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Nevzat Karabulut

Publications and source records attributed to Nevzat Karabulut.

At least 19 recordsLinked to original sources
PubMed2006

Diffusion-weighted MR imaging of viral encephalitis.

INTRODUCTION: The aim of this study was to evaluate the role of diffusion-weighted imaging (DWI) in the diagnosis of viral encephalitis and its relationship with the stage of the illness. METHODS: We performed conventional magnetic resonance imaging (MRI) including T1-W, T2-W and fluid attenuated inversion recovery (FLAIR) sequences and DWI in 18 patients with viral encephalitis diagnosed on the basis of laboratory, clinical and radiologic findings. Based on the qualitative and quantitative comparison of the conventional MRI and DWI, the patients were divided into three groups. Apparent diffusion coefficient (ADC) values of the involved and contralateral normal brain tissues were computed and compared for each group. The degree of correlation between the time (TI) from the onset of neurologic symptoms to the MR examination and ADC values was determined. RESULTS: In group I (n=11) DWI was superior to conventional MRI in detecting the encephalitic involved sites and in depicting the borders of the encephalitic lesions. In group II (n=4) DWI was similar to conventional MRI. In group III (n=3) conventional MRI was superior to DWI. Mean ADC values of affected versus contralateral normal brain tissues were 0.458+/-0.161 x 10(-3) versus 0.86+/-0.08 x 10(-3) in group I, 0.670+/-0.142 x 10(-3) versus 0.93+/-0.07 x 10(-3) in group II, and 1.413+/-0.211 x 10(-3) versus 1.05+/-0.06 x 10(-3) in group III. Patients in group I had significantly lower ADC values than those in group II, while patients in group III had the highest ADC values (P<0.05). The ADC values were significantly lower in the affected sites than in the unaffected sites of patients in groups I and II, but were significantly higher in the affected sites than in the unaffected sites of patients in group III (P<0.05). There was an excellent correlation between ADC values and duration of the disease (r=0.874, P=0.01). CONCLUSION: DWI is superior to other conventional diagnostic MR sequences in the detection of early viral encephalitic lesions and depiction of the lesion borders and, in combination with other sequences, DWI may contribute to the determination of the disease phase.

Adolescent↗
PubMed2006

Sinus cut-off sign: a helpful sign in the CT diagnosis of diaphragmatic rupture associated with pleural effusion.

The objective of our study was to describe the "sinus cut-off" sign at CT in the diagnosis of diaphragmatic rupture in patients with blunt abdominal trauma complicated with pleural effusion, and evaluate its utility in an experimental model. Between January 2004 and March 2005, we observed an unusual interruption of costophrenic sinus at CT in three patients with blunt abdominal trauma accompanied with pleural effusion. This observation prompted us to evaluate the utility of this sign in an experimental model. Laparotomically, we created 2 cm diapragmatic lacerations at each hemidiaphragm in two rabbits and pushed up the abdominal viscera with omentum through the defect. To simulate hemothorax, we also injected 5-10 mL of diluted contrast material into the pleural space. Using a dual-slice helical CT scanner, limited thoracoabdominal CT examination was performed before and after injection of intrapleural contrast material. The images were analyzed for the presence of CT signs for diaphragmatic injury. The left posterior costophrenic sulcus was interrupted in all of the three patients with left pleural effusion. While it was associated with other findings of diaphragmatic injury, the "sinus cut-off sign" was the sole finding in one patient. The sinus cut-off sign was observed on the CT scans of 100% of the rabbits with a left and right sided diaphragmatic rupture. The "sinus cut-off sign" is useful and can increase the CT detection of acute diaphragmatic injury associated with pleural effusion.

Animals↗
PubMed2006

The basal and TRH stimulated levels of prolactin in low risk climacteric patients with increased breast density: a matched pair case control trial.

OBJECTIVE: To detect any significant alteration of basal and TRH stimulated circulating prolactin levels in those with an extremely dense breast composition as compared to ones with a fatty pattern in mammography in climacteric patients with a low risk probability for developing invasive breast cancer within five years according to a validated risk model. MATERIALS AND METHOD: In this matched pairs case-control trial a total of 67 climacteric patients with an extremely dense breast composition were compared to a control group of 71 climacteric patients with an almost entirely fat pattern composition in terms of basal and TRH stimulated circulating prolactin levels. All participants in the study had an estimated 5 years breast cancer risk less than 1.67% according to the validated model of Gail. Subgroup analysis was done according to menopausal status (premenopausal versus postmenopausal) and according to the hormone replacement therapy (HRT) in postmenopausal patients (current users of HRT versus never used HRT). RESULTS: We did not detect any statistically relevant differences between groups or subgroups in terms of basal, stimulated and Delta levels (stimulated-basal) of prolactin (ng/ml). The differences between groups of extremely dense composition versus almost fatty pattern in terms of DeltaPRL (ng/ml) (+/-S.D.) were not statistically significant (68.1+/-34.5 versus 69.1+/-43.0; unpaired t test, Welch corrected p=0.88, 95% CI -12.1 to 14.0). CONCLUSION: Our results do not suggest a contribution of circulating prolactin to increased mammographic density in climacteric patients with low risk probability to develop breast cancer. A study of similar kind is warranted in high risk patients.

Breast↗
PubMed2006

Variability of the pulmonary oblique fissures presented by high-resolution computed tomography.

The purpose of the study was to evaluate the radiological anatomy of oblique fissures (OFs) on high-resolution computed tomography (HRCT) scans. We retrospectively reviewed HRCT scans of 144 patients with normal lung parenchyma. The uppermost level of OFs with respect to the ribs, configuration (concave, straight, convex and others), orientation (medial or lateral facing), rotation and completeness of OFs were recorded. The most cranial level of the left OF was seen between the third and sixth ribs, and all but one were seen above or at the same level as the right OF. The uppermost extent of the OF was between the third and fourth intercostal space and seventh rib on the right lung. Only 2.2% of the right and 1.6% of the left OFs followed a parallel course to the ribs. The configuration of the OFs was generally concave in the upper zones (85.8% on the right and 72.1% on the left) and convex in the middle and lower lung zones (79.3% on the right and 73.9% on the left); 62.5% of the right and 59.7% of the left OFs were incomplete. Suprahilar portions of both OFs (98.9% on the right and 96.7% on the left) and the infrahilar portion of the right OF (54.2%) were generally facing laterally, whereas the infrahilar portion of the left OF was facing medially (80.9%). Angles of the MFs differed at the upper and lower levels. We detected reversal of 21 OFs in their craniocaudal course. In conclusion, the radiological anatomy of the right OF differs from the left OF. The uppermost extent of the left OF is almost always higher than the right. Thus, higher position of the right OF compared with the left almost always indicates a pathological process. Assessment of the angles of the OFs or comparison of the two sides cannot be used for the diagnosis of parenchymal disease like atelectasis. Occasionally, the classical propeller-like configuration is disrupted by the reverse course of the caudal part of the OF.

Adolescent↗
PubMed2006

Mycobacterial infection of intraparenchymal bronchogenic cysts.

Bronchogenic cysts (BCs) may rarely cause some interesting and unusual complications. Although infection is a common complication of BCs, there are only two patients with BC infected with mycobacterium in English literature. Two intraparenchymal BCs infected with mycobacterium are presented here as unusual complications. Cystectomy was performed for the cysts. They were given antituberculosis treatment. No complication or recurrences were detected in follow up period.

Adult↗
PubMed2006

Low dose CT: practices and strategies of radiologists in university hospitals.

PURPOSE: We surveyed the practices and policies of the radiology departments of academic institutions in Turkey regarding the use of low dose CT in daily practice. MATERIALS AND METHODS: Surveys were mailed electronically to radiology departments of 40 university hospitals. Information gathered included modifications of standard protocols for dose reduction according to body parts being examined or depending on specific patient groups such as children, pregnant, or slim patients. RESULTS: Thirty-three radiology departments (82%) responded. Twenty-eight (85%) reported that they modify CT scanning parameters in order to reduce the patient dose. Of these, 5 (18%) reported that they always modulate the scan parameters, 10 (36%) often, 11 (39%) sometimes, and 2 (7%) seldom. Reduced dose CT is applied mostly in pediatric and pregnant patients, reported by 93% and 57% of respondents, respectively. The most common body part for the application of low dose CT was chest examination followed by imaging of paranasal sinuses, abdomen, and CT-guided interventions. The most common modification for dose reduction is using low mA, followed by increasing the pitch value. CONCLUSION: Most respondents are aware of low dose CT, but the frequency of application varies considerably in routine practice. Reduced mA and increased pitch are the most commonly used modifications.

Dose-Response Relationship, Radiation↗
PubMed2006

Contrast agents used in MR imaging of the liver.

Several categories of contrast agents with different biodistributions are currently available for magnetic resonance imaging of the liver. They improve lesion detection and characterization by increasing lesion-liver contrast. These agents include nonspecific extracellular gadolinium chelates, reticuloendothelial system- specific iron oxides, hepatocyte-selective agents, and combined perfusion and hepatocyte-selective agents. This article describes the currently used contrast agents in magnetic resonance imaging of the liver, summarizes their mechanisms of action, biodistributions, and safety profiles. Additionally, it reviews their main clinical indications, administration and imaging techniques, and the appearances of common hepatic lesions in contrast-enhanced studies.

Contrast Media↗
PubMed2005

Fat-containing lesions of the liver: cross-sectional imaging findings with emphasis on MRI.

OBJECTIVE: The purpose of this pictorial essay is to identify different types of liver lesions that contain fat. Cross-sectional imaging findings of fat- or lipid-containing lesions can help in characterizing focal liver lesions. We searched our archive retrospectively and reviewed the literature for fat-containing liver lesions and identified 16 different types. CONCLUSION: These lesions can contain macroscopic fat (i.e., angiomyolipoma, lipoma, liposarcoma, hydatid cyst, lipopeliosis, adrenal rest tumor, pseudolipoma, hepatic teratoma, pericaval fat, extramedullary hematopoiesis, and metastases) or intracellular lipid (i.e., focal steatosis, adenoma, focal nodular hyperplasia, regenerative nodules, and hepatocellular carcinoma). CT, MRI, and sonographic findings of these lesions can help in characterization by allowing specific diagnosis or narrowing the differential diagnosis of liver lesions.

Diagnosis, Differential↗
PubMed2005

Clinical utility of sonography in diagnosing plantar fasciitis.

OBJECTIVE: The purpose of this study was to investigate the efficacy of sonography in the detection of plantar fasciitis (PF) compared with magnetic resonance imaging (MRI) findings in subjects with inferior heel pain. METHODS: Seventy-seven patients with unilateral (n = 9) and bilateral (n = 68) heel pain were studied. Seventy-seven age- and sex-matched asymptomatic subjects served as a control group. Magnetic resonance imaging was used to establish a diagnosis of PF with sagittal T1-weighted, T2-weighted, and short tau inversion recovery sequences. The sonographic appearances of PF were compared with MRI findings. Plantar fascia and heel pad thickness were also measured on both imaging modalities. RESULTS: Compared with MRI, sonography showed 80% sensitivity and 88.5% specificity in assessing PF. A strong correlation was found between plantar fascia and fat pad thickness measurements done by sonography (P < .001; r = 0.854) and MRI (P < .001; r = 0.798). Compared with the asymptomatic volunteers, patients with PF had significant increases in plantar fascia and heel pad thicknesses, weight, and body mass index (P = .0001). Heel pad thickness was also significantly increased with pain duration (P = .021). CONCLUSIONS: Although MRI is the modality of choice in the morphologic assessment of different plantar fascia lesions, sonography can also serve as an effective tool and may substitute MRI in the diagnosis of PF.

Adult↗
PubMed2004

Doppler waveform of the hepatic veins in an obese population.

The objective is to investigate the effect of obesity and hepatosteatosis on the Doppler waveform pattern of the hepatic veins. B-mode and duplex Doppler sonography of the liver and the right hepatic vein was performed in 102 obese subjects and 84 healthy volunteers. The severity of fatty infiltration was graded as mild, moderate and severe. The flow pattern of the right hepatic vein was classified as triphasic, biphasic and monophasic. The Doppler flow pattern in the right hepatic vein was triphasic in 56 (55%), biphasic in 27 (26%) and monophasic in 19 (19%) obese patients, whereas it was triphasic in 83 (99%) and biphasic in 1 (1%) control subject, achieving a statistical significance (Mann-Whitney U-test, P<0.001). There was an inverse correlation between the sonographic grade of the hepatosteatosis and the phasicity of hepatic venous flow (r=-0.67, P<0.001). The hepatic vein pulsatility is significantly dampened in obese patients correlating with the grade of hepatosteatosis. The body habitus itself does not have an independent effect on hepatic venous waveform. The alteration in hepatic vein Doppler flow pattern in an obese population may suggest reduced vascular compliance in the liver because of fatty infiltration.

Adult↗
PubMed2004

[Thoracopancreatic fistula: imaging findings (case report)].

Thoracopancreatic fistula is a rare complication of acute and chronic pancreatitis caused by an inflammatory or traumatic injury to the main pancreatic duct or side branches. Rupture of the duct into the pleura, pericardium, and mediastinum may present as a pancreaticopleural fistula, mediastinal pseudocyst, pancreaticobronchial or pancreticopericardial fistula. We present the imaging findings in a rare case of thoracopancreatic fistula caused by recurrent pancreatitis.

Bronchial Fistula↗
PubMed2003

Comparison of MR and PET imaging for the evaluation of liver metastases.

PURPOSE: To compare the accuracy of fluoro-18-deoxyglucose positron emission tomography (FDG-PET) and dynamic-enhanced magnetic resonance imaging (MRI) scans in the diagnosis of liver metastatic lesions from colon and other sources. MATERIALS AND METHODS: Thirty consecutive patients with known or suspected metastatic lesions were scanned by both MRI and PET. Histopathology and/or clinical outcome, including cross-sectional imaging follow up, were used as a gold standard. RESULTS: Of 30 patients, 16 were positive by pathology and/or clinical outcome and 14 were negative for liver metastases. The sensitivity, specificity, and positive and negative predictive values on MRI were 85.7%, 100%, 100%, and 89%, respectively, compared to 71%, 93.7%, 90.9%, and 79% on FDG-PET. The difference between the two methods was not significant (X(2) = 0.2, P > 0.05). CONCLUSION: Our study showed no significant difference in detection of liver metastases using MRI or FDG-PET. However, MRI has advantages in spatial resolution and lesion characterization.

Adenocarcinoma↗
PubMed2003

High signal peripancreatic fat on fat-suppressed spoiled gradient echo imaging in acute pancreatitis: preliminary evaluation of the prognostic significance.

PURPOSE: To evaluate peripancreatic signal changes on fat-suppressed T1-weighted spoiled gradient echo images associated with acute pancreatitis and investigate potential utility in regards to relationship to clinical outcome. MATERIALS AND METHODS: The abdominal MR images in 31 patients with acute pancreatitis were reviewed, and evaluated for the presence of elevated signal intensity within the peripancreatic fat on fat-suppressed T1-weighted spoiled gradient echo images; the degree of signal changes was graded as mild, moderate, or severe. RESULTS: Ten of 31 patients demonstrated abnormal high signal intensity in the peripancreatic fat on fat-suppressed T1-weighted images. The degree of signal change was mild in three patients, moderate in one, and severe in six patients. All six patients with severe elevated peripancreatic soft tissue signal died within seven to 68 days (mean, 47 days) of their admission. All 21 patients without elevated peripancreatic fat signal survived without any complications. The correlation between the presence and severity of elevated peripancreatic MR signal and patient outcome was significant (P < 0.05). CONCLUSION: Elevated peripancreatic signal on fat-suppressed T1-weighted images is associated progressively with poor outcome in patients with acute pancreatitis, and may represent a simplified method for prognostic cross-sectional imaging.

Acute Disease↗
PubMed2003

[Comparison of low dose and standard dose CT in the evaluation of inflammatory diseases of paranasal sinuses].

PURPOSE: The aim of this study was to investigate the diagnostic value of low dose CT (LDCT) by comparing the identification of sinonasal anatomical structures, anatomic variations and detectability of inflammatory changes at low and standard dose CT (SDCT). MATERIALS AND METHODS: A total of 30 patients who were referred to CT scan for the assessment of paranasal sinuses underwent CT examinations at both standard [110 mA, 120 kV, 5 mm collimation (3 mm collimation at the level of the ostiomeatal unit)] and low dose [22 mA, 120 kV, 5 mm collimation (3 mm collimation at the level of the ostiomeatal unit)]. All images were photographed at identical window settings (window width, 4000 HU; window level, 50 HU) on laser film. Ten sinonasal anatomical structures (five on the right and five on the left) and inflammatory mucosal changes were recorded for each patient. The detectability and conspicuity levels were scored for each finding. RESULTS: A total of 297 sinonasal anatomical structures were identified at SDCT, whereas 296 structures were detected at LDCT. Inflammatory mucosal changes and anatomical variations were equally identified at both SDCT and LDCT (p > 0.05). There was no statistically significant difference between SDCT and LDCT in the detection on of anatomical structures, variations and inflammatory changes (p > 0.05). CONCLUSION: The low dose CT protocol used in this study provided images of adequate quality, and proved to be reliable in the evaluation of normal and diseased paranasal sinuses.

Adolescent↗
PubMed2002

Comparison of low-dose and standard-dose helical CT in the evaluation of pulmonary nodules.

The purpose of this study was to investigate the diagnostic accuracy of low-dose helical computed tomography by comparing the number of nodules detected at low- and standard-dose CT. The prospective study included 25 patients who were referred to CT scan for the assessment of pulmonary metastases. All patients underwent CT examinations at both standard- (200 mA, 120 kV, collimation 5 mm, table feed 10 mm per rotation) and low-dose (50 mA, 120 kV, collimation 5 mm, table feed 10 mm per rotation). The number of nodules detected at each protocol was recorded. The size of the nodules was measured electronically and categorized as <3, 3-4.9, 5-6.9, 7-9.9, and >/=10 mm. Finally, the nodules detected at only standard- or low-dose CT were assessed for the underlying causes of discrepancy. In 25 patients, 533 nodules were detected at standard-dose, whereas 518 nodules were observed at low-dose CT. There were no statistically significant differences in the number of nodules detected at standard- or low-dose CT ( p>0.05). Four hundred ninety-one (87.7%) nodules were detected at both standard- or low-dose CT, 42 (7.5%) nodules were observed only at standard-dose CT, and 27 (4.8%) nodules were seen only at low-dose CT. The sensitivity of low-dose CT was 92.5% for all nodules, 88.1% for nodules <5 mm, and 97.4% for nodules >/=5 mm. No significant image artifact interfering with nodule detection was observed at low-dose CT. The low-dose CT protocol used in this study provided images of adequate quality; thus, it can be used reliably in the detection or exclusion of pulmonary nodules.

Female↗
PubMed2002

Renal involvement in multifocal osteosarcoma.

A rare case of multifocal osteosarcoma metastatic to kidney, lung and lymph nodes is presented. Radiological findings included multiple foci of sclerotic lesions involving the axial and peripheral skeleton, a heterogeneous renal mass with areas of calcification, multiple pulmonary metastases with pneumothorax, and partially calcified enlarged mediastinal and abdominal lymph nodes.

Bone Neoplasms↗
PubMed2002

Cervical osteochondroma as a cause of spinal cord compression in a patient with hereditary multiple exostoses: Computed tomography and magnetic resonance imaging findings.

Spinal cord compression is a rare but extremely serious complication of hereditary multiple exostoses (HME). Imaging of the spine is important for surgical planning and follow up. We present CT and MR findings in a male patient with HME who developed spinal cord compression from a cervical osteochondroma. Complete recovery was achieved following surgery.

Cervical Vertebrae↗