Mehmet Ruhi Onur

Semiquantitative Strain Elastography of Liver Masses

This study was designed to determine the utility of semiquantitative strain elastography in differential diagnosis of solid liver masses.

The role of ADC measurement in differential diagnosis of focal hepatic lesions

PURPOSEnTo evaluate the utility of apparent diffusion coefficient (ADC) measurement in characterization of focal solid hepatic lesions and determine the role of ADC values in differentiation of solid benign and solid malignant hepatic lesions.nnnMATERIALS AND METHODSnBetween June 2006 and December 2010, a total of 95 focal solid hepatic lesions in 95 consecutive patients were evaluated by abdominal MRI. Diffusion weighted MRI was performed with b 100, b 600 and b 1000 gradients with ADC measurements. Comparison of mean ADC values between solid benign (focal nodular hyperplasia and other solid benign lesions) and solid malignant lesion (hepatocellular carcinoma, metastasis, and cholangiocarcinoma) groups and between each benign and malignant lesion was done. The ROC analyses were performed in order to determine cut-off ADC values for differentiation of benign and malignant lesion groups at 3 different gradients.nnnRESULTSnTwenty-six of 95 lesions were benign and 69 were malignant. Mean ADC values of solid benign lesions at b 100, b 600 and b 1000 gradients were 2.25±0.54×10(-3), 1.97±0.64×10(-3) and 1.52±0.47×10(-3) mm2/s, respectively. Mean ADC values of solid malignant lesions at b 100, b 600 and b 1000 gradients were 1.84±0.57×10(-3), 1.37±0.38×10(-3) and 1.08±0.22×10(-3) mm2/s, respectively. The ADC values of solid benign lesions were significantly higher than solid malignant lesions at all 3 gradients (P<0.05). Differentiation of benign and malignant subtype lesions from each other in their groups did not yield as significant findings as comparing results between benign and malignant lesions.nnnCONCLUSIONnAlthough ADC measurements were not helpful for differentiating subtypes of solid benign or solid malignant lesions, ADC measurements at 3 different gradients may be useful in differential diagnosis of benign lesions from malignant ones.

Radiological Imaging Features of Fasciola hepatica Infection – A Pictorial Review

Fascioliasis refers to a zoonosis caused by Fasciola hepatica, a trematode infecting herbivores, but also occurs in humans who ingest the metacercaria found in fresh water plants. Infection in humans is common in developing countries and is also not uncommon in Europe. Diagnosis of this infection is difficult, as the history and symptoms are nonspecific and stool analysis for eggs is negative until the disease is in an advanced state by when the parasite has reached the biliary system. The clinical course consists of two phases; first a hepatic parenchymal phase in which immature larvae invade the liver parenchyma, followed by a ductal phase characterized by the excretion of larvae into the bile ducts. Parenchymal Phase: Ultrasonography (US) findings are nonspecific in this early phase. Computerized tomography (CT) may demonstrate subcapsular low attenuation regions in the liver. Magnetic Resonance imaging (MRI) can also be utilized to establish liver parenchymal involvement, and is better than CT in characterizing hemorrhagic lesions, as well as identifying more lesions relative to CT. Ductal Phase: US examination is most useful at this stage, with its ability to demonstrate the live movement of the worms within the dilated ducts. A CT demonstrates dilated central biliary ducts with periportal tracking, whereas, mild ductal dilatation is poorly appreciated under MRI. Therefore, familiarity with the multimodality imaging features of fascioliasis, in combination with an available confirmatory enzyme-linked immunoassay, would be most helpful for early diagnosis.

The role of diffusion weighted magnetic resonance imaging in oncologic settings

There is growing interest in the applications of diffusion-weighted-imaging (DWI) in oncologic area for last ten years. DWI has important advantages as do not require contrast medium, very quick technique and it provides qualitative and quantitative information that can be helpful for tumor assessment. In this article, we present oncologic applications of DWI in the parts of the body. DWI has been applied to the evaluation of central nervous system (CNS) pathologies. Some technologic advances lead to using of DWI in the extracranial sites such as abdomen and pelvis. As well as tumor detection and characterization, DWI has been widely used for predicting and monitoring response to therapy. One of the most prominent contributions of DWI is differentiation of between malignant and benign tumoral process. Apparent-diffusion-coefficient (ADC) value is quantitative parameter of DWI which reflects diffusion movements of water molecules in various tissues. Most of the studies suggested that malignant tumors had lower ADC values than benign ones. DWI may be a routine sequence in oncologic settings and it provides much useful information about tumoral tissue. We think it can be added to conventional magnetic resonance imaging (MRI) sequences.

Utility of ADC measurement on diffusion-weighted MRI in differentiation of prostate cancer, normal prostate and prostatitis

To determine the utility of apparent diffusion coefficient (ADC) values in differentiation of prostate cancer from normal prostate parenchyma and prostatitis we obtained ADC values of 50 patients at b 100, 600 and 1,000 s/mm(2) diffusion gradients. The ADC values of prostate cancer group were significantly lower than normal prostate and prostatitis group at b 600 and 1,000 s/mm(2) gradients. The ADC values at high diffusion gradients may be used in differentiation prostate cancer from normal prostate and prostatitis.

Role of the apparent diffusion coefficient in the differential diagnosis of gastric wall thickening

To evaluate the role of the apparent diffusion coefficient (ADC) measurement made using diffusion‐weighted magnetic resonance imaging (DWMRI) in the differential diagnosis of benign and malignant gastric wall thickening.

Renal and Ureteral Trauma

Renal trauma can occur secondary to abdominal trauma or interventional procedures. Renal injury is encountered in 10 % of the abdominal trauma patients. Ureteral injury usually results from iatrogenic causes but can occur from trauma as well. Undetected renal trauma presents with urinoma, perinephric abscess, sepsis, delayed bleeding secondary to arteriovenous fistula or pseudoaneurysm, hypertension, hydronephrosis, calculus formation, and chronic pyelonephritis. Computed tomography is the most sensitive imaging method in detection of renal trauma. Intravenous pyelography, retrograde pyelography, antegrade pyelography, and CT urography can detect ureteral injury. In this chapter, imaging findings of kidney and ureteral trauma are classifications of renal trauma are presented.

Utility of semiquantitative strain elastography for differentiation between benign and malignant solid renal masses.

The aim of this study was to determine the role of semiquantitative strain elastography for differentiation of benign and malignant solid renal masses.

Diffusion weighted MRI in chronic viral hepatitis: correlation between ADC values and histopathological scores

ObjectiveTo investigate the utility of apparent diffusion coefficient (ADC) measurement in the diagnosis of chronic viral hepatitis (CVH) and correlation between ADC values and histopathologic severity of CVH.Materials and methodsThe ADC values of liver parenchyma on diffusion-weighted magnetic resonance imaging (DWMRI) were measured in 50 patients with a history of CVH and 51 healthy subjects at b 100, b 600 and b 1,000 gradients. Comparison between mean ADC values of the CVH and control groups and correlation results between ADC values and necroinflammation and fibrosis scores in CVH were obtained.ResultsMean ADC values of CVH patients were significantly lower than mean ADC values of the control group at b 100 and b 600 gradients (Pu2009<u20090.05). There was no significant difference between the CVH and control groups at the b 1,000 gradient (Pu2009>u20090.05). No significant correlation was found between ADC values and histopathologic scores of CVH (Pu2009>u20090.05).ConclusionADC values obtained at the b 100 and b 600 gradients can be used to distinguish between the liver parenchyma of CVH and healthy subjects. ADC measurement was not found to be useful for estimation of the degree of necroinflammation and fibrosis in CVH.Teaching Points• In chronic viral hepatitis apparent coefficient values are decreased in the liver• There is no correlation between ADC values and histopathologic severity of CVH• DW images obtained at low b values have more ability to demonstrate an ADC decrease in viral hepatitis

Diagnosis of Peritoneal Metastases with Abdominal Malignancies: Role of ADC Measurement on Diffusion Weighted MRI.

OBJECTIVEnThe purpose of our study was to evaluate the utility of the apparent diffusion coefficient (ADC) value measurement in the diagnosis of peritoneal metastases on diffusion weighted magnetic resonance imaging.nnnMATERIALS AND METHODSnDiffusion weighted imaging with conventional magnetic resonance imaging sequences was performed on twenty consecutive oncology patients (group I) with peritoneal metastases. The ADC values of the metastases, the peritoneal fat around the metastases (group I) and the peritoneal fat in patients with no malignancy (group II) at b(0-100), b(0-600), and (b 0-1000) s/mm(2) gradients were measured and compared.nnnRESULTSnThe apparent diffusion coefficient values of three gradients in peritoneal metastases (2.27±0.4; 1.67±0.7 and 1.09±0.4×10(-3) mm(2)/s at b 100, 600 and 1000 gradients, respectively) were significantly lower than the ADC values of the peritoneal fat around metastases (3.07±0.4; 2.07±0.4; 1.33±0.3×10(-3) mm(2)/s at b 100, 600 and 1000 gradients, respectively) (p<0.05). There was no significant difference between the ADC values of peritoneal fat in the patients of group I and group II at the 3 diffusion gradients (p>0.05).nnnCONCLUSIONnThe measurement of ADC values may be used as a complementary diagnostic method in differentiating peritoneal metastases from peritoneal fat on Diffusion Weighted MRI (DWMRI DWMRI).