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The main challenge of creating large interactive displays in the operating rooms (ORs) is in the definition of ways that are efficient and easy to learn for the physician. Apart from traditional input methods such as mouse and keyboard, we have developed a multimodal system with two different vision based human-computer interaction (HCI) systems that can simplify the way surgeons interact with the medical images shown on the LCD display. The purpose of this work is to construct a gesture recognition system with a fast, accurate, and easily attainable method. The first system is a laser pointer interaction framework that supports a 2D stroke gesture interface. The recorded laser gestures are recognized using two different algorithms: dynamic time warping (DTW) and one dollar (1$) recognizer. Our experimental results showed that the DTW algorithm performs better with an overall accuracy of 90 %. The second prototype presents an intuitive HCI to manipulate images using freehand gestures. In order to strengthen the gesture recognition process, the system incorporates contextual information to determine the intent of the user of interacting with the large display. Two cameras are used to observe the surgeon’s hand movements to continuously determine and monitor what the surgeon intends to perform. Experimental results showed that the system accuracy is 95 % for recognition with the effect of contextual integration.

Purpose: To determine the optimal 64-multidetector-row computed tomography scan delay from bolus-tracking trigger for the arterial phase and the evaluation of vascularization in healthy liver. Materials and Methods: One hundred twenty patients are randomized into 3 groups according to scan delay (5-, 10-, 15-second arterial phase) and underwent CT of the liver. Images were evaluated on the basis of quantitative and qualitative scores. A correlation analysis between them was managed to find the most effective scan delay for best radiologists' diagnostically performances. Results: Scanning too early results in images that are acquired before the vascular peak enhancement while scanning to late results in the increasing of liver parenchyma portal feeding. Good performances were obtained with a scan delay ranging between 10 and 19 seconds from the trigger. Conclusions: When a 64-multidetector-row computed tomography with a bolus-tracking program is used, only 1 arterial phase should be acquired, setting a scan delay of 10 to 19 seconds.

The authors describe the case of a large hepatocellular adenoma diagnosed in a 30-year old woman who came to us complaining of acute pain in the upper abdominal quadrants. The patient had been taking an oral contraceptive pill for the last ten years. We present the clinical features, the diagnostic work-up and the treatment prescribed.

Seo TS, Oh JH, Lee DH, et al. Radiologic anatomy of the rabbit liver on hepatic venography, arteriography, portography, and cholangiography. Invest Radiol 2001;36:186-192.The radiologic anatomy of rabbit liver has received little study but is important in many experimental investigations.Twenty-four rabbits were studied by using hepatic venograms, aortograms, hepatic arteriograms, cholangiograms, and portograms.In all cases, the right, middle, and left hepatic veins drained into the inferior vena cava just below the diaphragm, and the caudate lobe hepatic vein drained more inferiorly. The proper hepatic artery was a branch of the common hepatic artery in 96%. The first branch of the proper hepatic artery was the caudate lobe artery. The remaining main hepatic artery was divided into the right and left hepatic arteries. The left hepatic artery was further divided into the medial and lateral segmental branches in 95%. The anatomy of the portal vein or bile duct was the same as the hepatic artery in 100% of cases.Knowledge of the normal patterns and variations of the vessels and bile duct will be helpful for experiments of the rabbit liver in future studies.

Hepatic angiomyolipoma is a rare benign lipomatous tumor of the liver. Radiologic studies usually reveal a fat component, but since this may be minimal, such a component is not always detected. We report a case of atypical hepatic angiomyolipoma which because of the non-visualization of fat at CT and MR imaging, was difficult to differentiate from other hypervascular tumors.

The radiological features of cystic and alveolar echinococcal disease of the liver is described, based on 17 patients. Conventional radiographs, liver ultrasound and liver angiography are described.

The angiographic appearances of histologically proven hepatic infarction without vascular occlusion has not, to our knowledge, been previously described. A case of non-occlusive hepatic infarction in a diabetic patient is presented and correlated with scintigraphic and microscopic findings. It would appear to be the first recorded case of hepatic infarction associated with diabetic ketoacidosis. A follow-up angiogram showed resolution. The literature is briefly reviewed.

Hepatic angiography was performed in a double-blind two-group study in 60 patients using iohexol 350 mg I/ml and ***metrizoate 350 mg I/ml. A slight increase in serum values of hepatic enzymes was found when metrizoate was used, particularly in patients with impaired liver function. Iohexol gave considerably less pain and sensation of heat than did metrizoate. A non-expected significant increase of creatine kinase was recorded when iohexol was used. The reason for this is not yet known.

Two liver transplant recipients underwent serial hepatic arteriography, demonstrating a severe, rapidly progressive arteritis involving the hilar hepatic arteries. Liver biopsies in these patients demonstrated ischemic necrosis as a prominent feature. The angiographic appearance and therapeutic implications of liver transplant rejection arteritis are presented.

Seven examples of focal nodular hyperplasia of the liver have been demonstrated angiographically in 3 young women and 19-year-old girl. Six of these lesions were small and highly vascular, and appeared remarkably similar. One large solitary lesion was supplied by enlarged hepatic artery branches, contained a mass of abnormal, tortuous, irregular vessels and caused a dense, well-defined tumor stain. The angiographic differential diagnosis of these highly vascular, benign lesions is discussed and the radionuclide studies in these patients described.

Of 105 patients examined by liver scanning and celiac or hepatic angiography, a proved diagnosis was obtained in 77, with 26 cases of space-occupying masses and 35 cases of cirrhosis. The two techniques appear to be complementary to each other, although angiography usually provides more information and may show more and smaller intrahepatic lesions.

In 9 of 112 patients with hepatocellular carcinoma (HCC) examined by selective celiac and hepatic arteriography, an unusual finding, the “thread and streaks” sign, was observed. It began to appear shortly after the start of injection and was most clearly seen at 3.0–3.5 seconds. Histopathologic and radiographic studies of excised livers have demonstrated that these thin streaks correspond to the blood spaces and vessels which run longitudinally in and around a tumor cast growing in a large branch and trunk of the portal vein.

An intrahepatic arterioportal fistula causing portal hypertension was successfully palliated with steel coils. The patient remains well 2 1/2 years after embolization. The 13 previously reported cases of transcatheter embolization of large intrahepatic arterioportal fistulae are reviewed. Percutaneous transcatheter embolization with suitable embolic material should be preferred to surgery in the treatment of these fistulae.

Three cases of lymphocytic lymphoma are reported. The diagnosis of liver involvement is critical since it may be a determining factor in the selection of chemo- or radiotherapy. Angiographic diagnosis of liver lymphoma is frequently unsuccessful. Though liver lymphomas usually display a hypovascular pattern, the hypervascular pattern should be considered in the differential diagnosis of hepatic lesions.