Imaging On Call takes Quality Assurance in teleradiology very seriously.
Our radiologists are tested on real studies by our Teleradiology Quality Assurance Officer and Chief Radiologist prior to being offered a position with Imaging On Call. We keep detailed statistics on each reading radiologist and also send quarterly Quality Assurance reports to each customer detailing our performance. If a customer ever feels that there is a problem, we will act quickly to take any necessary corrective action.
Because IOC provides teleradiology services to many different hospitals and imaging centers across the country, our radiologists are often faced with rare and challenging studies. Below you’ll find one of our most interesting studies including the patient history, type of exam, IOC preliminary report, hospital radiologist’s final report and the surgical report.
Case study: 22 year old female with worsening headache
On nonenhanced CT, abnormal high density (representing thrombus) can be seen in the inferior sagittal sinus (1a)
vein of Galen (1b)
straight sinus (1c)
Sagittal reconstructed MR venogram shows complete lack of visualization of the inferior sagittal sinus, vein of Galen and straight sinus (arrows).
Diagnosis:
Inferior sagittal sinus, vein of Galen, and straight sinus thrombosis
Discussion:
Dural sinus/cerebral venous thrombosis is an uncommon form of venous thrombosis that involves the dural sinuses and veins of the brain. Obstruction of these vessels can result in backup of blood into the capillary system and resultant poor arterial perfusion to the involved tissue and tissue congestion, with resulting brain infarction.
The patient usually presents with worsening headache, sometimes with nausea and vomiting. If the lateral sinuses are involved, cranial nerve palsies are possible. As the brain tissue becomes congested, seizures, stroke and associated symptoms can occur. These venous infarcts can be hemorrhagic, and mass effect by the bleed can worsen symptoms. Without treatment, mortality can be up to 48%.
Causes of, and associations with, dural sinus/venous thrombosis include: hypercoagulable states & various hematologic diseases (e.g.: protein C deficiency, sickle cell); collagen vascular disease; some medications (such as oral contraceptives); nephrotic syndrome; inflammatory bowel disease; pregnancy and puerperium; and infections, such as meningitis & mastoiditis.
The most commonly involved dural sinuses are the superior sagittal sinus and the lateral sinuses. This case is of particular interest, since the thrombosis exclusively involved the deeper inferior sagittal sinus, straight sinus, and vein of Galen. There have only been a limited number of case reports of thrombosis involving these vessels.
The most sensitive imaging modalities include CT and MRI. Nonenhanced CT may show high density in the affected vein(s), representing thrombus. Sometimes the high density can be mistaken for blood, as in this case, where the initial suspicion at an outside institution was for parafalcine subdural hematoma. On enhanced CT, the clot manifests as a filling defect within the affected vein. MRI and MRV will show the abnormal sinuses/veins as vessels with lack of flow voids. Slow blood flow, however, can mimick thrombus on MRI.
The most common treatment involves anticoagulants, which help stabilize the thrombus and prevents progression. In the case of hemorrhage, the benefits of anticoagulation need to be weighed against the possibility of worsening bleeding due to anticoagulants. In carefully selected cases, direct catheter thrombolysis can be performed.
