3D structural complexity analysis of cerebellum in Chiari malformation type I.

Chiari malformation type I (CM-I), described by a descent of the cerebellar tonsils, is assumed to be a neurological developmental disorder. The aim of the present study was to investigate morphological variance in cerebellar sub-structures, including gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF), using magnetic resonance (MR) images with three-dimensional (3D) fractal dimension (FD) analysis in patients with CM-I. MRI data of 16 patients and 15 control subjects were obtained, and structural complexity analyses were performed using a box-counting FD algorithm. Results showed that patients with CM-I had significantly reduced FD values for WM and CSF in comparison with controls, and statistically significant differences in cerebellar GM and CSF volumes between patients and controls were found. Moreover, a significant difference was not found between the WM volumes. This may suggest that there are changes in structural complexity in WM even when its volume is unaffected. We conclude that the findings of this preliminary study indicate the possibility of using FD analysis to understand the pathophysiology of CM-I in patients.

The Avaibility of Strain Elastography in a Hydatid Cyst - Interobserver Study.

BACKGROUND: To differentiate the hydatid cyst (HC) types by ultrasound elastography using two different sizes (4 mm and 8 mm) of the region of interest (ROI) and asking two different radiologists (interobserver) for their opinion. MATERIAL/METHODS: Patients with HC were evaluated by USG elastography. The statistical anayses were performed using Strain index (SI) which is the unit of strain elastography. RESULTS: A total of 26 out of 33 patients were female, and 7 were male. The mean age was 38.85±17.62 (range from 10 to 72 years). Type I: 6, Type 2: 6, Type III: 6, Type IV: 11, Type V: 4. There was no significant difference in HC SI (regardless of types) between O1 and O2, and 4-mm and 8-mm ROI (p>0.05). There was no statistically significant difference between SI of HC types of interobservers (O1-O2) and ROI sizes (4-8 mm) (p>0.05 for all parameters). The highest correlation between HC types and ROI sizes was in ROI size of 4 mm. CONCLUSIONS: The correlation between SI and types was reliable in standard-applied 4-mm ROI. There was no statistically significant difference between interobservers in SI values. Thus, elastography tecnhnique is objective for HC but not appropriate to differentiate the types.

Cardiac Computed Tomography versus Echocardiography in the Assessment of Stenotic Rheumatic Mitral Valve.

PURPOSE: There are different clinical cardiac applications of dual source computed tomography (DSCT). Here, we aimed to compare the DSCT with the transthoracic echocardiography (TTE) for evaluating the Wilkins score and planimetric mitral valve area (MVA) of a rheumatic stenotic mitral valve. MATERIALS AND METHODS: We prospectively evaluated mitral valvular structure and function in 31 patients with known mitral stenosis undergoing electrocardiogram-gated, second-generation DSCT, in our heart center for different indications. Mitral valve was evaluated using Wilkins score, and also, the planimetric MVA was assessed. RESULTS: We found a significant difference between MVAs determined by DSCT (average 1.42 ± 0.44 cm2) and MVAs determined by TTE (average 1.35 ± 0.43 cm2 ; difference 0.07 ± 0.16 cm2; P = 0.018). Linear regression analysis revealed a good correlation between the two techniques (r = 0.934; P < 0.0001). The limits of agreement for DSCT and TTE in the Bland-Altman analysis were ±0.31 cm2 . DSCT using TTE as the reference enabled good discrimination between mild and moderate-to-severe stenosis and had an area under the ROC curve of 0.967 (CI 0.912-1.023; P < 0.0001). Wilkins scores obtained by DSCT (7.51 ± 1.17, range 5-10) and TTE (8.16 ± 1.27, range 6-10) had a moderate correlation (r = 0.686; P < 0.0001). CONCLUSION: We found that planimetric MVA measurements assessed by DSCT were closely correlated with MVA calculations by TTE. The moderate correlation was observed for the Wilkins score.

A new computer-tomography-based method of sex estimation: Development of Turkish population-specific standards.

The identification of victims involved in mass fatality incidents has become an increasingly important issue nowadays, and identification of unknown individuals is an important aspect in criminal cases and Disaster Victim Identification scenarios. Therefore, the sex estimation is one of the most important biological attributes towards establishing personal identity. In addition, several studies have demonstrated that metric sex determination methods of the skeleton are population-specific due to variation in size and patterns of sexual dimorphism. Unfortunately, the modern Turkish population still lacks wide and representative population standards for identification. Previous research has shown that modern technologies, such as CT scanning appear to offer promising means for the establishment of new standards for contemporary populations. The main aim of this project is to examine the application of measurements taken from the femur in order to assess sex, as well as to contribute to the establishment of discriminant function equations for the Turkish population for forensic applications. The sample population was composed of CT images taken from 200 adult hospital patients. The images of the femora were segmented from the surrounding bones to ensure correct usage of landmarks as accurately as possible. The 3D reconstructions were then created using the volume-rendering function in OsiriX (v.5.6.). Thirteen measurements were acquired using a 3D viewer and were located and marked on each of the CT reconstructed femora. Thirteen anthropometric parameters were measured and analysed by basic descriptive statistics and discriminant analysis methods using the SPSS 21.0 software package. The intra-observer variation was assessed by obtaining the inter-cross correlation coefficient in order to evaluate the accuracy of the linear measurements taken. The accuracy of sex prediction ranged from 63.5 to 88% with single variables. In stepwise analysis, Epicondylar Breadth, Femur Vertical Diameter of Neck and Medial Lateral Subtrochanteric Diameter were found to be the most discriminating variables providing an accuracy of 91%. Ultimately, it is envisaged that this research study will produce data and interpretations that will inform on and improve standards of sex estimation from postcranial osteometric landmarks. Additionally, this research will consider how this data provides value for a developing discipline of forensic anthropology and how it integrates within the existing systems of criminal investigation and Disaster Victim Identification practices in Turkey.

Fractal dimension analysis of cerebellum in Chiari Malformation type I.

Chiari Malformation type I (CM-I) is a serious neurological disorder that is characterized by hindbrain herniation. Our aim was to evaluate the usefulness of fractal analysis in CM-I patients. To examine the morphological complexity features of this disorder, fractal dimension (FD) of cerebellar regions were estimated from magnetic resonance images (MRI) of 17 patients with CM-I and 16 healthy control subjects in this study. The areas of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) were calculated and the corresponding FD values were computed using a 2D box-counting method in both groups. The results indicated that CM-I patients had significantly higher (p<0.05) FD values of GM, WM and CSF tissues compared to control group. According to the results of correlation analysis between FD values and the corresponding area values, FD and area values of GM tissues in the patients group were found to be correlated. The results of the present study suggest that FD values of cerebellar regions may be a discriminative feature and a useful marker for investigation of abnormalities in the cerebellum of CM-I patients. Further studies to explore the changes in cerebellar regions with the help of 3D FD analysis and volumetric calculations should be performed as a future work.

Comparison of different strategies of ivabradine premedication for heart rate reduction before coronary computed tomography angiography.

OBJECTIVE: The aim of this study was to assess the effectiveness and safety of different strategies of ivabradine therapy by comparing the effects on heart rate (HR), blood pressure (BP), and image quality of coronary CT angiography (CTA). METHODS: A total of 192 consecutive patients were randomly assigned to 3 groups of oral premedication with ivabradine 15 mg (single dose), 10 mg (single dose), and 5 mg twice daily for 5 days, prospectively. Patients using HR-lowering drugs and patients with ß-blockade contraindication were excluded. The target HR was 65 beats/min. In addition 5 to 10 mg of intravenous metoprolol was administered to the patients at the CT unit, if required. The systolic and diastolic blood BP values and the HRs were recorded. Image quality was assessed for 8 of 15 coronary segments with a 4-point grading scale. Results were compared with the Kruskal-Wallis test, one-way ANOVA, and χ2 test. RESULTS: Reductions in mean HR after the treatment were 18 ± 6, 14 ± 4, and 17 ± 7 beats/min for groups 1, 2, and 3, respectively. With the total additional therapies, 81.3%, 67.2%, and 84.3% of the patients achieved HR < 65 beats/min in groups 1, 2, and 3, respectively. The mean BP values before coronary CTA were not significantly changed except for patients in group 2. Unacceptable (score 0) image quality was obtained in only 4.5%, 10.2%, and 4.2% of all the coronary segments, in groups 1, 2, and 3, respectively. CONCLUSIONS: Our study indicates that coronary CTA with premedication with oral ivabradine in all 3 strategies is safe and effective in reducing HR, in particular with a ß-blockade combination. All 3 ivabradine regimes may be an alternative strategy for HR lowering in patients undergoing coronary CTA. Ivabradine 15 mg (single dose) and ivabradine 5 mg twice daily for 5 days are superior to the ivabradine 10-mg single-dose regime for HR lowering without adjunctive intravenous ß-blocker usage.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

OBJECTIVES: Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. METHODS: Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. RESULTS: A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. CONCLUSIONS: In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.

Comparison of diagnostic value of multidetector computed tomography and X-ray in the detection of body packing.

OBJECTIVE: Radiologists and other clinicians are facing an increasing number of illegal drug-related medical conditions. We aimed to draw attention to this growing global problem and to highlight some of the important points related to diagnosis and follow-up of body packing. We compare the diagnostic performance of unenhanced multidetector CT (MDCT) and abdomen X-ray for the detection of drug-filled packets. MATERIALS AND METHODS: Sixty-seven suspects, who underwent both CT and X-ray examinations, have been included in the study. All MDCT and X-ray images were independently and retrospectively reviewed by two observers with different degrees of experience in abdomen imaging. Fifty-two of them were identified as body packers finally. Interobserver agreement, sensitivity, specificity, positive and negative predictive value were calculated. RESULTS: Two types of packets with different characteristics were identified in all body packers. Type 1 packets (solid-state drug) were found in 41 patients and type 2 packets (liquid cocaine) in 11 patients. All statistical analyses concern the detection of any packets. That is, the whole evaluation has been performed per patient. Sensitivity/specificity values of type 1 and type 2 packets for MDCT were 100-98%/100-100% and 100-100%/100-100%, respectively. Besides, sensitivity/specificity values of type 1 and type 2 packets for X-ray were 93-90%/100-91% and 64-45%/73-71%, respectively. In addition, interobserver agreements for detection of any packets were excellent (κ=0.96) and good (κ=0.75) for interpretation of MDCT and X-ray, respectively. CONCLUSION: Unenhanced MDCT is a fast, accurate and easily used diagnostic tool with high sensitivity and specificity for the exact diagnosis of body packing.

Detection of body packing by magnetic resonance imaging: a new diagnostic tool?

PURPOSE: In this study, we aimed to describe non-contrast abdominal MRI findings in body packers and emphasize the role of this imaging technique in diagnosis of body packing. MATERIALS AND METHODS: Non-contrast abdominopelvic MRI was performed at the radiology department in 16 suspected body packers that were brought to our hospital, and 13 of them were diagnosed with body packing. We evaluated the presence, location, and shapes of packets as well as signal characteristics on T1- and T2-weighted images. RESULTS: We came across two types of packets: those containing solid substances (10 cases) and those filled with liquid cocaine (3 cases). Both types were accurately diagnosed with the help of MRI. Only 1 suspected body packer received a false positive diagnosis. CONCLUSION: Abdominopelvic MRI is a reliable and valuable method of diagnosing body packing.

Anastomoses of the vestibular, cochlear, and facial nerves.

The internal auditory canal (IAC) is 10 to 17 mm in length, and the facial nerve and vestibulocochlear nerve, which consist of the cochlear nerve, the superior vestibular nerve, and the inferior vestibular nerve, run together in the IAC packaged in dura mater. Oort first described the vestibulocochlear anastomoses in 1918, which is important for the understanding of the pathogenesis and pathophysiology of otologic disorders. The current study documents the existence of vestibulofacial and vestibulocochlear neural connections and topographical relationship of the nerves as part of a radiologic evaluation of 73 human temporal bones from brainstem to the lateral portion of IAC.

Direct venous spinal reabsorption of cerebrospinal fluid: a new concept with serial magnetic resonance cisternography in rabbits.

OBJECT: For nearly 100 years it has been believed that the main reabsorption of CSF occurs in arachnoid projections into the superior sagittal sinus, but a significant number of experiments and cases conflict with this hypothesis. According to recently published studies, CSF is permanently produced and absorbed in the whole CSF system. Clusters of arachnoidal villi, which are speculated to have a role in the reabsorption of CSF, have recently been revealed in the dorsal root of the spinal nerves. Huge absorptive surface areas of microvessels have been suggested to serve a putative role in reabsorption. The authors' aim was to observe direct venous connections between the subarachnoid space and the perispinal veins. METHODS: Eleven adult (6 months old) New Zealand white male rabbits weighing approximately 3.0 kg each were used in this experiment. After obtaining precontrast MR cisternography images, subarachnoid access was gained percutaneously via a cisternal approach by using a 20-gauge intravenous indwelling cannula. One rabbit died as a result of brainstem trauma during percutaneous cannulation before contrast administration, but contrast agent was still injected to see the possible MR imaging results of spinal CSF reabsorption after death. Magnetic resonance imaging was performed at 15, 60, 120, and 180 minutes after the administration of contrast agent. After intramuscular injections of anesthetic, 2 rabbits died 120 and 150 minutes after contrast injection, but the MR imaging study at 180 minutes after contrast injection was still performed. RESULTS: Direct connections between the subarachnoid space and the perispinal veins were observed in all rabbits during serial MR cisternography. The enhancement power was not affected by the amount of injected contrast agent or by cervical or lumbar penetration but was increased at higher contrast concentrations or upon seizure (physical activity). CONCLUSIONS: Extracranial reabsorption of CSF has been finally proved with direct radiological confirmation of spinal venous reabsorption of CSF using serial MR cisternography. The authors believe that this study can help to develop a more accurate model of CSF dynamics, which will allow understanding of many CSF-related diseases, as well as the development of new strategies for treatment.

Non-invasive diagnosis of stress urinary incontinence sub types using wavelet analysis, shannon entropy and principal component analysis.

Urinary incontinence is a common female disorder. Although generally not a serious condition, it negatively affects the lifestyle and daily activity of subjects. Stress urinary incontinence (SUI) is the most versatile of several incontinence types and is distinguished by physical degeneration of the continence-providing mechanism. Some surgical treatment methods exist, but the success of the surgery mainly depends upon a correct diagnosis. Diagnosis has two major steps: subjects who are suffering from true SUI must be identified, and the SUI sub-type must be determined, because each sub-type is treated with a different surgery. The first step is straightforward and uses standard identification methods. The second step, however, requires invasive, uncomfortable urodynamic studies that are difficult to apply. Many subjects try to cope with the disorder rather than seek treatment from health care providers, in part because of the invasive diagnostic methods. In this study, a diagnostic method with a success rate comparable to that of urodynamic studies is presented. This new method has some advantages over the current one. First, it is noninvasive; data are collected using Doppler ultrasound recording. Second, it requires no special tools and is easy to apply, relatively inexpensive, faster and more hygienic.

Multidetector CT angiography versus arterial duplex USG in diagnosis of mild lower extremity peripheral arterial disease: is multidetector CT a valuable screening tool?

OBJECTIVE: To prospectively compare the efficacy of 40-row multidetector computed tomography angiography (MDCTA) and duplex ultrasonography (DUS) to diagnose mild peripheral arterial occlusive disease (PAOD) in lower leg and to search whether MDCTA can be used as a screening tool. METHODS: Forty-three patients with intermittent claudication and leg pain, diagnosed as mild PAOD, had undergone DUS and MDCTA of lower limb. The arteries of lower leg were initially scanned by DUS, followed by MDCTA. Both modalities were compared for detecting the obstructed and stenotic segments. RESULTS: A total of 774 vessel segments were imaged by both modalities. When all arteries were considered, MDCTA detected obstructed or stenotic lesions in 16.8% of arteries, versus 11.1% compared to DUS. When suprapopliteal arteries alone were considered, MDCTA detected lesions in 15.0% of arteries, versus 11.0% with DUS. When infrapopliteal arteries only were considered, MDCTA detected lesions in 19.6% of arteries, versus 11.3% with DUS. MDCTA showed 5.7% (95% CI: [3.5%, 7.9%]) more lesions than DUS when all arteries were considered together, 8.3% (95% CI: [4.6%, 12.0%]) more lesions when only the infrapopliteal arteries were compared, and 4.0% (95% CI: [1.3%, 6.8%]) more lesions when only suprapopliteal arteries were compared (p<0.01 for all comparisons). CONCLUSION: 40-row MDCTA may be used as a screening tool in patients with mild lower extremity PAOD as it is a non-invasive and more accurate modality when compared to DUS.

A Radiological Study on the Topographical Relationships between the Vestibular, Cochlear and Facial Nerves.

OBJECTIVE: The purpose of our study was to investigate the topographical relationship between these nerves along their course from the brainstem through the internal acoustic canal IAC in the living human brain using MR imaging. MATERIALS AND METHODS: We performed three-dimensional gradient echo balanced Fast Field Echo (3D bFFE) sequence oblique parasagittal MR imaging in 73 healthy subjects. The IACs were analyzed from the brainstem end of the IAC to the fundus in contiguous sections. At five levels, the topographical relationships between the facial and vestibulocochlear nerves (VCN) were recorded. In the lateral portions of the IACs where they separated from each other, the relative sizes of the individual nerves were examined. RESULTS: In general, the facial nerve (FN), which is a round structure, is located anteriorly and superiorly to the vestibulocochlear nerve throughout its course. The vestibulocochlear nerve is usually rectangular; however, it was found to be round and at times triangular in shape near the brainstem, before it became crescent-shaped at the porus in 89% of the cases. The superior vestibular nerve kept its posterosuperior position in the canal, and the inferior vestibular nerve (IVN) and the cochlear nerve (CN) travelled inferior to it. The superior and inferior vestibular nerves were divided by the falciform crest in 53% of the cases. The inferior vestibular nerve was the smallest nerve in 52% of the cases, and the cochlear nerve was the largest in 36% of the cases. CONCLUSION: To the best of our knowledge, this study is the largest in vivo MR study, and most of our findings differ from previous cadaver studies. Determination of these topographical relationships may facilitate our understanding of the complicated physiological relationships between the 7(th) and 8(th) nerve complexes during surgery in this region.

Focal nodular hyperplasia vs. hemangioma: computed tomography and magnetic resonance imaging findings.

Focal nodular hyperplasia (FNH) and hemangioma are benign and generally asymptomatic hepatic tumors. With distinctive imaging findings on dynamic computed tomography (CT) and magnetic resonance imaging (MRI), differentiation of these benign hepatic tumors from metastases can be made. We described imaging findings of these hepatic lesions in a 57-year-old man who presented with rectal adenocarcinoma for staging.

Clinical evaluation and power Doppler sonography in rheumatoid arthritis: evidence for ongoing synovial inflammation in clinical remission.

OBJECTIVE: This study proposed to assess the relationship between power Doppler ultrasound examination and spectral Doppler analysis of hand joints with clinical and laboratory parameters in rheumatoid arthritis. METHODS: Patients receiving disease-modifying antirheumatic drugs or biologics (infliximab) underwent joint examination and were assessed by a Health Assessment Questionnaire, Duruoz's Hand Index, and Hand Function Test. All were categorized for disease activity using the American College of Rheumatology and disease activity score 28-joint (DAS28) criteria. Ten metacarpophalangeal joints and 4 wrist joints (ulnar-carpal and radiocarpal joints) in each patient were examined by power Doppler and spectral Doppler. Flow signal in the synovium was semiquantitatively graded. A cumulative flow signal score (CFS) and mean resistive index (RI) was calculated in each patient. RESULTS: Patients with active disease had significantly higher CFS compared with patients with inactive disease, but the mean RI was similar. Health Assessment Questionnaire, Duruoz's Hand Index, Larsen, and DAS28 scores correlated significantly with CFS, but the erythrocyte sedimentation rate and C-reactive protein scores did not. Mean RI did not correlate with clinical or laboratory parameters. A majority of patients who were in clinical remission according to American College of Rheumatology or DAS28 criteria had ongoing synovial inflammation on power Doppler ultrasound (58% and 62%, respectively). CONCLUSION: Power Doppler examination of rheumatoid hand joints is a practical method to estimate synovial inflammation. A modification of current remission criteria by combining imaging techniques with clinical and laboratory examination may be conceivable. These results underscore the necessity of more sophisticated research, assessing the agreement between long-term Doppler changes and clinical parameters.

Detection of bladder tumors with 3-dimensional sonography and virtual sonographic cystoscopy.

OBJECTIVE: Bladder tumors are among the most common types of malignant neoplasms of the urinary tract. The purpose of this study was to evaluate the potential value of 3-dimensional (3D) sonography and sonographic cystoscopy in detection of bladder tumors. METHODS: Thirty-one patients with suspected or known bladder tumors were included this study. All patients underwent 3D sonography and conventional cystoscopy within 15 days. The number, size, location, and morphologic features of the lesions were evaluated on gray scale, 3D virtual, and multiplanar reconstruction images obtained from the patients. The results of 3D sonographic cystoscopy were compared with the findings from conventional cystoscopy, which was considered the reference standard. RESULTS: Twenty-eight (90.3%) of 31 3D virtual sonographic cystoscopic studies had good or excellent image quality. Conventional cystoscopy revealed 47 lesions in 22 of 28 patients; 3D sonographic virtual cystoscopy showed 41 (87.2%) of 47 lesions. Three-dimensional virtual sonography alone had sensitivity of 96.2%, specificity of 70.6%, a positive predictive value of 93.9%, and a negative predictive value of 80% for tumor detection. The combination of gray scale sonography, multiplanar reconstruction, and 3D virtual sonography had sensitivity of 96.4%, specificity of 88.8%, a positive predictive value of 97.6%, and a negative predictive value of 84.2% for tumor detection. CONCLUSIONS: Three-dimensional sonography is a promising alternative noninvasive technique for use in detection of bladder tumors, their localization, and perivesical spreading. The location, size, and morphologic features of the tumors shown on 3D sonography agreed well with the findings of conventional cystoscopy.