast material as part of a standard cranial MRI examination [28]. This is especially true in patients with a normal plain scan. The present study underscores that an unselective application of contrast material avoids false-negative MR-reading in only one case and improves the sensitivity of the MR-examination from 99.5% to 99.6%. As contrast agents were routinely administered at our institution during the time period of data acquisition, we had no pre-selection bias. In a previous study conducted in 500 unselected patients referred for routine cranial MRI, T1 and T2 weighted pre-contrast images were compared with the combined study (pre- and post-contrast). The number of patients in whom contrast enhancement revealed abnormalities not apparent on pre-contrast images was much larger (15 of 500 cases, 3%) than in our study [29]. This difference is likely to be an effect of the increased sensitivity of the FLAIR sequence for brain lesions.

The sensitivity of the FLAIR sequence is dependent on sequence parameters. It has been shown, that longer TR/TI combinations and longer TE values than we used are able to improve the sensitivity of FLAIR imaging [30]. However, this work was performed at 1.5 Tesla. Our examinations were carried out with a 1.0 Tesla magnet, where longitudinal relaxation times of most materials are shorter than at 1.5 Tesla. Appropriately, we used shorter TR, TI and TE values.

In conclusion, negative FLAIR images provide a high negative predicitve value and are therefore an appropriate sequence to start with in any MR-examination of the brain. However, as demonstrated by the false negative cases, sensitivity is not 100%. Despite the high negative predictive value additional sequences must therefore be performed to further increase sensitivity. At the time of this study the unselective application of intravenous gadolinium application was routine for all standard cranial MRI exams. However, we only achieved an increase in sensitivity of 0.1% through contrast application. In the light of our results, the unselected application of contrast-material therefore seems to be inadequate in patients with negative FLAIR images.

Received for publication June 25, 2003. Revision received September 22, 2003. Accepted for publication November 12, 2003.


   References
Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 

  1. Thurnher MM, Thurnher SA, Fleischmann D, Steuer A, Rieger A, Helbich T, et al. Comparison of T2 weighted and fluid-attenuated inversion-recovery fast spin-echo MR sequences in intracerebral AIDS-associated disease. AJNR Am J Neuroradiol 1997;18:1601–9.[Abstract]
  2. Herskovits EH, Itoh R, Melhem ER. Accuracy for detection of simulated lesions: comparison of fluid-attenuated inversion-recovery, proton density-weighted, and T2 weighted synthetic brain MR imaging. AJR Am J Roentgenol 2001;176:1313–8.[Abstract/Free Full Text]
  3. Ashikaga R, Araki Y, Ishida O. MRI of head injury using FLAIR. Neuroradiology 1996;39:239–42.
  4. Palmer S, Bradley WG, Chen DY, Patel S. Subcallosal striations: early findings of multiple sclerosis on sagittal, thin-section, fast FLAIR MR images. Radiology 1999;210:149–53.[Abstract/Free Full Text]
  5. Demaerel P, Bosmans H, Caerts B, Herpels V, Vercruysse J, Verslegers I, et al. Fast FLAIR MRI in childhood white-matter abnormalities. Neuroradiology 1998;40:355–8.[CrossRef][Medline]
  6. Meiners LC, van Gils A, de Kort G, van der Graaf Y, Jansen GH, van Veelen CWM. Fast fluid-attenuated inversion recovery (FLAIR) compared with T2 weighted spin-echo in the magnetic resonance diagnosis of mesial temporal sclerosis. Invest Radiol 1999;34:134–42.[CrossRef][Medline]
  7. Taillibert S, Oppenheim C, Baulac M, Dormont D, Marsault C, Cabanis EA, et al. Yield of fluid-attenuated inversion recovery in drug-resistant focal epilepsy with noninformative conventional magnetic resonance imaging. Eur Neurol 1999;41:64–72.[CrossRef][Medline]
  8. Ikushima I, Korogi Y, Hirai T, Sugahara T, Shigematsu Y, Komohara Y, et al. MR of epidermoids with a variety of pulse sequences. AJNR Am J Neuroradiol 1997;18:1359–63.[Abstract]
  9. Noguchi K, Ogawa T, Seto H, Inugami A, Hadeishi H, Fujita H, et al. Subacute and chronic subarachnoid hemorrhage: diagnosis with fluid-attenuated inversion-recovery MR imaging. Radiology 1997;203:257–62.[Abstract/Free Full Text]
  10. Brant-Zawadzki M, Atkinson D, Detrick M, Bradley WG, Scidmore G. Fluid-attenuated inversion recovery (FLAIR) for assessment of cerebral infarction. Stroke 1996;27:1187–91.[Abstract/Free Full Text]
  11. Bakshi R, Kamran S, Kinkel PR, Bates VE, Mechtler LL, Janardhan V, et al. Fluid-attenuated inversion-recovery MR imaging in acute and subacute cerebral intraventricular hemorrhage. AJNR Am J Neuroradiol 1999;20:629–36.[Abstract/Free Full Text]
  12. Hashemi RH, Bradley WG, Chen DY, Jordan JE, Queralt JA, Cheng AE, et al. Suspected multiple sclerosis: MR imaging with a thin-section fast FLAIR pulse sequence. Radiology 1995;196:505–10.[Abstract/Free Full Text]
  13. Maubon AJ, Pothin A, Ferru JM, Berger VM, Daures JP, Rouanet JP. Unselected brain 0.5-T MR imaging: comparison of lesion detection and characterization with three T2 weighted sequences. Radiology 1998;208:671–8.[Abstract/Free Full Text]
  14. Aprile I, Iaiza F, Lavaroni A, Budai R, Dolso P, Scott CA, et al. Analysis of cystic intracranial lesions performed with fluid-attenuated inversion recovery MR imaging. AJNR Am J Neuroradiol 1999;20:1259–67.[Abstract/Free Full Text]
  15. Essig M, Wenz F, Schoenberg SO, Debus J, Knopp MV, van Kaick G. Arteriovenous malformations: assessment of gliotic and ischemic changes with fluid-attenuated inversion-recovery MRI. Invest Radiol 2000;35:689–94.[CrossRef][Medline]
  16. Casey SO, Sampaio RC, Michel E, Truwit CL. Posterior reversible encephalopathy syndrome: utility of fluid-attenuated inversion recovery MR imaging in the detection of cortical and subcortical lesions. AJNR Am J Neuroradiol 2000;21:1199–206.[Abstract/Free Full Text]
  17. Maeda M, Yamamoto T, Daimon S, Sakuma H, Takeda K. Arterial hyperintensity on fast fluid-attenuated inversion recovery images: a subtle finding for hyperacute stroke undetected by diffusion-weighted MR imaging. AJNR Am J Neuroradiol 2001;22:632–6.[Abstract/Free Full Text]
  18. Singer MB, Atlas SW, Drayer BP. Subarachnoid space disease: diagnosis with fluid-attenuated inversion recovery MR imaging and comparison with gadolinium-enhanced spin-echo MR imaging-blinded reader study. Radiology 1998;208:417–22.[Abstract/Free Full Text]
  19. Husstedt HW, Sickert M, Köstler H, Haubitz B, Becker H. Diagnostic value of the fast-FLAIR sequence in MR imaging of intracranial tumors. Eur Radiol 2000;10:745–52.[CrossRef][Medline]
  20. Essig M, Knopp MV, Schoenberg SO, Hawighorst H, Wenz F, Debus J, et al. Cerebral gliomas and metastases: assessment with contrast-enhanced fast fluid-attenuated inversion-recovery MR imaging. Radiology 1999;210:551–7.[Abstract/Free Full Text]
  21. Tsuchiya K, Inaoka S, Mizutani Y, Hachiya J. Fast fluid-attenuated inversion-recovery MR of intracranial infections. AJNR Am J Neuroradiol 1997;18:909–13.[Abstract]
  22. Boggild MD, Williams R, Haq N, Hawkins CP. Cortical plaques visualized by fluid-attenuated inversion recovery imaging in relapsing multiple sclerosis. Neuroradiology 1996;38:10–3.[CrossRef]
  23. Okuda T, Korogi Y, Shigematsu Y, Sugahara T, Hirai T, Ikushima I, et al. Brain lesions: when should fluid-attenuated inversion-recovery sequences be used in MR evaluation? Radiology 1999;212:793–8.[Abstract/Free Full Text]
  24. Stevenson VL, Gawne-Cain ML, Barker GJ, Thompson AJ, Miller DH. Imaging of the spinal cord and brain in multiple sclerosis: a comparative study between fast flair and fast spin echo. J Neurol 1997;244:119–24.[CrossRef][Medline]
  25. Tubridy N, Barker GJ, MacManus DG, Moseley IF, Miller DH. Optimisation of unenhanced MRI for detection of lesions in multiple sclerosis: a comparison of five pulse sequences with variable slice thickness. Neuroradiology 1998;40:293–7.[CrossRef][Medline]
  26. Bastianello S, Bozzao A, Paolillo A, Giugni E, Gasperini C, Koudriavtseva T, et al. Fast spin-echo and fast fluid-attenuated inversion-recovery versus conventional spin-echo sequences for MR quantification of multiple sclerotic lesions. AJNR Am J Neuroradiol 1997;18:699–704.[Abstract/Free Full Text]
  27. Singh SK, Agris JM, Leeds NE, Ginsberg LE. Intracranial leptomeningeal metastases: comparison of depiction at FLAIR and contrast-enhanced MR imaging. Radiology 2000;217:50–3.[Abstract/Free Full Text]
  28. Breslau J, Jarvik JG, Haynor DR, Longstreth WT, Kent DL, Maravilla KR. MR contrast media in neuroimaging: a critical review of the literature. AJNR Am J Neuroradiol 1999;20:670–5.[Abstract/Free Full Text]
  29. Elster AD, Moody DM, Ball MR, Laster DW. Is Gd-DTPA required for routine cranial MR imaging? Radiology 1989;173:231–8.[Abstract/Free Full Text]
  30. Rydberg JN, Riederer SJ, Rydberg C, Jack CR. Contrast optimization of fluid-attenuated inversion recovery (FLAIR) imaging. Magn Reson Med 1995;34:868–77.[Medline]



This article has been cited by other articles:


Home page
 Am. J. Neuroradiol.Home page
A. Cianfoni, M.G.M. Martin, J. Du, J.R. Hesselink, S.G. Imbesi, W.G. Bradley, and G.M. Bydder
Artifact simulating subarachnoid and intraventricular hemorrhage on single-shot, fast spin-echo fluid-attenuated inversion recovery images caused by head movement: A trap for the unwary.
AJNR Am. J. Neuroradiol., April 1, 2006; 27(4): 843 - 849.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Saleh, A
Right arrow Articles by Mödder, U
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Saleh, A
Right arrow Articles by Mödder, U

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
BJR DMFR IMAGING  ALL BIR JOURNALS