In some periodontal cases, biomechanical, esthetic, medical, or economic concerns make it difficult for clinicians to employ either traditional therapy or restoration with an implant-supported ...prosthesis. To avoid any compromise and ensure a good result in such cases, we chose a removable telescopic prosthesis on natural teeth. In this paper we present a new clinical and technical method for the telescopic prosthesis, and we show that this is a predictable, reliable solution that is easy to realize, inexpensive, and comfortable for patients.
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.
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.
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.
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.
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.
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.
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.
