Tuberculous Pericarditis Mimicking a Malignant Pericardial Tumor: A Case Report.

Tuberculous pericarditis is an extrapulmonary manifestation of tuberculosis that is most commonly associated with pericardial thickening, effusion, and calcification. We present a case of tuberculous pericarditis mimicking a malignant pericardial tumor in a 77-year-old male. CT revealed an irregular and nodular pericardial thickening. MRI revealed high signal intensity on T1-weighted fat-suppressed images and peripheral rim enhancement after gadolinium administration. MRI can be helpful in determining the differential diagnoses in cases of tuberculous pericarditis with nonspecific imaging findings.

Secondary diffuse large B-cell breast lymphoma developed in subcutaneous fat layer of the breast with cardiac involvement.

We present a rare case of diffuse large B-cell lymphoma developed in subcutaneous fat layer of the breast with cardiac involvement. Radiologists should perform an image-guided biopsy for pathologic confirmation of breast lymphomas and avoidance of unnecessary invasive treatment.

Effect of the respiratory motion of pulmonary nodules on CT-guided percutaneous transthoracic needle biopsy.

BACKGROUND: Computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) is highly affected by respiratory motion; however, respiratory motion of target nodule during the PTNB and its effect on CT-guided lung biopsy have not been studied. PURPOSE: To investigate the effect of the respiratory motion of pulmonary nodules on CT-guided PTNB. MATERIAL AND METHODS: We retrospectively reviewed the procedural CT scans of 426 pulmonary nodules that underwent PTNB during quiet breathing. Maximal and average respiratory motions were measured using the difference of table position of the targeted nodule between multiple procedural scans. Diagnostic performance, complications, and technical factors of PTNB in nodules with large motion (maximal motion >1 cm) were compared with those in nodules with small motion (≤1 cm). RESULTS: The mean maximal and average respiratory motions between tidal volume breathing were 5.4 ± 4.4 and 2.7 ± 2.6 mm, respectively. Sensitivity and accuracy were 93.1% and 96.1% in nodules with large motion, compared with 94.7% and 95.9% in nodules with small motion, respectively. Respiratory targeting (P < 0.001), needle modulation (P < 0.001), motion artifact of target (P < 0.001), target disappearance from scans (P < 0.001), and number of performed CT scans (P < 0.001) were significantly higher in the large motion group, with no significant difference in radiation dose and complications between the groups. CONCLUSION: The respiratory motion of pulmonary nodules during CT-guided PTNB may cause technical difficulties but does not affect diagnostic performance nor complications associated with PTNB.

Male breast cancer presenting in accessory axillary breast.

We present a rare case of male axillary accessory breast cancer, which is extremely rare and is indistinguishable from lymphadenopathy and other malignancies, such as lymphoma and skin-derived tumors. Clinicians should consider accessory breast cancer in the differential diagnosis even in men, particularly in those who present with superficially located tumors with adjacent accessory breast tissue.

Improving the Performance of Radiologists Using Artificial Intelligence-Based Detection Support Software for Mammography: A Multi-Reader Study.

OBJECTIVE: To evaluate whether artificial intelligence (AI) for detecting breast cancer on mammography can improve the performance and time efficiency of radiologists reading mammograms. MATERIALS AND METHODS: A commercial deep learning-based software for mammography was validated using external data collected from 200 patients, 100 each with and without breast cancer (40 with benign lesions and 60 without lesions) from one hospital. Ten readers, including five breast specialist radiologists (BSRs) and five general radiologists (GRs), assessed all mammography images using a seven-point scale to rate the likelihood of malignancy in two sessions, with and without the aid of the AI-based software, and the reading time was automatically recorded using a web-based reporting system. Two reading sessions were conducted with a two-month washout period in between. Differences in the area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, and reading time between reading with and without AI were analyzed, accounting for data clustering by readers when indicated. RESULTS: The AUROC of the AI alone, BSR (average across five readers), and GR (average across five readers) groups was 0.915 (95% confidence interval, 0.876-0.954), 0.813 (0.756-0.870), and 0.684 (0.616-0.752), respectively. With AI assistance, the AUROC significantly increased to 0.884 (0.840-0.928) and 0.833 (0.779-0.887) in the BSR and GR groups, respectively (p = 0.007 and p < 0.001, respectively). Sensitivity was improved by AI assistance in both groups (74.6% vs. 88.6% in BSR, p < 0.001; 52.1% vs. 79.4% in GR, p < 0.001), but the specificity did not differ significantly (66.6% vs. 66.4% in BSR, p = 0.238; 70.8% vs. 70.0% in GR, p = 0.689). The average reading time pooled across readers was significantly decreased by AI assistance for BSRs (82.73 vs. 73.04 seconds, p < 0.001) but increased in GRs (35.44 vs. 42.52 seconds, p < 0.001). CONCLUSION: AI-based software improved the performance of radiologists regardless of their experience and affected the reading time.

Silicon Oxide Etching Process of NF3 and F3NO Plasmas with a Residual Gas Analyzer.

The use of NF3 is significantly increasing every year. However, NF3 is a greenhouse gas with a very high global warming potential. Therefore, the development of a material to replace NF3 is required. F3NO is considered a potential replacement to NF3. In this study, the characteristics and cleaning performance of the F3NO plasma to replace the greenhouse gas NF3 were examined. Etching of SiO2 thin films was performed, the DC offset of the plasma of both gases (i.e., NF3 and F3NO) was analyzed, and a residual gas analysis was performed. Based on the analysis results, the characteristics of the F3NO plasma were studied, and the SiO2 etch rates of the NF3 and F3NO plasmas were compared. The results show that the etch rates of the two gases have a difference of 95% on average, and therefore, the cleaning performance of the F3NO plasma was demonstrated, and the potential benefit of replacing NF3 with F3NO was confirmed.

Postpartum Galactocele in Augmented Breast after Using Breast Pump Mimicking Breast Implant-Associated Anaplastic Large Cell Lymphoma: A Case Report.

Post-partum galactocele is a common benign disease among breastfeeding women, whereas retromammary and peri-implant galactocele are relatively rare conditions. Herein, a 34-year-old, 1 month-postpartum female, who had augmentation mammoplasty and a 1-month history of breast pump use, presented with left breast enlargement for 2 weeks. An initial left breast US revealed hyperechoic peri-implant fluid collection. Additional US-guided fine needle aspiration was done using a 21G-needle, draining the milk component in the process, and cytologic results revealed numerous crystals, suggestive of galactocele. Various diseases, especially breast implant-associated anaplastic large cell lymphoma, can cause peri-implant fluid collection in an augmented breast. Thus, correlating imaging features with clinical information and cytologic analysis plays an important role in appropriate management.

Comparison of Ultrasonography Features and K-TIRADS for Isthmic and Lobar Papillary Thyroid Carcinomas: A Single-Center Study.

Objective: This study aimed to compare ultrasonography (US) features and the Korean-Thyroid Imaging Reporting and Data System (K-TIRADS) categories for diagnosing isthmic and lobar papillary thyroid carcinomas (PTC). Methods: From January 2009 to December 2012, 163 patients who underwent thyroid surgery and were confirmed with a post-operative histopathological diagnosis of isthmic PTC were retrospectively included. Fifty-nine patients were excluded because their tumor size was <0.5 cm or because of other reasons. The control group comprised of 145 patients who underwent thyroid surgery from January to April 2013 for a classic type of PTC, with the largest diameter being ≥ 0.5 cm and located in the thyroid lobe. A single radiologist retrospectively reviewed the US features and K-TIRADS categories of each nodule using a picture archiving and communication system. Results: Among 104 patients with isthmic PTC, 95 and 9 had primary and secondary cancers, respectively. On the other hand, all 145 patients with lobar PTC had primary cancers. Isthmic PTC showed a lower prevalence of non-parallel orientation than lobar PTC (23.1 and 71%). Nodule orientation was the only US feature statistically different between the two groups (p < 0.0001). However, there was no significant difference in patient age, sex, nodule size, composition, echogenicity, microcalcification, spiculated/microlobulated margin, and K-TIRADS category between the two groups (p > 0.05). Conclusions: K-TIRADS may be useful in the diagnosis of both isthmic and lobar PTC.

Prevalence and Features of Thyroglossal Duct Cyst on Ultrasonography, According to Radioactive Iodine Therapy: A Single-Center Study.

Objective: The relationship between radioactive iodine therapy (RIT) and prevalence of thyroglossal duct cysts (TGDC) on ultrasonography (US) has not been reported. We assessed the prevalence and US features of TGDC according to RIT. Methods: From July 2017 to June 2018, 3,146 subjects underwent thyroid or neck US at our center. The presence or absence of TGDCs was prospectively investigated based on real-time US examination. Among the 3,146 subjects, 261 subjects were excluded because of <18 years of age, unclear information of RIT, or the presence of a radiation therapy history to the neck. Eventually, 2,885 subjects were included in this study. Results: Of the 2,885 subjects finally included, 126 (4.4%) showed a TGDC on US. Those with RIT history showed a higher prevalence of TGDCs than those without (no statistical difference, p = 0.062). In 697 male subjects, there were statistical differences in type of surgery, RIT history, and session number of RIT between those with or without TGDCs (p < 0.0001). In 126 subjects with TGDCs, only sex showed a significant difference between those with or without RIT history (p = 0.015). However, there were no significant differences in the location, size, and shape of TGDCs (p > 0.05). The common US features of TGDC were suprahyoid location, ~1 centimeter, and flat-to-ovoid or round shape. Conclusions: RIT may increase the prevalence of TGDCs, particularly in men.

Bilateral Triple Negative Invasive Ductal Breast Carcinoma in a BRCA1 Mutation Carrier with Discrepant Pathologic Response to Neoadjuvant Chemotherapy.

Herein, we report a case of synchronous bilateral triple negative invasive ductal breast carcinoma in a patient with discrepant pathologic response to neoadjuvant chemotherapy. Right and left breast cancer stages at the initial diagnosis were T1cN0M0 and T4dN3aM0, respectively. The patient was identified as a BRCA1 mutation carrier and treated with four cycles of adriamycin and cyclophosphamide, followed by four cycles of docetaxel. Bilateral breast cancer stages decreased with the first regimen. However, the bilateral breast cancers showed discrepant responses to chemotherapy with docetaxel. The right breast cancer showed a continuous tumor volume reduction while the left breast cancer showed marked progression. Finally, the tumor size was 0.3 cm and 12 cm in the right and left mastectomy specimens, respectively. As bilateral breast cancers of the same subtype may show discrepant responses to neoadjuvant chemotherapy, close monitoring and follow-up imaging are required to avoid delayed surgery.

Mucinous Breast Carcinoma Presenting as a Coarse and Densely Calcified Mass on Mammography: A Case Report.

We report herein a 46-year-old woman who presented with mucinous breast carcinoma that appeared as a coarse and densely calcified mass on mammography. The lesion was a 4.6-cmsized palpable, hyperechoic, calcified mass with posterior shadowing on ultrasonography. This finding is a unique feature of mucinous breast carcinoma and is also observed in unusual breast cancer variants such as metaplastic breast cancer with chondroid differentiation, extraosseous osteosarcoma, and breast chondrosarcoma. The lesion showed a slow-growing pattern throughout the 4-year observation period. Mammography performed 4 years ago revealed faint, grouped microcalcifications; the lesion increased in size over 2 years, presenting as a well-circumscribed, calcified mass, mimicking dystrophic calcification. As several unusual variants of breast cancer, including mucinous carcinoma, may present as coarse and densely calcified masses on mammography, immediate biopsy should be considered when they are observed.

Erratum: Bilateral Triple Negative Invasive Ductal Breast Carcinoma in a BRCA1 Mutation Carrier with Discrepant Pathologic Response to Neoadjuvant Chemotherapy.

[This corrects the article on p. 428 in vol. 81.].

Significance of baseline computed tomography assessment for predicting the pulmonary fibrosis during the course of chemotherapy-induced pneumonitis.

BACKGROUND: The purpose of our study is to evaluate risk factors for the development of pulmonary fibrosis in the baseline computed tomography (CT) during the course of chemotherapy-induced pneumonitis (CIP). METHODS: We retrospectively identified 80 cases of CIP by clinical, radiological, and pathological findings. When fibrosis developed during the follow-up, the extent of pulmonary fibrosis was evaluated at final follow-up CT in terms of a 5% volumetric score for six zones. Univariate and multivariate analyses were performed to identify the clinical and radiological risk factors for the development of fibrosis and severe fibrosis over 11% in extent. RESULTS: Fibrosis occurred in 26 of the 80 total patients (32.5%) during a mean 5.6 months of follow up. Risk factors for developing fibrosis were revealed as preexisting interstitial lung disease (ILD) and moderate to severe emphysema in multivariate analysis (OR = 10.12, 95% CI = 2.35-43.66, and OR = 12.85, 95% CI = 2.81-58.82, respectively). Risk factors for developing severe fibrosis over 11% in extent were revealed as a moderate to severe emphysema (OR = 5.78, 95% CI = 1.07-31.26) in multivariate analysis. CONCLUSIONS: Moderate to severe emphysema as well as preexisting ILD visible on baseline CT are risk factors for developing pulmonary fibrosis in the course of CIP. Thin-section CT may be helpful to predict the risk of pulmonary fibrosis before administering chemotherapy.

Comparison of Prevalence and Ultrasonography Features of Thyroglossal Duct Cyst in Adults According to Radioactive Iodine Ablation.

BACKGROUND This study aimed to evaluate the prevalence of thyroglossal duct cysts (TGDCs) on ultrasonography (US) and US features of TGDCs in adults, and to assess whether the prevalence or size of TGDCs increases after radioactive iodine ablation (RIA). MATERIAL AND METHODS Between July and December 2018, 2820 patients underwent thyroid or neck US examination, performed by 2 radiologists, at our center. On the basis of real-time US, the presence or absence of TGDCs was prospectively investigated by 2 radiologists. Among the 2820 patients, 54 patients who were <19 years of age or had a radiation therapy history to the neck were excluded. Eventually, 2766 patients were included. RESULTS Of the 2766 patients, 160 (5.8%) showed a TGDC on US. The mean size of TGDCs in RIA history (+) (n=36) and RIA history (-) (n=124) groups was 0.92±0.41 cm and 0.86±0.45 cm, respectively. There was no significant difference in size of TGDCs between RIA history (+) and RIA history (-) groups (p=0.684). Between the TGDC (+) and TGDC (-) groups, there was no significant difference in patient age, gender, reason for thyroid/neck US, type of thyroid surgery, and session number and application/no application of RIA (p>0.05). The prevalence rate of TGDCs in radiologist A and B was 4.9% (70/1427) and 6.7% (90/1339), respectively. TGDCs were more common in the suprahyoid neck, and the common shapes of TGDCs were flat-to-ovoid and round. CONCLUSIONS RIA may not be associated with the prevalence or enlargement of TGDCs.

Thyroid Imaging Reporting and Data System for Detecting Diffuse Thyroid Disease on Ultrasonography: A Single-Center Study.

Objective: This study aimed to compare the ultrasonography (US) features of diffuse thyroid disease (DTD) and normal thyroid parenchyma (NTP), and to propose a structured imaging reporting system for detecting DTD. Methods: This retrospective study assessed the findings for 270 consecutive patients who underwent thyroid US before thyroid surgery. The following US data were analyzed: DTD-specific features, parenchymal echotexture and echogenicity, anteroposterior diameter, glandular margin, and parenchymal vascularity. Univariate and multivariate analyses with generalized estimating equations were performed to investigate the relationship between US features and DTD. The fitted probability of DTD was analyzed by using a regression equation. Results: Of the 270 patients, there were NTP (n = 193), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 51), Graves' disease (n = 1), and diffuse hyperplasia (n = 1). The following US features were significantly associated with DTD: decreased or increased parenchymal echogenicity, coarse parenchymal echotexture, increased anteroposterior diameter, lobulated glandular margin, and increased parenchymal vascularity. Of these, coarse parenchymal echotexture was the most significant independent predictor of DTD. The numbers of abnormal US features were positively correlated with the fitted probability and risk of DTD. The diagnostic indices were highest when the chosen cut-off criterion was category III with the largest Az value (0.867, 95% confidence interval: 0.820-0.905), yielding a sensitivity of 68.8%, specificity of 92.2%, positive predictive value of 77.9%, negative predictive value of 88.1%, and accuracy of 85.6% (p < 0.001). Conclusions: Our sonographic reporting and data system may be useful for detecting DTD.

Unexpected Lung and Brain Metastases 9 Years After Thyroid Lobectomy for Follicular Adenoma: A Case Report.

Background: Benign thyroid follicular tumors without histological evidence of carcinoma can metastasize. However, the pathogenesis of metastasis remains unclear. Here, the new proposed terminology, "non-invasive follicular thyroid neoplasm with papillary-like nuclear features" should be considered. We present a case of an encapsulated type of follicular variant of papillary thyroid carcinoma (FVPTC) that exhibited distant lung and brain metastases and was initially diagnosed as follicular adenoma. Case Report: In December 2006, a 64-year-old woman underwent ultrasonography-guided fine-needle aspiration of the right thyroid nodule at our hospital because of a palpable right neck mass. Right lobectomy was performed, and a follicular adenoma was diagnosed. In October 2015, she visited our hospital owing to dry cough and mild dyspnea and underwent computed tomography-guided transthoracic core needle biopsy for the lung nodule owing to probably multiple lung metastasis on chest X-ray and computed tomography. Based on retrospective analysis of the primary thyroid tumor and lung nodule specimen, an encapsulated follicular variant of papillary thyroid carcinoma with lung metastasis was confirmed. Conclusion: We report a case of an encapsulated follicular variant of papillary thyroid carcinoma with unexpected metastasis to the lung 9 years after thyroid surgery in a patient who was initially diagnosed as follicular adenoma. A careful close follow-up with re-examination of the histopathology specimen may be needed in patients who were diagnosed with benign thyroid follicular tumors.

Utility of Preoperative Ultrasonography in Transferred Patients with Suspicious Malignancy on Ultrasonography-Guided Fine-Needle Aspiration Cytology of Thyroid Nodules: A Single-Center Retrospective Study.

BACKGROUND This study aimed to assess the utility and characteristics of preoperative ultrasonography (US) in patients transferred to referral hospitals from local clinics with a diagnosis of malignancy on US-guided fine-needle aspiration cytology of thyroid nodules. MATERIAL AND METHODS From January 2018 to June 2018, 109 transferred patients underwent preoperative US in our hospital for suspected thyroid malignancy on cytological analysis after US-guided fine-needle aspiration of thyroid nodules in local clinics. Preoperative US was performed by a single radiologist in all patients. Among them, 6 were excluded from the study because of refusal of thyroid surgery. Preoperative US and histopathological results were compared in all patients. RESULTS After thyroid surgery, pathological examination revealed papillary thyroid carcinoma (PTC) (n=98), follicular adenoma (n=1), and nodular hyperplasia (n=4). Of the 103 patients, 91 exhibited suspicious US findings on the preoperative US, whereas 12 did not. In the 91 patients with suspicious US findings, PTC (n=90) and follicular adenoma (n=1) were confirmed after thyroid surgery. In the 12 patients with no suspicious US findings, PTC (n=8) and nodular hyperplasia (n=4) were confirmed after thyroid surgery. On repeat analysis of the cytological slides of the 4 nodular hyperplasia cases from the local clinics, Bethesda category II (n=1) and III (n=3) were determined. CONCLUSIONS In the transferred patients with a malignant cytology, preoperative US might be helpful to detect false-positive cytology cases.

Comparison of cytological adequacy and pain scale score in ultrasound-guided fine-needle aspiration of solid thyroid nodules for liquid-based cytology with with 23- and 25-gauge needles: a single-center prospective study.

In ultrasound (US)-guided fine-needle aspiration (FNA) of solid thyroid nodules (STN) using liquid-based cytology (LBC), the most appropriate needle size for LBC remains unclear. This study compared the cytological adequacy and complications associated with using 23- and 25-gauge needles in US-guided FNA of STNs using LBC. US-guided FNA was performed in consecutive patients by one radiologist to diagnose STNs ≥ 5 mm in the largest diameter. The one-sampling technique through a single needle puncture and multiple to-and-fro needle motions was used in each patient. The 23- and 25-guage needles were used consecutively each day. After FNA, the pain and complications experienced by each patient were investigated by a nurse, who was blinded to the information of needle gauge used. A cytopathologist retrospectively analyzed the cytological adequacy and cellularity of the cases. Of the 99 STNs, eight (8.1%) exhibited inadequate cytology (4 each with 23- and 25-gauge needles). The rate of cytological adequacy was not statistically different between the groups (p = 0.631). The mean pain scale values with 23- and 25-gauge needles were 2.1 ± 1.3 and 1.6 ± 1.3, respectively (p = 0.135). There were no significant complications in either group. In conclusion, both 23- and 25-gauge needles are useful in LBC because cytological adequacy and complications were not statistically different with both sizes of the needles.

Dual-energy CT angiography-derived virtual non-contrast images for follow-up of patients with surgically clipped aneurysms: a retrospective study.

PURPOSE: To evaluate the diagnostic performance, image quality, artifacts, and radiation doses of virtual non-contrast (VNC) images, relative to true non-contrast (TNC) images, in patients with surgically clipped aneurysms. METHODS: Seventy-six patients who underwent unenhanced computed tomography (CT) and dual-energy (DE)-CT angiography after surgical clipping of 85 intracranial aneurysms were included in the study. Diagnostic performances of VNC and TNC images were compared with respect to sensitivity, specificity, and positive and negative predictive values. The results of quantitative and qualitative analyses were compared between VNC and TNC images. Radiation doses were also compared between VNC and TNC images. RESULTS: Diagnostic performance of VNC images was lower than that of TNC images; however, addition of contrast-enhanced images improved diagnostic performance. Image noise and mean attenuation of VNC images were significantly higher than those of TNC images in the centrum semiovale, cerebellum, and pons. The quality of VNC images was excellent or sufficient (85.5% for observer 1, 85.5% for observer 2), and complete acceptance of VNC images was achieved in 64.5% for observer 1 and in 71.0% for observer 2; however, the addition of contrast-enhanced images increased the level of acceptance (92.0% for observer 1, 90.9% for observer 2). Clip artifacts were significantly lower in VNC images than in TNC images. CT dose index, dose-length product, and effective dose were significantly lower without TNC images. CONCLUSION: VNC images showed lower diagnostic performance and image quality, and higher image noise than TNC images; however, VNC images could reduce clip artifacts and radiation doses.

Comparison of Postoperative Neck Pain and Discomfort, Swallowing Difficulty, and Voice Change After Conventional Open, Endoscopic, and Robotic Thyroidectomy: A Single-Center Cohort Study.

Background: The objective of this study was to compare the postoperative neck pain and discomfort, swallowing difficulty, and voice change after conventional open thyroidectomy (COT), endoscopic thyroidectomy (ET), or robotic thyroidectomy (RT) performed by a single surgeon. Methods: From January 2013 to December 2017, 254 patients underwent COT, ET, or RT performed by a single surgeon and completed a postoperative symptom survey conducted in the outpatient clinic by three nurses. The survey collected information on postoperative neck pain and discomfort, swallowing difficulty, and voice change. Results: Of the 254 patients, 169 underwent COT, 32 underwent ET, and 53 underwent RT. The mean age in the COT, ET, and RT groups was 50.1, 44.5, and 41.6 years, respectively. The mean interval between thyroidectomy and survey in the COT, ET, and RT groups was 42.7, 50.2, and 9.2 months, respectively. Postoperative neck pain was significantly higher in the ET and RT groups than in the COT group (p = 0.026). The average neck impairment index score in the RT group was significantly higher than that in the COT group (p < 0.001). There were no significant differences in pain scale scores, swallowing difficulty, swallowing impairment index, voice change, and voice hand index among the three groups. Conclusions: There were no significant differences in postoperative voice change or swallowing difficulty among the COT, ET, and RT groups, whereas neck pain and discomfort were more common after ET and RT than COT.