Etem Alhan

Contribution of Diffusion-Weighted Imaging to Dynamic Contrast-Enhanced MRI in the Characterization of Breast Tumors

OBJECTIVE The purpose of our study was to evaluate the diagnostic value of an imaging protocol that combines dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) in patients with suspicious breast lesions and to determine if additional information provided by DWI improves the diagnostic value of breast MRI. MATERIALS AND METHODS Eighty-four patients with breast tumors (37 benign, 47 malignant) underwent DCE-MRI and DWI before biopsy. Morphologic and kinetic analyses were performed on DCE-MRI and findings were classified according to the BI-RADS lexicon. Apparent diffusion coefficient (ADC) values were calculated from the DWI. The ADCs of the benign and malignant lesions were compared. For the combined MRI protocol, morphologic kinetic features and ADCs were evaluated together. Diagnostic values of DCE-MRI, DWI, and combined MRI were calculated. RESULTS Median ADCs of the benign and malignant lesions were 1.26 × 10(-3) mm(2)/s and 0.75 × 10(-3) mm(2)/s, respectively. Cutoff value of 0.92 × 10(-3) mm(2)/s for ADC provided 91.5% sensitivity and 86.5% specificity. DCE-MRI alone showed 97.9% sensitivity and 75.7% specificity. The combination of DCE-MRI with DWI provided 95.7% sensitivity and 89.2% specificity. The specificity of breast MRI improved by 13.5% (p = 0.063) without a significant decrease in the sensitivity (p = 1.000). CONCLUSION The combination of DWI and DCE-MRI has the potential to increase the specificity of breast MRI.

A study on 107 patients with acute mesenteric ischemia over 30 years

Acute mesenteric ischemia (AMI) is a life threatening cause of acute abdomen. The purpose of this study is to define risk factors that predict the adverse outcome of AMI and to present our experience in the last 30 years. Hospital records and clinical data of 107 patients undergoing surgical intervention for AMI during the last 30 year period were reviewed and clinical outcomes as well as factors influencing mortality were analyzed. Mesenteric arterial thrombosis, arterial embolism and nonocclusive mesenteric ischemia (NOMI) were the cause of AMI in 68 (63.6%), 28 (26%), and 11 patients (10.2%), respectively. Abdominal pain was the most common presenting symptom (90.6%). Peritonitis was observed in 96 patients (89.7%) and 24 patients (22.4%) were in shock. Abdominal ultrasonography was performed in 46 patients (42%), abdominal CT angiography in 36 patients (33%) and mesenteric angiography in 12 patients (10.5%). All patients were operated and 11 (10%) patients underwent a second-look operation. Bowel resection was necessary in 101 patients (93.4%) during the initial operation and in seven patients (6.5%) during the second-look operation. The hospital mortality was 55.1%. Mortality was mainly due to multiorgan failure (43%). Diabetes mellitus, use of digoxine and antiplatelet drugs, duration of the symptoms until before surgery, existence of shock, low levels of the pH and bicarbonate and re-laparotomy were found to be negative predictors of the perioperative mortality. The use of total parenteral nutrition and CT angiography was found to be a protective factor against mortality. A high index of suspicion with prompt diagnostic evaluation with CT angiography may reduce time prior to surgical intervention which may lead to improved patient survival.

MDCT with multiplanar reconstruction in the preoperative local staging of rectal tumor

ObjectiveTo evaluate the accuracy of MDCT with multiplanar reconstruction in the preoperative local staging of rectal tumor.Materials and methodsThirty-seven patients with rectal tumor underwent preoperative MDCT. Two radiologists evaluated the depth of tumor invasion (T staging), regional lymph node involvement (N staging) and mesorectal fascia involvement on axial, sagittal, and coronal multiplanar reconstruction images in consensus. MDCT findings were compared with pathologic results, which served as the reference standard. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were assessed.ResultsOverall accuracy was 86% in T staging, 84% in N staging, 89% in International Union Against Cancer (UICC) Staging, and 94.5% in the prediction of mesorectal fascia involvement.ConclusionMDCT with multiplanar reconstruction is an accurate technique in the preoperative local staging of rectal tumor.

Contrast-Enhanced MR Angiography of the Breast: Evaluation of Ipsilateral Increased Vascularity and Adjacent Vessel Sign in the Characterization of Breast Lesions

OBJECTIVE The purpose of this study was to investigate the role of evaluation of breast vascularity with contrast-enhanced MR angiography in the differentiation of malignant from benign lesions. MATERIALS AND METHODS Contrast-enhanced 3D MR angiograms of the breasts of 102 patients with unilateral and histopathologically confirmed breast lesions were evaluated retrospectively. All images were evaluated for both ipsilateral increased vascularity and adjacent vessel sign, and the values of these signs in the diagnosis of malignancy were assessed. RESULTS Histopathologic analysis of 102 patients revealed 50 malignant and 52 benign results. In 31 of the 50 patients with breast cancer and in 11 of the 52 patients with benign lesions, ipsilateral breast vascularity was increased. The resulting sensitivity and specificity of ipsilateral increased vascularity were 62% and 79%. The adjacent vessel sign was present in 37 of the 50 patients with breast cancer and six of the 50 patients with benign lesions. The resulting sensitivity and specificity of the adjacent vessel sign were 74% and 89%. The overall accuracies of ipsilateral increased vascularity and the adjacent vessel sign were 71% and 81%. CONCLUSION Both ipsilateral increased vascularity and the adjacent vessel sign were found to be associated with breast cancer in a significant percentage of patients. The adjacent vessel sign is more practical and generally applicable. There is a borderline significance in favor of the higher accuracy of the adjacent vessel sign in comparison with ipsilateral increased vascularity (p = 0.043).

Effects of the celecoxib on the acute necrotizing pancreatitis in rats.

The investigation of the effects of the celecoxib as a cylooxygenase-2 (COX-2) inhibitor on the course of the acute necrotising pancreatitis (ANP) in rats. ANP was induced in 72 rats by standardized intraductal glycodeoxycholic acid infusion and intravenous cerulein infusion. The rats were divided into four groups (six rats in each group): Sham + saline, sham + celecoxib, ANP + saline, ANP + celecoxib. Six hours later after the ANP induction, celecoxib (10 mg/kg) or saline was given i.p. In the 12th hour, routine cardiorespiratuar, renal parameters were monitored to assess the organ function. The serum amylase, alanine amino transferase (ALT), interleukin 6 (IL-6), lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, the serum concentration of the urea, the tissue activity of myeloperoxidase (MPO) and malondialdehyde (MDA) in pancreas and lungs were measured. The pancreas histology was examined. In the second part of the study, 48 rats were studied in four groups similar to the first part. Survival of all the rats after the induction of ANP was observed for 24 h. The induction of the pancreatitis increased the mortality from 0/12, in the sham groups to 4/12 (30%) in the acute pancreatitis with saline group, 5/12 (42%) in the acute pancreatitis with celecoxib group respectively, heart rate, the serum activities of amylase, ALT, the tissue activities of MPO, MDA in the pancreas and lung, and LDH in BAL fluid, the serum concentration of the urea and IL-6, the degree of the pancreatic damage and decreased the blood pressure, the urine production, pO2 and the serum concentration of calcium. The use of celecoxib did not alter these changes except the serum IL-6 concentration, urine production and MPO, MDA activities in the tissue of the lungs and pancreas. Serum urea concentration and pancreatic damage in ANP + celecoxib group were insignificantly lesser than ANP + saline group. Whereas treatment with celecoxib improves lung and renal functions, the degree of pancreatic damage partially and the serum IL-6 level completely, it does not improve the cardiovascular and liver functions, the mortality rate and the calcium level. Celecoxib may be useful for the support of some organ functions during ANP in rats.

Effects of Dopexamine on Acute Necrotising Pancreatitis in Rats

OBJECTIVE To examine the effects of dopexamine on pancreatic tissue oxygen tension (PtO2) and the extent of acinar injury in rats with acute necrotising pancreatitis DESIGN Laboratory study. SETTING Medical school, Turkey. ANIMALS 68 Sprague Dawley rats. MAIN OUTCOME MEASURES Cardiorespiratory measurements, pancreatic PtO2, effects on activity of serum amylase and concentration trypsinogen activation peptide (TAP). and histological picture. RESULTS The four study groups (sham + saline, sham + dopexamine, acute pancreatitis and acute pancreatitis + dopexamine) were each divided into two; in 9 rats in each, pancreatic biochemistry was studied, and in the remaining 8 in each group serum biochemistry and histology were studied. The groups were comparable with regard to mean arterial pressure, heart rate, arterial blood gases, packed cell volume, and serum amylase activity. The use of dopexamine increased pancreatic PtO2 in the sham + dopexamine group without the important blood pressure changes. The induction of pancreatitis resulted in a significant reduction in pancreatic PtO2 in the pancreatitis groups. The use of dopexamine did not increase pancreatic PtO2. There were no significant differences in plasma TAP concentration and the extent of acinar cell injury in the animals in the pancreatitis groups. CONCLUSION Treatment with dopexamine does not improve the pancreatic microcirculation or reduce the extent of acinar cell injury in acute necrotising pancreatitis and is therefore unlikely to be of benefit in patients with pancreatitis.

Diagnostic efficacy of the diffusion weighted imaging in the characterization of different types of breast lesions

To evaluate the diagnostic efficacy of quantitative Diffusion‐weighted imaging (DWI) in the characterization of breast lesions of mass and non‐mass enhancement (NME) types.

The effects of pentoxifylline on liver regeneration after portal vein ligation in rats

Aim: To determine the effects of pentoxifylline, a methyl xanthine derivative on hepatic cell production of uninterferred lobe after portal vein branch ligation.

Effects of ω–3 Fatty Acids on Acute Necrotizing Pancreatitis in Rats

The aim of this study was to investigate the influence ofω–3 fatty acids (ω3FA) on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. The induction of ANP resulted in significant increases in mortality rate, intestinal permeability, bacterial infection in pancreas and extrapancreatic organs, and serum activity of urea and amylase, alanine transferase (ALT), interleukin (IL)-6, tumor necrotizing factor-α (TNF-α), lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, tissue activity of myeloperoxidase (MPO) and malondialdehyde (MDA) in the pancreas and lung, and a considerable decrease of concentrations of calcium, protein and albumin. The use of ω3FA reduced mortality, phenol sulfophthalein excretion in urine, bacterial infection in pancreas, liver, spleen, MPO and MDA levels in pancreatic and lung tissue, LDH level in BAL fluid and serum IL-6 and TNF-α values. Serum triglyceride increased only in the ω3FA groups. Serum amylase, ALT, calcium, urea, protein, IL-1, and degree of pancreatic damage indicated no difference between the pancreatitis groups. Increased intestinal permeability and cytokine levels, and free radical damage play an important role during the course of acute pancreatitis. The treatment with ω3FA improves these effects. ω3FA may be useful in the treatment during ANP in rats. Therefore, it can be beneficial in patients with pancreatitis.

The Effects of Nitric Oxide Synthase Inhibitors on Acute Necrotising Pancreatitis in Rats

OBJECTIVE To investigate the effects of the constitutive nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-Name) and the inducible NO synthase inhibitor amino ethyl-isothiourea (AE-ITU) on acute necrotising pancreatitis (ANP) in rats. DESIGN Laboratory study. SETTING Medical school, Turkey. MAIN OUTCOME MEASURES Morbidity, mortality, effects on activities of various enzymes, and histological picture. RESULTS NO inhibitors increased the mortality (from 8/15, 53%, for ANP plus saline, to 12/15, 80%, for ANP plus L-Name, and 13/15, 87%, for ANP plus AE-ITU and serum amylase activity, but had no effects on serum calcium concentrations, volume of ascites, or degree of pancreatic damage. L-Name caused hypoglycemia, and AE-ITU reduced activities of lactate dehydrogenase and liver transaminases, and concentrations of urea and creatinine. CONCLUSIONS Constitutive NO synthase inhibition worsens the course of ANP, and inducible NO inhibition has beneficial effects on various systems.