Huseyin Onur Sildiroglu

Role of apparent diffusion coefficient values and diffusion-weighted magnetic resonance imaging in differentiation between benign and malignant thyroid nodules

OBJECTIVE The purpose of the study was to differentiate between benign and malignant thyroid nodules using nodule-spinal cord signal intensity and nodule apparent diffusion coefficient (ADC) ratios on diffusion-weighted magnetic resonance imaging (DW-MRI). MATERIALS AND METHODS Forty-four patients (27 females, 17 males; mean age, 49 years) with nodules who underwent DW-MRI were included in this study. The images were acquired with 0, 50, 400 and 1000 s/mm(2)b values. ADC maps were calculated afterwards. Fine needle aspiration biopsies (FNAB) were performed at the same day with DW-MRI acquisition. The diagnosis in patients where malignity was detected after FNAB was confirmed by histopathologic analysis of the operation material. The signal intensities of the spinal cord and the nodule were measured additionally, over b-1000 diffusion-weighted images. Nodule/cord signal intensity (SI) ratios were obtained and the digital values were calculated by dividing to ADC values estimated for each nodule. Statistical analysis was performed. RESULTS The (nodule SI-cord SI)/nodule ADC ratio is calculated in the DW images, and a statistically significant relationship was found between this ratio and the histopathology of the nodules (P<.001). The ratio was determined as 0.27 in benign and 0.86 in malignant lesions. The result of receiver operating characteristic (ROC) analysis was statistically significant, and the area under curve (100%) was considerably high. The threshold value was calculated as 0.56 according to the ROC analysis. According to this threshold value, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates for (nodule SI/cord SI)/ADC ratios in differentiating benign from malignant thyroid nodules are calculated as 100%, 97%, 83%, 100%, and 98%, respectively. CONCLUSION We have found that (nodule/cord SI)/nodule ADC ratio has the highest values for sensitivity and specificity among the tests defined for characterization of nodules.

Split-cord malformation and accompanying anomalies.

OBJECTIVE To present the magnetic resonance imaging (MRI) appearances of spinal split-cord malformation (SCM) and to investigate the various types of congenital spinal disorders associated with SCM. MATERIALS AND METHODS MR examinations of 23 patients with SCM were carried out in our hospital between June 2002 and May 2007 and retrospectively analysed. RESULTS Nineteen (82.6%) patients were diagnosed as type I SCM, while four (17.4%) were diagnosed as type II SCM. The most commonly involved site of SCM was the dorsolumbar area (47.8%) while cervical involvement was the least common (4.3%). No accompanying congenital spinal disorders were detected in four patients (17.4%). In 19 patients (82.6%), congenital spinal disorders accompanying SCM were detected, the most common of which was a low-lying cord, found in 14 patients (60.9%). Other anomalies included hydromyelia in seven patients (30.4%), lipoma in six (26%), meningomyelocele in four (17.4%), thick filum in three (13%) and dermoid cyst in three (13%). CONCLUSION In preoperative planning for SCM, its characteristics and those of the accompanying anomalies should be determined. MRI is a valuable tool for making such determinations.

MRI appearance of retrocalcaneal bursitis and rheumatoid nodule in a patient with rheumatoid arthritis

Rheumatoid arthritis is an autoimmune disorder of unknown etiology characterized by symmetric, erosive synovitis and sometimes multisystem involvement. Rheumatoid nodules have been reported in as many as 20–30% of patients with rheumatoid arthritis; however, they are not commonly seen in the feet. We present magnetic resonance (MR) findings of a rarely seen case of rheumatoid bursitis in the retrocalcaneal bursa associated with a subcutaneous rheumatoid nodule inferior to the calcaneus which histologically confirmed the rheumatoid arthritis. To the best of our knowledge, this is the first case that rheumatoid bursitis in the retrocalcaneal bursa associated with the rheumatoid nodule in the foot was revealed by MR imaging.

Relationship between tuberculous otomastoiditis and tuberculous meningitis

OBJECTIVE The aim of this study was to determine the correlation between tuberculous meningitis and tuberculous otomastoiditis. MATERIALS AND METHODS Meningeal involvement sites were investigated by magnetic resonance imaging in 32 patients (21 males, 11 females) who had previously been diagnosed with tuberculous meningitis. Clinical and laboratory findings and responses to anti-tuberculous treatment were evaluated, and the presence of concomitant tuberculous otomastoiditis was also investigated. RESULTS The meningeal involvement site was unilateral (in the sylvian fissure and the perimesencephalic cistern) in 28 patients (87.5 per cent), and bilateral and widespread in four patients (12.5 per cent). Tuberculous otomastoiditis was found in 11 of the patients with tuberculous meningitis (34.3 per cent). Otomastoiditis was on the same side as the meningeal involvement in nine of these 11 patients. Bilateral otomastoiditis with meningeal involvement was observed in two patients. CONCLUSIONS Tuberculous meningitis is frequently accompanied by otomastoiditis, although the exact causal relationship between the two conditions is unclear. Since meningitis is a serious clinical condition, concomitant otomastoiditis generally remains unrecognised. Tuberculosis should be considered in the differential diagnosis of patients with otitis or otomastoiditis who do not respond to antibiotic therapy.

Breast cancer presenting with intramedullary cervical spinal cord metastasis.

A 45-year-old female patient was admitted to our hospital with complaints of weakness in her legs. There was no disturbance in sphincter function. Neurologic examination revealed generalized weakness and numbness in all four limbs. Examination of cranial nerves and tendon reflexes revealed normal functioning. Magnetic resonance imaging of the cervical spine demonstrated a 3 cm×0.9 cm×1.1 cmmass between the inferior two thirds of C2 and superior third of C3 (Figure). The mass was isointense on T1-weighted images, hyperintense on T2-weighted images, and homogeneously enhancing on post-contrast T1-weighted images. Sagittal T2-weighted images showed a pencil-shaped hyperintensity extending proximal to the lesion (Figure). The features were typical for intramedullary spinal cord metastasis (ISCM) [1]. An Ffluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) scan showed a left breast lesion and multiple liver lesions. The patient underwent biopsy of the left breast mass and a liver mass. The breast mass was found to be a poorly differentiated, estrogen/progesterone (ER/ PR)-negative infiltrating ductal carcinoma, and an enlarged 1.6-cm left axillary lymph node biopsy revealed metastatic adenocarcinoma. The liver mass biopsy was reported to be an ER/PR-negative adenocarcinoma, consistent with metastatic breast cancer. The patient was started on dexamethasone, chemotherapy, and local external beam radiation therapy to the cervical spinal cord. After completion of the radiotherapy, there was improvement in the weakness and numbness of the extremities. The patient remained stable neurologically for 2 months after the diagnosis of breast cancer until death due to the liver metastases. Breast cancers can present with symptoms of the spinal cord metastasis. Intramedullary spinal cord metastasis of breast cancer is an extremely rare but severe condition that can cause neurologic deficits. Metastatic breast cancer should be considered when the typical features of ISCM are seen on spinal magnetic resonance imaging.

Neurenteric cyst presented with progressive head and neck pain

A 37-year-old female patient was admitted to the neurology department of a hospital because of headache. Neurologic examination of the patient was normal. Magnetic resonance imaging of the craniocervical junction region revealed a well-defined extra-axial cystic lesion measuring 1.0×0.6×1.3 cm located ventral from the medulla to the C1 vertebra without cord compression. T1-, T2-, and post-gadolinium T1-weighted images showed a homogeneously hyperintense cyst (Fig. 1) without enhancement. The patient was diagnosed with neurenteric cyst. She was followed up as an outpatient. One year later, she visited the hospital because of neck pain. Because we observed cord compression at the C1 and C2 levels on control magnetic resonance imaging (Fig. 2), the patient underwent total excision of the lesion and the histopathologic diagnosis was neurenteric cyst.