Thyroid nodules with Bethesda System IV Cytology: Can Ultrasonography Differentiate Malignancy from Benign?

PURPOSE: The purpose of this study is to identify clinical and imaging parameters that can be used in differentiation of benign versus malignancy of preoperative FNA diagnosis of Bethesda system IV nodules. MATERIALS AND METHODS: We analyzed clinical, ultrasonographic, and CT findings of 28 thyroid nodules with Bethesda system IV cytology on FNA, which were proven as follicular or Hurthle cell neoplasms on surgical pathology. RESULTS: No statistically significant differences according to age, sex, and ultrasonographic parameters, including echogenicity, margin, calcification, shape, cystic component, and degree of vascularity and enhancement on CT were observed between benign and malignant follicular neoplasms. Only the lesion size was significantly different (p<0.05). CONCLUSION: The size of follicular neoplasm is predictive of malignancy. If a thyroid nodule with the Bethesda IV cytology is larger than 24.5 mm, there will be a greater probability of malignancy.

Characteristics of Acquired beta-lactamase Gene in Clinical Isolates of Multidrug-resistant Pseudomonas aeruginosa / 대한임상미생물학회지

BACKGROUND: Recently, there have been reports of infections with multidrug-resistant Pseudomonas aeruginosa. To determine the mechanism of the resistance, we investigated the prevalence of Ambler class A and D beta-lactamases, their extended-spectrum derivatives, and class B and D carbapenemase in multidrug-resistant P. aeruginosa isolates. METHODS: During the period of March 2006 to May 2007, clinical isolates of multidrug-resistant P. aeruginosa were collected from patients in Chungnam National University Hospital, Daejeon, Korea. Inhibitor-potentiated disk diffusion tests were used for the screening of metallo-beta-lactamase (MBL) production. PCR and DNA sequencing were conducted for the detection of beta-lactamase genes. We also employed the enterobacterial repetitive intergenic consensus (ERIC)- PCR method for an epidemiologic study. RESULTS: A total of 37 consecutive, non-duplicate, multidrug-resistant P. aeruginosa were isolated. Twenty- nine of 37 isolates harbored blaOXA-10 (56.8%), blaOXA-2 (18.9%), and blaOXA-1 (5.4%). Only one isolate produced IMP-1, and it also harbored blaOXA-1. None harbored Ambler class A beta-lactamase or class D carbapenemase. The strains producing OXA type beta-lactamases showed a significantly higher resistance to aminoglycoside compared to non-producers. The ERIC-PCR pattern of the 19 OXA-10 producing strains indicated that the isolates were closely related in terms of clonality. CONCLUSION: OXA type beta-lactamases are the most prevalent among the acquired beta-lactamases produced by multidrug-resistant P. aeruginosa isolated at a university hospital in Chungcheong Province. Besides beta-lactam antibiotics, the strains harboring OXA type beta-lactamase showed a significantly higher resistance to aminoglycoside and qunolone.

Interested Cases Encountered in the Breast Clinic

Many patients present to the breast clinic with variable symptoms. The degree of palpability is the important symptom for patients and clinicians. Both mammography and ultrasonography play an important role in the diagnosis of breast diseases by indicating the cause of the symptoms and aiding in the selection of treatment for the disease. Sometimes, however, we meet unexpected results. In this paper, we will illustrate the ultrasonographic and mammographic findings of interesting, unusual or perplexing breast cases in order to familiarize ourselves with these breasts through these cases and thereby assist in future diagnosis.

Unilateral Breast Edema: Spectrum of Etiologies and Imaging Appearances

Breast edema is defined as a mammographic pattern of skin thickening, increased parenchymal density, and interstitial marking. It can be caused by benign or malignant diseases, as a result of a tumor in the dermal lymphatics of the breast, lymphatic congestion caused by breast, lymphatic drainage obstruction, or by congestive heart failure. Here we describe several conditions, that cause unilateral breast edema with the aim of familiarizing radiologists with these disease entities.

Abnormal Imaging Findings of the Breast Related to Hormone Replacement Therapy: Analysis of Surgically Excised Cases

PURPOSE: To correlate the mammographic and ultrasonographic findings with the pathologic results in women undergoing hormone replacement therapy (HRT), and to determine the characteristic clinical, mammographic or histologic findings of breast cancer in these patients. MATERIALS AND METHODS: Twenty-five breast lesions in 25 patients aged 44-65 (mean, 55.5) years undergoing HRT were surgically removed due to abnormal mammographic findings or the presence of palpable masses. Mammograms in all patients and ultrasonograms in 23 were retrospectively analyzed in terms of the shape and margin of the mass, and microcalcifications, and the imaging findings were correlated with the pathologic results. As a control group, 45 cancer patients not undergoing HRT were selected. Using the student t test, detection methods, tumor size, mammographic findings, and the proportion of intraductal cancers were compared between the two groups. RESULTS: Surgical excision revealed ten benign lesions (four fibroadenomas and six cases of fibrocystic change) and 15 cancers (three intraductal and twelve invasive ductal cancers). Abnormal findings at mammography were a mass in 16 cases, clustered microcalcifications in seven, and a mass with microcalcifications in two. Mammography showed that all four circumscribed masses were benign. Five of seven ill-defined masses (71%) and all six spiculated masses were malignant. Three of seven cases (43%) with microcalcification, and both with a mass and microcalcification, were malignant. In two cases in which ultrasonography revealed cystic lesions, histologic examination showed that fibrocystic change had occurred. Compared to non-HRT-related cancers, HRT-related cancers were more often detected by mammography (60% vs 16%; p <0.001), smaller (17 mm vs 24 mm, p <0.01), showed microcalcification only (20% vs 13%; p <0.05), and were intraductal (20% vs 7%; p <0.01). CONCLUSION: In patients with HRT, mammographic findings of an ill-defined or spiculated mass, or one with microcalcifications, were associated with breast cancer. Compared to non-HRT-related cancers, breast cancers in patients undergoing HRT tend to manifest more frequently as a mammographic abnormality, and to be intraductal.

The Effect of Supraclavicular Lymph Node Irradiation upon the Thyroid Gland in the Post-operative Breast Carcinoma Patients

To identify the effect of post-operative irradiation to the thyroid gland in patients with breast carcinoma. Seventy seven patients with partial or total mastectomized breast carcinoma who received routine irradiation therapy (Hockey stick method: supraclavicular, internal mammary lymph nodes, and chest wall irradiation with 5, 040 rads, divided into 30 treatments) were reviewed in terms of their ipsilateral thyroid gland response. All patients had the bilateral thyroid sizes measured annually by ultrasonography before and after radiation therapy. In the one-year follow-up group (n=77), 32 patients (41.5%) demonstrated decreased ipsilateral thyroid gland size after Hockey Stick irradiation therapy (p=0.428), in the two-year follow-up group (n=37), 26 patients (70.3%) demonstrated decreased gland size after Hockey Stick irradiation (p=0.001), and in the three-year follow-up group (n=21), 15 patients (71.4%) showed a decreased thyroid gland size (p=0.005). Most the patients with breast carcinoma (32/77 at the one-year follow-up, 26/37 at the two-year follow-up, and 15/21 at the three-year follow-up) after post-operative Hockey Stick irradiation therapy showed reduced ipsilateral thyroid gland size. Routine en face treatment of the supraclavicular lymph nodes, using the Hockey Stick method, should be reconsidered.

Clinical Image Evaluation of Mammograms: A National Survey

PURPOSE: The goal of this study was to survey the overall quality of mammographic images in Korea. MATERIALS AND METHODS: A total of 598 mammographic images collected from 257 hospitals nationwide were reviewed in terms of eight image quality categories, namely positioning, compression, contrast, exposure, sharpness, noise, artifacts, and examination identification, and rated on a five-point scale: (1=severe deficiency, 2=major deficiency, 3=minor deficiency, 4=good, 5=best). Failure was defined as the occurrence of more than four major deficiencies or one severe deficiency (score of 1 or 2). The results were compared among hospitals of varying kinds, and common problems in clinical image quality were identified. RESULTS: Two hundred and seventeen mammographic images (36.3%) failed the evaluation. Poor images were found in descending order of frequency, at The Society for Medical Examination (33/69, 47.8%), non-radiology clinics (42/88, 47.7%), general hospitals (92/216, 42.6%), radiology clinics (39/102, 38.2%), and university hospitals (11/123, 8.9%) (p<0.01, Chi-square test). Among the 598 images, serious problems which occurred were related to positioning in 23.7% of instances (n=142) (p<0.01, Chi-square test), examination identification in 5.7% (n=34), exposure in 5.4% (n=32), contrast in 4.2% (n=25), sharpness in 2.7% (n=16), compression in 2.5% (n=15), artifacts in 2.5% (n=15), and noise in 0.3% (n=2). CONCLUSION: This study showed that in Korea, 36.3% of the mammograms examined in this sampling had important image-related defects that might have led to serious errors in patient management. The failure rate was significantly higher in non-radiology clinics and at The Society for Medical Examination than at university hospitals.

Analysis of 193 Mammographic Phantom Images

PURPOSE: To evaluate the actual state of quality control in Korea through an analysis of mammographic phantom images obtained from a multicenter, and to determine the proper exposure conditions required in order to obtain satisfactory phantom images. MATERIALS AND METHODS: Between April and June, 2002, 193 phantom images were referred to the Korea Food and Drug Administration for evaluation. Two radiologists recorded the number of fibers, specks and masses they contained, and the "pass" criteria were as follows: checked number of fibers: four or more; specks, three or more; masses, three or more (a total of ten or more features). Images in which optical density was over 1.2 were classified as satisfactory. In addition, changes in the success ratio, and difference between the two groups (i.e. "pass" and "fail", with regard to exposure conditions and optical density) were evaluated. RESULTS: Among the 193 images, 116 (60.1%) passed and 77 (39.9%) failed. Among those which passed, 73 /100 (73%) involved the use of a grid, 80/117 (68.3%) were obtained within the optimal kVp range, 50/111 (45.0%) involved the use of optimal mAs, and 79/112 (70.5%) were obtained within the optimal range of optical density. Among those which failed, the corresponding figures were 17/52 (32.6%), 33/66 (50.0%), 31/69 (44.9%), and 35/65 (53.8%). There were statistically significant differences between the pass and fail rates, and with regard to kVp, optical density, and the use of a grid, but with regard to mAs, statistical differences were not significant. If only phantom images with an optical density of over 1.2 [as per the rule of the Mammographic Quality Standard Act (MQSA)] was included, the success rate would fall from 60.1% to 43.0%. CONCLUSION: The pass rate for mammographic phantom images was 60.1%. If such images are to be satisfactory, they should be obtained within the optimal range of optical density, using optimal kVp and a grid.

Foreign Body Granuloma and Breast Cancer in the Augmented Breast: Mammography, US, MRI, and FDG-PET

The mammographic or physical evaluation of breast parenchymal abnormalities in the presence of radiopaque implants or silicone injections is difficult; mammography often fails to discriminate between breast cancer and a radiopaque dense breast. Although the sonographic evaluation of a palpable mass in an augmented breast may be impaired by the presence of posterior acoustic shadowing, the modality may be helpful in evaluating such masses, and dynamic contrast-enhanced MR imaging facilitates differentiation. FDG-PET is a possible alternative diagnostic tool for the evaluation of parenchymal lesions under these circumstances, but its drawbacks are its high cost and limited availability. The sensitivity and specificity of both FDG-PET and MRI can be improved by correlating their findings with those of radiological studies, and through an awareness of potential false-negative and false-positive causes.

Sonographic Findings of Metastatic Disease to the Thyroid

The goal of this study was to evaluate the sonographic findings of thyroid metastases arising from non-thyroid primaries. The study over a 5-year period comprised nine patients who had histopathologically proven metastatic disease to the thyroid. Ultrasonography was available in all cases. Ultrasound-guided needle aspiration was performed on 10 suspected nodules as determined by ultrasound. The Ultrasonographic findings were analyzed in two different ways. The first analysis included only those nodules biopsed, and the second analysis included all the nodules, biopsed and non- biopsed. The primary neoplasms were breast carcinoma (n=6), uterine leiomyosarcoma (n=1), cervical carcinoma (n=1), and nasopharyngeal carcinoma (n=1). Excluding 2 nodules, the 8 remaining metastatic nodules exhibited ill-defined hypoechoic character with heterogeneous texture. The other two nodules showed relatively circumscribed iso- or hypo-echoic character with cystic portion. From the analysis of ultrasonographic findings including all thyroid nodules irrespective of pathologic proof, 7 cases - excluding the 2 cases from the 9 cases - showed unilateral or bilateral multiple nodules suspected of metastasis. There was no evidence of microcalcification in any thyroid nodules. In conclusion, the sonographic findings of the thyroid metastatic nodules were not specific, but unilateral or bilateral multiple suspected thyroid nodules without evidence of microcalcification may be suggestive of metastatic nodules among patients with a known primary non-thyroidal tumor.

Imaging Findings of Metastatic Disease to the Breast

The purpose of this study was to evaluate imaging findings of metastatic disease to the breast. We analyzed 15 cases that had been previously examined by radiographic study (comprising a total of 11 mammograms, 13 ultrasounds and 3 chest CT). Primary malignancies included the following: 6 breast cancers, 5 stomach cancers, 2 melanomas, 1 cervical cancer, and 1 lung cancer. Radiologic findings were analyzed and the 15 cases were divided into two groups: hematogeneous and lymphangitic metastasis. Eleven cases were classified as lymphangitic metastasis (73.3%) and 4 cases were hematogeneous metastasis (26.7%). Multiple masses were shown in 13 cases (86.7%), and 12 cases displayed unilateral lesions (80%). There was no evidence of calcification. In the 11 cases with available mammogram, 7 cases (63.6%) revealed multiple masses with well-defined (2 cases, 28.6%) or ill-defined margin (5 cases, 71.4%) and 6 cases (54.5%) showed diffuse increased density and skin thickening. Among the 11 cases that revealed mass lesions on ultrasound, 2 cases showed a well-defined margin (18.2%) and 9 cases showed an ill-defined margin (81.8%). Posterior shadowing of the mass was seen in only 1 case. Four cases (36.3%) showed a minimal echogenic boundary around the mass. Eight cases showed diffuse skin thickening (53.3%). Three cases with chest CT showed multiple masses and/or diffuse skin and trabecular thickening of the breast. In conclusion, the characteristic imaging findings of metastatic disease to the breast are multiple ill-defined masses with a lack of desmoplastic reaction and no calcification, as compared to primary breast carcinoma. The diffuse lesions without evidence of breast mass on mammogram and US could be distinguishable from inflammatory carcinoma of breast origin.

Mammographic and Sonographic Findings of Periductal Mastitis: A Case Report

Periductal mastitis arises from major ducts. Radiographic reports describing the phases of duct ectasia and secretory calcifications, have been published, but descriptions of the phases of periductal mastitis are rare. We report the mammographic and ultrasonographic findings of periductal mastitis in a 30-year-old woman who presented with a breast lump.

Evaluation of Results and Radiologic Follow-up in Detachable Balloon Occlusion Thera py of the Internal CarotidArtery Aneurysms

PURPOSE: The author has studied the clinical results of CT and MR findings of proximal carotid artery occlusion using detachable balloons in the treatement of unclippable internal carotid (IC) aneurysms. MATERIALS AND METHODS: From 1987 to 1995, twenty-eight patients with IC aneurysms were treated by proximal arteryocclusion with detachable balloons. Of these patients, 4 had aneurysms arising from the supraclinoid portion ofthe IC artery, 23 had aneuryms arising from cavernous portion of the IC artery, and one had aneurysm arising fromcervical portion of the IC artery. Of the 28 patients, 7 patients without CT or MR examinations were excluded inthis study. The mean follow-up period was 18.6 months. The causes of aneurysm formation were spontaneous in 17cases and traumatic in 4 cases. RESULTS: Of 20 patients with aneurysms arising from supraclinoid and cavernousportion of the IC artery, 16 patients (80%) had cranial nerve symptoms by mass effect. Five patients had epistaxis(3 patient), carotid cavernous fistula (1 patient) or subarachnoid hemorrhage (1 patient) due to aneurysmrupture. Two patients, each with aneuryms arising from supraclinoid and cervical portion of carotid artery had 9thand 12th cranial nerve symptom. There were three instances of complication after permanent occlusion; two patientshad subarachnoid and intracerebral hemorrhage by aneurysm rupture and expired. One patient had ischemia ofposterior cerebral artery teritorry after one day. Delayed ischemic event did not occur during the follow-upperiod. All aneurysms of the carotid artery below the level of ophthalmic artery presented radiographic proof ofcomplete thrombosis within two months. However, complete thrombosis of aneurysm was considerably delayed in twoaneurysms arising from the supraclinoid portion of the carotid artery. In long-term follow-up study, complete-lythrombosed aneurysms decreased in size slowly. But incompletely thrombosed aneurysms did not decrease in size fora long time and began to contract after formation of complete thrombosis. All three traumatic pseudoaneurymscharacteristically decreased in size rapidly, comparing with spontaneous aneurysms. CONCLUSION: In conclusion,proximal IC balloon occlusion for unclippable IC aneurysms is a convenient, safe, and effective way of producinganeurysm obliteration. Longer-term follow-up study is needed for incompletely thrombosed aneuryms after balloonocclusion of the proximal IC artery.

MR Evaluation of Rectal Carcinoma: Pelvic Phased-Array Coil versus Endorectal-Pelvic Phased-Array Coil

PURPOSE: To compare the accuracy of MR imaging using an endorectal-pelvic and a pelvic phased-array coil forpreoperative local staging of rectal carcinoma. MATERIALS AND METHODS: To determine preoperative staging, 38patients with rectal carcinoma underwent MR imaging. All patients were examined with both an endorectal-pelvic anda pelvic phased-array coil. All underwent surgery and staging was pathologically confirmed. Two radiologistsblinded to pathologic stage analyzed perirectal invasion and perirectal node metastasis, and scored according to afour-point scale. Radiologic and pathologic findings were correlated. Receiver operating characteristic (ROC)analysis of Wilcoxon statistic (W values) was used to compare diagnostic accuracy between the two different MRmethods. Interobserver variation was measured using kappa statistics. RESULTS: For perirectal invasion, T1WIendorectal-pelvic phased-array coil images (reader 1: 0.854, reader 2: 0.818) showed higher W values than pelvicphased-array coil images (reader 1: 0.755, reader 2: 0.811). On T2WI, W values were higher according to pelvicphased-array coil images (reader 1: 0.828, reader 2: 0.861) than according to endorectal-pelvic phased-array coilimages (reader 1: 0.813, reader 2: 0.786). For perirectal node metastasis, pelvic phased-array coil images (reader1: 0.745, reader 2: 0.792) showed higher W values than endorectal-pelvic phased-array coil images (reader 1:0.722, reader 2: 0.775), according to both reader 1 and 2. The defference kappa values between the two readers wasless than 0.4 ; agreement between them was poor. CONCLUSION: The use of an endorectal-pelvic phased-array coildid not significantly improve the accuracy of assessment of perirectal invasion and perirectal node metastasis,and in MR imaging of rectal corcinoma, the routine use of an endorectal coil is not advocated.

Facial nerve schwannomas: CT and MR findings

The present study was undertaken to analyze the radiologic findings of intratemporal and extratemporal schwannoma (ITS & ETS). We retrospectively reviewed the CT (9 cases), MR (3 cases) and medical records of 10 facial schwannoma patients. After classifying these into ITS and ETS, radiologic and clinical findings were analyzed. The most common clinical manifestations were facial nerve dysfunction (6/6 cases, 100%) and hearing impairment (5/6 cases, 83.3%) in ITS and parotid mass (4/4 cases, 100%) in ETS. Geniculate ganglion (GG) was the most commonly involved segment of ITS (5/6 cases, 83.5%). On CT, ITS arising in GG (4 cases) showed erosion of the petrous bone (4 cases), cochlea (3 cases), lateral semicircular canal (1 case) and ossicles (3 cases). ITS arising in the mastoid segment (1 case) showed the destruction of the jugular plate and external auditory canal wall. All three ITS in which MRI was performed showed iso- to hypointensity on T1WI, hyperintensity on T2WI and well-enhanced on post-enhanced T1WI. ETS showed various findings, but all four ETS were located in the posterolateral portion of the retromandibular vein and extended toward the stylomastoid foramen. In conclusion, ITS shows the schwannoma on MR. ETS shows various findings. However, if the tumor is located along the extratemporal facial nerve course, then facial schwannoma may be suspected.

Multiphasic spiral CT of renal masses: Comparison among phases following contrast injection

PURPOSE: To assess the utility of multiphasic spiral CT for characterizing renal masses. MATERIALS AND METHODS: The study included 36 patients (53 lesions) referred for the evaluation of renal masses suspected on the basis of the results of sonography or radiography. Spiral CT of the kidneys was performed prior to and following power injection of intravenous contrast material (Optiray-320). Postcontrast imaging data were obtained and analyzed during early and late corticomedullary (20-30-second delay), nephrographic (60-70-second delay), and excretory (5-minute delay) phases. During each phase, the ability to detect renal masses was evaluated, and the ability to diagnose these masses on routine and multiphasic CT was assessed. Routine precontrast and excretory phase CT studies were performed and the usefulness of each phase for the diagnosis of renal cell carcinoma (RCC) and transitional cell carcinoma (TCC) was evaluated. RESULTS: The rates for the detection of renal masses were as follows: 94.3% on precontrast scan, 93.8% during the early corticomedulolary phase (ECMP), 98.1% during the late corticomedullary phase (LCMP), 100% during the nephrographic phase (NP), and 98.1% during the excretory phase (EP). During both routine and multiphasic CT, diagnostic accuracy was 96.2%, though for differential diagnosis, multiphasic CT was more helpful than routine CT in 4/16 cases of RCC and 2/8 cases of TCC. The highest for lesion characterization, during the LCMP in RCC, and the LCMP and NP in TCC ; for evaluation of tumor margin during the EP in both RCC and TCC ; for delineation of the renal artery, during the LCMP in both RCC and TCC ; for delineating the renal vein, during the NP in RCC, and the LCMP in TCC. CONCLUSION: For the detection and correct diagnosis oflesions, multiphasic CT was not superior to routine CT, but for the characterization of RCC and TCC, the former was helpful. The most useful phase can differ according to the kind of renal mass, and so for characterization of the mass, the most appropriate phase must be selected.

Granular Cell Tumor of the Presacral Space: A Case Report

Granular cell tumors are rare lesions of probable Schwann cell origin and are composed of oval to fusiform cells with abundant granular eosinophilic cytoplasm. We report ultrasonography, barium enema, computed tomography and magnetic resonance imaging findings in a case of granuar cell tumor in the presacral space in a 34-year-old woman.

Radiologic Findings of Facial Nerve Schwannoma

PURPOSE: To analyze the radiologic findings of facial nerve schwannoma. MATERIALS AND METHODS: The authors retrospectively reviewed CT and/or MR images and clinical history of eight patients with histologically provenfacial nerve schwannoma. After classifying this extratemporal and intratemporal types, clinical and radiologic findings were analysed. RESULTS: The most common clinical findings of facial nerve schwannoma were facial nervepalsy and hearing impairment in an intratemporal schwannoma(4/5), and a palpable parotid mass in an extratemporal schwannoma(3/3). On CT, each involved segment of intratemporal schwannomas(five cases) showed characteristic radiologic findings, while extratemporal schwannomas(three cases) showed masses of various types. On MRI, all tumors(two cases) showed hypointensity on T1WI, hyperintensity on T2WI, and strong enhancement on Gd-DTPA enhanced T1WI. CONCLUSION: Intratemporal facial nerve schwannomas can be easily diagnosed by characteristic clinical and radiologic findings. Extratemporal facial nerve schwannomas show nonspecific findings. However, if the tumor islocated between the superficial and the deep lobe of the parotid gland and extends to the posterior portion of thestyloid process, then facial nerve schwannoma is strongly suspected.