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Purpose: To determine sensitivity, specificity and diagnostic accuracy of contrast-enhanced magnetic resonance angiography (CE MRA) compared to digital subtraction angiography (DSA) in the study of carotid stenosis., Methods and Material: We studied 23 patients with suspected cerebro-vascular insufficiency by carotid stenosis. Diagnostic examinations by means of CE MRA and DSA were carried out within 24 hours of each other. A 1.5 T superconductive magnet (Signa-General Electric) was used for CE MRA. This technique was performed using a fast spoiled gradient echo recalled (SPGR) sequence acquired in coronal plane 13 sec after injection of contrast medium. Imaging parameters were: TR/TE/FA 8 msec/1 msec/60 degrees, matrix 256 x 128, 1 excitation, FOV 18 x 13 cm, 28 slices per slab, slice thickness of 1 mm, acquisition time of 32 sec. The post-processing was performed using maximum intensity projection (MIP) and targeted MIP. For DSA examinations a Politron 1000 VR unit (Siemens) was used., Results: In the identification and quantification of lesions, CE MRA showed values of 100%. In particular, in comparison to DSA, CE MRA was accurate in diagnosing all true negative and positive cases. The location of stenosis evaluated with CE MRA agreed in all cases with DSA., Conclusion: In our experience CE MRA proved to be a very valuable technique in diagnosing carotid stenosis, showing the same diagnostic accuracy as DSA. In this way CE MRA appears to be a substantial alternative technique to conventional MRA and other non-invasive diagnostic methods.

This study was carried out in order to investigate the possible detrimental effects on bone of levothyroxine (l-T4) suppressive therapy in female patients who had undergone surgery for differentiated thyroid cancer (DTC). Twenty female (14 premenopausal and 6 postmenopausal) patients receiving l-T4 suppressive therapy for DTC were studied. The sample was selected in such a way as to avoid factors influencing bone metabolism other than l-T4. All patients were monitored by sensitive thyroid-stimulating hormone, free triiodothyronine and free thyroxine assays throughout the follow-up. Nineteen healthy (12 premenopausal and 7 postmenopausal) matched women served as controls. In all subjects bone turnover was evaluated by the measurement of global skeletal uptake of technetium-99m methylene diphosphonate (GSU); bone mineral density (BMD) was measured by quantitative computed tomography at the lumbar spine (LS) and by dual-energy X-ray absorptiometry both at the LS and at three femoral sites: the femoral neck, Ward's triangle and the greater trochanter. No significant difference was found in either GSU or BMD between patients (treated for an average period of 68 months) and controls in the whole sample or in any subgroup. Furthermore, no correlations were found between either GSU or BMD and the duration of therapy, daily doses of l-T4 or results of thyroid function tests. Our data show that carefully monitored l-T4 therapy does not influence skeletal turnover (directly reflected by GSU) or the bone density of the spine and femur.

In a multicenter evaluation the precision and stability of single slice peripheral Quantitative Computed Tomography (pQCT) systems were assessed. Compared to central Europe the peripheral QCT device is also widely used in the Italian health care system. Phantoms were measured frequently on each machine in four pQCT scanners over a two-year period using an identical automated software program. Intrasite and intersite phantom mineral densities, expressed in units of mg/cm3, were analyzed and examined. The short and long term precision were estimated from the consistency of these measurements using the root mean square error and expressed as coefficient of variation in percent (% CV). Short term precision was good (mean intrasite coefficient of variation (CV) 0.21 +/- 0.056 standard deviation (SD)). Intersite measurements of a single phantom revealed differences between machines of the same type of not more than 2.9 mg/cm3. At four sites frequent phantom measurements revealed a mean CV of 0.18% (range 0.12-0.28). No significant changes in the regression slopes (drift of the machine versus time) were observed. We conclude that the in vitro precision and stability of the single slice pQCT systems are sufficiently high and unlikely to negatively affect the in vivo precision.

Bone involvement is a common clinical feature in acromegalic patients, though previous studies gave divergent results possibly because of the different gonadal status of the patients studied. To study the influence of estrogen milieu in these patients, we evaluated 23 acromegalic patients with active disease, subdivided into two groups: menstruating and amenorrheal patients, comparable for duration and activity of disease. Forty-two matched women served as controls. Skeletal involvement was studied by measuring: (a) the main biomarkers of bone turnover: serum alkaline phosphatase total activity (AP), bone GLA protein (BGP), serum carboxy-terminal propeptide of type I collagen (PICP), serum type I cross-linked N-telopeptide (ICTP), and urinary pyridinoline and deoxypyridinoline corrected for creatinine (Pyr/Cr, D-Pyr/Cr) and urinary calcium/creatinine ratio (Ca/Cr); (b) bone mineral density (BMD), as measured by quantitative computed tomography both at lumbar spine and distal radius, and by dual X-ray absorptiometry both at lumbar spine and at three femoral sites (Ward's triangle, femoral neck, and great trochanter). AP, BGP, ICTP, Pyr/Cr, D-Pyr/Cr were significantly higher in patients than in controls, independent of the menstrual pattern. Higher PICP levels were found in the whole group and in menstruating acromegalics when compared with control women; no difference was found in amenorrheal patients, who in turn showed higher urinary Ca/Cr values. When patients were considered all together, BMD at spine, femoral neck, and trochanter was higher than in controls. In contrast, when the gonadal status was taking into account and, menstruating and amenorrheal subjects were considered separately, BMD at spine, but not in other sites, was significantly higher in menstruating patients than in controls. In contrast, no difference of BMD values at any site was observed between amenorrheal patients and controls. The mean BMD Z scores allowed us to detect an unequal involvement of different skeletal sites. Our results show that bone turnover is increased in acromegalic women and suggest that GH anabolic effect on bone is more evident in the presence of estrogens and that different skeletal sites may be affected differently by hormone excess.

Introduction: A new noninvasive technique, dynamic Magnetic Resonance Angiography (MRA) during rapid infusion of paramagnetic contrast medium, has been recently developed for the study of neck vessels. This study was carried out to optimize technical parameters., Materials and Methods: Twenty healthy volunteers (10 men and 10 women; age range: 25 to 50 years) were examined with a 1.5 T MR unit equipped with fast imaging software and a dedicated coil. Dynamic MRA was performed using fast spoiled gradient recalled (fast SPGR) sequences acquired on the coronal plane 13 s after contrast medium injection. Imaging parameters were: Echo Time (TE): 1 ms, Repetition Time (TR): 8 ms, flip angle: 60 degrees, matrix 256 x 128, number of excitations: 1, field of view: 18 x 13 cm, number of partitions per slab: 28, slice thickness: 1 mm, acquisition time: 32 s. A dose of .2 mmol/kg of paramagnetic contrast medium was administered with an MR compatible automatic injector, at a speed rate of 1.5 ml/s. Angiographic images were postprocessed with the maximum intensity projection (MIP) and targeted MIP algorithms., Results: Using the above parameters and rapid contrast medium injection, the carotid arteries on the coronal plane (including the vessels from the proximal aspect of the common carotid arteries to the intracranial tract of the internal carotid arteries) in 18 cases. In the other two cases the tortuosity and the position of the carotid arteries on two different planes, prevented their complete visualization. The vertebral arteries were completely demonstrated in 50% of the investigated population. Partial or total overlapping of jugular veins did not affect the recognition of the carotid vessels in 10 cases, also with targeted MIP postprocessing., Discussion: The vascular semiology of dynamic gadolinium enhanced MRA seems to be closer to that of conventional angiography than of conventional MRA, likely due to the same modality of vessel depiction, based on contrast medium administration. Flow artifacts, the major pitfall of conventional MRA causing signal void and overestimation of stenosis grade, are not frequent in dynamic MRA., Conclusions: Gadolinium enhanced dynamic MRA ensures panoramic and high resolution angiographic-like depiction of the neck vessels, providing rapid and excellent definition of vascular morphology. Thus dynamic MRA appears to be a substantial alternative to conventional MRA and conventional angiography.

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 report their personal experience with postoperative neuroradiologic studies in surgical patients with a herniated disk and/or degenerative cervical spondylosis. Twenty-six patients were enrolled: 16 of them underwent anterior diskectomy, 7 posterior decompressive laminectomy and 3 vertebral body removal. The patients were submitted to pre- and postoperative MRI with high field equipment (Signa 1.5 T, General Electrics), using sagittal SE T1- (TR/TE 360/15), PD and T2-weighted (TR/TE/FA 2000/40/120) sequences and T2-weighted GE axial sequences (TR/TE/FA 400/34/30). FSE sequences (TR/TE/ETL 4000/95/8) were used in 15 cases instead of the above T2-weighted SE sequences. The main postoperative MR findings were analyzed. In particular, the morphological and signal features of bone grafts, of vertebral end-plates, of the subchondral bone and of the surgical site were studied. After anterior diskectomy, the most frequent MR features were massive signal changes in the bone graft and lower vertebral plates, which were hypointense in T1 and hyperintense in T2; the adjacent subchondral bone also exhibited signal changes. Other postoperative MR findings accounted for early postoperative mobility (4 cases of persistent myelomalacia and 3 of bone graft fracture with consequent spinal instability) and late mobility (2 cases of herniated disk, 5 of spinal stenosis and one pseudomeningocele). The main limitation of MRI in postoperative cervical spine studies was the presence of ferromagnetic artifacts during SE, and even more GE, sequences; these artifacts were the main cause of misdiagnoses. In our experience, this troublesome limitation was overcome with FSE sequences but diagnostic accuracy remained poor in 4 patients. MRI, thanks to its multiparametric and multiplanar yield, is the gold standard for the examination of several early and late postoperative features and of postoperative mobility in the cervical spine. Moreover, T2-weighted FSE acquisitions are better than conventional SE to this purpose, because examination time is shorter, myelographic effect is improved and the sensitivity to ferromagnetic artifacts reduced.

Purposes: To investigate the capabilities of fast spin echo (FSE) sequences in diagnosing spinal metastases and to compare two fat-suppression techniques: CHESS (chemical shift selective saturation) and STIR (short T1 inversion recovery). Fat suppression is recommended with FSE sequences because on them, different from conventional spin echo (SE) sequences, fat has high signal intensity in both T1 and T2 weighting, masking such high-signal bone lesions as metastases., Methods: Ninety metastatic lesions in 32 patients were studied with T1-weighted SE and T2-weighted FSE sequences with and without fat suppression (FSE-CHESS and STIR-FSE). Quantitative analyses (metastasis size, signal intensity, margins and conspicuity) and qualitative analyses (artifacts and fat saturation homogeneity) were carried out of both fat-suppression sequences. Signal-to-noise (S/N) and contrast-to-noise (C/N) ratios were calculated in 20 metastatic lesions. The results were analyzed with the chi 2 method and the paired t-test., Results: Both fat-suppression FSE sequences were more sensitive to focal lesions (100%) than T1-weighted SE sequences (96.6%). Lesion signal was higher than that of surrounding bone in 95.5% of fat-suppressed images, which facilitated the recognition of spinal metastases. On the contrary, conspicuity was higher (73.3%) and the margins more definite (68.8%) on T1-weighted SE than on T2-weighted FSE sequences. Fat suppression was more apparent on STIR-FSE than on FSE-CHESS sequences, even with no significant difference in C/N ratio., Conclusion: Both STIR-FSE and FSE-CHESS sequences are rapid and useful techniques to obtain fat saturation in FSE images. CHESS saturation is selective on fat signal, while STIR suppresses the signal of all the substances with the same short T1 as fat.

This study was aimed at investigating if fast spin echo (FSE) pulse sequences can increase the diagnostic capabilities of MRI in the patients with degenerative disease of the postoperative cervical spine, considering their lower magnetic susceptibility than that of conventional spin echo (SE) sequences. The patient population consisted of 15 patients submitted to diskectomy after Cloward and Caspar. MR images were acquired with a 1.5-T unit (Signa, General Electric) with T2-weighted FSE versus conventional T1- and T2-weighted SE images. Thanks to fewer metallic artifacts, FSE images of the postoperative cervical spine yielded more pieces of information than conventional SE sequences in demonstrating the spine and its content. The best results were obtained in the patients with canal stenosis (8 patients) and myelomalacia (2 patients). In addition, the myelographic effect, another major semiologic feature of the FSE technique, provided further diagnostic information in these patients. Moreover, shorter examination times resulted in better patients tolerance, especially in those with recent surgery. Finally, reducing motion, blood flow or CSF flow artifacts definitely improved FSE image quality.

A major application of Magnetic Resonance Imaging (MRI) consists in the "myelographic effect", characterized by high signal intensity of the CSF, which permits to visualize spinal subarachnoid spaces and nerve root sheaths. Such new ultrafast pulse sequences as fast spin echo (FSE) further enhance CSF high signal intensity. In addition, suppressing background with the fat suppression technique and with maximum intensity projection (MIP), a particular algorithm already used in MR angiography, FSE sequences yield 3D myelography-like images. Our study was aimed at assessing the clinical role and the reliability of this technique. Our preliminary experience is based on 21 patients with pain in the lower back and legs and on 5 healthy volunteers; all the myelography-like images were obtained with a 1.5-T MR system (Signa, General Electric). The parameters for FSE myelography-like images included: TR = 6000, TE = 200, ETL = 32, thickness = 3 mm, matrix = 256 x 224, Nex = 4, FOV = 20 cm, fat presaturation, no phase wrap, acquisition time = 2 min 58 s. MR myelography sequences were acquired after a standard FSE T1/T2-weighted exam. MR-myelography results confirmed the diagnosis of disk herniation made on conventional T1/T2-weighted images, especially in thecal sac compression and/or amputation of nerve root sheaths. MR myelography appeared to be especially useful in migrated disk herniation or in abnormal origin of nerve roots. Moreover, it allowed full and panoramic visualization of the subarachnoid spaces and excellent definition of the thecal sac, nerve roots and nerve root sheaths. In one patient only movement artifacts affected image quality. To conclude, even though it fails to yield any functional information, MR myelography appears to be an easy, rapid and noninvasive support to conventional MRI of the lumbar spine, to replace conventional myelography.

A case of an isolated recurrent cardiac hydatidosis with multiple intrapericardial cysts is presented. The patient, who underwent 2 previous surgical resection of intramyocardial and pericardial hydatid cysts, presented with atypical chest pain. The ECG and the perfusion scintigraphy with 201-thallium showed a previous lateral myocardial infarction. The diagnosis of recurrent cardiac hydatidosis was made by two-dimensional echocardiography and computed tomography and was confirmed by clinical and biochemical findings.

In everyday practice, the radiologist is concerned with the diagnosis of inflammatory conditions of the nose and paranasal sinuses. This paper was aimed at evaluating and comparing the diagnostic efficacy of the main diagnostic imaging procedures currently available. Fifty-six patients were studied: 25 with computed radiography (CR) and CT, 21 with CR and MRI (0.22 T resistive magnet), and 10 with CR, CT, and MRI. From the diagnostic point of view, the conventional-like CR image was assumed as analog to the conventional radiographic (RX) one on the basis of previous personal experience. The following elements were separately considered for RX, CR, CT, and MRI: anatomical structure identificability, spatial resolution, dosimetry, time consumption, diagnostic results, and economics. A global performance index was calculated (RX less than 1; CR = 1; MRI ranging 1.2-2.2; CT = 7.3). CR was superior to RX, from both a diagnostic and a dosimetric point of view, but buying the equipment is nowadays expensive. CT and MRI were superior to both RX and CR in the diagnosis of inflammatory conditions of the nose and paranasal sinuses. When an inflammatory condition is unquestionable, MRI is more accurate than CT, but the latter (thanks to its optimal documentation of both bony walls and soft tissues) is superior to MRI in the differential diagnosis of a generic disease of the nose and paranasal sinuses--that is, when the inflammatory nature is questionable. MRI limitations were poor visualization of bone walls, high cost, and poor access. Thus, CT emerged as the technique of choice, thanks to its diagnostic results, easy access and low cost, with a negligible radiation dose to patients.

Photostimulable phosphor computed radiography (CR) is a new technique. The authors applied direct magnification CR to hand study (IP matrix: 1770 x 2370), and compared the results with conventional radiography ones (high MTF industrial type film, without screens, 5 x optic enlargement reading). In both cases, a mammographic unit was employed for acquiring the images. Thirty patients affected with renal osteodystrophy, psoriatic arthropathy or rheumatoid arthritis, and 20 normal subjects were examined. Digital images were processed by a particular sensitometry curve and spatial filtering with unlinear unsharp masking: we obtained good visualization of small lesions (subperiosteal resorption, cortical bone tunnelling, minute periosteal necrosis), not inferior to that obtained with conventional techniques. CR has further advantages, such as low economic and biological cost, wide exposure and recording range, image processing, easy archiving and networking.

Acute pancreatitis is a rare complication of intrabiliary rupture of an hydatid cyst. The Authors report a new case and discuss its clinical, radiological and surgical findings with special emphasis to the diagnostic approach and surgical management.