Reader variability in reporting breast imaging according to BI-RADS assessment categories (the Florence experience).

The inter- and intraobserver agreement (K statistic) in reporting according to BI-RADS assessment categories was tested on 12 dedicated breast radiologists, with little prior working knowledge of BI-RADS, reading a set of 50 lesions (29 malignant, 21 benign). Intraobserver agreement (four categories: R2, R3, R4, R5) was fair (0.21-0.40), moderate (0.41-0.60), substantial (0.61-0.80) or almost perfect (>0.80) for one, two, five or four radiologists, or (six categories: R2, R3, R4a, R4b, R4c, R5) fair, moderate, substantial or almost perfect for three, three, three or three radiologists, respectively. Interobserver agreement (four categories) was fair, moderate or substantial for three, six, or three radiologists, or (six categories) slight, fair or moderate for one, six, or five radiologists. Major disagreement occurred for intermediate categories (R3=0.12, R4=0.25, R4a=0.08, R4b=0.07, R4c=0.10). We found insufficient intra- and interobserver consistency of breast radiologists in reporting BI-RADS assessment categories. Although training may improve these results, simpler alternative reporting methods (systems), focused on clinical decision-making, should be explored.

Categorizing breast mammographic density: intra- and interobserver reproducibility of BI-RADS density categories.

The inter- and intraobserver agreement (kappa-statistic) in reporting according to Breast Imaging Reporting and Data System (BI-RADS((R))) breast density categories was tested in 12 dedicated breast radiologists reading a digitized set of 100 two-view mammograms. Average intraobserver agreement was substantial (kappa=0.71, range 0.32-0.88) on a four-grade scale (D1/D2/D3/D4) and almost perfect (kappa=0.81, range 0.62-1.00) on a two-grade scale (D1-2/D3-4). Average interobserver agreement was moderate (kappa=0.54, range 0.02-0.77) on a four-grade scale and substantial (kappa=0.71, range 0.31-0.88) on a two-grade scale. Major disagreement was found for intermediate categories (D2=0.25, D3=0.28). Categorization of breast density according to BI-RADS is feasible and consistency is good within readers and reasonable between readers. Interobserver inconsistency does occur, and checking the adoption of proper criteria through a proficiency test and appropriate training might be useful. As inconsistency is probably due to erroneous perception of classification criteria, standard sets of reference images should be made available for training.

Diffusion and perfusion MR imaging in cases of Alzheimer's disease: correlations with cortical atrophy and lesion load.

BACKGROUND AND PURPOSE: Perfusion and diffusion-weighted MR imaging are powerful new imaging techniques for evaluating tissue pathophysiology in association with many neurologic disorders, such as neurodegenerative diseases. The purpose of our study was to evaluate the sensitivity and specificity of dynamic susceptibility contrast-enhanced MR imaging and diffusion-weighted MR imaging in cases of Alzheimer's disease and to assess the role of atrophy in the quantification of cortical perfusion. METHODS: Thirty-nine participants were studied: 18 patients with moderate cognitive impairment with probable Alzheimer's disease, 16 patients with mild impairment with possible or probable Alzheimer's disease, and 15 group-matched elderly healthy comparison volunteers. Relative values of temporoparietal, sensorimotor, and hippocampal regional cerebral blood volume (rCBV) were measured as a percentage of cerebellar rCBV, and group classification was assessed with logistic regression. Brain atrophy was used as a covariate to assess its role in rCBV quantification. Regions of interest placed on orientation-independent apparent diffusion coefficient maps allowed the calculation of apparent diffusion coefficient values and relative anisotropic indices of the head of the caudate nuclei, thalamus, parietal, frontal, and hippocampal cortices bilaterally, genu and splenium of corpus callosum, and anterior and posterior white matter in patients with Alzheimer's disease and in control volunteers. RESULTS: Temporoparietal rCBV ratios were reduced bilaterally in the patients with Alzheimer's disease. Sensitivity was 91% in moderately affected patients with Alzheimer's disease and 90% in patients with mild cases. Specificity was 87% in healthy comparison volunteers. Lower values of sensitivity and specificity were obtained for sensorimotor (73%, 50%, and 67%, respectively) and hippocampal cortices (80%, 80%, and 65%, respectively). Using brain atrophy as a covariate, patients with Alzheimer's disease still showed a statistically significant reduction of rCBV compared with control volunteers. Diffusion-weighted MR imaging analysis only showed a trend, with no statistic significance, of reduction of anisotropy in posterior white matter. CONCLUSION: Dynamic susceptibility contrast-enhanced MR imaging of rCBV may be an alternative to nuclear medicine imaging for the evaluation of patients with Alzheimer's disease. When brain atrophy is used as a covariate, differences in rCBV still persist between patients with Alzheimer's disease and control volunteers, suggesting that perfusion impairment is unrelated to atrophy. No significant results for either white or gray matter were obtained using diffusion-weighted MR imaging.

Cerebral hemodynamics in asymptomatic patients with internal carotid artery occlusion: a dynamic susceptibility contrast MR and transcranial Doppler study.

BACKGROUND AND PURPOSE: Perfusion imaging with dynamic susceptibility contrast MR imaging (DSC-MRI) has been used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. The aim of the present study was to determine the hemodynamic changes occurring in asymptomatic patients with unilateral internal carotid artery (ICA) occlusion by use of DSC-MRI with transcranial Doppler (TCD) measurement of the breath-holding index (BHI). METHODS: Nine patients with asymptomatic unilateral ICA occlusion underwent DSC-MRI and TCD examination. One patient was excluded from final analysis because of severe movement artifacts. On a separate workstation, regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional mean time to peak (rMTT) were calculated on the basis of signal decay rate during the passage of gadolinium bolus through the sampled volume in the territory of the middle cerebral artery. TCD-BHI was calculated in all patients. Six healthy subjects underwent the same MR protocol as the patients. RESULTS: Compared with control subjects, patients with unilateral ICA occlusions had hemodynamic changes in the ipsilateral hemisphere: rCBF was significantly lower than in controls (P <.01), and r MTT was significantly increased in both white (WM) and gray matter (GM) in the affected side (WM: P <.01; GM: P <.05). No statistically significant difference in rCBV was found in the group of patients (occluded versus contralateral, P <.1) or between the patient and control groups (occluded side versus controls, P <.1). The correlation of rCBV and BHI showed a strong relation of the two variables, showing a decrease of the latter when the former increased. CONCLUSION: DSC-MRI is a valuable tool for measuring hemodynamic changes in the presence of carotid disease with hemodynamic impairment. In our opinion, hemodynamic changes and efficiency of collateral pathways can be evaluated in occlusive carotid disease by using paired measurement of BHI and DSC-MRI. In the patient group, MR-determined rCBV and TCD-determined BHI showed a significant inverse correlation, suggesting similar significance of the two indices.

Case report: subependymal diffuse heterotopia. Clinical, EEG, and neuroimaging findings.

We report the case of a 41 year-old woman with a slight mental retardation and epilepsy. MRI showed a diffuse subependymal heterotopia. The cognitive level supports the view that the ectopic cells are probably not important for the normal cortical functions but that they are likely able to maintain some of the electric properties of normal neurons, even if with altered discharge modalities. The genetic etiology of subependymal neuronal migration disorders is discussed. This is the second reported case of diffuse subependymal heterotopia in a female patient.

Early postoperative MRI findings following surgery for herniated lumbar disc.

MRI is routinely used in the evaluation and management of patients with failed back surgery syndrome (FBSS). However, its value is unclear in the early detection of signs that can negatively affect that later course of surgical cases. The purpose of the present study is to describe the MR images of early postoperative MRI at 3 days in 30 unselected patients who underwent lumbar microdiscectomy, and to correlate the findings with follow up MRI at 8 weeks and with final outcome. The findings are correlated with literature data. Early postoperative MRI findings were consisting of pseudohernia in 24 patients (80%), annular rent in 23 patients (80%), and other non-specific postoperative findings. On the late MRI the pseudohernia persisted in 12 patients (50%), the annular rent in 4 patients (15%) and asymptomatic pseudo-spondylodiscitis was apparent in 3 patients (10%) as was a case of true spondylodiscitis. Therefore, early postoperative findings have limited value in the management of patients after surgery for lumbar disc herniation, since the images were not correlated with the immediate clinical course after surgery nor with the late radiological and clinical outcome. The evident imaging changes in the early postoperative period after lumbar disc surgery limit the accuracy of the interpretation of MRI examinations.

Early postoperative MRI findings following surgery for herniated lumbar disc. Part II: A gadolinium-enhanced study.

The aim of our study was to evaluate the contrast-enhanced MR imaging (MRI) findings, in the early postoperative period, in unselected patients undergoing lumbar microdiscectomy (15/16 had total resolution of their symptoms). Contrast-enhanced imaging studies were performed, in all 16 patients of our series, before surgery, and at the third postoperative day and, two months after surgery. Postoperative paraspinal muscles enhancement was present in all patients. In the postoperative period, nerve root enhancement was present in 5/16 patients at the early survey and persisted in one after two months. A pseudohernia depicted as epidural intermediate signal intensity tissue, was seen in 13 patients at the third day MRI, and only in eight after two months. This pseudohernia enhanced peripherally in 8/13 patients and enhanced homogeneously in the remaining five at the first postsurgical examination; in the late MRI the peripheral enhancement was appreciable in only two patients while a homogeneous enhancement was observed in six. Clinical symptoms resolved completely in 14/16 patients on clinical evaluation at the third postoperative day, while the remaining two patients showed residual symptoms and signs of radicular compression. At the early MRI these two patients showed intradural nerve root enhancement. Two months later, one patient did not show the previously described nerve root enhancement and improved clinically, while the other had a positive Straight Leg Raising Sign with persistent intradural nerve root enhancement. In conclusion, no correlation between clinical course and contrast-enhancement of pseudohernia and extradural nerve root was appreciable, although intradural nerve root enhancement seems to represent a clinically relevant finding.

[Impingement syndrome of the shoulder. Clinical data and radiologic findings]. / Il conflitto antero-interno della spalla. Dati clinici e bilancio radiologico.

Subcoracoid impingement syndrome pain is elicited by some positions of the upper limbs, i.e., adduction and inward rotation, whenever coracohumeral space reduces. Although acquired or congenital malformations of the humeral head and/or coracoid apophysis are the most common causes of painful syndromes, repeated flections and inward rotations of the upper limbs, typical of some sports, such as swimming and tennis, and of some sports, such as swimming and tennis, and of some kinds of work, are predisposing factors. The subcoracoid impingement syndrome exhibits on pathogenomonic signs at clinics and the specificity of diagnostic methods is low, which calls for reliable radiologic assessment of this condition. Fifteen patients with subcoracoid impingement syndrome underwent X-ray, US, CT and MR studies. Plain radiography detected no specific signs of this syndrome, but yielded useful information regarding other painful syndromes of the shoulder, such as anatomical variants of the acromion and degenerative changes. US yield was poor because of the acoustic window of the coracoid apophysis, but supraspinatus tendon changes were demonstrated in 2 cases. CT and MRI proved to be the most reliable and accurate diagnostic methods, the former thanks to its sensitivity to even slight bone changes and to its capabilities in measuring coracohumeral distance and acquiring dynamic scans and the latter because it detects tendon, bursa and rotator cuff changes. To conclude, in our opinion, when the subcoracoid impingement syndrome is clinically suspected, plain X-ray films should be performed first and followed by MR scans.

[Magnetic resonance angiography in liver transplant patients. Follow-up of vascular anastomoses]. / Angiografia con Risonanza Magnetica nei pazienti sottoposti a trapianto epatico. Controllo delle anastomosi vascolari.

Twenty liver transplant patients were examined with MRA and color-Doppler US 18 to 40 days after surgery to investigate the onset of vascular complications after surgical liver revascularization. Vascular anastomoses are the most frequent location for such complications as stenoses, occlusions, pseudoaneurysms and vessel ruptures. In liver transplant there are 4 vascular anastomoses, i.e. hepatic artery, portal vein and superior and inferior anastomoses of the inferior vena cava. MRA images were acquired with a superconductive unit operating at 1.5 T, using fast low angle shot (FLASH) 2D sequences on the coronal plane; all images were postprocessed with the MIP algorithm. The presence of a paramagnetic artifact, the "double black spot sign", caused by the suture wire used to make the vascular anastomoses, allowed us to precisely detect the site and the flow pattern alterations at this level. MRA images were studied by two independent observers and vascular anastomosis depiction was rated as "good", "fair" and "poor". The demonstration of portal vein anastomoses was good in the whole series (20/20 patients). The superior anastomosis of the inferior vena cava was clearly depicted in 19 cases and fairly depicted in only 1 patient. The inferior anastomosis of the inferior vena cava was clearly depicted in 19 patients and fairly depicted in 1 case. Hepatic artery anastomoses were far more difficult to demonstrate than the others, considering their caliber and flow pattern, but its depiction was nevertheless good in 12 cases, fair in 6 and poor in only 2 patients. In our series, only one portal vein stenosis was observed, which was clearly depicted on both MRA and US images. In conclusion, MRA is a useful and reliable noninvasive diagnostic tool to study vascular anastomoses in liver transplant patients.

[Magnetic resonance imaging in denervated muscle. A preliminary study]. / Imaging con risonanza magnetica nel muscolo denervato. Studio preliminare.

Ten patients with various forms of peripheral neuropathy and spinal radiculopathy were examined with MRI using a low-field permanent magnet (0.2 T) and spin echo (SE)/inversion recovery (IR) sequences, with an adequate inversion time to suppress healthy muscle signal. In acute denervation MR sensitivity was low on both sequences; in subacute denervation the damaged muscle was more intense than the healthy muscle only on IR sequences. MRI adequately depicted fatty infiltration in chronic denervation. In conclusion, MRI is a promising tool for mapping and noninvasively monitoring denervated motor units in skeletal muscles, whose role is currently complementary to that of electromyography.

[An introduction to fast and ultrafast sequences in magnetic resonance]. / Introduzione alle sequenze veloci ed ultraveloci in risonanza magnetica.

The main limitations of magnetic resonance imaging (MRI) are due to the long acquisition time needed for data sampling. Fast and ultrafast sequences, thanks to progress in hardware and software technology, allow the acquisition times to be dramatically reduced. Such improvements will definitely increase MR capabilities and make MRI a fast and dynamic technique no longer depending on patients' cooperation and limited by patients' conditions--e.g., trauma, pediatric, or claustrophobic patients--or even by the anatomic features of the region of interest. The latest experimental studies are aimed at increasing the clinical applications and the perspectives of clinical MRI and at such ambitious goals as MR-fluoroscopy, interventional MRI, total body examination in less than one minute and functional MRI. In this paper the technical principles and the main indications of this new kind of sequences are reported, with a special emphasis on Gradient-Echo (GE), Turbo Spin-Echo (turbo SE) or Fast Spin-Echo (fast SE), Turbo FLASH and Echo Planar (EP) sequence. A smaller flip angle (FA) and the substitution of the 180 degrees RF pulse with a gradient reversal are the main differences of GE from SE sequences. From GE sequences, several fast sequences are derived, such as angiographic and turbo FLASH sequences. The latter, thanks to 180 degrees preinversion RF pulse, using idoneous inversion times (IT), provide flexible contrast. Turbo SE sequences, which are directly derived from conventional SE sequence, allow the acquisition time to be markedly shortened, by acquiring several Fourier lines of K-space for each TR. The repetition of several 180 degrees pulses following the excitatory 90 degrees RF pulse does the trick through the creation of multiple echoes for a single TR. EP sequences are the fastest ones currently available: with them, an image can be acquired in 30-100 ms. However, the limited availability of the relative hardware and the need of both quality implementation and the definition of clinical indications are major obstacles to the widespread use of these sequences. The SE T2-weighted sequence, the main responsible for the long examination time, will be replaced soon. Further implementation of these sequences will make MRI a fast, flexible and adaptable method to any exam and patient disability.