Hepatic T2-weighted MRI: a prospective comparison of sequences, including breath-hold, half-Fourier turbo spin echo (HASTE)

The purpose of this study was to quantitatively compare the hepatic contrast characteristics of conventional spin-echo (CSE) and fast spin-echo (FSE) sequences with breath-hold T2-weighted images acquired with half-Fourier turbo spin echo (HASTE). Forty-five patients were examined with a phased-array surface coil. Nineteen patients had focal hepatic lesions, including eight malignant tumors, 10 cavernous hemangiomas, and one hepatic adenoma. Twenty-six patients had no focal hepatic lesions. T2-weighted images with comparable TE were acquired with CSE, FSE, and HASTE pulse sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for liver, spleen, and lesions were measured. FSE demonstrated significantly better quantitative performance than CSE for liver-spleen CNR (P .0084). No statistically significant difference was demonstrated between FSE and CSE for liver or spleen SNR. FSE demonstrated clear scan time and resolution advantages over CSE. HASTE performed significantly poorer than CSE and FSE for liver-spleen CNR (P < .0001), liver SNR (P = .0002 for CSE and P < .0001 for FSE), and spleen SNR (P < .0001). Optimized FSE images with a short echo train length performed comparably to CSE images of equivalent TE. Liver-lesion CNR was suppressed on HASTE images, suggesting that long echo train length FSE sequences could diminish solid lesion detection compared to CSE and short echo train length FSE.     

Four new mutations in the apolipoprotein B gene causing hypobetalipoproteinemia, including two different frameshift mutations that yield truncated apolipoprotein B proteins of identical length

Magnetic resonance imaging is frequently complicated by the presence of motion and susceptibility gradients. Also, some biologic tissues have short T2s. These problems are particularly troublesome in fast spin-echo (FSE) imaging, in which T2 decay and motion between echoes result in image blurring and ghost artifacts. The authors reduced TE in conventional spin-echo (SE) imaging to 5 msec and echo spacing (E-space) in FSE imaging to 6 msec. All magnetic gradients (except readout) were kept at a maximum, with data sampling as fast as 125 kHz and only ramp waveforms used. Truncated sinc radio-frequency pulses and asymmetric echo sampling were also used in SE imaging. Short TE (5.8 msec) SE images of the upper abdomen were compared with conventional SE images (TE = 11 msec). Also, FSE images with short E-space were compared with conventional FSE images in multiple body sites. Short TE significantly improved the liver-spleen contrast-to-total noise ratio (C/N) (7.9 vs 4.1, n = 9, P < .01) on T1-weighted SE images, reduced the intensity of ghost artifacts (by 34%, P < .02), and increased the number of available imaging planes by 30%. It also improved delineation of cranial nerves and reduced susceptibility artifacts. On short E-space FSE images, spine, lung, upper abdomen, and musculoskeletal tissues appeared crisper and measured spleen-liver C/N increased significantly (6.9 vs 4.0, n = 12, P < .01). The delineation of tissues with short T2 (eg, cartilage) and motion artifact suppression were also improved. Short TE methods can improve image quality in both SE and FSE imaging and merit further clinical evaluation.     

Hyperparathyroidism--comparison of flash imaging with spin echo MR imaging

MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck.     

Multiple myeloma presenting as parasellar syndrome and cranial nerve palsies

Cranial and intracranial locations have been rarely reported in multiple myeloma. Their occurrence as a harbinger of multiple myeloma seems to have a particular significance. In this report, we discuss a case of multiple myeloma presenting as parasellar syndrome and cranial nerve palsies. A 75-year-old woman was admitted to the hospital in June, 1994, with a 3-month history of headache and a 3-week history of diplopia and photophobia. Physical examination revealed right third, fourth and sixth cranial nerve palsies. MRI scan demonstrated a homogeneous, voluminous mass, isointense in T1-weighted images with the cerebral parenchyma and hyperintense in T2-weighted images, occupying the sphenoid sinus and extending within the sella turcica and right cavernous sinus. Lying above the mass and apparently separated from it by a thin rim of hypointensity was a normal pituitary gland. X rays revealed destructive changes of the sella turcica. A minimal disturbance of endocrine function together with a radiologically abnormal pituitary fossa indicated that the primary lesion might lie outside the pituitary fossa. A diagnosis of IgG-kappa type multiple myeloma was made by pertinent laboratory studies. She received local radiation to the intracranial mass (50 Gy) and conventional chemotherapy. Sixteen months after the therapy she is in good health.     

Three-dimensional echocardiographic planimetry of maximal regurgitant orifice area in myxomatous mitral regurgitation: intraoperative comparison with proximal flow convergence

The purpose of this study was to evaluate the usefulness of multishot echo-planar imaging in detecting liver tumors in comparison with respiratory triggered T2-weighted fast-spin-echo (FSE) imaging. Thirty-two patients with 70 focal liver lesions were imaged using a 1.5-T high speed MR imager. Eight-shot echo-planar images covering the whole liver were acquired during a single breath-hold period. FSE images were acquired with respiratory triggering in approximately 4 minutes. Lesion detectability and image quality of the two pulse sequences were analyzed qualitatively. Quantitative analysis was performed by means of signal-to-noise and tumor-liver contrast-to-noise analysis. Lesion detectability was comparable in both solid (86.3% vs 90.2%: .3 < P < .5) and nonsolid lesions (89.5% vs 100%: .3 < P < .5) between echo-planar and FSE images. Echo-planar imaging provided significantly reduced image artifact, better lesion conspicuity, and anatomic detail compared with FSE imaging. The signal-to-noise and contrast-to-noise ratios of echo-planar images were significantly higher than those of FSE images. Breath-hold eight-shot echo-planar imaging can be an alternative to T2-weighted FSE imaging because it can provide comparable image quality in a substantially decreased acquisition time.     

Focal malignant hepatic lesions: MR imaging enhanced with gadolinium benzyloxypropionictetra-acetate (BOPTA)--preliminary results of phase II clinical application

PURPOSE: To investigate enhancement with gadolinium benzyloxypropionictetraacetate (BOPTA) at magnetic resonance (MR) imaging to detect focal malignant hepatic lesions. MATERIALS AND METHODS: A phase II trial was performed in 34 patients. Gd-BOPTA-enhanced spin-echo (SE) and gradient-recalled-echo (GRE) T1-weighted MR imaging were performed at 40 and 90 minutes after intravenous injection of 0.05 and 0.10 mmol/kg Gd-BOPTA. RESULTS: The percentage of enhancement in liver parenchyma was significantly (P<.05) increased on GRE T1-weighted compared with SE T1-weighted images at 40 and 90 minutes after injection of the higher dose and compared with SE and GRE T1-weighted images obtained with the lower dose. The contrast-to-noise ratio of metastases was significantly increased on GRE T1-weighted images (0.10 mmol/kg) at 90 minutes compared with precontrast images. Significantly more small primary metastases were detected on GRE T1-weighted images (0.10 mmol/kg) at 90 minutes compared with precontrast SE T1-weighted images. CONCLUSION: Gd-BOPTA is a safe hepatobiliary contrast agent that helps detection of small metastases.     

MR imaging of the anterior cruciate ligament: frequency of discordant findings on sagittal-oblique images and correlation with arthroscopic findings

OBJECTIVE: The purposes of this study were to determine the frequency of discordant MR findings of the anterior cruciate ligament (ACL) using sagittal-oblique images and the arthroscopic integrity of the ACL in knees with a discordant MR appearance. MATERIALS AND METHODS: The frequency of discordant MR features was determined by independently reviewing the sagittal-oblique images of 53 consecutive patients undergoing subsequent arthroscopic surgery. The first 25 consecutive knees were examined using a conventional, dual-echo, T2-weighted spin-echo (SE) sequence; the subsequent 28 consecutive knees were examined using both a T1-weighted SE(T1) and a fat-suppressed, fast spin-echo (FSE) T2-weighted sequence. Two examiners who were unaware of patient identification and arthroscopic results evaluated only the sagittal images that included the ACL. Each reviewer graded the ACL as torn or intact. The MR appearance was considered discordant when one MR sequence showed disrupted or poorly seen ACL fibers and the other sequence showed intact ACL fibers. The arthroscopic integrity of the ACL was determined for the 20 knees with a discordant MR appearance. RESULTS: A discordant MR appearance of the ACL was seen in 20 of the 53 knees (38%), including 10 knees evaluated using conventional T2-weighted sequences (40%) and 10 knees using T1/FSE T2 (36%) sequences. Arthroscopic examination of these knees showed intact ACL fibers in all 20 knees; the ACL was normal in 18 knees and a partial tear was questioned in two knees. CONCLUSION: A discordant appearance of the ACL was frequently encountered (38%) using either conventional T2-weighted sequences or T1 and FSE MR sequences in the sagittal-oblique plane. Intact ACL fibers were found during arthroscopy in all 20 knees with a discordant MR appearance.     

Surgical indications for and limitations of staged transsphenoidal surgery for large pituitary tumors

Surgical indications and limitations of transsphenoidal surgery and intentionally staged transsphenoidal surgery for large pituitary tumors were investigated by retrospective analysis of the surgical and neuroradiological findings of 22 patients with large tumor and suprasellar extension. Twelve patients underwent intentionally staged transsphenoidal surgery, and 10 underwent combined transsphenoidal and transcranial surgeries. Successful removal by intentionally staged surgery required descent of the suprasellar part following the first transsphenoidal surgery. Analysis showed that a smooth suprasellar extension and/or soft tumor are indications for intentionally staged transsphenoidal surgery even in patients with small sella. However, lobulated suprasellar extension, fibrous and firm tumor without descent, and small sella with normal pituitary gland located at the bottom of the sella are contraindications for staged transsphenoidal surgery. The first transsphenoidal surgery is always indicated to achieve histological confirmation and decompression of optic nerves. Transcranial surgery should be attempted instead of repeated transsphenoidal surgeries when the residual tumor does not descend following the first transsphenoidal surgery.     

Projections of the ventral tegmental area of the midbrain, the substantia nigra, and the amygdaloid body in different parts of the putamen in the dog

INTRODUCTION: We investigated the accuracy of endorectal coil Magnetic Resonance Imaging (MRI) and Fast Spin Echo (FSE) technique in staging prostate cancer. MATERIAL AND METHODS: MRI was performed in 70 patients with biopsy proved prostatic cancer. A total of 33 patients subsequently underwent radical prostatectomy. T2-weighted FSE sequences (TR 3400-4100, TE 120, Echo train length 13) were acquired in all patients. Axial, sagittal and coronal 4-5 mm images were obtained with 13-14 cm field of view and 256 x 256 matrix. Additional T1-weighted spin echo images were acquired in 9 patients. Lesion staging on MR images was performed according to the American Urological System. MR data were compared with the pathologic findings of whole-mount sections of the surgical specimens. RESULTS: Overall accuracy for endorectal coil MR imaging was 60%; ten cases were underestimated and 3 cases were overestimated. The sensitivity and the specificity of endorectal coil MRI in diagnosing capsular penetration were 77% and 81%, respectively. Seminal vesicle invasion was detected with 87% sensitivity and 96% specificity. CONCLUSIONS: Endorectal coil MRI provides a more accurate preoperative local staging.     

Differential expression of DNA topoisomerase II alpha and II beta genes between small cell and non-small cell lung cancer

The purpose of this study is to describe the appearance of bowel-related abscesses on magnetic resonance (MR) images. Sixteen consecutive patients who had bowel-related abscesses underwent MR examination at 1.5T. MR sequences included T1-weighted fat-suppressed imaging pre- and post-intravenous gadolinium chelate administration (all patients) and breathing-independent single-shot T2-weighted half Fourier turbo (fast) spin echo (6 patients). Patients with pelvic abscesses also underwent sagittal imaging with post-gadolinium T1-weighted images (9 patients) and T2-weighted turbo (fast) spin echo (8 patients). Abscesses were confirmed by open surgery or surgical drainage (6 patients), percutaneous drainage (8 patients), or combined physical examination, fluoroscopic fistulogram, and clinical follow-up (2 patients). Oval-shaped fluid collections were identified in all of the patients, which ranged in diameter from 2 cm to 18 cm, mean: 8 cm. Abscesses were low to intermediate in signal on T1-weighted images, heterogenous and moderately high signal on T2-weighted images, and low signal on post-gadolinium images. A layering effect of lower signal material in the dependent portion of the abscess was noted in abscesses in 6 of 14 patients on T2-weighted images. Post-gadolinium images demonstrated a definable 3- to 7-mm thick abscess wall, which enhanced substantially with contrast. Definition of the wall was best shown on fat-suppressed images post-gadolinium. Substantial enhancement of surrounding periabscess tissues was demonstrated in all cases and was most clearly defined on fat-suppressed images. Image acquisition in two orthogonal planes was of value to demonstrate that fluid collections were oval, and separate from bowel. Image acquisition in the sagittal plane was useful in the evaluation of pelvic abscesses. The results from this preliminary study show that bowel-related abscesses are demonstrable on MR images using gadolinium-enhanced fat-suppressed T1-weighted and turbo (fast) spin-echo T2-weighted sequences. The presence of a thickened, enhancing lesion wall and enhancement of perilesional tissues on T1-weighted fat-suppressed images were observed in all abscesses. A layering effect of low signal intensity material in the dependent portion of the abscess was an important ancillary feature.     

Post radiation hemorrhagic cystitis: MR findings

We report on the magnetic resonance findings in two patients with hemorrhagic cystitis secondary to radiation therapy. One patient's bladder wall was high in signal intensity on T1-weighted fat-suppressed spoiled gradient echo and low in signal intensity on T2-weighted fat-suppressed spin echo images, findings consistent with intracellular methemoglobin in the setting of subacute intramural hemorrhage. The second patient's bladder wall had regions that were low in signal intensity on T1-weighted fat-suppressed spin echo and high in signal intensity on T2-weighted fat-suppressed spin echo, and other regions that were high in signal intensity on T1-weighted fat suppressed spin echo and on T2-weighted fat-suppressed spin echo images, findings that were consistent with active bleeding and late subacute hemorrhage, respectively. Imaging findings correlated with the patients' clinical picture. Our two cases illustrate that magnetic resonance images may demonstrate changes of hemorrhagic cystitis and may permit determination of disease acuity.     

Monitoring of radio frequency tissue ablation in an interventional magnetic resonance environment. Preliminary ex vivo and in vivo results

RATIONALE AND OBJECTIVES: The authors evaluate the feasibility of monitoring radio frequency (RF) ablation in an interventional, open-configuration, 0.5-tesla magnetic resonance (MR) environment. METHODS: Ex vivo and in vivo RF coagulation necrosis were induced in porcine paraspinal muscle tissue using a 300 kHz monopolar RF generator applying 5 to 20 W over 3 to 9 minutes. Images were acquired simultaneous to RF application, after RF application, and in an intermittent mode (60 seconds of RF followed by 15 seconds of MR imaging). Temperature changes were monitored based on amplitude (ex vivo) and phase alterations (in vivo) of a T1-weighted graded refocused echo (GRE) sequence enabling an update every 2.5 seconds. A standardized color-coded subtraction technique enhanced signal changes. Additionally, T2- and T1-weighted spin echo (SE) images were acquired with and without intravenous contrast. Macroscopic coagulation size was compared with lesion size seen on MR images. RESULTS: Although lesion diameters were related directly to applied RF power, the application mode had no significant impact on coagulation size (P > 0.05). As could be expected, MR imaging during RF ablation resulted in major image distortion. Radio frequency effects were seen on images acquired in the continuous and intermittent modes. Coagulation size seen on GRE images correlated well with macroscopy both ex vivo (r = 0.89) and in vivo (r = 0.92). Poorer correlation was found with postinterventional SE sequences (r = 0.78-0.84). CONCLUSIONS: Magnetic resonance monitoring of RF effects is feasible both ex vivo as well as in vivo using temperature-sensitive sequences in an open-configuration MR environment.     

Chronic pulmonary histoplasmosis in Brazil: report of two cases with cavitation diagnosed by transthoracic needle biopsy

OBJECTIVE: To compare fat-suppressed fast spin-echo (FSE) T2-weighted images with gradient-recalled echo (GRE) T2*-weighted images in the evaluation of anteroinferior labral tears. DESIGN: MR images were retrospectively reviewed by two radiologists masked to the history and arthroscopic findings. They separately interpreted the anteroinferior labrum as torn or intact, first on one pulse sequence and then, 4 weeks later, on the other sequence. The MR interpretations were correlated with the arthroscopic findings. PATIENTS: Nine patients with anteroinferior labral tears, and nine similarly-aged patients with normal, labra were studied. RESULTS AND CONCLUSIONS: Observer 1 had a sensitivity of 0.56 on the GRE images and 0.67 on the FSE images (P > 0.5), with a specificity of 1.0 for both sequences. Observer 2 had a sensitivity of 0.78 and a specificity of 0.89 for both sequences. In this small study there is no significant difference between GRE and fat-suppressed FSE images in their ability to diagnose anteroinferior labral tears. When evaluating the labrum with conventional MRI, axial fat-suppressed FSE T2-weighted images can be used in place of GRE images without a loss of accuracy.     

Lumbar spine magnetic resonance imaging: comparison between fast spin echo proton density and spin echo T1 axial scans

Spin echo (SE) T1 axial scans are routinely obtained in magnetic resonance imaging of the lumbar spine in many centres. This study directly compared matched SE T1 and fast SE (FSE) proton density (PD) axial scans. Both SE T1 and FSE PD axial scans of the lumbar spine were obtained in 116 consecutive patients. The imaging parameters (field-of-view, slice thickness, interslice gap, number of excitations and matrix size) and scan levels were identical for each pair of sequences. At two selected levels, L4/5 and L5/S1, various structures were independently graded by two observers. In 232 lumbar levels analysed, the bone marrow, epidural fat, disc, extradural nerve root and facet joint were equally well seen on both sequences by both observers (combined mean grades of 2.93-2.99). The thecal sac was marginally better depicted on FSE PD than on SE T1 images, with mean grades of 2.96 and 2.88, respectively. The psoas muscle was adequately visualized for diagnostic purposes on both sequences (mean grades of 2.30-2.32). The cauda equina were better seen on FSE PD (mean grade 1.92) than on SE T1 (mean grade 1.00) images. In conclusion, FSE PD scans are comparable to and may potentially replace SE T1 axial MR scans of the lumbar spine.     

Fast spin-echo MR imaging of the eye

Magnetic resonance imaging of the eye usually includes T2-weighted images both for screening purposes and for characterization of melanoma. Conventional T2-weighted spin-echo (SE) imaging suffers both from long acquisition times and incomplete recovery of the vitreous' signal. A fast SE sequence was therefore compared prospectively with conventional sequences in 29 consecutive patients with lesions of the eye. Fast SE images delineated melanoma and other lesions of the eye from vitreous better than conventional T2-weighted images. Image quality and lesion conspicuity were improved on the fast sequence. Whereas melanoma appeared hypointense to vitreous on both types of images, subretinal effusion was hypointense on fast images and hyperintense on conventional T2-weighted images. Ghosting of the globe, which, however, did not decrease diagnostic value, was more pronounced on fast images. Conventional T2-weighted images may be replaced by fast SE images in MR studies of the eye with a gain in lesion conspicuity and significant time saving.     

Sequences and techniques in spinal MR imaging

The optimal protocol in spinal MR imaging is not evident. Sagittal T2 weighted FSE, sagittal T1 weighted SE and axial T2 weighted FSE sequences are widely accepted for imaging patients with sciatica and/or lumbar pain. Because of the limited amount of CSF compared to the lumbar spine, the choice of sequences is much more complex in the study of the cervical spine. Sagittal T2 FSE, sagittal T1 SE and axial 2D GE images are suggested in routine cervical spine imaging. To assess the bone marrow, a STIR sequence can be added to this protocol on both lumbar and cervical spine examinations. The 2D GE produces an acceptable image quality to differentiate between the disc and bony protrusions. The use of FLAIR for imaging spinal cord lesions remains controversial in the literature.     

The accuracy of CT and MR evaluation of the sella turcica for detection of adrenocorticotropic hormone-secreting adenomas in Cushing disease

PURPOSE: To document the accuracy of CT and MR of the sella turcica for detecting adrenocorticotropic hormone-secreting adenomas in Cushing disease. METHODS: The radiologic findings of the sella turcica prior to transsphenoidal surgery are reviewed in 141 patients who had biochemical evidence of pituitary-dependent Cushing disease. Axial thin-collimation CT scans with sagittal and coronal reformations before and after contrast enhancement were obtained in 125 patients. Seventy-eight patients had MR examinations with a 1.5-T superconducting magnet. In 11 of the patients gadolinium-enhanced MR scans were also obtained. The preoperative interpretation of the imaging studies was correlated with the surgical findings and patients follow-up. RESULTS: The sella turcica was enlarged in 43 cases (30%). In 125 patients reformatted or direct coronal thin-collimation CT scans were available. Seventy-eight of the patients had MR. In the 12 patients with pituitary macroadenomas, the accuracy of CT (n = 10) and MR (n = 10) in respect to detection of the lesion was 100%. Of the 98 microadenomas assessed by CT, 47 (48%) were directly depicted as distinct hypodense lesions. In only 31 of 73 cases (42%), however, could CT predict the precise anatomic location and extent of the lesions. Only patients in whom the hypercortisolism was corrected by later surgery were considered for the correlation analysis. Of the 52 microadenomas assessed by MR, 28 (53%) were directly depicted as distinct lesions of reduced signal intensity on T1-weighted images, and in only 21 of 41 cases (52%) did MR show good correlation to the surgical findings. Some degree of partially empty sella was found in 22% of the patients. CONCLUSIONS: Although both the sensitivity and the diagnostic accuracy of imaging methods of the sella turcica have been considerably improved in comparison with previous reports, they still provide only a minor contribution to the diagnosis and differential diagnosis of Cushing syndrome.     

Bioequivalence of a combination of levothyroxine and iodine in comparison with levothyroxine only. A controlled double-blind study of bioavailability]

RATIONALE AND OBJECTIVES: The authors assessed the ability of a low-field-strength extremity-only magnet to provide visualization of the triangular fibrocartilage and the scapholunate and lunotriquetral ligaments. METHODS: Twelve human wrists were examined with a 0.2 T extremity-only magnet. T1-weighted spin echo, proton density-weighted, and T2-weighted turbo spin echo, short-tau inversion recovery, and three-dimensional gradient recalled echo images were acquired, and sections of the specimens were then made that corresponded to the magnetic resonance images. Masked imaging analyses were correlated with macroscopic and limited histopathologic findings. RESULTS: Low-field-strength extremity-only magnet allowed consistent visualization of the triangular fibrocartilage and accurate assessment of a small number of complete tears of the triangular fibrocartilage. The scapholunate ligaments in all cases were identified using a combination of imaging sequences. Consistent visualization of the lunotriquetral ligament with a low-field-strength extremity magnet was difficult. CONCLUSIONS: Magnetic resonance imaging with a low-field-strength extremity-only magnet can be used to visualize the triangular fibrocartilage and the scapholunate ligament, but not the lunotriquetral ligament.     

Fast spin echo vs conventional spin echo in cervical spine imaging

The major attraction of fast-spin-echo (FSE) imaging is reduced acquisition time; however, careful review of the literature reveals many weaknesses: phase-encoded blurring, truncation artefact, bright fat signal, reduced magnetic susceptibility and increased motion artefact. Our aim was a prospective, blinded comparison of FSE and conventional spin echo (CSE) in the cervical spine. Both sequences were performed in 43 patients (19 males and 24 females; mean age 45 years, range 15-66 years). Twenty-eight patients were studied at 1.5 T and 15 at 0.5 T. Typical sequence parameters were: at 1.5 T, TR/TE 2000/90 CSE and 3000/120 FSE, and at 0.5 T, 2200/80 CSE and 2800/120 FSE. Time saved on the FSE was used to increase the matrix and the number of acquisitions. Two neuroradiologists evaluated the images for pathology, artefacts, disc signal intensity, thecal sac compression and image quality. Ten patients had cord lesions; 2 (20 %) were missed on CSE. In 4 of 10 patients with moderate/severe thecal sac compression, the degree of stenosis was apparently exaggerated on CSE. The mean degree of confidence for the CSE sequences was 1.8 and for the FSE 1.1, where 1 is optimal. For cervical spine imaging, FSE should be preferred to CSE.     

Presaccadic omnidirectional burst activity in the basal interstitial nucleus in the monkey cerebellum

The endocrine function and pituitary imaging in Sheehan's syndrome more than 30 years after causative events were evaluated. Magnetic resonance imaging (MRI), a combined anterior pituitary test, plasma vasopressin-to-osmolality adaptation study, and antithyroid and antipituitary cell antibody measurement were performed in 6 women with Sheehan's syndrome. The interval from delivery to the onset of symptoms of hormonal deficiency ranged from 3 to 32 years. Since clinical onset, all had received glucocorticoid and thyroid replacement therapy. Cranial MRI examination showed an "empty sella" in 5 cases. Among these, 2 of 5 (40%) demonstrated panhypopituitarism and the other 3 (60%) maintained gonadotropin response. The pituitary gland was normally discernible but with a low-intensity lesion on T1-weighted images in a patient who maintained PRL and gonadotropin responses. Posterior pituitary function was abnormal in 3 of 6 (50%) despite the absence of polyuria. No antipituitary antibodies were detected in any of the cases. Thyroid peroxidase antibody was negative in all cases, but antithyroglobulin antibody was detected in 2 of 6 (33%). Thyroid-stimulating antibody was not detected, but one case had an anti-TSH antibody. Thirty years after the initial events, most patients with Sheehan's syndrome showed signs of an empty sella on MRI, all having noticeable suppression of anterior and/or posterior pituitary hormones with no related autoimmunity.