Ahmet Firat

Evaluation of in vivo cerebral metabolism on proton magnetic resonance spectroscopy in patients with impaired glucose tolerance and type 2 diabetes mellitus

The aim of this study was to investigate possible metabolic alterations in cerebral tissues on magnetic resonance spectroscopy (MRS) in patients with impaired glucose tolerance (IGT) and with type 2 diabetes mellitus (T2-DM). Twenty-five patients with T2-DM, 13 patients with IGT, and 14 healthy volunteers were included. Single-voxel spectroscopy (TR: 2000 ms, TE: 31 ms) was performed in all subjects. Voxels were placed in the frontal cortex, thalamus, and parietal white matter. N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and myo-inositol (MI)/Cr ratios were calculated. Frontal cortical Cho/Cr ratios were increased in patients with IGT compared to control subjects. Parietal white matter Cho/Cr ratios were significantly higher in patients with IGT when compared to patients with T2-DM. In the diabetic group, frontal cortical MI/Cr ratios were increased, and parietal white matter Cho/Cr ratios were decreased when compared to the control group. Frontal cortical NAA/Cr and Cho/Cr ratios and parietal white matter Cho/Cr ratios were decreased in diabetic patients with poor glycemic control (A1C>10%). A1C levels were inversely correlated with frontal cortical NAA/Cr and Cho/Cr ratios and with parietal white matter Cho/Cr ratios. T2-DM and IGT may cause subtle cerebral metabolic changes, and these changes may be shown with MRS. Increased Cho/Cr ratios may suggest dynamic change in membrane turnover in patients with IGT. Diabetic patients with poor glycemic control may be associated with neuronal dysfunction/damage in brain in accordance with A1C levels and, in some, extend with insulin resistance.

Diffusion‐weighted images differentiate benign from malignant thyroid nodules

To reveal the possible role of diffusion‐weighted images (DWI) in the differential diagnosis of benign and malignant thyroid nodules by comparing the results of fine‐needle aspiration cytology (FNAC).

Sonographic evaluation of the carpal tunnel after provocative exercises

Objective. Dynamic carpal tunnel syndrome (CTS) is a subtype of CTS in which symptoms usually subside with rest and return with repetitive motions. In this subgroup, nerve conduction studies, performed at rest, are often inconclusive. In this study, the diagnostic value of provocative sonography was evaluated in patients with dynamic CTS. Methods. Twenty wrists of 13 patients with dynamic CTS and 10 control subjects were investigated with sonography before and immediately after provocative exercises imitating work‐related stresses. In addition to conventional indices (palmar displacement, nerve area at the middle level, and swelling ratio before and after exercise), 2 newly formed indices (provocative nerve area ratio and provocative palmar displacement ratio) were investigated. Results. In the pre‐exercise period, there were no significant differences between patients and control subjects regarding palmar displacement and the swelling ratio. The difference was significant (P = .035) for the nerve area at the middle level. In the post‐exercise period, all parameters were significantly different between patients and control subjects. The nerve area at the middle level and the swelling ratio had higher significance (P < .0001) than palmar displacement (P = .015). The post‐exercise swelling ratio had the highest sensitivity (95%) in diagnosing dynamic CTS when a cutoff value of 1.26 was used. The provocative palmar displacement ratio had high sensitivity (80%) and the highest specificity (90%) for a cutoff value of 1.28. Conclusions. Provocative exercises increase sensitivity and specificity and contribute to the sonographic diagnosis of dynamic CTS. This examination should be performed if electrodiagnostic test results are negative.

Advanced MRI findings in patients with breast hamartomas.

PURPOSE Although it has been stated that breast hamartomas are rare tumors, radiologists frequently encounter them in their daily practices. Fat, glandular and fibrous tissues all produce a mass of disorganized but mature specialized cells. Because hamartomas do not have specific diagnostic histological features, the clinical and radiological findings are important in their diagnosis. The aim of this study is to present the advanced magnetic resonance imaging (MRI) findings of breast hamartomas. MATERIALS AND METHODS Eight patients with breast hamartomas were examined using MRI techniques in addition to ultrasonographic and/or mammographic findings. RESULTS Each of the lesions examined showed a gradual enhancement pattern in its time-signal intensity curve on dynamic contrast-enhanced MRI. On MR spectroscopy, water and lipid peaks were detected that resembled normal breast tissue. The diffusion features of the lesions were variable due to the different ratios of the tissue elements constituting them on diffusion-weighted imaging (DWI). CONCLUSION Advanced MRI findings may clarify diagnoses by providing additional information following sonography, especially in lactating or pregnant women, in whom mammographic examination is not preferred.

Neuroimaging Findings in Hyperargininemia

In hyperarginenemia, there is a defect in argininase enzyme, which is a catalyzer of urea cycle. Though the pathogenesis of neuronal damage in hyperargininemia is not clear, high serum and cerebrospinal fluid arginine levels can be directly related with neuronal damage. In this study, our aim was to assess brain magnetic resonance images and magnetic resonance spectroscopy (MRS) patterns of two siblings with hyperarginenemia. We acquired single voxel MRS from the white matter to show the myelination pattern and to figure out any abnormal peak of metabolite stored due to enzymatic defect. We observed mild cerebral and cerebellar atrophy and infarct at bilateral posterior putamen and insular cortex localization on conventional images and elevated choline/creatine ratios and abnormal peak at 3.8 ppm, most likely representing arginine deposition. To the best of our knowledge, this is the first article revealing the brain MRS pattern of hyperargininemia. We reported the clinical and imaging findings of patients and discuss the correlation.

Ciprofloxacin-Induced Urticaria and Tenosynovitis: A Case Report

Background: Tendon disorders are rare events associated with fluoroquinolone congestion. Skin reactions are more frequent than tendon disorders. We reported this case as the combination of ciprofloxacin-induced urticaria and tenosynovitis has been unreported in young women. Case: A 28-year-old woman without underlying disease developed urticarias and tendinopathy 4 days after the initiation of ciprofloxacin treatment for urinary infection. MRI of the left foot revealed increased synovial fluid surrounding the tendon of the flexor hallucis longus muscle representing tenosynovitis. Ciprofloxacin was ceased due to the possibility of ciprofloxacin-induced tendinopathy and urticaria. Complete resolution of her symptoms and findings occurred 3 days after discontinuation of ciprofloxacin without any additional treatment. Conclusion: Early discontinuation of fluoroquinolone therapy when tendinopathy is suspected is the basis of therapy. So, it should be kept in mind that fluoroquinolone-induced tendinopathy may occur in an otherwise healthy young patient with no risk factors and in a site other than the Achilles tendon.

Magnetic resonance spectroscopic characteristics of glutaric aciduria type II

Magnetic resonance spectroscopy (MRS) of a 12-year-old female patient with glutaric aciduria type II was compared with data obtained from four healthy age- and sex-matched volunteers. In the clinically active phase, conventional magnetic resonance imaging showed mild ventricular dilatation. Frontal lobe choline/creatine (Cho/Cr) ratio (1.98) was higher than the ratios reported for the comparison participants (1.64 [SD 0.21]). The N-acetylaspartate/creatine (NAA/Cr) ratio (1.95) was lower than normal limits (2.66 [SD 0.23]). After successful riboflavin treatment and dietary restriction for proteins, the NAA/Cr ratio was within the normal range (2.44) and Cho/Cr ratio was below the normal range (1.15), suggesting riboflavin-responsive multiple acyl-coA dehydrogenase deficiency. An elevated Cho/Cr ratio and decreased NAA/Cr ratio is consistent with a demyelinating process in the active phase of glutaric aciduria type II. MRS helps to monitor the progress of the disease and the efficacy of treatment by revealing changes in NAA/Cr and Cho/Cr ratios.

The comparison of plate-screw and tension band techniques in the osteosynthesis of Danis-Weber Type A and B lateral malleolar fractures.

OBJECTIVE The aim of this study was to compare the clinical and radiological results of plate-screw and tension band fixation in isolated Danis-Weber Type A and B lateral malleolar fractures. METHODS A total of 135 cases of lateral malleolar fractures (82 Danis-Weber Type B and 53 Type A) operated on in 4 different centers and 6 orthopaedic clinics between November 2005 and December 2010 were reviewed retrospectively. Eigthy-one patients (55 Type B and 26 Type A) had lateral 1/3 tubular plate and screw fixation (Group 1), while the remaining 54 patients (27 Type B and 27 Type A) were operated on with tension band technique (Group 2). The clinical and radiological results of the groups were compared. Student t test was used in statistical analysis. RESULTS The mean length of surgical incision scar was 4.9 cm (4.5-5.4 cm) for Type A fractures and 6.8 cm (5.6-7.5 cm) for Type B in Group 1 and 4.0 cm (3.5-5.2 cm) for Type A and 5.3 cm (5.0-5.9 cm) for Type B fractures in Group 2. Radiological union was obtained at mean of 10 weeks (7-13 weeks) in Group 1 and 9 weeks (7-12) in Group 2. The implant had to be removed in 12 patients in Group 1 and in one patient in Group 2. The mean AOFAS Score was 90 (72-100) and 92 (70-100) in Groups 1 and 2, respectively. CONCLUSION Both plate-screw and tension band techniques revealed excellent results in isolated Danis-Weber Type A and B fractures. The tension band technique may be an alternative fixation method in the treatment of these fractures.

Surgical Technique: Supine Patient Position With the Contralateral Leg Elevated for Femoral Intramedullary Nailing

BackgroundIntramedullary nailing can be performed with a fracture table or manual traction. Manual traction can be applied with the patient in either the supine or lateral decubitus (LD) position. However, in either of these positions, the reduction can be difficult because the fractured extremity is not positioned parallel to the floor and the contralateral leg on the operating room table overlaps the fractured limb while the fractured extremity is in full adduction. Therefore fluoroscopy time may be increased. Accordingly, we developed a technique with the patient supine and the contralateral leg elevated (SCLE).Description of TechniqueWe performed anterograde femoral intramedullary nailing with the patient in the supine position with the contralateral leg elevated to allow easy nail entry, reduction, and locking. In this position, the uninjured leg was placed on the leg holder in a semilithotomy position to allow full hip adduction.MethodsWe retrospectively reviewed 63 patients treated with intramedullary nailing: 30 with the SCLE position (mean age, 38 years; 30% female) and 33 with the LD position (mean age, 37 years; 36% female). From the medical records we extracted demographic information, fracture pattern, intramedullary nail diameter, duration of fluoroscopy and operation, and complications. At the last visit, extremity lengths, rotation, and alignment were determined. Minimum followup was 46 months (mean, 46 months; range, 20–72 months).ResultsThe mean durations of surgery and fluoroscopy were shorter for the SCLE group than the LD group: 98 versus 108 minutes and 3.4 versus 3.8 minutes, respectively. The open reduction rate was less in the SCLE group when compared with the LD group: 10% versus 36%.ConclusionsWe believe the SCLE technique is a reasonable treatment choice for femoral intramedullary nailing as it facilitates obtaining orthogonal views of the femur while possibly shortening surgery and fluoroscopy times.Level of EvidenceLevel III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Protective role of melatonin in pinealectomized rat brains: in vivo magnetic resonance spectroscopic analysis

Abstract:  The goal of this study was to investigate the effect of melatonin on basic cerebral metabolites in pinealectomized (Px) rat brains. Twenty‐one rats were randomly divided into three groups with seven rats per group. The study groups included sham‐operated rats, Px rats and Px rats treated with melatonin. Melatonin administration began at 60 days following pinealectomy and continued for 21 days. At the end of the study, in vivo single voxel magnetic resonance spectroscopy was performed on whole brains to determine choline (Cho), creatine and N‐acetyl aspartate (NAA) concentrations. Px rats had significantly lower NAA levels (P < 0.05), and significantly higher Cho levels (P < 0.05) when compared with sham‐operated rats. Administration of melatonin had normalized NAA and Cho levels in Px rats. We propose that pinealectomy causes significant changes in cerebral metabolites which are compatible with neural loss. Melatonin administration prevents the disruptive effects of pinealectomy on brain tissue.