Clinical diagnosis
Case 326
【Discussion】
In a clinical reality, brain hemorrhage, hemothorax, gastrointestinal bleeding, intraperitoneal bleeding, pericardial hematoma, and subcutaneous hemorrhage, are often encountered. They are sometimes fresh, relative fresh and aging. CT values of fresh, relative fresh or aging might be different. How makes them differentiate using CT values?
It is known that aortic ring sign and interventricular septum sign presents in patients with anemia (1). CT values of less than 30 HU are also indicative of anemia (2). CT values of Case 1 with subdural hematoma are instructive: CT values of high attenuation in lower part of hematoma are 51 HU, while those of low attenuation in upper part of hematoma are 19 HU. This indicates coagulation or red blood cell accumulation can increase more than 50, plasma or hemolytic fluid decrease less than 20. Namely, CT values of whole blood with mixture of red blood cells and plasma are 30-40 HU.
Measuring CT values of hematoma might be useful to suspect aging of hematoma. CT values of fresh hematoma should be the same as those of great vessel lumen of 30-40 (3). As time progress a bit, fresh hematoma separates into coagula and plasma, CT values of coagula component increase and those of fluids component decrease. In Case 3 with retroperitoneal hemorrhage from small aneurysm pancreatic arcade branch artery probably due to pancreatitis, CT values of hematoma were 49.8 – 54.9, indicative of fresh to relatively fresh hemorrhage.
Meanwhile, in Case 2, CT values of pericardial effusion were 19, indicative of no blood cells but plasma or hemolytic fluids. The patient received pericardial drainage. The draining fluids of this case were green-red-dark colored, indicative of hemolytic fluids. Namely, pericardial fluids are not fresh hematoma but old, gradually increasing hematoma and inducing hemolysis (4-6). First, we were afraid that increased pericardial effusion might lead tamponade and then, speedy pericardial drainage was conducted. The treatment process was not problematic, but the patient might have had time to spare.
【Summary】
We presented three cases: with subdural hematoma, with pericardial hem fluid and with abdominal bleeding. Subdural hematoma composed of two parts; high attenuation part, CT values 51 HU: low attenuation part, CT values 19. CT values of pericardial fluids are 19 HU, dark green colored fluid by drainage, indicative of aged bleeding or hemolytic fluids, and CT values of retroperitoneal bleeding from pancreas arcade branch aneurysm due to pancreatitis are 49.8-54.9 indicative of relatively fresh bleeding. It is borne in mind that CT values of fresh bleeding are 30-40HU, those of coagula, 50 or greater and plasma or hemolytic fluids are less than 20HU. Further, CT values of less than 30 indicate marked anemia associated with radiological findings of aortic ring sign and ventricular septum sign.
【References】
1.Abbasi B, et al. Evaluating anemia on non-contrast thoracic computed tomography. Scientific Reports volume 12, Article number: 21380 (2022)
2.Chaudhry AA, et al. Quantitative Evaluation of Noncontrast Computed Tomography of the Head for Assessment of Anemia. J Comput Assist Tomogr 2015 Nov-Dec;39(6):842-8
3.Kaewlai R, Avery L, Asrani A, Novelline R. Multidetector CT of Blunt Thoracic Trauma. Radiographics. 2008;28(6):1555-70.
4.Lubner M, Menias C, Rucker C et al. Blood in the Belly: CT Findings of Hemoperitoneum. Radiographics. 2007;27(1):109-25.
5.Restrepo CS, Lemos DF, Lemos JA et-al. Imaging findings in cardiac tamponade with emphasis on CT. Radiographics. 2007;27 (6): 1595-610
6.Wang Z, Reddy G, Gotway M et-al. CT and MR Imaging of Pericardial Disease1. Radiographics. 2003;23 (suppl 1): S167-S180.
2024.3.5