A preliminary study on the combination of high iodine flow rate and high noise index in reducing the radiation dose of CT angiography for head and neck / 中国医学装备

Objective:To carry out preliminarily study on the combination of high iodine flow rate (IDR) and high noise index (NI) in reducing radiation dose of CT angiography (CTA) for head and neck.Methods:A total of 120patients with lesions on head and neck who underwent head and neck CTA in the hospital were divided into high IDR combined with high NI group (high IDR+NI group, 50 cases) , middle IDR combined with middle NI group (middle IDR+NI group, 40 cases) and low IDR combined with low NI group (low IDR+NI group, 30 cases) according to the random number table method.The scanned images were reconstructed by the iterative reorganization algorithm (ASiR) 2.0.The CT values of head and neck, signal to noise ratio (SNR) , contrast noise ratio (CNR) of all images in three groups were analyzed objectively and scored subjectively.And the CT dose index (CTDI) , dose length product (DLP) , effective radiation dose (ED) of the iodine intake and radiation dose were recorded.Results:The differences of CT value of ascending aorta, upper common carotid artery or lower internal carotid artery among the three groups were no significant, respectively.The SNR and CNR in high IDR+NI group were significantly higher than those in middle IDR+NI group and low IDR+NI group (F=47.908, F=52.525, P<0.05) , respectively.And there was no significant difference in subjective scores among the three groups.The differences of CTDI, DLP and ED in high IDR+NI group were significantly lower than those in middle IDR+NI group and low IDR+NI group (F=224.861, F=199.610, F=412.443, P<0.05) , respectively.Conclusion:The combination of high IDR and high NI for patients who undergoes head and neck CT can reduce the radiation dose when ensure the image quality, and it is worthy in clinical application.

Radiation dose reduction to the lens of eye with bismuth shielding in head and neck MSCT / 中华放射医学与防护杂志

Objective To explore the effects on image quality and dose reduction to the lens when using bismuth shielding in head and neck MSCT.Methods The standard phantom and the cadaveric head with none,1,2 and 3 layers of bismuth shielding were scanned with protocols of brain,temporal bone and paranasal sinuses using a 16-MDCT scanner.The organ dose to the lens in each scanning was measured with thermoluminescence dosimeters(TLD).The above scanning with sinus protocol was repeated with a sponge with thickness of 5,10,15 and 20 mm placed between the shielding and phantom/head.The CT attenuation of phantom with the distance of 2,4,6 and 8 cm to shielding were measured.The image quality was subjectively evaluated by 2 physicians.Results The organ doses of the lens with protocols of brain,temporal bone and sinuses were 24.31,27.60 and 20.01 mGy,respectively.The doses were decreased significantly when using bismuth shielding.With the increase of the shield gap,the degree of dose reduction was reduced,but the increasing degree of CT attenuation significantly reduced.Using 2-layer and 3-layer bismuth shield in brain and temporal bone CT scan,the radiation doses were reduced by 47.1％ and 59.1％,respectively while maintaining the diagnostic image quality.Using 1-layer shield without gap and 2-layer shield with 1.5 cm gap in sinus CT,the radiation doses were reduced by 31.5％ and 34.5％,respectively.Conclusions Reasonable usage of bismuth shielding can effectively reduce the radiation dose to the lens of eye in head and neck MSCT.

Non-Recurrent Inferior Laryngeal Nerve in Thyroid Surgery: The Usefulness of Preoperative Neck CT and Clinical Review / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: We investigated the expression of glucose uptake transporter-1 (GLUT-1) and epidermal growth factor receptor (EGFR) in the head and neck squamous cell cancer (HNSCC) and their influence on survival rate. We also aimed to demonstrate the relationships between the expressions of GLUT-1 and EGFR and the maximal standardized uptake values (mSUV) of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET). SUBJECTS AND METHOD: Surgical specimens from 50 patients with HNSCC, who had undergone surgical intervention, were first processed for tissue array and then for immunochemistry for GLUT-1 and EGFR. Expressions of GLUT-1 and EGFR were analyzed according to the differentiation of tumor, T & N stage and invasiveness of the tumor etc. The relationship between PET-mSUV and the expressions of EGFR and GLUT-1 was evaluated as well as its possibility as a prognostic factor of SUV. RESULTS: The expression of EGFR was significantly high in the lymph node of the positive group. Associated with the expression of GLUT-1, a tendency of increased index score (IS) values in the advanced T stages was observed but it was not statistically significant. The mSUV in FDG-PET showed statistically significant association with the maximal tumor size (pearson correlation 0.569, p=0.023); however, no association with GLUT-1 and EGFR was observed. A universal strong expression of GLUT-1 could have made it difficult to figure out statistically significant correlations. Disease free survival was to be influenced by T stage, moderate and poor differentiation and GLUT-1 expression. Only the T stages had independent significance in the multivariate analysis using the Cox regression model. CONCLUSION: We found that the expression of GLUT-1 could not show statistically significant correlation with PET-mSUV. Since the expression of EGFR has significant correlation with lymph node metastasis, EGFR may have the possibility of being a target for anticancer molecular therapy.

Comparison of Neck CT and ¹⁸F-FDG PET-CT for Making the Preoperative Diagnosis of Lymph Node Metastasis in Papillary Thyroid Cancer / 대한내분비외과학회지

PURPOSE: Lymph node metastasis is one of the most important prognostic factors for patients with papillary thyroid cancer. In this study we compared the diagnostic accuracy of neck CT with that of ¹⁸F-FDG PET-CT for the preoperative evaluation of lymph node metastasis. METHODS: We reviewed the medical records of 56 patients who received surgery for papillary thyroid cancer at the Department of Surgery, Konkuk University Medical Center, from August, 2006 to January, 2009. All the patients were checked with neck CT and ¹⁸F-FDG PET-CT preoperatively for evaluating their lymph node status. RESULTS: Neck CT showed a sensitivity of 40%, a specificity of 74.2%, a positive predictive value of 55.6%, a negative predictive value of 60.5% and an accuracy of 58.9%. ¹⁸F-FDG PET-CT showed a sensitivity of 48%, a specificity of 80.6%, a positive predictive value of 66.7%, a negative predictive value of 65.8% and an accuracy of 66.1%. ¹⁸FFDG PET-CT had greater sensitivity, specificity, positive predictive value, negative predictive value and accuracy than did neck CT (P=0.02) for predicting lymph node metastasis in patients with papillary thyroid cancer. CONCLUSION: ¹⁸F-FDG PET-CT can be more dependable than neck CT for preoperatively assessing lymph node metastasis in patients with papillary thyroid cancer.

Cervical Spondylolysis in Child with Four Levels of Simultaneous Involvement: A Case Report

Cervical spondylolysis is a rare condition, and less than 100 cases have been reported in the world literature. Cervical spondylolysis is defined as a well corticated defect in the posterior element of a cervical vertebra. Although the etiology of cervical spondylolysis is unknown, its association with dysplastic changes and spina bifida occulta suggest that the lesion is congenital. Here, we describe the radiographs and CT images of cervical spondylolysis involving four levels in a 9 year old boy.

Radiological Findings of Pilomatricoma: Case Report

Pilomatricoma is a rare benign neoplasm arising from the outer sheath of hair follicles. A firm, freely movable, and well-circumscribed subcutaneous nodule is a characteristic clinical feature of pilomatricoma. Diagnosis is usually based on clinical features, and surgical excision is performed without the use of imaging. Radiological evaluation has been used primarily as a means for differentiating pilomatricoma from other tumors or inflammatory conditions and also for examining unusually large or aggressive tumors. As a result it is important to be familiar with radiological characteristics of pilomatricoma. In this report, three cases of pilomatricoma from a pool of 28 pathologically confirmed cases are examined. Characteristic radiological findings of pilomatricoma are well-defined, oval shaped subcutaneous nodules adherent to the overlying skin with various amounts of calcification on plain radiography, CT scan, and ultrasound.

Jugular Bulb Diverticulum Combined with High Jugular Bulb: A Case Report with CT and MRA Findings

Jugular bulb diverticulum is a rare condition that is characterized by the outpouching of the jugular bulb, and this can lead to hearing loss, tinnitus and vertigo. A few reports have revealed the radiologic findings about jugular bulb diverticulum, but none of them have described the MRA findings concerning this lesion. We present here the CT and MR venography findings in regards to a large high jugular bulb and diverticulum we observed in a 47-year-old woman.

Squamous Cell Carcinoma Arising from SecondBranchial Cleft Cyst: Case Report

Primary branchiogenic carcinoma is a rare malignant tumor resulting from the malignant transformation of a branchial cleft cyst. In the case we describe, CT scanning and ultrasonography demonstrated the characteristic findings of a second branchial cleft cyst located in the anterior triangle of the neck, along the anterior margin of the sternocleidomastoid muscle. This lesion presented as a well-defined cystic mass with a thick irregular inner wall and central septa, and associated multiple neighboring necrotic lymph nodes. Microscopic examination revealed a transition zone from squamous epithelium to squamous cell carcinoma.

Measurement of Normal Size of Styloid Process with 3D Reconstruction CT

PURPOSE: To measure the normal size of the styloid process using 3D (three-dimensional) reconstruction CT. MATERIALS AND METHODS: We retrospectively analyzed 3D reconstruction images obtained after coronal and axial CT scanning of the temporal bone or neck of 115 patients. The length and shape of both sides of the styloid process, the location of its tip, and calcification of the stylohyoid ligament were retrospectively analysed. RESULTS: The mean length of the styloid process was 26.6 (+/-7.9)mm on the right side, and 26.4(+/-8.3)mm on the left, a statistically insignificant difference (p=0.694). Its mean length was 26.2 (+/-8.5)mm in men and 26.7 (+/-7.2)mm in women, a statically in significant difference (p=0.733). As for variation with age, mean length tended to increase until the third decade, but not beyond. Segmental type (104/230, 45.2%) and fragmental type (73/230, 31.7%) were more commonly seen in shape of styloid process, and tapering tip of styloid process (156/230, 67.9%) is more commonly seen than clubbing tip of it (74/230, 32.1%). The process was angulated in six cases (2.6%); its tip was more frequently located between the internal and external carotid artery (211 cases, 91.7%) than more medially (19 cases, 8.3%). In the former location, the length of the process was 26.2(+/- 7.2)mm, and in the latter, 37.0(+/-6.0)mm. The difference was statistically significant (p=0.000). Calcification had occurred in 33 cases (14.3%). CONCLUSION: The length of a normal styloid process was 18-32 mm. There were no statistically significant differences between its two sides, or between the sexes. Length tended to increase until the third decade, but not beyond. Predominantly the tip was located between the internal and external carotid artery, though the process was longer when its tip was located medially.

Second Branchial Cleft Cyst of the Oropharyux: A Case Report

We report a very rare type of second branchial cleft cyst located at the oropharynx, and include a review of the literature. CT scans of the neck revealed a homogeneous non-enhancing low-density mass in the right posterolateral mucosal wall of the oropharynx. Only the peripheral capsule of the mass was enhanced. The cyst was resected perorally and proved to be a type-IV second branchial cleft cyst.

CT Findings of Supraglottitis in Adults

PURPOSE: To determine the CT findings and to evaluate the role of CT scanning in adult supraglottitis. MATERIALS AND METHODS: The CT findings of five male patients aged between 29 and 69 (mean, 53) years with adult supraglottitis were reviewed and evaluated. Particular attention was focussed on swelling of epiglottis and laryngeal structures, abscess formation and extension of the inflammatory process to adjacent neck spaces. In addition, the findings of CT were compared with those of plain radiography. RESULTS: In all patients, CT revealed swelling of the epiglottis and aryepiglottic folds, while in four, swelling of the paralaryngeal space was noted. Abscesses in the epiglottis were seen in four patients, and in three of these, small abscesses in the preepiglottic, parapharyngeal, or peritonsillar space or palatine tonsil, were also noted. One patient had an emphysematous epiglottitis, and in three, inflammation extended to adjacent regions of the neck, namely the parapharyngeal, retropharyngeal, submandibular, or peritonsillar space. Plain radiographs gave only restricted information regarding abscess formation and the extension of inflammation to adjacent neck space. CONCLUSION: CT is useful for assessing the extent of adult supraglottitis and for evaluating ensuing complications. It may also be useful for differentiating this condition from other supraglottic diseases, for the planning of treatment, and for evaluating the results of therapy.

CT Findings of Kikuchi Disease: Correlation with Pathologic Findings

PURPOSE: To evaluate by means of retrospective analysis of neck CT scans the CT findings which suggest kikuchi disease. MATERIALS AND METHODS: The authors evaluated the CT findings of seven cases of Kikuchi disease histologically confirmed by excisional biopsy. Four males and three females aged between 12 and 43 (mean; 28) years were included. The authors retrospectively analyzed distribution, bilaterality, the presence of aggregation, the presence of intranodal low density after contrast enhancement, the number, size, shape and location of areas of intranodal low density, and the presence of extracapsular extension in involved nodes, as seen on pre- and post-contrast CT scans. Attempts were then made to correlate the CT with the pathologic findings. RESULTS: The range of conditions affecting patients included palpable(7/7) and tender (6/7) nodes, fever(5/7), night sweat(2/7), leukopenia(2/7), and weight loss(1/7). The internal jugular and spinal accessory chains were involved in all seven cases, followed by the submandibular(6/7), submental(5/7), supraclavicular(1/7) and axillary( 1/7) nodes. The findings observed also included bilateral involvement of the internal jugular chain(6/7), the spinal accessory chain(5/7), and the submandibular(4/6) and supraclavicular nodes(1/1). CT revealed that in all cases, pathologic lymph nodes showed aggregation in one or several nodal groups, namely a mixed homogeneous( mean, 60%) or inhomogeneous(mean, 40%) enhancement pattern; intranodal low densities with the number(1 -7), size(1 -7mm) and shape(oval, round, or elongated) of varying degree and predominantly ( 92%) peripheral location, and extracapsular extension. CONCLUSION: The CT findings which suggest Kikuchi disease in cervical lymphadenopathy were (1) involvement varying from no intranodal low density to prominent intranodal low densities; (2) intranodal low densities, with the number, size and shape of varying degree and predominantly peripheral location, which were correlated with pathologic findings, including variable intranodal areas of necrosis areas in mainly cortical and paracortical regions of nodes.

Primary Malignant Lymphoma of Larynx: A Case Report

Primary malignant laryngeal lymphoma is rare. In this case, diffuse wall thickening of the vocal cord and infraglottic larynx was seen on initial CT scan. After chemotherapy, follow-up CT neck scans showed a marked decrease of diffuse wall thickening of the vocal cord and infraglottic larynx ; diffuse laryngeal wall thickening is, however, a nonspecific finding which can be seen in other disease processes. If clinical evidence of infection and inflammation or remarkable change after antibiotics treatment is not definite, biopsy should be performed to rule out laryngeal lymphoma.

Pleomorphic Adenoma Arising from Heterotopic Salivary Gland Tissue in the Neck: A Case Report

We report a rare case of pleomorphic adenoma arising from heterotopic salivary gland tissue in the upper neck. Although it is difficult to differentiate this condition from lymph node diseases-including metastasis- on the basis of radiologic findings alone, it should be included in the differential diagnosis of a solitary unilateral solid cervical mass, particularly one in the upper neck.

Dynamic CT Findings of Bilateral Castleman Disease in the Neck: A Case Report

We present a case of hyaline vascular type Castleman disease involving the bilateral cervical lymph nodes. To our knowledge, no previous case of this localized form of the disease has been reported. Dynamic CT demonstrated a hypervascular pattern of enhancement, with central less enhanced areas that corresponded histologically to fibrosis. For the diagnosis of this uncommon lymph node disease, these findings might be helpful.

Kikuchi Disease in the Neck: CT and US Appearances

PURPOSE: This study was undertaken to evaluate the CT and ultrasonographic characteristics of Kikuchi disease showing cervical lymphadenopathy. MATERIALS AND METHODS: We evaluated the radiological findings of seven patients with histologically proven kikuchi disease. Two males and five females aged between 14 and 27 years(mean, 24.8)were included. Contrast enhanced CT scan was performed in six patients, and US in two. RESULTS: Clinical symptoms presented included palpable cervical lymphadenopathy(n=7), fever(n=5) and tenderness(n=6). In five patients, CTshowed upper and middle internal jugular chains and spinal accessory chains, right lower internal jugular chainand right supraclavicular node in one. Five of seven patients had bilateral involvement. On contrast-enhancedCT(n=6), homogeneous lymph node enhancement was seen in three patients with isodense enhancement in two, and hyperdense enhancement in one patients. Another three patients had inhomogeneously enhanced lymph nodes with central low density. Extranodal extension was seen in five. On US(n=3), the nodes were homogeneously isoechoic and smoothly marginated in two patients, and another patient had inhomogeneous lymph nodes with central hypoechogenicity and a thick rim. CONCLUSION: Clinical and radiological finding in our Kikuchi disease patients were nonspecific, and the diagnosis should be established only after lymph node biopsy. We suggest that Kikuchi disease be should included in the differential diagnosis of conglomerated cervical lymphadenopathy, especially inyoung women.