Ahmet Muhtesem Agildere

STIR Sequence for Depiction of Degenerative Changes in Posterior Stabilizing Elements in Patients with Lower Back Pain

OBJECTIVE The aims of this study were to investigate whether degenerative posterior paraspinal changes are a cause of lower back pain and to determine the age- and sex-related distribution of these changes on MR images acquired with a STIR sequence. SUBJECTS AND METHODS The lumbar MRI findings of 372 patients (141 men, 231 women; mean age, 51.2 years) with nonradicular lower back pain and of 249 healthy persons acting as controls (126 men, 123 women; mean age, 49.3 years) were analyzed. The sagittal STIR sequence was used for all MRI examinations. Presence of interspinous ligament edema, facet joint effusion, neocysts, paraspinal muscle edema, subcutaneous edema, disk herniation, and disk degeneration was evaluated, and the incidence of each finding was determined. All findings were grouped according to age and sex. Chi-square, Fishers exact, and independent-samples Students t tests and Spearmans rank correlation analysis were used for statistical analysis. RESULTS The incidences of facet joint effusion, interspinous ligament edema, neocyst formation, and paraspinal muscle edema were found to be statistically significantly higher in patients with lower back pain than in controls. The incidences of intervertebral disk degeneration, disk herniation, and subcutaneous edema in persons with and those without lower back pain were similar. Intervertebral disk degeneration, disk herniation, subcutaneous edema, and muscle edema were found to increase with age in both persons with and those without symptoms. CONCLUSION Degenerative changes in the posterior paraspinal structures were found in a higher percentage of subjects with lower back pain than in controls. Use of a STIR sequence with homogeneous fat suppression facilitates visualization of these changes.

Value of Apparent Diffusion Coefficient Calculation in the Differential Diagnosis of Parotid Gland Tumors

Background: The differential diagnosis of parotid gland tumors is often difficult with conventional magnetic resonance imaging. Purpose: To determine whether the calculation of the apparent diffusion coefficient (ADC) is valuable for making the differential diagnosis of parotid tumors. Material and Methods: Thirty parotid masses in 28 patients and 24 healthy parotid glands in 12 controls were examined in this prospective study. Diffusion-weighted magnetic resonance imaging with echo-planar spin-echo sequences was used to evaluate each subject. The ADC of each tumor and each healthy parotid gland was calculated. Tumor diagnoses were confirmed by the results of histopathologic analysis. Results: The following types of masses were identified: 11 Warthin tumors, nine pleomorphic adenomas, seven malignant tumors, one basal cell adenoma, and two benign cysts. The mean ADC value for the Warthin tumors was 0.97±0.16×10−3 mm2/s, for the pleomorphic adenomas was 1.74±0.37×10−3 mm2/s, for the malignant tumors was 1.04±0.35×10−3 mm2/s, and for the normal parotid glands was 0.34±0.20×10−3 mm2/s. The respective ADC value for the single basal cell adenoma was 1.40×10−3 mm2/s. Statistically significant differences were identified between the subjects with pleomorphic adenoma and those with another type of parotid tumor, and between subjects with healthy parotid glands and those with a tumor. Conclusion: Calculating the ADC appears to be useful in differentiating pleomorphic adenomas from other types of parotid gland tumors.

CT features of a pericardial gossypiboma.

Abstract. We report a case of surgically retained pericardial sponge as a cause of paracardiac mass in a woman who had thoracotomy 3 weeks prior for replacement of mitral valve prosthesis. Computed tomography examination showed a thin-walled mass containing relatively high-density material in the central part with low-density rim at the periphery suggesting a haematoma with clot formation at first. Surgically removed mass was a retained sponge between right atrium and pericardium. Gossypiboma should be included in the differential diagnosis of an intrathoracic mass besides haematoma and abscess formation in any patient who has had previous thoracotomy.

Thoracic CT findings in long-term hemodialysis patients.

Purpose: To evaluate thoracic CT findings of long-term hemodialysis patients. Material and Methods: Thoracic CT findings of 117 uremic patients (61 men, 56 women) with complaints of cough, dyspnea, low-grade pyrexia, malaise, weight loss, and profuse perspiration were retrospectively documented. Results: Atelectasis (60%), cardiomegaly (60%), pleural effusion (51%), vascular congestion (44%), parenchymal consolidation (38%), parenchymal scarring-fibrosis (31%), and lymphadenopathy (29%) were the most common CT findings in the thoraces of the long-term hemodialysis patients. Staphylococcus aureus was detected in 13 patients (11%) who had parenchymal infiltration. Thoracic tuberculosis was identified in 15 patients (13%), 11 of these cases being confined to the lung parenchyma, 3 to the pleura, and 1 involving the pleura and pericardium. Conclusion: In patients under long-term hemodialysis treatment, parenchymal consolidation, secondary to infectious agents such as S. aureus and Mycobacterium tuberculosis, is the most important CT finding since these lesions can be detected and treated successfully if they are considered as etiologic factors early on.

Osmotic demyelination syndrome with a dysequilibrium syndrome: reversible MRI findings

Abstract Neurological disorders may be seen in end-stage renal disease patients due to uraemia or to complications of dialysis. A dysequilibrium syndrome may be seen, usually soon after or towards the end of haemodialysis. This group of patients has no particular findings on MRI. On the other hand, the osmotic demyelination syndrome has definitive MRI findings, not to date reported with the dysequilibrium syndrome. We report a patient with end-stage renal disease and the dysequilibrium syndrome who showed findings of osmotic demyelination on MRI. The patient had a convulsion after a first haemodialysis, with quadriparesis and hyperactive deep tendon reflexes and bilateral Babinski signs. The upper motor neurone signs lasted for a week. Meanwhile, he was also dysarthric and had dysphagia. He recovered neurologically without any residuum following appropriate treatment and there was improvement on MRI.

Chondromyxoid fibroma of the temporal bone: CT and MRI findings

Abstract. We present the case of a 44-year-old woman with chondromyxoid fibroma of temporal bone origin. Since this is the least common bone tumor of cartilaginous origin, it is highly unusual to find this tumor in the skull. In fact, the literature describes 18 cases of this form of neoplasia arising in the skull, only 4 of these having originated in the temporal bone. To date, the radiological features of these tumors, and especially features detected using the latest imaging modalities, have not been described in detail. This report is unique in that it is the first to present a case of chondromyxoid fibroma of the temporal bone accompanied by detailed CT and MRI findings.

Preoperative local staging of rectal cancer with endorectal MR imaging: comparison with histopathologic findings.

The purpose of this prospective study was to assess the accuracy of endorectal MR imaging in the preoperative local staging of rectal cancers. In 20 cases, we correlated endorectal MR imaging findings with postoperative histopathologic staging according to TNM classification. The accuracy of endorectal MR for determining the T stage of rectal cancer was 85%. The sensitivity and specificity for detecting lymph node metastases were 90.9% and 55.5%, respectively.

MR rectography evaluation of rectoceles with oral gadopentetate dimeglumine and polyethylene glycol solution

AbstractBackground: We assessed the value of magnetic resonance (MR) rectography in diagnosing rectocele by using a combination of oral gadopentetate dimeglumine and polyethylene glycol solutions. Methods: T1-weighted, breath-hold, fast low-angle shot sequences were made in 22 patients in resting and straining states in the supine position before and after administration of oral paramagnetic contrast. Twelve patients received polyethylene glycol solution in addition to contrast, and 10 received contrast only. The pubococcygeal line was the reference used for diagnostic measurements. The quality of each sequence was graded. Paired t test, chi-square test, and the Kolmogorov-Smirnov test were applied for statistical analysis. Results: The results of noncontrast images were inconclusive. There was a statistically significant difference between MR imaging diagnosis of rectocele in patients in the straining position without and with contrast (p < 0.05), and the difference was more prominent in patients using polyethylene glycol solution (p < 0.001). Using oral contrast plus polyethylene glycol produced significantly better MR examinations in the resting and straining positions (p < 0.05). Conclusion: The combination of oral contrast and polyethylene glycol solution improves the diagnostic value of MR rectography and is particularly useful when noncontrast examinations are inconclusive.

Primary choriocarcinoma of the stomach and pancreas: CT findings

Abstract. In this report we present the CT findings of two non-gestational,extragonadal choriocarcinomas, one arising within the stomach and one in the pancreas. These are rare tumours and a pancreatic primary site has not been previously described.

Correlation of quantitative dynamic magnetic resonance imaging findings with pathology results in renal transplants: a preliminary report

ENAL transplantation is being used worldwide to spare chronic renal insufficiency patients from hemodialysis and to improve their quality of life. Medical and surgical complications have increased along with the number of transplantations performed. There are many causes of renal allograft dysfunction, the most significant being acute rejection, cyclosporine (CyA) toxicity, acute tubular necrosis, and chronic rejection. 1 It is particularly important to differentiate between acute rejection and CyA toxicity, because the dosage of immunosuppressive therapy should be increased in the former, but decreased in the latter condition. Biopsy remains the technique of choice for reaching a definitive diagnosis, but this procedure carries the risk of complications, such as major hemorrhage and infection that can occasionally result in graft loss. 2,3 Various noninvasive methods have been used to evaluate renal allograft dysfunction. The most common are serum creatinine levels, Doppler ultrasonography, and renal scintigraphy. However, none of these are specific enough to differentiate acute rejection from CyA toxicity. 4,5 The aim of this study was to assess dynamic magnetic resonance imaging (MRI) as a possible effective noninvasive technique to differentiate between rejection and CyA toxicity.