A comparison of conventional film, CR hard copy and PACS soft copy images of the chest: analyses of ROC curves and inter-observer agreement.

Study Objective: The aim of this study was to determine whether the accuracy of diagnosis of a spectrum of chest pathology was affected by the imaging technique used, and to compare conventional film/screen, hard copy computed (phosphor plate) radiography (CR) and soft copy CR (PACS) images.

Materials And Methods: For each of 44 patients who had a CT examination of the thorax, PA and lateral chest radiographs were produced using conventional film, hard copy CR and soft copy PACS images. Five radiologists independently scored all images for the presence of abnormalities.

Subvoxel image registration of multislice (2D) magnetic resonance images in patients with high-grade gliomas of the brain.

Aims: To implement a multislice two-dimensional (2D) T2-weighted sequence suitable for subvoxel image registration and to assess its usefulness in detecting change in high-grade intracranial gliomas.

Materials And Methods: Twenty patients with high-grade gliomas were studied on two or more occasions. T2-weighted multislice pulse sequences with a Gaussian slice profile, 50% overlapping slices and nearly isotropic voxels were acquired.

Magnetic resonance: magic angle imaging of the Achilles tendon.

Tendons do not normally produce detectable signals with conventional magnetic-resonance techniques and are recognised as dark signal voids. However, if tendons are examined at 55 degrees to the static magnetic field (the "magic angle"), signals become detectable and the tendons can become the brightest structure on the image. We have used this approach to establish tendon relaxation times and magnetisation transfer ratios and to show contrast enhancement.

FLAIR imaging using nonselective inversion pulses combined with slice excitation order cycling and k-space reordering to reduce flow artifacts.

High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered by Inversion-time for each Slice Position" (KRISP) to achieve constant contrast in a multislice acquisition. Theory shows that with this method the CSF point spread function (PSF) has a minimum at the center and attenuated side lobes, providing CSF suppression, but residual edge signals remain.

MRI changes in multiple sclerosis following treatment with lofepramine and L-phenylalanine.

As part of a large, randomized placebo-controlled trial of inpatients with multiple sclerosis (MS), a subsample of 15 underwent cerebral MRI at baseline and 6-months (eight on lofepramine and l-phenylalanine; seven on placebo). Unlike the placebo group, the active group showed a significant reduction in lesion number visible on T1-weighted scans (p < 0.05).

Contributions of an adiabatic initial inversion pulse and K-space re-ordered by inversion-time at each slice position (KRISP) to control of CSF artifacts and visualization of the brain in FLAIR magnetic resonance imaging.

Aim: The aim of this study was to compare the performance of three fluid attenuated inversion recovery (FLAIR) pulse sequences for control of cerebrospinal fluid (CSF) and blood flow artifacts in imaging of the brain. The first of these sequences had an initial sinc inversion pulse which was followed by conventional k-space mapping. The second had an initial sinc inversion pulse followed by k-space re-ordered by inversion time at each slice position (KRISP) and the third had an adiabatic initial inversion pulse followed by KRISP.

Reduction of CSF and blood flow artifacts on FLAIR images of the brain with k-space reordered by inversion time at each slice position (KRISP).

Background And Purpose: Our purpose was to test a new variant of the fluid-attenuated inversion-recovery (FLAIR) sequence that was designed to reduce CSF and blood flow artifacts by use of a non-slice-selective inversion pulse and k-space reordered by inversion time at each slice position (KRISP).

Methods: With the KRISP FLAIR sequence, the slice order was cycled so that each inversion time (TI) was associated with a region of k-space rather than a particular slice, and the effective inversion time (TI(eff)) was chosen to null the signal from CSF. Scans were obtained with both conventional and KRISP FLAIR sequences.

Evaluation of a FLAIR sequence designed to reduce CSF and blood flow artifacts by use of k-space reordered by inversion time at each slice position (KRISP) in high grade gliomas of the brain.

The objective of this study was to compare conventional and KRISP (k-space reordered by inversion time at each slice position) fluid-attenuated inversion recovery (FLAIR) sequences in high grade gliomas for artifact control, conspicuity of intracranial structures, and lesions as well as sensitivity to contrast enhancement. Artifacts were lower with the KRISP FLAIR sequence, and the conspicuity of all assessed structures and lesions was better. The degree of contrast enhancement was similar with T1-weighted and KRISP FLAIR sequences.

Cerebral nocardia abscesses in a patient with AIDS: correlation of magnetic resonance and white cell scanning images with neuropathological findings.

We present a case of cerebral nocardiosis in a patient with AIDS. Space-occupying lesions were identified using magnetic resonance imaging (MRI) and white cell scanning. Nocardia asteroides was isolated from blood cultures.

Cerebellar infarction and atrophy in infants and children with a history of premature birth.

Background And Objective: We wished to determine the pattern of cerebellar disease in children with a history of premature birth and early ultrasound evidence of intraventricular haemorrhage and/or parenchymal lesions of the cerebral hemispheres.

Materials And Methods: MRI findings for all premature infants examined in a 3-year period (73 patients) were reviewed to determine the nature and frequency of lesions of the cerebellum and the results were correlated with clinical data.

Results: Six cases of unilateral cerebellar infarction were identified.

Use of subvoxel registration and subtraction to improve demonstration of contrast enhancement in MRI of the brain.

To assess the potential of registration of images before and after contrast medium for improving the demonstration of contrast enhancement, we compared conventional 2D T1-weighted spin-echo images with precisely registered 3D volume images and subtraction images derived from them in 2 normal subjects and 30 patients with a variety of brain disease. The volume images were registered to subvoxel accuracy using a rigid body translation and rotation, sinc interpolation and a least-squares fit; subtraction images were obtained from these. Normal contrast enhancement was demonstrated better with positionally registered volume and subtraction images than with conventional images in the meninges, ependyma, diploic veins, scalp, skin, orbit and sinuses.

MRI in chronic spinal cord trauma.

Eighty-seven patients aged 16-68 years have been examined by magnetic resonance imaging (MRI) following spinal injury. The MRI findings have been correlated with length of history between trauma and investigation, extent of residual function and site of injury. They include changes at the site of injury consistent with myelomalacia in 37%, a syrinx in 40%, persistent cord compression in 32% and atrophy in 18%.

Magnetic resonance imaging of the abdomen--1988.

This article reviews the current clinical use of magnetic resonance imaging (MRI) in the abdomen with regard to recent technological advances, organ analysis and the integration of MRI in diagnostic imaging. The authors conclude that while MRI is not at present establishing itself as a leading diagnostic imaging method in the abdomen, if MRI machines were to become more widely available, abdominal applications could become a reality.

Ultrasound, CT, and MRI comparison in primary and secondary tumors of the liver.

Thirty-five patients with surgically removed or percutaneous biopsy-proven tumors were examined by ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). This retrospective study describes the appearance of the primary tumors and metastases and compares the sensitivity and specificity of the 3 imaging methods. Ultrasound, CT, and MRI examinations as well as clinical, operative, and/or histologic data were available for all 35 patients.

The role of magnetic resonance imaging techniques in the evaluation of orbital and ocular disease.

Technical developments have resulted in a great improvement in the quality of magnetic resonance imaging (MRI) of the orbit. With surface coil data acquisition spatial resolution of less than a millimetre can now be achieved, and contrast discrimination is such that the cortex and nucleus of the lens can be distinguished. The application of MRI to the diagnosis of orbital and ocular pathology was studied in a group of 51 patients with a wide range of pathology.

[The role of ultrasonography in the diagnosis of diffuse liver disease].

131 patients thought to have diffuse liver disease underwent ultrasonography and percutaneous liver biopsy. The ultrasonographic criteria examined were hepatic echogenicity compared to that of the renal cortex, homogeneity of hepatic parenchyma, and regularity of hepatic outline. On the basis of histologic examination of liver biopsies, several groups of pathologic lesions (not diagnostic entities) were established.

Acoustic neuromas: Gd-DTPA enhancement in MR imaging.

Magnetic resonance (MR) imaging examinations were performed in ten patients with 12 acoustic neuromas before and after intravenous administration of 0.1 mmol/kg body weight gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). The degree of enhancement was greatest with the inversion recovery sequence 1,500/500/44 (repetition time [TR]/inversion time/echo delay time [TE]), followed by spin-echo (SE) 544/44 (TR/TE) sequences, then by SE 1,500/44 and SE 1,500/80 sequences.

MRI in acoustic neuroma: a review of 35 patients.

This retrospective study is aimed to assess the diagnostic efficacy of MRI in relation to contrast enhanced CT and air-CT-cisternography. MRI examinations were performed in 35 patients with suspected neurosensorial damage and suggestive of acoustic neuroma: 27 presented on MRI with unilateral tumors, 3 patients had a bilateral tumor and 5 patients were negative on all imaging modalities. The total number of acoustic neuromas detected was therefore 33.

MRI of the abdomen.

Clinical MRI of the body has not so far produced results consistently comparable with X-ray CT or high-resolution real-time ultrasound. Present development in MRI technology (new sequences, respiratory gating) and the application of paramagnetic contrast agents are however promising features. MRI might play a useful rôle also in abdominal examination.

Use of closely coupled receiver coils in MR imaging: practical aspects.

The use of closely coupled receiver coils in magnetic resonance (MR) imaging of the brain and body is described. Design considerations are outlined, aspects of the choice of materials are discussed, and clinical applications are illustrated. Closely coupled receiver coils can provide a useful improvement in MR image quality.

[Magnetic resonance in cases of brain tumor].

MR patterns of brain tumours are presented. Tumour, edema, shifting of surrounding tissues, hemorrhages, neoplastic calcifications and contrast enhancement by means of para-magnetic media administered in some patients are analysed.

Myonecrosis induced by drug overdose: pathogenesis, clinical aspects and radiological manifestations.

The authors report five cases of myonecrosis varying in degree of severity and extent of the lesions, following drug overdose in young patients. The pathogenesis of this condition is discussed with reference both to the literature and the radiological findings of the present study. The clinical and radiological manifestations are described and a possible differential diagnosis is suggested, based on these data.