PubMed Health⌕ Search

Biomedical subjects

K Ocran

Publications and source records attributed to K Ocran.

At least 19 recordsLinked to original sources
PubMed2006

Image guided respiratory gated hypofractionated Stereotactic Body Radiation Therapy (H-SBRT) for liver and lung tumors: Initial experience.

To evaluate our initial experience with image guided respiratory gated H-SBRT for liver and lung tumors. The system combines a stereoscopic x-ray imaging system (ExacTrac X-Ray 6D) with a dedicated conformal stereotactic radiosurgery and radiotherapy linear accelerator (Novalis) and ExacTrac Adaptive Gating for dynamic adaptive treatment. Moving targets are located and tracked by x-ray imaging of implanted fiducial markers defined in the treatment planning computed tomography (CT). The marker position is compared with the position in verification stereoscopic x-ray images, using fully automated marker detection software. The required shift for a correct, gated set-up is calculated and automatically applied. We present our acceptance testing and initial experience in patients with liver and lung tumors. For treatment planning CT and Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) as well as magnetic resonance imaging (MRI) taken at free breathing and expiration breath hold with internal and external fiducials present were used. Patients were treated with 8-11 consecutive fractions to a dose of 74.8-79.2 Gy. Phantom tests demonstrated targeting accuracy with a moving target to within +/-1 mm. Inter- and intrafractional patient set-up displacements, as corrected by the gated set-up and not detectable by a conventional set-up, were up to 30 mm. Verification imaging to determine target location during treatment showed an average marker position deviation from the expected position of up to 4 mm on real patients. This initial evaluation shows the accuracy of the system and feasibility of image guided real-time respiratory gated H-SBRT for liver and lung tumors.

Aged↗
PubMed2004

Perforation of a pancreatic pseudocyst induced by abdominal sonography.

A fifty-year-old man complained of abdominal pain, nausea, loss of appetite, postprandial vomiting and loss of weight. Abdominal sonography revealed a chronic calcifying pancreatitis with a tubular stenosis of the common bile duct, dilatation of the pancreatic duct and multiple pancreatic duct stones. Distal of the pylorus there was an intramural pseudocyst, which had led to the obstruction of the duodenal lumen. Shortly after the ultrasound examination abdominal pain increased. In addition, an elevation of serum lipase levels was noted, but reclined rapidly the next day and was normalized a few days later. The patient was well the next morning, the symptoms of gastric retention disappeared and he had a good appetite. A CT of the abdomen two days later showed the chronic pancreatitis but could not confirm the pseudocyst and a subsequent repeat sonography revealed only a remnant of the pseudocyst. In conclusion it can be assumed that the intramural pseudocyst ruptured when pressure was applied with the ultrasound transducer to displace interfering colonic gas. Although it cannot be advised as a treatment measure for a pseudocyst, regression of a pseudocyst due to emptying into the gastrointestinal tract has to be expected.

Calcinosis↗
PubMed2004

Sonographic findings in hepatic involvement of hereditary haemorrhagic telangiectasia.

AIM: Hereditary haemorrhagic telangiectasia, or Rendu-Osler-Weber disease, is an autosomal-dominant disorder characterised by angiodysplastic lesions (telangiectases and arteriovenous malformations) which affect many organs including the skin, lungs, gastrointestinal tract, and brain. A broad spectrum of vascular and structural changes have been reported. Our objective was to systematically examine the prevalence of sonographic findings in hepatic involvement in patients with hereditary haemorrhagic telangiectasia (HHT). METHODS: We studied 22 consecutive patients with hereditary haemorrhagic telangiectasia by ultrasonography in combination with colour-Doppler and pulsed wave-Doppler for liver involvement. The clinical diagnosis of HHT was based on the Curaçon criteria. RESULTS: Sixteen of the 22 patients had signs of hepatic involvement including prominent common hepatic artery (14 of 16), dilatation of the intrahepatic part of the hepatic arteries (15 of 16) and intrahepatic AV-shunts (16 of 16). Ectasia of the hepatic vein, fibrotic parenchymal changes, left accessory hepatic artery and focal hepatic lesions were found less frequently. CONCLUSION: Diagnosis of liver involvement in HHT can be made by sonography with colour-Doppler. The main features of this involvement include prominent common hepatic artery, dilatation of the intrahepatic part of the hepatic arteries and intrahepatic AV-shunts.

Adult↗
PubMed2003

Differentiation of neuroendocrine tumors from other pancreatic lesions by echo-enhanced power Doppler sonography and somatostatin receptor scintigraphy.

BACKGROUND AND AIMS: Echo-enhanced power Doppler sonography is a noninvasive procedure that has been increasingly used for the differential diagnosis of pancreatic tumors. However, to our knowledge, the diagnostic accuracy of this procedure in comparison with somatostatin receptor scintigraphy for the differentiation of neuroendocrine lesions from other pancreatic tumors has never been investigated in a prospective, controlled study. SUBJECTS AND METHODS: One hundred thirty-seven patients were included in the study; the patients were selected from 190 consecutive patients (mean age, 59.8 years; range, 16-85 years) who presented to our department from January 1998 through June 2001 with suspicion of a pancreatic tumor. An experienced examiner who was unaware of the patients' clinical diagnoses performed sonography. Twenty-nine patients with sonographically and/or clinically suspected neuroendocrine tumors were investigated additionally by somatostatin receptor scintigraphy. The exact diagnosis was based upon histologic evidence from biopsy examination (surgical and transabdominal fine-needle biopsy) or a follow-up of at least 18 months. RESULTS: The sensitivity of echo-enhanced power Doppler sonography for diagnosing a neuroendocrine pancreatic tumor was 94%, and its specificity was 96%. The corresponding values for somatostatin receptor scintigraphy were 54% and 81%, respectively. CONCLUSIONS: Echo-enhanced power Doppler sonography has high sensitivity and high specificity for the differentiation of neuroendocrine lesions from other pancreatic tumors. However, histologic evidence is the standard of reference for the differential diagnosis of pancreatic tumors.

Adolescent↗
PubMed2002

[Differential diagnosis of frequent pancreatic tumours with echo-enhanced power-Doppler sonography - presentation of case reports].

UNLABELLED: The echo-enhanced Power-Doppler sonography is useful for the differential diagnosis of pancreatic tumours. Tumour criteria for the differentiation of pancreatic tumours with this procedure are explained using selected cases in the present publication. Ductal carcinomas are often hypovascularised compared with the surrounding tissue. On the other hand, neuroendocrine tumours are hypervascularised lesions. Tumours associated with pancreatitis have a different vascularisation pattern depending on inflammation and necrosis. Cystadenomas frequently show many vessels along the fibrotic strands. CONCLUSIONS: Pancreatic tumours have different vascularisation patterns in the echo-enhanced Power-Doppler sonography. These characteristics can be used for the differential diagnosis.

Adenocarcinoma↗
PubMed2002

[Evaluation of Doppler sonographic criteria for the differentiation of hepatocellular carcinomas and regenerative nodules in patients with liver cirrhosis].

AIM: In order to improve the differentiation between hepatocellular carcinomas and regenerative nodules in patients with liver cirrhosis, Doppler-sonographic criteria for the tumours were evaluated. METHOD: Patients with histologically proven hepatocellular carcinoma (n = 35) and regenerative nodules (n = 10) were investigated by B-mode sonography as well as fundamental and echo-enhanced power-Doppler sonography focusing on specific properties of the tumours. The results were correlated to the histological findings. RESULTS: Hepatocellular carcinomas and regenerative nodules showed a different contrast behaviour with echo-enhanced power-Doppler sonography. The following features of hepatocellular carcinomas were frequently found: peritumoural signal detection in the early arterial phase, chaotic and centripetal contrast enhancement in the arterial phase, hypervascularization in the capillary phase, and loss of portalvenous blood flow. CONCLUSION: Hepatocellular carcinomas and regenerative nodules display different vascularization patterns in the echo-enhanced power-Doppler sonography. These characteristics can be useful for their differential diagnosis.

Carcinoma, Hepatocellular↗
PubMed2002

[Contrast behaviour of a angiomyolipoma of the liver at echo-enhanced power-Doppler sonography].

Angiomyolipomas of the liver are rare tumours. Differentiation from other liver lesions using imaging techniques is difficult. This is the first report describing the contrast behaviour of an angiomyolipoma of the liver with echo-enhanced power-Doppler sonography. A rapid signal enhancement of the arteries within the tumour and an immediate drainage of the blood into the liver veins was demonstrated. Furthermore, spectrums similar to av-fistulas could be detected. Portal venous blood flow, irregular calibre of the vessels or chaotic vascular patterns could not be found.

Angiomyolipoma↗
PubMed2001

[Pancreatic metastases of renal cell carcinomas - evaluation of the contrast behavior at echo-enhanced power-Doppler sonography in comparison to primary pancreatic tumors].

BACKGROUND: Renal cell carcinomas are the most common primary tumors leading to pancreatic metastases. The differentiation of metastases from primary pancreatic tumors is important for the prognosis. Echo-enhanced power-Doppler sonography may be used for the differential diagnosis of tumors. In this study, the contrast behavior of metastases of renal cell carcinomas was evaluated in comparison to primary pancreatic tumors. PATIENTS AND METHODS: Each 5 patients with pancreatic metastases of a renal cell carcinoma, a ductal carcinoma, a neuroendocrine tumor and a pancreatitis-associated mass were investigated by B-mode sonography, fundamental and echo-enhanced power-Doppler sonography. RESULTS: Similar to neuroendocrine tumors, metastases of renal cell carcinomas were found to be hypervascularized. In contrast, ductal carcinomas are hypovascularized compared to the surrounding tissue. Tumors associated with pancreatitis show different vascularization pattern depending on inflammation and necrosis. CONCLUSIONS: Metastases of renal cell carcinomas and ductal carcinomas show different vascularization pattern at echo-enhanced power-Doppler sonography. Renal cell metastases and neuroendocrine tumors have similar contrast behaviors, therefore, clinical symptoms should be referred for their differentiation. However, histology is the standard of reference for the differential diagnosis of pancreatic tumors.

Adenocarcinoma↗
PubMed2000

[Evaluation of doppler ultrasonography criteria for the differential diagnosis of pancreatic tumors].

AIM: In order to improve the differential diagnosis of pancreatic lesions, dopplersonographic criteria for the tumours were evaluated. METHODS: 35 patients diagnosed by conventional ultrasound as having a tumour of pancreas were further investigated by B-mode sonography, fundamental and echo-enhanced power-Doppler sonography focusing on specific properties of the tumours. The results were correlated to the histological findings. RESULTS: Ductal carcinomas and cystadenocarcinomas are often hypovascularized in comparison to the surrounding tissue. In contrast to this, neuroendocrine tumours and cystadenomas are mostly hypervascularized. Tumours associated with pancreatitis show different vascularization patterns depending on inflammation and the extent of necrosis. CONCLUSIONS: Pancreatic tumours display different vascularization patterns in the echo-enhanced power-Doppler sonography. These characteristics can be useful for the differential diagnosis of pancreatic tumours.

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1996

Childhood lead poisoning in Africa: a growing public health problem.

Gasoline sold in most African countries contain 0.5-0.8 g/l lead. In urban and rural areas and near mining centers, average lead concentrations reach 0.5-3.0 mu g/m3 in the atmosphere and > 1000 mu g/g in dust and soils. In addition to automotive and industrial sources, cottage industries and the burning of paper products, discarded rubber, battery casings and painted woods for cooking and heating represent additional hazards to individual households. Lead paint, lead solder and lead cosmetics are unregulated in some countries. Although African children are particularly predisposed to environmental lead exposure, because of their lifestyle and socioecological factors, a true picture of childhood lead poisoning in the continent remains undefined. Recent prevalence studies show that over 90% of the children in urban and rural communities of the Cape Province, South Africa have blood lead levels > or = 10 mu g/dl. Studies in other countries likewise suggest that childhood lead poisoning is a widespread urban health problem throughout the continent.

Africa↗
PubMed1996

A case of the yellow nail syndrome associated with massive chylous ascites, pleural and pericardial effusions.

A 26-year-old male patient with a history of chronic peripheral lymphedema, yellowish coloured slow growing nails and pleural effusions since early childhood is described. After 23 years he developed a chylous ascites and scintigraphy with technetium-99m labeled albumin clearly demonstrated a diffuse protein loss involving the whole jejunum and ileum. Subsequent jejunal and duodenal biopsies showed the typical histological findings of intestinal lymphangiectasia thereby confirming a diffuse intestinal lymphatic damage. In addition to the gastrointestional symptoms the patient developed a pericardial effusion diagnosed by echocardiographic imaging. Dietary treatment with middle chained triglycerides and intravenous human albumin supplementation was followed by the reduction of the ascites and improvement of the peripheral lymphedema. To our knowledge this is the first description of the yellow nail syndrome associated with a diffuse lymphangiectasia involving the whole small bowel.

Adult↗
PubMed1996

[Hereditary hemorrhagic telangiectasia with hepatic involvement and including gastric vessels. A case report].

Hereditary hemorrhagic teleangiectasia (HHT) (Osler-Weber-Rendu-disease) is characterized by a combination of muccocutaneous vascular malformations with recurrent spontaneous bleeding and a familiar predisposition. Among visceral manifestations of this disease are only a few descriptions of hepatic involvement. We describe a 53-year-old woman with HHT whose first symptoms of hypercirculatory heart failure developed 1.5 years before the final diagnosis of HHT. We measured a heart-time-volume of 14-151/min. by echocardiography and a flow-volume of 5-9 l/min. in the proper hepatic artery by dopplersonography on admission. We were able to demonstrate multiple intra- and extra-hepatic and gastric arteriovenous malformations by arteriography. Branches of the proper hepatic artery and the left gastric artery were embolized in three serial sessions. By this procedure we were able to reduce the flow-volume in the proper hepatic artery from 5-9l/min. to 1.5l/min. and the heart-time-volume to a minimum of 9.8l/min. and thus stop progression of the hyperdynamic heart failure.

Angiography↗
PubMed1995

[Adrenal cortex insufficiency and hypothyroidism in advanced age].

In geriatric patients symptoms of endocrine disorders easily can be regarded to be due to the patient's old age. This is demonstrated in a case of an 80-year-old woman suffering from the combination of adrenal insufficiency and hypothyroidism. Early recognition of typical clinical signs and adequate, simply performed replacement therapy results in a significant improvement of the patient's quality of life.

Adrenal Insufficiency↗