Hypodense cerebral venous sinus thrombosis on unenhanced CT: Time-dependent change of CT attenuation in intravenous thrombus

Cerebral venous sinus thrombosis (CVST) is an important cause of stroke, which accounts for 0.5%-1% of all strokes. CVST is principally manifested as headaches, papilledema, psychiatric symptoms, impaired consciousness and seizure disorders, with or without neurological defects.We encountered a case of CVST after subacute phase, revealing a hypodense thrombus in the superior sagittal sinus (SSS) on unenhanced CT. Retrospective observation of the serial unenhanced CT images taken at another hospital showed that the SSS thrombus changed from high to low attenuation for 10 days.RBCs dominant CVST at acute phase shows high attenuation on unenhanced CT and is effective for heparin therapy, whereas CVST after subacute phase shows low attenuation on unenhanced CT by the thrombus contents of fibrin, hemosiderin and collagen, and may be ineffective to heparin therapy. Therefore, it is important to accurately identify high attenuation of the CVST at acute phase on unenhanced CT and treat with heparin as early as possible

Massive true thymic hyperplasia with osseous metaplasia

True thymic hyperplasia is defined as an increase in both the size and weight of the gland, while maintaining a normal microscopic architecture. Massive true thymic hyperplasia is a rare type of hyperplasia that compresses adjacent structures and causes various symptoms.Limited reports address the imaging findings of massive true thymic hyperplasia. Herein, we report a case of massive true thymic hyperplasia in a 3-year-old girl with no remarkable medical history. Contrast-enhanced CT revealed an anterior mediastinal mass with a bilobed configuration containing punctate and linear calcifications in curvilinear septa, which corresponded to lamellar bone deposits in the interlobular septa. To our knowledge, this is the first report of massive true thymic hyperplasia with osseous metaplasia. We also discuss the imaging features and etiology of massive true thymic hyperplasia with osseous metaplasia

Choroid plexus and pituitary gland hemochromatosis induced by transfusional iron overload: Two case reports

Hemochromatosis is a primary or secondary pathological condition characterized by the deposition of excess iron in the body tissues, which can eventually lead to cellular damage and organ dysfunction. Although excess iron deposition in the central nervous system is rare, involvement of the choroid plexus, pituitary gland, cortical surfaces, and basal ganglia has been reported to date. This case report describes 2 cases of transfusion-induced hemochromatosis involving the choroid plexus and pituitary gland, which were diagnosed by magnetic resonance imaging (MRI). In both cases, gradient echo (GRE) sequences, such as T2 star-weighted image and susceptibility-weighted imaging demonstrated markedly low signal intensity in the choroid plexus. Furthermore, the pituitary gland showed low signal intensity on T2-weighted images in Patient 2. Because these low signal intensities were not seen prior to red blood cell transfusion, they were diagnosed with transfusion-induced hemochromatosis. Brain MRI with GRE sequences was useful in detecting iron deposition in the choroid plexus. Considering that iron deposition in the body tissues can lead to irreversible organ damage, MRI with GRE sequences should be considered for patients with suspected iron overload