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Biomedical subjects

Okan Akhan

Publications and source records attributed to Okan Akhan.

At least 19 recordsLinked to original sources
PubMed2006

Liver manifestations of cystic fibrosis.

Chronic liver disease is one of the major complications of cystic fibrosis (CF). Significant liver disease is seen in 13-25% of children with CF. Improved life expectancy and prolonged follow-up have favored better characterization of the hepatic manifestations of CF and allowed direct observation of an increasing number of liver-related events. Liver disease typically develops in the first decade of life, with the incidence dropping rapidly after the age of 10 years. The wide spectrum of liver disease ranging from asymptomatic gallbladder abnormalities to biliary cirrhosis will be reviewed in this article.

Cystic Fibrosis↗
PubMed2006

Imaging findings in congenital hepatic fibrosis.

Congenital hepatic fibrosis (CHF) is a rare congenital multisystemic disorder, mostly inherited in autosomal recessive fashion, primarily affecting renal and hepatobiliary systems. Main underlying process of the disease is the malformation of the ductal plate, the embryological precursor of the biliary system, and secondary biliary strictures and periportal fibrosis ultimately leading to portal hypertension. The natural course of the disease is highly variable ranging from minimally symptomatic disease to true cirrhosis of the liver. However, in most patients the most common manifestations of the diseases that are related to portal hypertension, particularly splenomegaly and bleeding varices. Many other disease processes may co-exist with the disease including Caroli's disease, choledochal cysts and autosomal recessive polycystic kidney disease (ARPKD) reflecting the mulstisystemic nature of the disease. The associating biliary ductal disease led the authors to think that all these entities are a continuum and different reflections of the same underlying pathophysiological process. Although, conventional method of diagnosis of CHF is the liver biopsy the advent of imaging technologies and modalities, today, may permit the correct diagnosis in a non-invasive manner. Characteristic imaging features are generally present and recognition of these findings may obviate liver biopsy while preserving the diagnostic accuracy. In this article, it is aimed to increase the awareness of the practising radiologists to the imaging findings of this uncommon clinical disorder and trail the blaze for future articles relating to this issue.

Humans↗
PubMed2006

Liver imaging findings of Wilson's disease.

Wilson's disease is a rare, autosomal-recessive inherited disorder of copper metabolism resulting in accumulation of copper in liver. The form of liver disease varies, depending on the severity of the disease at the time of diagnosis and pathological findings include fatty changes, acute hepatitis, chronic active hepatitis, cirrhosis and occasionally fulminant hepatic necrosis. Liver imaging findings reflect a wide range of physiopathological processes of the disease and also demonstrate the associated findings of cirrhosis in cases with advanced disease.

Diagnostic Imaging↗
PubMed2006

Multidetector CT and MRI findings in periportal space pathologies.

Periportal region is an anatomic space around portal vein comprising hepatic artery, bile duct, nerves, lymphatics and a potential space. Periportal pathologies may involve any of these structures diffusely or focally with characteristic radiologic findings. Radiologic findings can be helpful in differential diagnosis of pathologies of periportal structures including periportal cavernomatous transformation, hepatic artery aneurysm, biliary diseases, neurofibromatosis, lymphoma, langerhans' cell histiocytosis, periportal fatty infiltration and other causes of periportal halo in adult and pediatric patients. Lobar/segmental intrahepatic involvement can be seen in neurofibromatosis, cavernomatous transformation, fatty infiltration and periportal edema. In this review, we discuss CT and MRI findings of periportal pathologies which can be in the form of diffuse or segmental/lobar involvement.

Humans↗
PubMed2006

Imaging of hepatic steatosis and fatty sparing.

Radiology has gained importance in the non-invasive diagnosis of hepatic steatosis. Ultrasonography is usually the first imaging modality for the evaluation of hepatic steatosis. Unenhanced CT with or without dual kVp measurement and MRI with in and out of phase sequence can allow objective evaluation of hepatic steatosis. However, none of the imaging modalities can differentiate non-alcoholic steatohepatitis/fatty liver disease from simple steatosis. Evaluation of hepatic steatosis is important in donor evaluation before orthotopic liver transplantation and hepatic surgery. Recently, one-stop shop evaluation of potential liver donors has become possible by CT and MRI integrating vascular, parenchymal, volume and steatosis evaluation. Moreover hepatic steatosis (diffuse, multinodular, focal, subcortical, perilesional, intralesional, periportal and perivenular), hypersteatosis and sparing (geographic, nodular and perilesional or peritumoral) can cause diagnostic problems as a pseudotumor particularly in the evaluation of oncology patients. Liver MRI is used as a problem-solving tool in these patients. In this review, we discuss the current role of radiology in diagnosing, quantifying hepatic steatosis and solutions for diagnostic problems associated with fatty infiltration and sparing.

Adipose Tissue↗
PubMed2006

MRCP diagnosis of Mirizzi syndrome in a paediatric patient: importance of T1-weighted gradient echo images for diagnosis.

We report a 15-year-old boy with Mirizzi syndrome diagnosed by MR cholangiopancreatography (MRCP). Respiratory-triggered 3D MRCP was performed during free breathing. An impacted gallstone was noted in the infundibulum; this was not visible on T2-weighted images, but was hyperintense on T1-weighted gradient-echo images. This case illustrates the utility of 3D MRCP with parallel imaging in paediatric patients and the importance of T1-weighted gradient-echo images for the diagnosis of impacted gallstones.

Adolescent↗
PubMed2006

Correlation between the renal resistive index (RI) and nonenhanced computed tomography in acute renal colic: how reliable is the RI in distinguishing obstruction?

OBJECTIVE: The purpose of this study was to determine the sensitivity of renal color Doppler sonography in differentiating obstructive and nonobstructive urinary calculi in patients with acute renal colic and to compare findings with nonenhanced helical computed tomography (CT). METHODS: Sixty-five patients referred to the emergency department with acute renal colic underwent nonenhanced CT and renal resistive index (RI) measurement with color pulsed Doppler sonography within 8 to 10 hours of the onset of the symptoms. Computed tomographic evaluation was based on the detection of urolithiasis and classification according to location and the presence of obstruction. The mean RI of each kidney and the difference between the mean RI (DeltaRI) of both kidneys were calculated and compared with CT findings. RESULTS: A total of 164 stones were identified. Computed tomography revealed obstruction in 33 patients. Mean RI values for the obstructive and nonobstructive groups were 0.64 and 0.63, respectively. Mean DeltaRI values were 0.01312 and 0.01000 in the obstructive and nonobstructive groups. The differences in the mean RI and DeltaRI for the patients with and without obstruction were statistically insignificant (P = .73). No significant relationship was found between the RI values, calculus location, and degree of obstruction. CONCLUSIONS: The RI is insensitive for detection of obstruction in patients with acute renal colic, and its value in routine practice seems quite controversial.

Acute Disease↗
PubMed2006

Percutaneous treatment of Wirsung's duct stenosis secondary to chronic pancreatitis: balloon dilatation and insertion of a plastic stent.

Chronic pancreatitis is one of the indications for pancreatic duct stenting. The success rate of endoscopic stenting of the pancreatic duct is very high (98%). Reports of percutaneous stenting of the Wirsung's duct are very sparse. We present a case with Wirsung's duct stenosis secondary to chronic pancreatitis, which was treated by percutaneous antegrade balloon dilatation and insertion of a plastic stent. We also report on the long-term follow-up of this patient.

Catheterization↗
PubMed2006

Evaluation of radiotherapy response of cervical carcinoma with gray scale and color Doppler ultrasonography: resistive index correlation with magnetic resonance findings.

PURPOSE: To investigate the role of the resistive index measured with transvaginal color Doppler ultrasonography (TVCDUS) for assessing the radiotherapy response of cervical carcinoma and to compare it with magnetic resonance findings. MATERIALS AND METHODS: A total of 13 patients with advanced stage cervical carcinoma (>IIA) underwent magnetic resonance imaging (MRI) and TVCDUS exams 6 months prior to and 6 months after radiotherapy. Pre- and post-treatment resistive indices obtained from the central and peripheral zones of the tumor were compared. These values were also compared with MRI findings and resistive indices obtained from the control group. RESULTS: Tumoral masses could be visualized in all patients with B-mode TVCDUS prior to the treatment. Resistive indices before and after treatment were 0.20-0.82 (mean: 0.52+/-0.15), and 0.70-0.99 (mean: 0.81+/-0.14), respectively. Eleven out of 13 patients responded to the treatment completely and no mass was detected in MRI and TVCDUS. Investigations were performed in areas with flow within the tumor-free cervix. A residual mass was noted in 2 patients with MRI and TVCDUS. There was a statistically significant difference between complete response to the treatment and increased resistive indices (P=0.001). In 2 patients with residual masses, no increase in resistive indices was detected. The mean resistive index of the control group was 0.65+/-13 and the difference was statistically significant compared to the resistive indices of the patients prior to the treatment. CONCLUSION: Since there was a significant correlation between the MRI findings and resistive indices, the spectral parameters obtained with TVCDUS were a good alternative to such an expensive modality as MRI in the evaluation of the response of cervical cancer to the treatment.

Adult↗
PubMed2006

Radiofrequency ablation of unresectable hepatic tumors.

PURPOSE: To evaluate the efficacy and safety of radiofrequency ablation (RFA) in the treatment of primary and metastatic liver malignancies. MATERIALS AND METHODS: Twenty-nine consecutive patients who have primary (n=9) and metastatic (n=20) liver malignancies were treated with RFA. The total number of lesions were 62 at the initiation of treatment and 28 new lesions were diagnosed at the follow-up period. Totally, 84 lesions were ablated with RFA technique at 46 sessions. Primary tumors that gave rise to metastatic lesion were all colorectal cancer except one with gallbladder carcinoma. The greatest tumor diameter immediately before treatment was 0.8-5 cm with a mean of 2.5 cm. RESULTS: In the hepatocellular carcinoma (HCC) group, 1 patient was lost to follow-up, 5 deceased due to extensive disease, and 3 are still on the follow-up. In the metastatic liver disease group, 8 patients died due to progression of disease, 1 deceased due to stroke, and 3 were lost to follow-up. Nine patients with HCC had 14 nodules with a mean of 1.75 lesions/patient and 20 patients had 70 metastatic lesion with a mean of 3.1 lesions/patient. Residual viable neoplastic tissue was found at control computed tomography in 1 (1/14) lesion and recurrence occurred in 3 (3/14) lesions in HCC group. Recurrence occurred in 7 lesions (7/70) of 4 patients (4/20) in the metastatic liver disease group. Drainage requiring empyema took place in 1 patient and skin burn was observed in 2 as complications due to procedure. CONCLUSION: RFA of primary and metastatic liver malignancies is a safe and effective tool for local control of disease in unresectable hepatic malignancies.

Adolescent↗
PubMed2005

Efficacy of transvaginal contrast-enhanced MRI in the early staging of cervical carcinoma.

The objective of this study was to evaluate the efficacy of transvaginal contrast for local staging of cervical carcinoma. Fifty patients diagnosed with cervical carcinoma prospectively underwent magnetic resonance (MR) imaging before and after vaginal opacification (VO) with a mixture of 25 ml saline and 25 ml barium. T2-weighted (T2W) TSE images in axial and sagittal planes were compared before and after vaginal opacification. Dynamic T1W images in sagittal and fat-suppressed T1W images in transverse planes were also evaluated after intravenous contrast administration. Involvement of vaginal wall, lumen, and fornices; parametrium; rectum; and bladder were noted. Changes in local tumor staging and in treatment planning were also assessed after vaginal opacification. MR results were later compared with surgical pathological findings. Twenty-eight patients who went through surgical staging were included in the study. VO did not change any of the MR interpretations in 14 patients (50%). Correct staging was achieved with T2W TSE images with and without VO (in sagittal and transverse planes) in 78.5% and 50% of the patients, respectively. VO correctly lowered staging in seven and increased it in three patients compared with sagittal standard T2W images. Treatment planning was also changed in four (14%) of these patients. When overall accuracy of MR staging to indicate the appropriate treatment was evaluated, patients would have received the proper treatment in 90% and 79% of the cases when only T2W sagittal images with and without VO were evaluated, respectively. Dynamic gradient-echo images in sagittal planes and postcontrast T1W images in transverse planes evaluated with T2W series after VO, accomplished correct staging in 23 (82%) of the patients. MRI staging in early cervical cancer may be difficult and overestimated, especially if the tumor is slightly extended into the proximal vagina. Use of vaginal contrast medium is an easy, well-tolerated, and effective method to better delineate the borders of the tumor. It increases the specificity and accuracy of MR staging by showing the exact relation of the tumor with the vaginal wall and beyond.

Adult↗
PubMed2005

Long-term results of single-session percutaneous drainage and ethanol sclerotherapy in simple renal cysts.

PURPOSE: To demonstrate the efficacy and long-term results of the single-session ethanol sclerotherapy in simple renal cysts. MATERIALS AND METHODS: Ninety-eight cysts in 97 patients (range: 18-76 years; mean age, 54 years) were included in the study. Indications were determined as flank pain in 74, hydronephrosis in 12, hypertension in 8, patient reassurance due to increasing cyst size in three patients. Mean follow-up period was 24.4 months. Procedures were performed with the guidance of fluoroscopy and ultrasonography at all times using 5-7 Fr pigtail catheters. After the cystogram that was obtained in all cases, 95% ethanol with a volume of 30-40% of the cyst volume was used as a sclerosing agent on an outpatient basis. Maximum volume of the injected ethanol was 200 ml. Follow-up examinations were performed 1, 3, 6 and 12 months after the procedure and once every year thereafter. RESULTS: Average cyst volume reduction was 93% at the end of the first year. The cysts disappeared completely in 17 (17.5%) patients. After the procedure, in 67 (90%) patients improvement in flank pain was noted. Sixty-one (82%) patients were free of pain and in 6 (8%) of them the pain decreased. Normotension was obtained in 7 (87.5%) of the 8 hypertensive patients and no hydronephrosis was detected in 10 (83.3%) of the 12 patients after the procedure. Second intervention was required in 2 (2%) patients due to recurrence of cysts and related symptoms. One (1%) patient had small retroperitoneal hematoma that resolved spontaneously and in another (1%) patient spontaneous hemorrhage was detected into the cyst 1 year after the procedure. No other complication was detected during the procedure and follow-up. CONCLUSION: Percutaneous treatment of simple renal cysts with single-session sclerotherapy is a safe, effective and minimally invasive procedure and can be used as an alternative to multiple-session sclerotherapy with comparable results. High volume, up to 200 ml ethanol can be used without adverse effects for large renal cysts.

Adolescent↗
PubMed2005

Percutaneous management of parapneumonic effusions.

Parapneumonic effusions continue to be a significant source of morbidity and mortality. Treatment at earlier stages before fibrous peel and loculations occur has a much better prognosis. Using image guidance, addition of intracavitary fibrinolytic instillation, close follow-up with drainage of residual or new collections are some of the other factors that improve prognosis. In this article, we discussed treatment strategies, percutaneous management of parapneumonic effusions, its alternatives and results.

Chest Tubes↗
PubMed2005

Radiologic imaging and percutaneous treatment of pelvic lymphocele.

Pelvic lymphocele, also known as lymphocyst, is a cystic structure caused by lymphatic injury usually secondary to pelvic lymphadenectomy and renal transplantation. Lymphoceles can cause morbidity and rarely mortality by compression of adjacent structures and infectious complications. This review discusses etiology and treatment options for pelvic lymphoceles including surgical and percutaneous methods with emphasis on percutaneous techniques particularly in conjunction with sclerotherapy. Percutaneous catheter drainage with sclerotherapy procedure with various sclerosing agents is described in detail. Ethanol, povidone-iodine, tetracycline, doxycycline, bleomycin, talc and fibrin glue can be used as sclerosing agents. Combination of sclerosing agents to percutaneous catheter drainage significantly improves success rate in the treatment of pelvic lymphoceles. Infected lymphoceles are usually treated solely with percutaneous catheter drainage. Percutaneous treatment can be tailored according to volume of lymphoceles. We generally prefer single session sclerotherapy and 1 day catheter drainage in lymphoceles less than 150 mL, and larger ones are treated by multi-session sclerotherapy until daily drainage decreases below 10 mL. Percutaneous treatment preferably with sclerotherapy should be considered as the first-line treatment modality for pelvic lymphoceles due to its effectiveness, widespread applicability on an outpatient basis, ease of procedure and low complication rate.

Drainage↗
PubMed2005

Celiac ganglia block.

Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation.

Abdominal Neoplasms↗
PubMed2005

Electrolyte abnormalities at diagnosis of acute lymphocytic leukemia may be a clue for renal damage in long-term period.

The objective of this study was to determine the frequency of electrolyte perturbations and their relationship with leukemic status before and after chemotherapy in patients with acute lymphocytic leukemia. Blood biochemistry, liver and renal function tests, and renal sonograms were examined at diagnosis and during induction therapy in 334 patients. Renal and electrolyte disturbances were then studied in 116 patients between 3 and 110 months after cessation of the St. Jude chemotherapy treatment protocol. Glomerular filtration rate, electrolyte, protein, and beta-2-microglobulin levels were determined in fresh urine samples, and serum electrolyte levels were examined in blood samples. Renal sonographic examinations and scintigraphic examinations were performed with DMSA and MAG-3. Renal leukemic involvement was detected by sonographic examination in 32 patients who had also presented with hyperphosphatemia or hyperuricemia. Patients with electrolyte disorders at diagnosis were less likely to have tumor lysis syndrome during induction chemotherapy. This may be explained by correction of their electrolyte disorders at the time of diagnosis, which may protect them from tumor lysis syndrome. Hypocalcemia and hyponatremia at the time of diagnosis were found to be significant initial risk factors for renal scan abnormalities and microproteinuria, respectively, during the late therapy period (P < 0.05). Electrolyte abnormalities and renal changes were commonly observed before and after therapy for leukemia. Patients presenting with hypocalcemia and hyponatremia should be examined for microproteinuria and should undergo renal scanning during the late therapy period.

Adolescent↗