Mononeuropathy following subcutaneous interferon-beta injection.
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Biomedical subjects
Publications and source records attributed to N Magarelli.
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OBJECTIVE: To evaluate the sensitivity, specificity and diagnostic accuracy of a cut-off of the resistive index of 0.5 for the differentiation between inflammatory and neoplastic primary lymphadenopathies. SUBJECTS AND METHODS: We measured the resistive index of superficial enlarged lymph nodes in a total of 50 patients (29 males and 21 females; age range 12-72 years, mean age 41.6 year) using an ATL 5000 HDI. A resistive index greater than or equal to 0.5 indicated an inflammatory lymph node and a resistive index <0.5 was consistent with neoplastic primary lymphadenopathies. The gold standard was either surgical biopsy or lymph-node reduction seen with ultrasound examination after antibiotic therapy. RESULTS: The sensitivity of the resistive index for distinguishing inflammatory from neoplastic lymphadenopathy was 84.6%, the specificity 100% and the diagnostic accuracy 95.7% (P < 0.001, statistically significant). CONCLUSION: The results of this study indicate that power-Doppler using a resistive index cut-off of 0.5 was a valid technique for distinguishing between inflammatory and primary neoplastic lymph nodes in patients with superficial lymphadenopathies.
The purpose of this study was to first evaluate Levovist (Schering, Berlin, Germany), an echo-contrast agent, during power Doppler sonography (PDS) in patients with synovitis using asymptomatic joints as controls. Then we evaluated the accuracy of this technique against contrast-enhanced MRI. Forty patients (19 men and 21 women; mean age 40 years) were enrolled on the basis of clinical signs, laboratory tests, and radiographic findings positive for articular inflammatory disease. They were examined with conventional ultrasonography (US) and PDS techniques before and after intravenous contrast medium injection. Fourteen patients then underwent MRI with and without contrast medium 8-14 days after PDS studies. Three expert readers independently evaluated each examination. After contrast medium, synovium in inflammatory arthritis enhanced on PDS compared with normal joints in the same patient. Power Doppler sonography after contrast medium and MRI were concordant in all cases. Power Doppler sonography with contrast medium showed a qualitative increase in signal from synovial vessels, the first sign of synovial changes in inflammatory diseases.
PURPOSE: To compare the diagnostic accuracy of a digital film viewer (Smartlight 2000 Plus) versus a conventional view box for the identification of bone and joint disorders. MATERIAL AND METHODS: In order to evaluate the qualitative and quantitative differences of digital and conventional film viewers, 100 plain films of patients with bone and joint disorders taken in an emergency room January through May 1998 were reviewed utilizing both types of view boxes. Three radiologists expert of bone and joint disorders, independently compared the films, filled a form about the qualitative and quantitative analysis of the lesions depicted for each patient, and reported a few notes on the technical quality of the plain films in terms of exposure. The results were compared using the chi-square test (p < 0.005). RESULTS: Data analysis showed that the digital film viewer permitted a quicker reading of the film while decreasing the perception threshold for elementary lesions and ocular fatigue. All the radiographs read with the digital film viewer were considered technically adequate: the film quality was considered good in 10 cases and sufficient in 2. Two of the same radiographs read with the conventional view box were considered of good quality, nine were considered sufficient and one was considered insufficient due to overexposure. There were six cases of agreement and six of disagreement for the diagnosis: four were due to overexposure of the radiograph and two to better conspicuity provided by the digital film viewer. DISCUSSION: Correct image illumination is the first element a radiologist evaluates when reading a radiograph. A conventional view box may, when it is not properly maintained or when the radiograph is overexposed, decrease the radiologist's visual capacity. This increases the time required to read the radiograph and, therefore, physical and ocular fatigue, which in turn increases the risk of missing or misevaluating a lesion. A digital film viewer emits light with a variable intensity which is proportional to the optical density of the film. This increases the visual capacity of the radiologist and the lesion contrast, while reducing the factors which affect the radiograph reading. CONCLUSIONS: The use of a digital film viewer increased the visual capacity of the radiologist and eliminated the negative elements which complicated the radiograph reading and permitted the use of radiographs that would otherwise have been considered of poor quality due to overexposure. This, combined with the experience of the radiologist, decreased of the risk of missing or misevaluating a lesion.
OBJECTIVE: to optimize magnetic resonance angiography technique for the selective study of the anatomy of pulmonary veins. MATERIALS AND METHODS: twenty consecutive patients (13 males and seven females; mean age 30.5 years) prospectively studied were enrolled. Magnetic resonance angiography was performed using a 1 T superconductive magnet and three dimensional time of flight technique (3D TOF). Imaging with steady-state free precession sequence during intravenous infusion of contrast medium (Gd DTPA 0.2 mmol kg(-1)) administration was employed using the following parameters: FA 20 degrees, TR 58 ms, TE 6 ms, MA 192 x 256, NEX 1, slice thickness 4 mm and slice orientation on the Z and Y planes. RESULTS: in the right lung magnetic resonance angiography well visualized 124 venous vessels on the coronal plane versus 106 venous vessels on the sagittal plane, whereas in the left lung magnetic resonance angiography visualized 96 vessels on the coronal plane versus 44 visualized on the sagittal plane. Our data suggest that 3D time of flight with contrast medium is a promising evaluation technique for pulmonary veins, and that combined evaluation of acquisitions on coronal and sagittal planes allows the visualization of a higher number of venous vessels. CONCLUSION: 3D time of flight with contrast medium and without breath-hold permits to visualize a venous vascular map of the lungs.
We performed a preliminary study comparing three-dimensional time-of-flight (3 D TOF) magnetic resonance angiography (MRA) and spiral CT angiography (SCTA) in the detection and assessment of internal carotid artery stenosis. Digital subtraction angiography (DSA) was the reference examination. We examined 20 patients with signs of cerebrovascular insufficiency, who underwent MRA, SCTA and DSA within a 3 day period. Both internal carotid arteries were assessed by three blinded readers for degree of stenosis at two different levels (bulb and remaining section) giving a total of 80 assessments. Interobserver variability, sensitivity, specificity, diagnostic accuracy, concordance, overestimation and underestimation were assessed. Interobserver variability was not statistically significant. MRA showed higher sensitivity, specificity, diagnostic accuracy and concordance than SCTA (92.0% vs 80.8%, 98.2% vs 96.4%, 96.3% vs 91.3% and 96.0% vs 88.0%, respectively). MRA gave rise to a 5.0% overestimation rate, whereas SCTA occasioned a 7.5% underestimation rate. These differences are not statistically significant. These results suggest that MRA is a more useful, noninvasive modality for assessment of the internal carotid artery with a more than 70% stenosis.
The aim of this study was to compare high-resolution 2D TOF with high-resolution 3D TOF in the study of internal carotid artery disease. Sixty-four patients with clinical signs of cerebrovascular insufficiency were studied with a superconductive 1.5 T magnet using two techniques: 2D and 3D TOF. Digital subtraction angiography (DSA) was the gold standard. The 2D TOF technique was performed using the following parameters: TR/TE/FA/MA 49 ms/9 ms/60 degrees/512 x 256; the 3D TOF was performed with the following parameters: TR/TE/FA/MA 50 ms/8 ms/20 degrees/512 x 256. The 2D TOF agreed with DSA in 116 of 128 diagnostic judgments (90%) and overestimated seven times. The 3D TOF technique agreed with DSA in 125 of 128 diagnostic judgments (97%) with one overestimation and two underestimations. There was no statistically significant difference (P < 0.05) between the two different techniques. Our study confirms the high reliability of the methodology carried out with the high-resolution 2D and 3D technique.
PURPOSE: To compare the accuracy of three different magnetic resonance angiography (MRA) techniques for studying steno-occlusive disease of carotid arteries. METHODS: 64 patients were evaluated with three MRA techniques- three-dimensional (3D) time-of-flight (TOF), two-dimensional (2D) TOF, and 3D Phase-Contrast (PC); the acquisition was in the axial plane, the volume included the carotid bifurcation. Digital subtraction angiography (DSA) was considered the 'gold standard'. The MRA images were reprojected with a maximum intensity pixel ray-tracing (MIP) algorithm. The three MRA techniques were blindly graded as normal, mildly stenotic (0-29%), moderately stenotic (30-49%), severely stenotic (70-99%), or occluded. RESULTS: DSA provided 128 diagnostic judgments: 92 were negatives and 36 positives. 2D TOF was in agreement with angiography in 116 of 128 cases (90%), but overestimated the results in seven cases and underestimated in five cases. 3D TOF agreed with angiography in 125 of 128 cases (97%), with one overestimation and two under estimations. 3D PC was concordant in 116 of 128 cases (90%), overestimating in six cases, underestimating in six cases. The sensitivity, specificity and diagnostic accuracy for 2D TOF was, respectively 84%, 94%, and 92%, while for 3D TOF was 94%, 100%, and 98%, and for 3D PC 86%, 98%, and 95%. The comparison of the three different MRA techniques provided no statistically significant difference (Friedman test P < 0.05). CONCLUSION: The high degree of diagnostic accuracy of MRA found in the study of the steno-occlusive disease of the carotid arteries confirms the high degree of reliability of this methodology carried out with the 3D TOF technique, compared to 2D TOF and 3D PC.
INTRODUCTION: We optimized the technique of contrast-enhanced Magnetic Resonance Angiography (MRA) with a .5 T superconductive magnet. MATERIAL AND METHODS: Forty patients with normal blood pressure and heart rate gave their informed consent to MRA studies with contrast agent administration. The carotid arteries were studied in 10 patients, the pulmonary arteries in 10, the thoracic aorta in 10 and the abdominal aorta and renal arteries in 10. All the examinations were performed with a .5 T superconductive magnet (Philips T5) acquiring 3D T1-weighted GE sequences with contrast agent administration. The parameters were: TR/TE/FA 13 ms/4 ms/60 degrees; 256 x 256 MA; 2 mm slice thickness; 1 NEX. The contrast agent was administered with an automatic injector (.2 mmol/kg at 1.5 flowrate) after a bolus test to evaluate circulation time. The images were studied by a radiologist rating artery visualization as "good" or "poor" on a multiple choice card. The signal-to-noise ratio was evaluated using regions of interest positioned on the examined vessels (signal) and muscles (noise). RESULTS: The mean start delay was 12.2 s for the abdominal aorta, 10.3 s and 8.7 s for the thoracic aorta and pulmonary arteries, and 10.3 for the carotid arteries. Fifty-eight of 70 vessels were well visualized and 12 were poorly visualized. The signal-to-noise ratio exceeded 1 in all districts. CONCLUSIONS: Our experience shows that enhanced MRA provides diagnostic images of body arteries even at .5 T.
PURPOSE: To verify the hypothesis that a drug that causes vasodilation can contribute to improvement in MRA spatial resolution. To test this hypothesis, a comparison was made between the images obtained using the high resolution time-of-flight (TOF HR 3D) technique and the TOF 3D MTC TONE technique. METHODS: From November 1993 to December 1994, we studied 40 patients, of which 20 patients (16 males and 4 females; average age of 10 years; range from 3 to 20 years) we examined after they had inhaled Isoflurane (experimental group), and 20 patients (16 males and 4 females; average age 9.7 years; range from 3 to 12 years) were examined with standard MRA (control group). RESULTS: The vasodilator in both HR MRA and MTC TONE MRA permits a better spatial visualization with respect to the clinical routine MRA. On the other hand, it is true that MTC TONE gives better visualization of the small vessels. DISCUSSION: In our experience, this preliminary study indicates that with respect to routine MR, the spatial resolution is notably increased when Isoflurane is used. The signal-to-noise ratio is increased but, moreover, the ability to visualize small vessels is increased. CONCLUSION: The preliminary results obtained in this study indicate that a pharmacological drugs is capable of increasing the vascular detail of MRA images of the intracranial vessels and that continued research this direction is called for.
This prospective study was aimed at comparing the diagnostic accuracy of magnetic resonance angiography (MRA) with colour-Doppler ultrasonography (colour-Doppler US) in the assessment of abdominal aortic aneurysms (AAA). Twenty patients with abdominal aortic aneurysms underwent MRA, colour-Doppler US, digital subtraction angiography (DSA) and CT. The MRA technique and colour-Doppler findings were compared with DSA as well as surgical and pathological findings, which were considered as the gold standard. In 6 patients who refused surgery, CT and DSA were considered as the gold standard. The MRA technique always correctly assessed the size and site of the aneurysms, the involvement of the renal and common iliac arteries, the course of the left renal vein, the thrombotic component and the calcifications. Colour-Doppler US always correctly assessed the size and site of the aneurysms, the thrombotic component and calcifications and the involvement of the iliac arteries. Our preliminary results suggest that MRA together with colour-Doppler US represents a valid alternative to invasive imaging in the assessment of AAA.
We assessed the comparative sensitivity, specificity and diagnostic accuracy of 3D time of flight (TOF) versus 3D phase contrast (PC) MRA in the study of stenoses/occlusions of the extracranial carotid artery. Fifty-four patients were submitted to MRA because of their symptoms or of signs of cerebrovascular insufficiency. 3D TOF and 3D PC axial slices were acquired with a high field magnet; digital angiography was the gold standard. The parameters of 3D TOF acquisitions were: TR/TE/FA 50/8/20, 1 NEX, 512 x 256 matrix, 16 x 12 FOV, 1 axial slab of 60 slices, 1 mm slice thickness, superior presaturation band, ramp pulse, TA 10-18 minutes. 3D PC parameters were: TR/TE/ FA 25/9/20, 1 NEX, 256 x 128 matrix, 18 x 13 FOV, 1 axial slab of 60 slices, 1 mm slice thickness, VENC 35 cm/s, TA 10-15 minutes. 3D TOF MRA was in agreement with digital angiography in 95.6% of cases (22/23), overestimating a grade 3 stenosis as grade 4 (one case, 4.3%) and underestimating no stenoses. 3D PC MRA was in agreement with digital angiography in 78.2% of cases (18/23), overestimating three stenoses (13%); one grade 1 as grade 2 and two grade 4 as grade 5; two stenoses were underestimated (8.6%); one grade 4 as grade 3 and one grade 4 as grade 2. Sensitivity, specificity and diagnostic accuracy were 91.4%, 98.9% and 95.7% for 3D TOF, versus 83.2%, 97.2% and 92.3% for 3D PC, respectively. The two MRA techniques had different semiology. In spite of outstanding background noise suppression, 3D PC poorly depicted the turbulent flow at the carotid bifurcation in carotid stenoses. Therefore, 3D TOF appears a better technique to study stenoses/occlusions of the extracranial carotid arteries.
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PURPOSE: To determine sensitivity, specificity and diagnostic accuracy of spiral CT angiography (S-CTA) compared to Digital Subtraction Angiography (DSA). MATERIALS AND METHODS: We studied 40 patients with suspected cerebro-vascular insufficiency by carotid stenosis. Diagnostic examinations by means of S-CTA and DSA were carried out within 24 hours of each other. Twelve of these patients underwent thromboendoarterectomy (TEA). Prospeed SX GE was used for S-CTA. Post-processing was performed using Maximum Intensity Projection (MIP) after deleting osteo-muscular structures and CT angiograms were displayed in an oblique anterior view at an angle of 10 degrees-15 degrees along the longitudinal axis. For DSA examinations, a Siemens Politron 1000 VR unit was used. RESULTS: In this study S-CTA showed values of sensitivity, specificity and diagnostic accuracy of 88%, 100% and 96%, respectively. CONCLUSIONS: In the future, with the improvement of non-invasive techniques (S-CTA, MRA), DSA should be replaced, as the gold-standard, in the evaluation of stenotic disease of the carotid bifurcation.
The aim of this work was to optimize the magnetic resonance angiography (MRA) technique for the selective study of the pulmonary veins. Twenty consecutive patients (13 men and 7 women; mean age: 30.5 years) were examined. MRA was performed with a 1 T superconductive magnet and the 3D time of flight (TOF) technique. Fast sequences (3D FISP: TR 58 ms, TE 6 ms, FA 20 degrees, matrix 192 x 256; and 2D FLASH: TR 44 ms, TE 10 ms, FA 30 degrees, matrix 192 x 256) were used. Coronal and sagittal images were submitted to MIP processing; presaturation pulses for the pulmonary arteries were located in the mediastinal region. In the right lung, 3D TOF on the coronal plane well showed 124 veins, while sagittal images showed 106 veins. In the left lung, 3D TOF on the coronal plane well showed 96 vessels, while sagittal images showed 44 vessels. In the right lung, 2D TOF on the coronal plane well showed 54 veins, while sagittal images showed 36 vessels. In the left lung, 2D TOF on the coronal plane well showed 22 vessels, while sagittal images showed 21 vessels. Therefore, 3D TOF yielded better results than 2D TOF (p < 0.05). To conclude, 3D TOF with contrast agent administration is a useful tool to study the pulmonary veins; those with a larger caliber are better depicted and the integration of coronal and sagittal images depicts more veins.
INTRODUCTION: We tried to optimize the technique of contrast enhanced MR Angiography (MRA) in the study of the main body arteries. MATERIALS AND METHODS: Fifty volunteers were examined with contrast enhanced MRA with a superconductive magnet at 1.5 T (Signa GE) and 3D SPGR sequences acquired with the following parameters: TR 8.2 +/- 1.3 ms, TE 1.8 +/- 7 ms, FA 60 degrees, MA 128 X 256; the images were acquired on the sagittal or coronal planes. The contrast agent (Gd-DTPA) was injected with MedRad Spectris system, with the bolus technique and the following standard parameters: velocity 1.5 mL/s and single dose; circulation time was optimized with 2D SPGR for each vessel (pretest). The carotid and pulmonary arteries, the thoracic-abdominal aorta and the iliac arteries were studied. The reader used a multiple choice card to evaluate image quality, signal-to-noise ratio (SNR) and circulation time. RESULTS: Circulation time was 10.2 s in the carotid arteries, 8.1 s in the pulmonary arteries, 10.3 s in the thoracic aorta, 12.2 s in the abdominal aorta and 13.8 s in the iliac arteries. The signal was 181.8 vs the noise 3.1 in the carotid arteries, 256.8 vs 23.2 in the thoracic aorta, 518.4 vs 23.5 in the pulmonary arteries, 258.8 vs 24.5 in the abdominal aorta and finally 262.7 vs 25.4 in the iliac arteries. CONCLUSIONS: Our experience suggests that contrast enhanced MRA is a good technique to study body arteries.
The authors investigated the diagnostic capabilities of gradient echo sequences (magnetic resonance angiography) in the study of induratio penis plastica. Twenty patients (mean age: 39 years) were examined. MRA was performed with a superconductive magnet (1.5 T) and a Helmoutz coil; the dynamic test with PGE (20-40 mg) was also carried out. The images acquired on the axial and sagittal planes were processed according to the MIP. The FLASH 2D sequence was used with the following parameters: FA 18 degrees, TR 40 ms, TE ms, MA 256 x 256, slice thickness 5 mm. A multiple choice card was filled in by a reader with the following diagnostic information: identification and localization of the plaques and involvement by the plaques of the albuginea, corpora cavernosa, septum and dorsal vein; surgery was the gold standard. MRA showed 10/11 plaques ranging 8-30 mm in diameter and missed a 5-mm plaque. Moreover, MRA depicted the infiltration of the albuginea in 10/10 cases, of the septum in 3/3 cases, of the dorsal vein in 4/4 cases and of the corpora cavernosa in 9/9 cases. Our preliminary experience shows that in the study of induratio penis plastica, the gradient echo sequence (MRA) permits better depiction of the plaques and of the infiltration of the corpora cavernosa, septum and albuginea.
The authors optimized the Magnetic Resonance Angiography (MRA) technique for the study of the different portions of the pulmonary artery-i.e., the common trunk, right and left main arteries and the lobar, segmental and subsegmental branches. Twenty volunteers were examined with MRA of the pulmonary arteries with a 1-T superconductive magnet (Impact) and the time-of-flight (TOF) technique. The volunteers were divided into two groups by age (ranges: 20-40 and 41-70 years). The trunk and main branches were studied with the 2D TOF technique, while 2D TOF images were compared with 3D TOF images in the study of peripheral (lobar, segmental and subsegmental) branches. The images were processed with the maximum intensity projection (MIP). In the statistical comparison between 2D and 3D TOF images, the t-test was used (p < 0.05). The 2D TOF images acquired on the sagittal oblique and coronal planes, with presaturation pulses, permitted optimal depiction of the trunk and of the right and left branches in all the volunteers. Both 2D and 3D TOF images yielded excellent images in the study of the lobar branches. In the volunteers under 40 years of age, 3D TOF sequences visualized the peripheral (segmental and subsegmental) vessels better than 2D TOF sequences (451 vs. 361); the difference was statistically significant. In the volunteers over 41 years of age, the ratio was reversed: 467 for 2D TOF vs. 362 for 3D TOF sequences; again, the difference was statistically significant. The correct integration of 2D and 3D TOF sequences, according to the different segments of the pulmonary artery and to patients' age, permitted the complete and accurate visualization of the pulmonary arteries with MRA.