Use of dual energy CT urography in evaluation of urinary stone and complex cyst.

BACKGROUND: Dual-energy computed tomography scans can provide significant benefits to the urinary system. The aim of this study is to determine the limitations and benefits of using dual energy CT urography in patients with urinary system stones and cysts. METHODS: In the analysis of the images, the virtual noncontrasted images obtained from the combined nephrogenicexcretory phase and the true noncontrasted images were evaluated. The true noncontrast images were accepted as the gold standard for stone detection. RESULTS: Eighty-three different stones were detected in 26 of the 115 patients included in the study. Sensibilities of virtual noncontrast images in detecting urinary system stones were 66.7% and 65.4% according to the first and second radiologists, respectively. In this study, 32 hyperdense cysts were detected. According to iodine map images, there was no enhancement in 26 of 32 cysts; only 5 cysts showed minimal contrast enhancement. One patient could not decide on contrast enhancement. DISCUSSION: As a result, if CT urography is performed with dual energy, it can provide additional information in patients with urinary system disorder.

MRI findings and utility of DWI in the evaluation of solid parathyroid lesions.

PURPOSE: To evaluate the MRI findings of solid parathyroid lesions and to elaborate on a possible improvement of MRI detection of parathyroid lesions by the use of additional DWI. MATERIALS AND METHODS: MRI and DWI properties of pathologically proven 20 solid parathyroid lesions were retrospectively reviewed. Mean ADC values (b50 + b400 + b800/3) of parathyroid lesions were compared with that of normal appearing thyroid parenchyma (TP), sternocleidomastoid muscle (SCM) and jugulodigastric lymph nodes (JDLN). RESULTS: Of lesions, 4 were parathyroid hyperplasia, 13 parathyroid adenoma and 3 parathyroid adenocarcinoma. All parathyroid lesions were very bright on fat-saturated T2W images. Parathyroid hyperplasia and adenoma were small sized, homogenous, well-defined and low on T1W, high on T2W and avidly enhancing. Parathyroid carcinoma was large sized, ill-defined and very heterogeneous on MRI including DWI. Means ADC values of parathyroid hyperplasia, adenoma, and adenocarcinoma, TP, SCM and JDLN were measured as 2.3 ± 0.14 × 10-3, 1.7 ± 0.45 × 10-3, 1.5 ± 1.48 × 10-3, 0.87 ± 0.40 × 10-3, 0.55 ± 0.21 × 10-3 and 0.96 ± 0.33 × 10-3 mm2/s, respectively. All parathyroid lesions had high diffusion properties comparing other soft tissue structures of head and neck region. By increasing strength (b value) of diffusion tensor on DWI, solid parathyroid lesions still kept their brightness comparing other soft tissue structures of head and neck region because of their high T2 properties. CONCLUSION: Solid parathyroid lesions had higher diffusion properties comparing other soft tissues structures of head and neck region. This feature makes them easily differentiate from nearby structures on fat-saturated T2W and DWI.

Diffusion tensor imaging findings of the brainstem in subjects with tonsillar ectopia.

We aimed to evaluate the differences between apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) values obtained from different cranial sites in subjects with Chiari I Malformation (CM-I) and borderline tonsillar ectopia (BTE), and to determine correlations between diffusion tensor imaging (DTI) metrics and the severity of tonsillar ectopia. A total of 73 subjects with CM-I and BTE and 35 control underwent MRI and DTI. In our study, ADC values measured from the level of medulla oblongata and the RD values measured in middle cerebellar peduncles, thalamus, and globus pallidus were higher in CM-I patients than in controls. FA values at the medulla oblongata level and AD values at the medulla oblongata and pons level higher in patients with CM-I. ADC and AD values measured at the pons level were higher in BTE subjects than in controls. Compared with BTE, the CM-I subjects' ADC values at the medulla oblongata and AD values at the pons level were higher. In addition, FAs at the pons and medulla oblongata level were higher. At the medulla oblongata level, a positive correlation was observed between ADC and the size of tonsillar ectopia. AD and FA values measured at the level of medulla oblongata and pons were positively correlated with the size of tonsillar ectopia. These findings may be related to the severity of microstructural changes involving neuronal tracts at the brainstem level due to tonsillar ectopia. DTI may be useful in determining the extent of microstructural changes at the tissue level in subjects with tonsillar ectopia.

Relationships of DTI findings with neurocognitive dysfunction in children with Type 1 diabetes mellitus.

OBJECTIVE: To determine whether there were diffusion tensor imaging (DTI) changes in the brain among children with Type 1 diabetes mellitus (DM) and investigate the correlation between the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and neurocognitive functions. METHODS: 35 children with Type 1 DM and 21 age-matched healthy control subjects were included. Neurocognitive functions of subjects with Type 1 DM were evaluated. In both groups, FA and ADC values were calculated in 20 different locations. The association between neurocognitive function tests and FA and ADC values was investigated. RESULTS: Subjects with diabetes had significant changes in FA and ADC values in widespread brain regions compared with the healthy control group. ADC values in the caudate nucleus were negatively associated with verbal point. Increased ADC values in the genu of the corpus callosum were positively associated with Stroop test. There was a negative correlation between the ADC values of the parietal white matter and the judgment of line orientation test. FA values of the inferior longitudinal fasciculus were positively correlated with performance point. However, a negative correlation was noted between FA values of mid-brain and intelligence quotient level as well as another negative correlation between FA values of the posterior crus of the internal capsule and thalamus with verbal point. CONCLUSION: Subjects with diabetes demonstrated significant changes in FA and ADC values in widespread brain regions, and such changes could be early features of injury to myelinated fibres or axonal degeneration. Our findings suggest that brain damage may have begun at the cellular level in the initial stage of Type 1 diabetes and neurocognitive impairments may be inevitable. ADVANCES IN KNOWLEDGE: DTI can demonstrate ADC and FA changes which are well correlated with neurocognitive dysfunction in the brains of children with Type 1 DM. This may help us in guiding preventive measures in early period of the disease before deterioration of neurocognitive functions.

Microstructural effects of Ramadan fasting on the brain: a diffusion tensor imaging study.

PURPOSE: We aimed to examine whether the brain displays any microstructural changes after a three-week Ramadan fasting period using diffusion tenson imaging. METHODS: This study included a study and a control group of 25 volunteers each. In the study group, we examined and compared apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the participants during (phase 1) and after (phase 2) a period of fasting. The control group included individuals who did not fast. ADC and FA values obtained in phase 1 and phase 2 were compared between the study and control groups. RESULTS: In the study group, ADC values of hypothalamus and, to a lesser extent, of insula were lower in phase 1 compared with phase 2 and the control group. The FA values of amygdala, middle temporal cortex, thalamus and, to a lesser extent, of medial prefrontal cortex were lower in phase 1 compared with phase 2 and the control group. Phase 2 ADC and FA values of the study group were not significantly different compared with the control group at any brain location. CONCLUSION: A three-week Ramadan fasting period can cause microstructural changes in the brain, and diffusion tensor imaging enables the visualization of these changes. The identification of brain locations where changes occurred in ADC and FA values during fasting can be helpful in diagnostic imaging and understanding the pathophysiology of eating disorders.

Radiologic findings of idiopathic granulomatous mastitis.

AIM: To describe the radiological findings of idiopathic granulomatous mastitis (IGM). MATERIAL AND METHODS: Radiologic findings of 30 women with histopathological diagnosis of IGM were retrospectively evaluated. All had breast feeding history. All the patients had ultrasonography (US), with 12 of them having additional Doppler US. Of 30 patients, 11 had mammography (MG) and 5 MRI. RESULTS: US showed multiple irregular hypoechoic masses and collection areas with tubular connections in 25 of 30. The collection area with low-level internal echoes but without tubular connections, suggesting an abscess were seen in 2 of 30 (6.6%); a hypoechoic mass with an indistinct border in 2 of 30 (6.6%); multiple milimetric hypoechoic nodular masses in 1 of 30 (3.3%). On MG, normal findings were noted in 5 (45.4%); focal asymmetric density in 4 (36.4%), parenchymal distortion in 1 (9%) and diffuse asymmetric opacity with trabecular thickening in 1 (9%) of 30 patients. On MRI, segmental T2 hyperintensity with contrast-enhancement on T1 were seen in 4 of 5 (80%). An enhancing T2 hypointense mass with irregular margin was present in 1 of 5 (20%). Time-signal intensity curve of lesions showed slow enhancement in 1 and moderate in 4 of 5 patients. CONCLUSIONS: In IGM, MG findings were nonspecific. In US, multiple irregular hypoechoic masses and collections with tubular connections with fingerlike aspects, and fistulae formation to the skin in patients with breastfeeding history suggested IGM rather than carcinoma. Due to the limited number of patients, no conclusion was reached regarding MRI of IGM.

Susceptibility weighted imaging features of nonketotic hyperglycemia: unusual cause of hemichorea-hemiballismus.

Nonketotic hyperglycemia has been described as a metabolic cause of Hemiballism-hemichorea (HB-HC), especially in elderly patients with poorly controlled diabetes. Pathophysiology is not known yet. MRI features tend to be hyperintense in the putamen on T1-weighted images. We present conventional MRI with diffusion weighted imaging (DWI) and susceptibility weighted imaging (SWI) features of two cases with nonketotic hyperglycemia. T1 hyperintensity without diffusion restriction on DWI and minimal putaminal hypointensity without phase shift on SWI were compatible with either pathological mineralization or petechial microhemorrhage or protein denaturation. In the type 2 diabetic patients with HC-HB, conventional MRI together with SWI and DWI will guide to clinician to plan treatment approach.

Magnetic resonance spectroscopy features of Heschl's gyri in patients with unilateral acoustic neuroma: preliminary study.

RATIONALE AND OBJECTIVES: To evaluate neurochemical alterations in Heschl's gyri and determine the most affected side in case of unilateral acoustic neuroma using magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: Fifteen patients with unilateral acoustic neuroma were studied. Following routine cranial MRI sequences, MRS of Heschl's gyri on tumor and nontumor sides was obtained. MRS metabolite values of both Heschl's gyri were statistically compared. RESULTS: The values of N-acetylaspartate (NAA) and Cr on nontumor side Heschl's gyrus (HG) were significantly lower than that on tumor side. CONCLUSIONS: We found nontumor side HG more affected with lower NAA and Cr values, suggesting neuronal damage and decreased energy metabolism compared to the tumoral side.

CSF otorhinorrhea in a child with inner ear dysplasia: diagnosis with T2-weighted and intrathecal contrast-enhanced MR cisternography.

During the follow-up of recurrent pneumonia in a 9-month-old girl, rhinorrhea with discharge of a positional and intermittent nature was discovered. Radiological assessment was requested to detect any skull base openings and cerebrospinal fluid (CSF) leakage. T2-weighted MR cisternography showed bilateral inner ear dysplasia, communication of the internal auditory canal with the vestibule, and effusion in the right middle ear. Intrathecal contrast-enhanced MR cisternography revealed a CSF fistula from the right internal auditory canal to the Eustachian tube. The patient was operated upon on the right side, and the presence of a CSF leak near the oval window was confirmed. No adverse effects were seen during the short-term and long-term follow-up. Diagnosing this case required special attention, careful examination, and relevant investigations to find the site of CSF leakage in this patient with bilateral inner ear dysplasia.