Application Of256-row Spiral CT And Ultrasound In The Diagnosis Of Aortic Intramural Hematoma

Objectives: To evaluate the clinical value of256-row Spiral CT andUltrasound in the diagnosis of aortic intramural hematoma(IMH).Methods：Between January2009and January201127patients (male19,female8) who were examined by256-row Spiral CT and Ultrasound werediagnosed with IMH. Scanner is Philips Brilliance256-row CT. Scan range isfrom thoracic entrance to bilateral common iliac artery.Double tube highpressure syringe inject a contrast agent.①Non ionic contrast media Ultravist(Utravist, Sehefing) is about70~80ml with the speed of4.5ml/s；②Thesaline of30~40ml with the speed of3.0ml/s were injected simultaneouslylinked scan.The first line elbow venous puncture vein passage, the patientsupine scan posteroanterior and lateral positioning, set monitoring level ontracheal carina1cm level, region of interest (ROI) in the thoracic aorta, thetrigger threshold for100Hu.Contrast injection after10s using Bolus Trackingsoftware1s interval scan monitoring aortic arch level of contrast agentconcentration changes, reach120Hu automatically triggered when scanning.Scanning parameters: voltage120kv, current250mAs, thickness of1mm,0.8mm interval matrix layer,512x512, DFOV to350mm, collimator(Collimation) width:64x0.625, pitch (Pitch):0.704, scan time is12~14s,Rotation time:0.5sec.The clinical data and images findings were analyzed.Results: The CT angiographic(CTA) direct features of aortic IMH werecircular or crescent thickening of aortic wall without intimal flap as well asfalse and true lumen. The aortic wall was significantly thicker, acrescent-shaped, annular or circular concentric thickening, thickness≥5mm.Scan the wall thickening and the lumen of the aorta in density, cannoteasily distinguish, only a few cases showed mixed density or hematoma formation during the acute phase of tube wall for high density, adapted into anarrow window width can be distinguished, after contrast agent injection tubewall thickening is slightly enhanced, CT value of about55~80Hu, with normalfull of contrast agent in the lumen of the aorta contrast between the two, notraffic.Range of lesions involving the aorta, or involving the aortic full. Bymeasuring the thickness of hematoma, cross-sectional images of hematoma atthe maximum transverse diameter of the lumen of the artery, through thethickness of hematoma and hematoma at the maximum transverse diameter ofthe arterial lumen ratio can reflect the local vascular dilation, and contribute tothe diagnosis of IMH.Sometimes hematoma edge can see annular high densityreinforced ring, prompting the IMH may be due to nutrient artery rupturecaused by high density, intensive ring may vessel wall hyperplasia caused bynutrient artery imaging. Such as aortic thickening in3~5mm, though notreached IMH diagnostic criteria, but clinically should be closely observed, maybe the hematoma in the early state.The indirect features were asfollows,penetrating ulcer(14cases),:displacement of intimal calcification (18cases), pleural effusion(14cases).atherosclerosis (15cases).Among the27cases, Stanford A type and Stanford B type were involved in12and15,respectively.The complication signs were true aneurysm (3cases) of15Stanford B type IMH. The diagnostic accuracy of Ultrasound were29.6%,whileThe diagnostic accuracy of. CT were100%They are different(P<0.05),Conclusion:256row CT in displaying the IMH aortic wall thickening,penetrating ulcer, calcification within shift and pleural effusion were superior toultrasound examination, the Z axis high resolution, so that the image to achievea real isotropic, coupled with a variety of processing technology of integratedapplications can well show the lesion of vascular morphology, range, as well asbranch involvement after treatment technology, including volume rendering(VR), maximum intensity projection (MIP), multiple planar reconstruction (MPR), surface recombination (CRP), virtual endoscopy (VE), the postprocessing techniques have a characteristic each, in the diagnosis of vasculardiseases can complement each other. At the same time, CTA thanultrasonography image strong integrity, could account for the clinical operationdoctors with lesions of the aortic vascular picture, facilitates the operationscheme. CTA can be IMH and Takayasu’s arteritis, mural thrombus as well astypical AD differential open, not only can be diagnosed early, after review andassessment has important application value. Multi row spiral CT original axialimage in display mural thrombus, determine the tube wall plaque, display tubewall calcification and calcified plaque shift also has unique advantages.Ascending aortic pulsatile motion artifacts generated on vascular imagingeffect is larger, sometimes even will strip of motion artifact mistaken for aorticdissection in the film, the application prospective ECG gated scan technique inaortic examination can effectively reduce ascending aortic pulsatile motionartifacts generated, but also reduce the patients affected by ray dose at the sametime, to ensure the radiologists to make accurate diagnosis, for clinical provideshigh quality images.256-row Spiral CT is a noninvasive,safe and fast method for the diagnosisof aortic IMH and can show the direct and indirect signs of aortic IMH.256-row Spiral CT has his clear advantages. All these signs have importantvalue for clinical diagnosis and treatment.