Characterization of focal liver lesions: use of mangafodipir trisodium (MnDPDP)-enhanced MR images.

BACKGROUND/AIMS: We evaluated the characterization and detection of liver lesions using mangafodipir trisodium. METHODS: A total of 51 patients with liver lesions [13 hepatocellular carcinomas, 18 metastases, 14 hemangiomas, three cholangiocellular carcinomas, two hydatic cysts, and one focal nodular hyperplasia (FNH)] were examined by unenhanced and mangafodipir trisodium-enhanced MRI. RESULTS: After administration of mangafodipir trisodium by slow intravenous infusion, mangafodipir trisodium-enhanced MRI was performed at 15-30 min and 24 h. The enhancement appeared in normal liver parenchyma and all of the hepatocellular lesions (HCCs and FNH). The lesions in hepatocellular carcinomas patients showed a non-homogeneous enhancement pattern. Non-hepatocellular lesions (hemangiomas, metastases, CCCs) had no enhancement on mangafodipir trisodium-enhanced MRI examinations. The rim-like enhancement pattern was demonstrated in all patients with cholangiocellular carcinomas, and in 14 metastases and 11 hemangiomas. CONCLUSIONS: Mangafodipir trisodium-enhanced MRI permits reliable distinction between hepatocellular and non-hepatocellular tumors. Mangafodipir trisodium-enhanced MRI can show more functional and morphologic features of hepatocellular lesions. Some non-hepatocellular lesions which went undetected on unenhanced MRI were visualized after contrast enhancement of the liver. The rim-like enhancement pattern is not specific for metastases. Mangafodipir trisodium-enhanced MRI is safe and well tolerated and may aid in noninvasive diagnosis of liver lesions.

Detection of colonic masses with MR colonography.

BACKGROUND/AIMS: Magnetic resonance colonography based on magnetic resonance imaging is a relatively new diagnostic modality for diagnosing colon pathology. The aim of this study was to evaluate its performance in detecting colorectal masses. METHODS: Thirty-three patients (20 male, 13 female; age range 28-85 years; mean age 78.7) suspected of having colonic lesions because of rectal bleeding, positive fecal occult blood test results or altered bowel habits underwent magnetic resonance colonography and subsequent conventional colonoscopy. All patients underwent standard bowel preparation 24 h before magnetic resonance colonography. Patients were placed in a supine position on the magnetic resonance table. After placement of a rectal tube, the colon was filled with of a mixture of 1000-1800 ml 0.9% NaCl solution and 15-20 ml 0.5 mmol/L gadopentetate dimeglumine solution. Once colonic distension was achieved, 3D GRE magnetic resonance colonography and complementary Magnetic resonance images were taken in all cases. RESULTS: Sensitivity of magnetic resonance colonography for colorectal masses was 90% and specificity was 100%. Percentage of correct diagnosis of magnetic resonance colonography was 94.3%. Magnetic resonance colonography was well tolerated without sedation or analgesia. CONCLUSIONS: Magnetic resonance colonography is a new technique for imaging of the colon. Magnetic resonance colonography has potential advantages of multiplanar capabilities and of being a less-invasive imaging technique; it can be implemented in daily practice and has a role in accurately staging colorectal cancers. In symptomatic patients, this new technique shows promising results for the detection and imaging of colorectal masses.

Experimental evaluation of the effects of zoledronic acid on regenerate bone formation and osteoporosis in mandibular distraction osteogenesis.

PURPOSE: The aim of this study was to evaluate the effects of systemically administered zoledronic acid (ZA) on the bone mineral density (BMD) and bone mineral content (BMC) at mandibular distraction sites in rabbits. MATERIALS AND METHODS: Eighteen New Zealand white rabbits were randomly divided into 2 groups. Bone lengthening was performed in the left portion of the mandible through distraction osteogenesis at a rate of 0.5 mm every 12 hours for 5 days. While the experimental group rabbits were administered intravenous 0.1 mg/kg ZA, control group rabbits were given only saline infusion during operation. All animals were sacrificed at the end of the consolidation period of 28 days. The mandibles of all animals were removed and both the anterior and posterior pin regions of the regenerate and regenerate region were evaluated by dual energy x-ray absorptiometry (DEXA). BMD and BMC data were statistically analyzed. RESULTS: Except for 1 rabbit from the experimental group that had an infection at the external pin region, all animals showed complete clinical healing. When the values in the group receiving ZA were compared with those of the control group, it was observed that the BMD values of the anterior pin region of regenerate, regenerate region, and posterior pin region increased by 23%, 20%, and 31%, respectively; and BMC values increased by 22%, 24%, and 32%, respectively. When data of these regions were compared, both BMD and BMC were found statistically different in all regions (P < .05). CONCLUSION: Results of this study showed that ZA had positive effects on new bone formation at and around the distraction gaps of the lengthened rabbit mandibles by distraction osteogenesis.

Three-dimensional MR and axial CT colonography versus conventional colonoscopy for detection of colon pathologies.

AIM: To evaluate the sensitivity and specificity of MR colonography (MRC) and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy. METHODS: Forty-two patients suspected of having colonic lesions, because of rectal bleeding, positive fecal occult blood test results or altered bowel habits, underwent the examinations. After insertion of a rectal tube, the colon was filled with 1000-1500 mL of a mixture of 9 g/L NaCl solution, 15-20 mL of 0.5 mmol/L gadopentetate dimeglumine and 100 mL of iodinized contrast material. Once colonic distension was achieved, three-dimensional gradient-echo (3D-GRE) sequences for MR colonography and complementary MR images were taken in all cases. Immediately after MR colonography, abdominal CT images were taken by spiral CT in the axial and supine position. Then all patients were examined by conventional colonoscopy (CC). RESULTS: The sensitivity and specificity of MRC for colon pathologies were 96.4% and 100%, respectively. The percentage of correct diagnosis by MRC was 97.6%. The sensitivity and specificity of CT for colon pathologies were 92.8%, 100%, respectively. The percentage of correct diagnosis by CT was 95.2%. CONCLUSION: In detecting colon lesions, MRC achieved a diagnostic accuracy similar to CC. However, MRC is minimally invasive, with no need for sedation or analgesics during investigation. There is a lower percentage of perforation risk, and all colon segments can be evaluated due to multi-sectional imaging availability; intramural, extra-intestinal components of colonic lesions, metastasis and any additional lesions can be evaluated easily. MRC and CT colonography are new radiological techniques that promise to be highly sensitive in the detection of colorectal mass and inflammatory bowel lesions.

Mangafodipir trisodium-enhanced magnetic resonance imaging for evaluation of pancreatic mass and mass-like lesions.

AIM: To investigate the role of mangafodipir trisodium (MnDPDP) in focal pancreatic masses and mass-like lesions by evaluating contrast uptake features of the lesions and pancreatic parenchyma after contrast medium injection. METHODS: A total of 37 patients with pancreatic mass or mass-like lesions were examined by unenhanced and MnDPDP-enhanced magnetic resonance imaging (MRI). RESULTS: MRI was obtained 20-40 min after infusion of MnDPDP and homogeneous contrast enhancement was observed in normal pancreas parenchyma. In patients with atrophic pancreas there was no enhancement in pancreatic parenchyma on MnDPDP-enhanced MRI. In 37 patients with 41 pancreatic masses and mass-like lesions, contrast enhancement was observed at 5 lesions on MnDPDP enhanced MRI. Three of these 5 lesions were focal pancreatitis and the other 2 were adenocarcinoma. No contrast enhancement was determined in 36 pancreatic masses and mass-like lesions in 32 patients. CONCLUSION: MnDPDP contrast-enhanced MRI, especially in cases with no parenchyma atrophy, can distinguish focal pancreatic lesion margins. Information about the function of pancreatic parenchyma can be obtained out of tumor. MnDPDP facilitates staging of pancreatic tumors by detection of metastatic lesions in the liver. In addition, diminished heteregenous uptake of MnDPDP in patients with pancreatitis may be helpful in differential diagnosis.

Spontaneous rupture of choledochal cyst presenting in childhood.

Spontaneous rupture of choledochal cysts is one of the rare complications, and can sometimes be the initial manifestation. It should be considered in the presence of bile-like fluid. A 10-year-old girl had acute onset of abdominal pain, vomiting, and elevated bilirubin, alkaline phosphatase, glutamic oxaloacetic transaminase and glutamic-pyruvic transaminase levels. There was no trauma in her history. In ultrasonography and computed tomography, dilated common bile duct, cystic mass of 10 x 6 cm, and free intraperitoneal fluid in abdominal cavity were demonstrated. Radiological methods, especially intraoperative cholangiography, should be performed for evaluation. We report a case of spontaneous rupture of the choledochal cyst with clinical and radiological findings.

Distal femur morphometry: a gender and bilateral comparative study using magnetic resonance imaging.

Among the anthropometric factors to be considered, anatomic differences in the distal femur and intercondylar notch have been implicated as a cause of the different rates of anterior cruciate ligament (ACL) rupture between men and women; therefore, in this study our aim was to evaluate a number of morphometric measurements in the distal part of the femur. Two hundred knee MRI examinations were analyzed: 56 male right, 44 male left, 42 female right and 58 female left. Measurements of the intercondylar height (ICH), intercondylar width (ICW), medial condylar width (MCW), lateral condylar width (LCW) and epicondylar width (EW) were obtained. The notch shape index (NSI) was also calculated. Statistical analysis for comparisons was done by Student's t-test. Correlations between the parameters studied were calculated by Pearson correlation coefficients. Significant bilateral differences were not found (p > 0.05). In all measurements, males showed significantly greater values than females (p < 0.001). No difference was seen in the NSI between males and females (p > 0.05). Conversely a significant association was obtained between age and all parameters. We conclude that the results of this study may be useful for anatomic evaluation of the distal femur region prior to orthopaedic operations.

Diagnostic value of diuretic-enhanced excretory MR urography in patients with obstructive uropathy.

PURPOSE: Ultrasonography and conventional intravenous urography are most common methods in diagnosis of obstructive uropathies. The disadvantage of ultrasonography is inability of visualizing middle and lower one thirds of ureter, while intravenous urography is using radiation, also functionally extra loading effect on kidneys. In this study, the diagnostic value of MR urography on obstructive uropathy were investigated. MATERIALS AND METHODS: Forty five patients who were suffered from obstructive uropathy examined by ultrasonography, intravenous urography and diuretic-enhanced excretory MR urography by using MR-contrast-agent. RESULTS: MR urography established accuracy rate of 92.8% for stone diseases which formed the largest group in this study, however, in other causes of obstructive uropathy, MR urography provide 100% correct diagnosis. CONCLUSION: MR urography provide high quality images for diagnosing and determining causes of urinary obstruction defining position and severity of dilatations as well as showing localization of the pathology. We think that MR urography should be a primary investigation in patients with obstructive uropathy who have contrast agent and X-ray contrindication.

Mesenteric ischemia: an unusual presentation of fistula between superior mesenteric artery and common hepatic artery.

Chronic mesenteric ischemia is an uncommon condition associated with a high morbidity and mortality. We reported a 36-year old women with postprandial abdominal pain due to chronic mesenteric ischemia caused by a fistula between superior mesenteric and common hepatic artery.

[Plexiform neurofibroma in the gingiva]. / Gingivada pleksiform nörofibroma.

Neurofibromatosis type 1 is the most common autosomal dominant disorder of the nerve sheath and best defined phakomatosis. It usually affects skeletal system, central nervous system, eye, endocrine gland and cardiovascular system. Gingival involvement is very rare. We report radiological findings of three patients with plexiform neurofibroma who had diffuse, unilateral gingival involvement.

The role of hyperbaric oxygen in the management of subarachnoid hemorrhage.

OBJECTIVE: To determine the role of hyperoxic and hyperbaric therapy following experimental subarachnoid hemorrhage (SAH). DESIGN: Prospective, randomized, controlled animal study. SUBJECTS: Thirty male Wistar rats. INTERVENTIONS: Thirty rats were assessed for an initial neurologic status as double-blinded by two different neurosurgeons using a neurologic severity score (NSS) and then underwent an initial angiographic examination. Two days later, 0.3 ml of homologous blood was injected into the cisterna magna to produce a SAH-induced cerebral vasospasm. The NSS and angiographic examination were then repeated. The rats having no spasm or a spasm under 50% (n=8) and 50% or over 50% (n=22) were grouped separately, as groups 1 and 2, respectively. The rats having 50% or more spasm were further divided randomly into group 2A and 2B. The rats in groups 1 and 2A (n=11) underwent a 60-min course of 100% oxygen at the atmospheric pressure 1 atmosphere absolute (ata), and group 2B (n=11) received 100% oxygen at 3 ata for 1 h. Neurologic assessment was repeated on the next day and 7 days later. MEASUREMENTS AND MAIN RESULTS: The animals having no spasm or less than 50% spasm had a better NSS and outcome when compared with the animals having 50% or more spasm. But the animals with 50% or more spasm which underwent hyperbaric therapy were shown to have a better outcome compared to the animals having hyperoxic therapy. CONCLUSION: Exposure to hyperbaric oxygen therapy seemed to accelerate the recovery of neurologic deficits secondary to experimental SAH.

Contrast media-enhanced power Doppler sonography for evaluation of hemangiomas and malignant tumors in the liver.

AIM: To evaluate the characterization of liver hemangiomas and malignant tumors using power Doppler sonography before and after intravenous injection of a sonocontrast agent. METHODS: Forty-five patients with 57 liver tumors (22 hemangiomas, 24 metastases, 10 hepatocellular carcinomas (HCC) and one cholangiocellular carcinoma) were examined prospectively. The distribution (peripheral, central, mosaic) and extent (none, minimal, moderate and strong) of intratumoral flow pattern in each sonographic examination was subjectively classified. RESULTS: The administration of the sonocontrast agent by bolus injection caused enhancement to gradually increase up to 2 min and lasted for 4-5 min. After injection of contrast agent, flow signals appeared or increased in 34 tumors. No signal enhancement was observed in 18 hemangiomas, four metastases and one HCC. The sensitivity and specificity of intratumoral vascularity for the detection of malignant liver tumors was 37.1 and 90.9% for unenhanced power Doppler sonography, and 85.7 and 81.8% for contrast-enhanced power Doppler sonography, respectively. CONCLUSION: Contrast-enhanced power Doppler sonography is superior to unenhanced power Doppler sonography in the demonstration of malignant tumor vascularity, and is helpful in differentiating between hemangiomas and malignant liver tumors. A specific flow pattern within the tumor is not established in primary and metastatic malignant tumors with contrast-enhanced power Doppler sonography.

Bilateral common carotid occlusion without neurological deficit.

A 40-year-old man presented with pain and numbness in his right arm. On his clinical examination, no neurological deficit was found. Bilateral common carotid artery duplex sonography scan demonstrated no flow in either lumen. No abnormality was recognized on brain CT. On cerebral digital substraction angiogram, total occlusion of the brachiocephalic trunk and left carotid artery were shown. There was a modest stenosis in the left vertebral artery. Collateral circulation feeding the intracranial carotid system mainly originated from the left vertebrobasilar system. Previous cases of bilateral carotid occlusion are reviewed and discussed.