PURPOSE: We retrospectively performed this study to evaluate the characteristic findings of maxillomandibular ameloblastomas on CT and MR imaging. MATERIAS AND METHODS: We reviewed histologically proved 12 cases of ameloblastomas, of which 7 cases were postoperative recurrent tumors. one of twelve cases was presumed ameloblastic carcinoma. Eleven cases were examined with CT and 3 cases with MR. RESULTS: The types were solid in 4, unicystic in 4, and mixed in the rest 4. CT and MRI of 11 ameloblastomas showed concentric expansile mass(n=11), cortical bone thinning and focal bone destruction by the tumors(n=9), well-margined, expansile destruction of surrounding sturctures(n=9), focal bulging of the tumors(n=6) and focal poorly-marginated invasion of tissue planes(n=4). Ameloblastic carcinoma showed ill defined irregular margin, aggressive invasion of surrounding structures and hematogeneous lung metastasis. Unerupted teeth or mural nodules were found in unicystic ameloblastomas. All three tumors examined by MRI showed isointensity to muscle on T1 weighted images and slight hyperintensity on T2 weighted images. The wall, septa and solid portions of the tumors were strongly enhanced on MR imaging. There was no difference in CT or MR finding between primary and recurrent tumors. CONCLUSION: Ameloblastomas showed solid, cystic or mixed pattern, and commonly well marginated expansile contour with local aggressiveness. Presence of mural nodules on CT in unicystic ameloblastoma with unerupted tooth was helpful in distinguishing ameloblastoma from dentigerous cyst.
Abdominal Pain ; Ameloblastoma* ; Ameloblasts ; Body Temperature ; Catheters ; Dentigerous Cyst ; Ethanol* ; Follow-Up Studies* ; Humans ; Kidney ; Liver ; Lung ; Magnetic Resonance Imaging* ; Neoplasm Metastasis ; Recurrence ; Retreatment ; Retrospective Studies ; Sleep Stages ; Tooth, Unerupted ; Ultrasonography

We retrospectively analyzed the Magnetic Resonance (MR) imaging findings in 41 cases of histologically proved malignant tumors of oral cariey. The diagnostic value of MR imaging in detection and delineation of the lesions was assessed. The value of MRI was compared with that of Computed Tomography (CT) in 14 patients. Thirty-four cases of 41 malignant tumors were squamous cell carcinomas. Adenoic cystic carcinomas (2 cases), malignant melanomas (2 cases), non-Hodgkin lymphomas (2 cases) and mucoepidermoid carcinoma(1 cases) were also included in this study. Most of the lesions were isointense or slightly hyperintense to muscle on T1 weighted images and showed variable degrees of high signal intensity on T2 weighted images. Two cases of malignant melanomas showed characteristic hyperintensity on T1 weighted images. T2 weighted image was better in detection and delineation of tumor in most of the cases. In 6 cases, Gd-DTPA-enhanced T1 weighted image was better than T2 weighted image. T2 weighted image was useful for the evaluation of deep tissue infiltration and T1 weighted image was useful for the evaluation of bone invasion and superficial tissue plane invasion. The lesion was detected only by MR in 3 cases of 14 in which CT was also performed. MR imaging was more sensitive in the evalustion of bone marrow involvement. MR imaging is very useful modality in evaluating oral cavity malignany and is superior to CT in delineation of the as well as in the evaluation of mandible invasion.
Bone Marrow ; Carcinoma, Squamous Cell ; Humans ; Lymphoma, Non-Hodgkin ; Magnetic Resonance Imaging* ; Mandible ; Melanoma ; Mouth* ; Retrospective Studies

PURPOSE: The purpose of this study is to describe the anglographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of anglographic assessmant needed before embolization. MATERIALS AND METHODS: We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous realformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n=5), branches of external carotid artery (n=2) and common carotid artery (n=3). Common carotid artery or internal carotid artery (n=9), vertebral artery (n=5), ipsilateral external carotid artery (n=4), contralateral external carotid artery (n=5), costocervical trunk (n=2), thyrocervical trunk (n=2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. RESULTS: The collateral vascular channels were inferolateral trunk of internal carotid artery (n=8), vertebral artery (n=5), contralateral external carotid artery (n=5), ipsilateral external carotid artery (n=4), deep cervical artery (n=2) and ascending cervical artery (n=l). Embolizations were performed in 9 cases with operative cannulation(n=4), embolization via collateral branches of ipsilateral external carotid artery (n=l), embolization via collateral branches of contralateral external carotid artery (n=3) and balloon occulusion via direct puncture (n=l). CONCLUSION: The collateral channels in cervicofacial vascular lesions with previouly ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete anglographic assessment of possible collateral channels is mandatory for the effective and safe embolization.
Angiography ; Arteries ; Arteriovenous Malformations ; Carotid Arteries* ; Carotid Artery, Common ; Carotid Artery, External ; Carotid Artery, Internal ; Fistula ; Hemangioma ; Punctures ; Retrospective Studies ; Vertebral Artery

Ultrasound (US) is the essential primary imaging modality for preoperative staging of differentiated thyroid cancer. Although contrast-enhanced neck CT has been routinely used for the evaluation of general head and neck malignancy, routine use of contrast-enhanced CT is not recommended for the differentiated thyroid cancer by most international thyroid societies, and they recommend very conservative selective use of CT only for locally advanced thyroid cancers. This recommendation seems based on the fact that iodinated contrast media may interfere with radio-iodine treatment and the added value of CT has been little investigated. Although the safety issue of CT contrast media is still controversial, the effect of CT contrast media on radio-iodine treatment seems not clinically significant if there is more than 2 month interval between intravascular administration of iodinated contrast media and radio-iodine treatment. Although CT has been widely used for preoperative evaluation of differentiated thyroid cancers in Korea, the added value of CT for detection of metastatic nodes has been little investigated. Compared with US, CT has advantages of less operator dependency and capability of scanning the whole neck. This suggests that CT may have complementary roles for detection of possible missing diagnosis of metastatic nodes by US and for detection of metastatic nodes at retropharyngeal area and low central neck (level 7 and low level 6 in some cases) which are not accessible by US. Because CT features of metastatic lymph nodes are different from those of US, combination of US and CT may have a potential to increase the diagnostic sensitivity for detection of metastatic cervical nodes. Recent studies suggest that CT may have a helpful complementary role for the evaluation of cervical metastatic nodes in differentiated thyroid carcinoma. However, added diagnostic value of CT and indication for CT use should be further investigated in the preoperative staging of differentiated thyroid carcinomas.
Contrast Media ; Dependency (Psychology) ; Head ; Korea ; Lymph Nodes ; Neck ; Thyroid Gland ; Thyroid Neoplasms

Purpose: This study aimed to determine whether the normal parotid gland (PG) and submandibular gland (SMG) can be used as reference standards for normal thyroid echogenicity. Methods: In total, 1,302 consecutive patients with normal salivary glands were included in this study. The echogenicity of the SMG and PG was assessed during real-time ultrasound examinations, and the glands were categorized as hyperechogenic, isoechogenic, and hypoechogenic relative to the thyroid parenchyma in patients without diffuse thyroid disease (group 1, n=1,106) and with diffuse thyroid disease (group 2, n=196). The frequency of the echogenicity categories of the normal PG and SMG was assessed according to patients’ age. Results: In group 1, the normal PG showed isoechogenicity in 94.0% and hypoechogenicity or hyperechogenicity in 6.0%, and the normal SMG showed isoechogenicity in 73.6% and hypoechogenicity in 26.4% of patients (P<0.001). There was no significant association of the frequency of isoechoic PG with age (P=0.834); however, there was a trend for an increasing frequency of isoechoic SMG with aging (22.9%-81.4%) (P<0.001). Similar findings were found in group 2 patients without decreased thyroid echogenicity. Conclusion The normal PG was mostly isoechoic to the normal thyroid parenchyma, whereas the normal SMG showed hypoechogenicity at various frequencies according to age. The echogenicity of the normal PG can be used as an alternative reference standard for normal thyroid echogenicity; however, the normal SMG is not suitable for a reference standard when assessing thyroid nodule echogenicity in patients who have diffuse thyroid disease with decreased parenchymal echogenicity.

PURPOSE: The purpose of this study is to correlate the MR findings with clinical stage and clinical outcome, and to describe the evolutional changes of abnormal MR findings of transverse myelitis. MATERIALS AND METHODS: Medical records and spinal MR images of 23 patients with both clinical and radiological diagnosis of transverse myelitis were retrospectively reviewed. MR findings were correlated with clinical stages including interval between MR imaging and full development of clinical symptoms, and compared with the clinical outcome. RESULTS: Diffuse high signal intensity of the spinal cord on T2-weighted image with mild cord bulging (67%) and focal contrast enhancement of the cord (75%) were observed within the first four weeks after full development of clinical symptoms. The findings decreased in extent or vanished later than four weeks on either initial or follow-up MR images. Most patients with either cord atrophy or focal hemorrhagewithin the cord lesion had poor clinical outcome. CONCLUSION: The MR findings of transverse myelitis are nonspecific, which may be seen in a variety of diseases. Serial MRIs, especially follow up examination over at least one month after full development of clinical symptoms are useful in the diagnosis of transverse myelitis and predicting its prognosis.
Atrophy ; Diagnosis ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Medical Records ; Myelitis, Transverse* ; Prognosis ; Retrospective Studies ; Spinal Cord

PURPOSE: Subacute necrotizing myelopathy(SNM) is a rare non-tumorous disease of spinal cord characterized by subacute clinical course of progressive neurological deterioration. We report MR findings of a patient with pathologically proved SNM. MATERIALS AND METHODS: 1 case of pathologically proved subacute necrotizing myelopathy. RESULTS: The patient was a 56-year-old man with progressive motor weakness and sensory loss of the lower extremities, and urinary and fecal incontinence for 11 months. Spine MRI revealed diffuse enlargement of the thoracic spinal cord from T2 to T7 level. Signal intensity of the expanded spinal cord was isointense relative to normal cord on T1 -weighted image and hyperintense on proton-density and T2-weighted images. On contrast enhanced T1-weighted image, there was diffuse homogeneous enhancement in the expanded cord lesion. CONCLUSION: MR demonstration of stable persistence of spinal cord lesion or atrophy over months or years with clinical findings of radual progressive neurologic deterioration may be helpful in the diagnosis of SN M(1 ).
Atrophy ; Diagnosis ; Fecal Incontinence ; Humans ; Lower Extremity ; Magnetic Resonance Imaging ; Middle Aged ; Spinal Cord ; Spinal Cord Diseases* ; Spine

Ultrasonography (US) has been a primary tool for assessing malignancy risk, fine-needle aspiration (FNA) decision, and management after FNA in patients with thyroid nodules. US also has an essential role for preoperative evaluation of primary tumor and cervical lymph nodes, for surveillance of postoperative patients with thyroid cancer, and for imaging guidance for nonsurgical ablation therapy. In the revised recommendations of Korean Society of Thyroid Radiology (KSThR), Korean Thyroid Imaging Reporting and Data System (K-TIRADS), a revised risk stratification system of thyroid nodules, was suggested to increase the efficacy of FNA and provide supplementary information for thyroid nodules after FNA. The role of US assessment of cervical lymph node needs to be emphasized for optimal management decision of thyroid nodules, preoperative staging, and postoperative surveillance of patients with thyroid cancers, and CT has a complementary role for the diagnosis of metastatic nodes in patients with thyroid carcinomas.
Biopsy ; Biopsy, Fine-Needle ; Diagnosis* ; Humans ; Information Systems ; Lymph Nodes* ; Thyroid Gland* ; Thyroid Neoplasms ; Thyroid Nodule* ; Ultrasonography*