title: Identification of internal carotid artery dissection by transoral carotid ultrasonography.
abstract: OBJECTIVE
  Conventional transsurface carotid ultrasonography (TSCU) via the cervical surface often fails to detect dissection of the extracranial internal carotid artery (ICA). The role of transoral carotid ultrasonography (TOCU) in the detection of ICA dissection was examined.
  
  
  METHODS
  Patients with unilateral extracranial ICA dissection identified by digital subtraction angiography (DSA) from our database of patients with ischemic stroke or transient ischemic attack (TIA) were reviewed. Findings of dissection were compared between TSCU and TOCU.
  
  
  RESULTS
  Eight patients (7 men, 37-69 years old), including 7 with ischemic stroke and 1 with TIA, had ICA dissection. By DSA, dissection was identified between the first and third vertebrae in 4 patients and from the third cervical vertebra to the intracranial level in the remaining 4. TOCU images revealed an intimal flap as definite evidence of dissection in all patients. In 7 patients, color flow signals were not seen in false lumens, indicating thrombosed lumens. Four patients showed morphological changes of dissection on follow-up TOCU, including a patient with recovery of color flow signals in false lumens. The diameter of the dissected ICA was 7.3 ± 0.7 mm and that of the contralateral ICA was 4.9 ± 0.6 mm (p = 0.008). In contrast, TSCU did not enable any conclusive findings of ICA dissection to be made in any patient. Six patients had intramural hematoma on T(1)-weighted MRI, and 2 had an intimal flap with a double lumen on magnetic resonance angiography.
  
  
  CONCLUSIONS
  TOCU has advantages over TSCU in achieving an accurate diagnosis and follow-up evaluation of ICA dissection.
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Suzuki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Koga
authors.forename: Kazunori
authors.initials: K
authors.lastname: Toyoda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Uemura
authors.forename: Hikaru
authors.initials: H
authors.lastname: Nagasawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yakushiji
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriwaki
authors.forename: Naoaki
authors.initials: N
authors.lastname: Yamada
authors.forename: Kazuo
authors.initials: K
authors.lastname: Minematsu
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D020215:Carotid Artery, Internal, Dissection / Q000150:complications / Q000000981:diagnostic imaging*; D002344:Carotid Body / Q000000981:diagnostic imaging*; D016208:Databases, Factual; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000000981:diagnostic imaging; D009460:Neurologic Examination; D012307:Risk Factors; D020521:Stroke / Q000209:etiology; D014463:Ultrasonography