Biomedical subjects

N Cem Balci

Publications and source records attributed to N Cem Balci.

16 recordsLinked to original sources

PubMed2006

Serial contrast-enhanced MRI of the pancreas: correlation with secretin-stimulated endoscopic pancreatic function test.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the relationship between the pancreatic enhancement on serial contrast-enhanced MRI (CEMRI) and pancreatic exocrine function using the secretin-stimulated endoscopic pancreatic function test (ePFT). MATERIALS AND METHODS: A total of 30 patients with clinical symptoms consistent with chronic pancreatitis underwent CEMRI of the abdomen and ePFT within a 1- to 4-week interval. CEMRI was performed in arterial, early venous, and late venous phases. Secretin ePFT was performed with the measurement of HCO(3) concentration from the duodenal aspirates after secretin stimulation. Contrast enhancement ratio of the arterial phase to early venous phase was measured on CEMRI (SIRa/SIRv). A three-point evaluation system was used for grading the HCO(3) concentration and the enhancement ratio on MRI. For the significance of correlation, kappa statistics was used. Sensitivity and specificity of CEMRI was determined for the diagnosis of early chronic pancreatitis accepting ePFT as a reference. RESULTS: Twenty patients had identical scores on both secretin ePFT and CEMRI. Ten patients revealed discrepancy in scores. Kappa statistics revealed moderate agreement between MRI and ePFT (kappa = 0.44). Sensitivity and specificity values for the diagnosis of pancreatitis were 82% and 57%, respectively. Positive predictive value was 56%, and negative predictive value was 86%. CONCLUSION: The results of our data indicate that serial CEMRI is an appropriate imaging technique to rule out early chronic pancreatitis. However, secretin-stimulated imaging or ePFT may still be needed for the definite diagnosis of pancreatic exocrine dysfunction.

Adult↗

PubMed2006

Magnetic resonance imaging of the liver: how I do it.

The present paper provides a brief overview of the rationale behind magnetic resonance imaging (MRI) techniques, a description of the most common sequences used, and a general approach to performing liver MRI.

Humans↗

PubMed2005

Renal-related perinephric fluid collections: MRI findings.

We retrospectively reviewed MR studies on 10 patients with renal-related perinephric fluid collections who underwent MRI in three institutions between January 2001 and August 2004. All patients underwent MRI of the abdomen and T1-weighted, T2-weighted and serial contrast-enhanced images, including delayed-phase contrast-enhanced images 10-12 min after contrast injection, were obtained. Perinephric fluid collections in 5 patients revealed MRI findings of simple fluid content (i.e., hypointense on T1-weighted images and hyperintense on T2-weighted images). In another 5 patients, a complex perinephric fluid content (i.e., mixed hyper/hypointense on T1-weighted images and mixed hypo/hyperintense on T2-weighted images compatible with blood breakdown products and pus) was observed. In 5 patients, contrast extravasation on late-phase images that was compatible with urine leak was demonstrated. Our results suggest that MRI may determine the content of perinephric fluid collections on noncontrast T1-weighted and T2-weighted images and that contrast extravasation on late-phase images is associated with urine extravasation from renal collecting systems.

Adolescent↗

PubMed2005

Future horizons in MR imaging.

In this article, we defined the major areas of active research in clinical MR imaging. Further increases in the number of parallel coils within an imaging array and in advances in parallel imaging pulse sequences and postprocessing will lead to further reductions in imaging time analogous to the impact of multidetector CT on helical CT. The synergism between parallel and high-field imaging will aid the development of high-field imaging. The combined dynamic and hepatic parenchymal enhancement of new contrast agents that have or may soon receive FDA approval will enable improved detection and characterization of liver lesions. The lymphotropic SPIO agents will remain an active area of clinical research to further assess their role in oncologic staging. Molecular imaging contrast research using magnetic particles and MR microscopy will continue to flourish. Screening examinations by MR imaging will re-main an area of research for the short- and intermediate term, with the final outcome dependent more on socioeconomic costs than the underlying capability of achieving high-quality screening studies.

Contrast Media↗

PubMed2005

Contrast agents for MR imaging of the liver.

Imaging of the liver is performed most often to detect and characterize focal liver lesions. MR imaging has been the method of choice to assess focal liver lesions accurately. Nonspecific intravenous contrast agents have been used for routine abdominal MR imaging protocols including liver imaging. Over the last 10 to 15 years new contrast agents have been developed that combine the excellent contrast resolution of MR imaging with improved tissue specificity. This article reviews various contrast agents that are in clinical use for liver MR imaging and discusses their potential clinical role.

Contrast Media↗

PubMed2005

Focal lesions in normal liver.

A variety of lesions occur in the normal liver. This review will describe the most common benign, malignant, and infectious lesions. Illustration will be made of the magnetic resonance imaging (MRI) appearance of the most common of these. Due to the high accuracy for liver lesion detection and characterization, and the intrinsic safety of the modality, MR should be considered the primary imaging tool to investigate liver diseases.

Humans↗

PubMed2003

Juxtapapillary diverticulum: findings on MRI.

The purpose of our study was to describe the imaging findings of juxtapapillary diverticulum on magnetic resonance imaging (MRI). The MRI and magnetic resonance cholangiopancreatography (MRCP) examinations of 14 patients with juxtapapillary diverticula that were diagnosed on endoscopic retrograde cholangiopancreatography (ERCP) (N = 8) or endoscopy (N = 6) were retrospectively evaluated. T1-weighted spoiled gradient-echo, T2-weighted half Fourier single shot fast spin-echo (HASTE), and T2-weighted True FISP (fast imaging with steady state precession) images and thin-slice MRCP images were obtained on all patients. In five patients, diluted gadolinium DPTA (1/100) was used as an oral contrast. T2-weighted True FISP and HASTE images demonstrated air-fluid levels within all diverticula. Hyperintense oral contrast on T1-weighted spoiled gradient-echo images aided detection of the smaller diverticula. MRCP images obtained in the coronal plane best demonstrated the relationship of the diverticula to the papilla. MRI with the use of HASTE, True FISP, and oral contrast-enhanced T1-weighted sequences was able to depict juxtapapillary diverticula in our series.

Aged↗

PubMed2003

Assessment of the anomalous pulmonary circulation by dynamic contrast-enhanced MR angiography in under four seconds.

The purpose of this study was to demonstrate the initial results of the dynamic contrast-enhanced MRA in under four seconds in the assessment of anomalous pulmonary circulation. We performed dynamic contrast enhanced MRA on ten patients with a temporal resolution of 2-3 sec for each phase. Five patients had pulmonary vascular anomaly and five patients had reconstructed pulmonary circulation. On nine patients catheter angiography was performed for the correlation. Dynamic contrast-enhanced MRA successfully demonstrated congenital pulmonary vascular anomalies and the pathway of anomalous pulmonary circulation in our series. With the improved temporal and spatial resolution, the dynamic contrast-enhanced MRA can be used in children and infants for the assessment of congenital vascular disease.

Child↗

PubMed2002

Intrahepatic arterioportal fistula: demonstration by dynamic 3D magnetic resonance angiography in under four seconds.

We report a case of a 35-year-old patient with clinical symptoms of portal hypertension that underwent dynamic contrast-enhanced 3D magnetic resonance angiography (MRA) of the abdomen. On breath-hold dynamic contrast-enhanced MRA in less than 4 seconds, contrast passage from the arterial to the portal system was successfully demonstrated. Patient was managed according to MRA findings.

Adult↗

PubMed2002

Primary epiploic appendagitis: MRI findings.

Primary epiploic appendagitis (PEA) occurs secondary to inflammation of an epiploic appendage, and is considered to be a rare cause of acute abdomen. In this case report, we describe the magnetic resonance imaging (MRI) findings of PEA correlated with computed tomographic (CT) findings. MRI findings included an oval shaped fat intensity mass with a central dot on T1- and T2-weighted images, which possessed an enhancing rim on postgadolinium T1-weighted fat saturated images. The lesion was best visualized on postcontrast T1-weighted fat saturated images. MRI findings of PEA should be considered in the differential diagnosis with the other causes of acute abdominal pain.

Abdomen, Acute↗

PubMed2002

MR imaging of infective liver lesions.

This article discusses MR imaging of infective liver lesions including pyogenic liver abscesses, amebic liver abscesses, echinococcal disease, hepatic fungal abscesses, granulomatous hepatic infections, schistosomiasis, and fascioliasis.

Echinococcosis, Hepatic↗

PubMed2000

Neuroendocrine tumors of the pancreas: spectrum of appearances on MRI.

We reviewed our 8.5 year experience with magnetic resonance imaging (MRI) in the demonstration of neuroendocrine tumors of the pancreas using precontrast fat-suppressed T1-weighted, fat-suppressed T2-weighted, and serial post-gadolinium T1-weighted images, to describe the spectrum of appearances of these tumors. All MR examinations of patients with histologically proven neuroendocrine tumors were retrospectively reviewed. Histological type, tumor location, tumor diameter, signal intensity on precontrast images, enhancement patterns, and presence and appearance of metastases were determined. Twenty-two patients had histologically proved neuroendocrine tumors detected by MRI over the 8.5 year period. Histological types were gastrinoma (n = 8), insulinoma (n = 3), glucagonoma (n = 2), somatostatinoma (n = 1), VIPoma (n = 1), ACTHoma (n = 1), carcinoid (n = 1), and five untyped tumors. Primary tumors ranged in diameter from 1 to 6.2 cm. There was one histopathology-proven false-positive neuroendocrine tumor. The positive predictive value for MRI in the detection of these tumors was 96%. The most common appearance on precontrast images was low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, which was observed in tumors in 18 of 22 patients. Moderate or intense early enhancement of all or portions of the primary tumors was observed in tumors in 19 of 22 patients either as uniform homogeneous, ring, or diffuse heterogeneous enhancement. Enhancement was minimal on these images in the other three patients. Gastrinomas enhanced in a ring pattern in 7 of 8 patients whereas the majority (9 of 11 patients) of noninsulinoma-nongastrinoma and untyped tumors enhanced in a diffuse heterogeneous fashion. Liver metastases were present in 13/22 patients including 3/8 with gastrinoma and 9/11 with noninsulinoma-nongastrinoma tumors. Most neuroendocrine tumors of the pancreas are low signal intensity on fat-suppressed T1-weighted images and moderately high in signal intensity on fat-suppressed T2-weighted images, although variations do exist. Tumors most often enhance in an early moderately intense fashion. Gastrinomas are often different in appearance than other neuroendocrine tumors in that they usually enhance in a ring fashion whereas nongastrinoma-noninsulinoma tumors usually enhance in a heterogeneous fashion.

Adult↗

PubMed2000

Breath-hold 3D gradient-echo MR imaging of the lung parenchyma: evaluation of reproducibility of image quality in normals and preliminary observations in patients with disease.

This study evaluates the reproducibility and image quality of a three-dimensional (3D) gradient-echo sequence for imaging the lung parenchyma, with and without gadolinium administration, using a 2D spoiled gradient-echo sequence for comparison. Twenty patients without lung disease (normals) and five patients with lung disease (lung disease) underwent paired 2D and 3D gradient-echo sequences, without contrast (24 patients) and with contrast (18 patients). Images were retrospectively reviewed independently in a blinded fashion by two investigators. Artifacts and demonstration of central lung, peripheral lung, heart, pulmonary arteries, and esophagus were evaluated. Image quality of the central lung was rated as fair or good in 5 and 4 (reader one and two) patients with non-contrast 2D gradient-echo, 24 and 25 patients with non-contrast 3D gradient-echo, 3 and 1 patient(s) with contrast-enhanced 2D gradient-echo, and 19 and 19 patients with contrast-enhanced 3D gradient-echo imaging. Differences in image quality between 2D and 3D sequences were significant (P < 0.001). Heart-related phase artifacts were negligible in 2 and 0 patients with non-contrast 2D gradient-echo, 23 and 25 patients with non-contrast 3D gradient-echo, 0 and 0 patients with contrast-enhanced 2D gradient-echo, and 17 and 19 patients with contrast-enhanced 3D gradient-echo imaging. Differences in heart-related phase artifact in the central lung between 2D and 3D sequences were significant (P = 0.001). Infiltrates, lung cancer, and pulmonary metastasis were better shown on the gadolinium-enhanced 3D gradient-echo sequences than on the other sequences. Breath-hold 3D gradient-echo imaging results in good image quality and negligible image artifacts and is superior to 2D spoiled gradient-echo imaging. Preliminary results in patients with disease appear promising.

Artifacts↗

PubMedDate not supplied

Hepatic adenomatosis: MRI demonstration with the use of superparamagnetic iron oxide.

This case report describes a case of a 38-year-old woman with hepatic adenomatosis. MRI revealed five hyperintense nodular liver lesions on T1-weighted images which were hypo-isointense with the liver parenchyma on T2-weighted images. Serial gadolinium-enhanced images did not reveal distinctive imaging findings. With the use of superparamagnetic iron oxide (SPIO) particles, hyperintense adenomas revealed signal loss on T1-weighted images after SPIO. Two subcapsular adenomas were resected based on MRI findings and histopathology confirmed MRI diagnosis.

Adenoma↗

PubMedDate not supplied

Juxtapapillary diverticulum: findings on CT and MRI.

The purpose of this study was to evaluate the computed tomography (CT) and magnetic resonance imaging (MRI) features of juxtapapillary diverticulum. CT and/or MRI examinations of 12 patients were evaluated. The size, location of the diverticula and imaging findings of associated pancreaticobiliary disease were assessed. On CT, oral contrast air level was the characteristic imaging feature. On MRI, T2-weighted images demonstrated the air fluid level with hyperintense fluid and signal void air level above. Associated imaging findings were dilated common bile duct (CBD), cholecystitis, cholecystolithiasis and chronic pancreatitis.

Aged↗

PubMedDate not supplied

Hepatic angiomyolipoma: demonstration by out of phase MRI.

Hepatic angiomyolipoma is a rare liver pathology. In this case report, we describe MRI features of a hepatic angiomyolipoma with a high fat content, which was indeterminate on CT. In phase and out of phase T1-weighted spoiled gradient echo technique, T2-weighted fat suppressed fast spin echo technique and dynamic enhanced T1-weighted in phase gradient echo technique were used. Out of phase gradient echo sequence was the most sensitive technique identifying the fat content of the lesion in its mixed tissue composition.

Angiomyolipoma↗