Sinusoids. are specialized blood vessels in the liver. Sinusoids appear congested (your question suggests you are quoting from an imaging report) when blood pools there usually because of problems in the right side of the heart, such as heart failure, damming up the blood in the liver. Lung problems can also cause this congestion. Cirrhosis may ultimately result. It is serious and needs careful analysis.
Increased venous. it means that the veins draining the liver have high pressure likely due to poor heart pumping action. Over time this can cause scarring of the liver. Best treatment for low heart pumping (heart failure) includes correcting cause of heart failure, a combination of medicines- ACE inhibitors, aldosterone antagonists, ARB medicines and beta blockers, salt and fluid restriction, water pill like Lasix (furosemide).
Liver . I am assuming this was finding on a liver ultrasound. It has to be looked in the larger context of your history and symptoms. It by itself suggest that the there may be issues with the drainage of the portal blood to the central vein. The cause list is long and has to be looked at in context of the patient. The full report needs to be looked at. Best of luck .