Hye Jung Choo

Subungual Tumors: Clinicopathologic Correlation with US and MR Imaging Findings

Various types of tumors can affect the subungual space, including benign solid tumors (glomus tumor, subungual exostosis, soft-tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma), benign cystic lesions (epidermal and mucoid cysts), and malignant tumors (squamous cell carcinoma, malignant melanoma). Imaging plays an important role in the detection and differentiation of subungual tumors because of their small size, nonspecific clinical manifestations, and functional significance. Ultrasonography (US)-in particular, high-resolution US with color Doppler studies-provides useful information regarding tumor size, location, shape, and internal characteristics (cystic, solid, or mixed), but it is limited in the further characterization of tissue. Magnetic resonance (MR) imaging has an important role in categorizing tumors according to their anatomic location, pathologic origin, and signal characteristics. There is some overlap between the US and MR imaging features of subungual tumors; however, certain features can allow accurate diagnosis and expedite management when correlated with clinical and pathologic findings.

Imaging findings of intravascular papillary endothelial hyperplasia presenting in extremities: correlation with pathological findings

ObjectiveTo describe magnetic resonance imaging (MRI) and ultrasound (US) findings of intravascular papillary endothelial hyperplasia (IPEH) arising in extremities.Materials and MethodsSix patients with IPEH confirmed by surgical resection were reviewed retrospectively. Before resection, 3 patients underwent both MRI and US and 3 patients underwent only MRI. Two radiologists retrospectively reviewed MR/US imaging results and correlated them with pathological features.ResultsThe 6 IPEHs were diagnosed as 4 mixed forms and 2 pure forms. The pre-existing pathology of four mixed forms was intramuscular or intermuscular hemangioma. By MRI, the mixed form of IPEH (nu2009=u20094) revealed iso- to slightly high signal intensity containing nodule-like foci of high signal intensity on T1-weighted images (T1WI) and high signal intensity-containing nodule-like foci of low signal intensity on T2-weighted images (T2WI). The pure form of IPEH (nu2009=u20092) showed homogeneous iso- signal intensity on T1WI and high and low signal intensity containing nodule-like foci of low signal intensity on T2WI. On gadolinium-enhanced fat-suppressed T1WI, 50% of cases (nu2009=u20093: mixed forms) revealed peripheral, septal, and central enhancement. The other IPEHs (nu2009=u20093: 1 mixed and 2 pure forms) showed peripheral and septal enhancement or only peripheral enhancement. By US, two mixed forms of IPEH showed well-defined hypoechoic masses containing hyperechoic septa and central portion with vascularities. One pure form of IPEH was a homogeneous hypoechoic mass with septal and peripheral vascularities on color Doppler imaging. The foci of high signal intensity on T1WI, foci of low signal intensity on T2WI, and non-enhancing portions on MRI and the hypoechoic portion on US were histopathologically correlated with thrombi and the peripheral/septal or central enhancing areas on MRI, hyperechoic septa and the central portion on US, and septal/central or peripheral vascularities on color Doppler imaging corresponded to hypertrophic papillary epithelium and a fibrovascular core.ConclusionsEven though imaging findings of the pure form of IPEH are rather nonspecific, the mixed form of IPEH should be considered a possible diagnosis when a well-defined mass with T2 hyperintense signal containing nodule-like foci of low signal intensity, T1 iso- to slightly hyperintense signal containing nodule-like foci of high signal intensity, and peripheral/septal or central enhancement on MRI is seen in extremities, along with the US finding of a hypoechoic mass containing hyperechoic septa with vascularities.

Delaminated Tears of the Rotator Cuff: Prevalence, Characteristics, and Diagnostic Accuracy Using Indirect MR Arthrography

OBJECTIVE. The purpose of this study was to evaluate the prevalence, radiologic characteristics, and accuracy of diagnosing delaminated tears at the supraspinatus tendon-infraspinatus tendon (SST-IST) on indirect MR arthrography. MATERIALS AND METHODS. Of 531 consecutive shoulders that underwent indirect MR arthrography, 231 shoulders with tears at the SST-IST were included. On the MR images, delaminated tears at the SST-IST, defined as intratendinous horizontal splitting between the articular and bursal layers of the SST-IST with or without different degrees of retraction between the two layers, were identified and classified into six types. Other radiologic findings of the SST-IST, such as the presence of intramuscular cysts, were evaluated. We used video records of 127 arthroscopic surgeries to determine the diagnostic accuracy of indirect MRI for the detection of the delaminated tears at the SST-IST. RESULTS. On MRI, 56% (129/231) of shoulders with SST-IST tears had delaminated tears. Articular-delaminated full-thickness tears (n = 58) and articular-delaminated partial-thickness tears (n = 64) were the most common types. Approximately 82% (36/44) of articular-delaminated full-thickness tears occurring at the SST were combined with articular-delaminated partial-thickness tears at the IST. SST-IST footprint tears and intramuscular cysts were significantly more common in the shoulders with delaminated tears. The sensitivity and specificity of indirect MR arthrography for detection of delaminated tears were 92% and 94%, respectively. CONCLUSION. On indirect MR arthrography, approximately half of the shoulders with SST-IST tears had delaminated tears. The diagnostic accuracy of indirect MR arthrography for detection of delaminated tears was high.

Ultrasonography of the ankle joint

Ankle disorders are a relatively common pathological condition, and ankle injuries account for approximately 14% of sports-related orthopedic emergency visits. Various imaging modalities can be used to make a diagnosis in cases of ankle pain; however, ultrasound (US) has several benefits for the evaluation of ankle pain, especially in the tendons, ligaments, and nerves of the ankle. The purpose of this article is to review the common causes of ankle pathology, with particular reference to US features. In addition, the importance of a dynamic evaluation and a stress test with US is emphasized.

Pancreatitis, panniculitis, and polyarthritis (PPP) syndrome: MRI features of intraosseous fat necrosis involving the feet and knees.

Pancreatitis, panniculitis, and polyarthritis (PPP) syndrome is extremely rare and presents as a triad of the three diseases. The patient usually presents with mild or absent abdominal symptoms. Here, we report on a case of a 66-year-old male who presented with pain and swelling in both legs and mild abdominal pain. He was diagnosed with acute pancreatitis by pancreatic enzyme analysis and abdominal computed tomography (CT) and with skin lesions of panniculitis through a biopsy. Magnetic resonance imaging (MRI) revealed multifocal intraosseous fat necrosis and arthritis involving both the feet and the knees. Therefore, we report a case of PPP syndrome with intraosseous fat necrosis involving both the feet and the knees.

Distally extended muscle belly of the flexor digitorum within the carpal tunnel: is it a risk factor for carpal tunnel syndrome?

Background The distally extended muscle belly of the flexor digitorum (MB-FD) within the carpal tunnel has been suggested as a plausible cause for carpal tunnel syndrome (CTS) based on cadaveric studies. Purpose To evaluate whether MB-FD within the carpal tunnel is a risk factor for CTS by comparing asymptomatic volunteers and patients with CTS. Material and Methods Presence, length, and cross-sectional area of MB-FD within the carpal tunnel were evaluated in 63 wrists of 32 asymptomatic volunteers and 52 wrists of 33 patients with CTS using ultrasonography. Length of MB-FD within the carpal tunnel was measured as the distance between the distal end of MB-FD and the palmar margin of the distal radius longitudinally. On a transverse scan, the cross-sectional area of MB-FD at the proximal limit of the carpal tunnel was measured. Results MB-FD in the carpal tunnel was found in 39 (62%) asymptomatic volunteers and 35 (67%) patients with CTS (Pu2009=u20090.549). There was a female preponderancy of MB-FD within the carpal tunnel in asymptomatic volunteers (Pu2009=u20090.044), but not in patients. Length and cross-sectional area of MB-FD within the carpal tunnel were significantly greater in male-CTS patients than in male volunteers (Pu2009=u20090.022 and 0.012, respectively). These qualities were risk factors for CTS in men, though not in women. Conclusion The presence of distally extended MB-FD within the carpal tunnel was not a risk factor for CTS. In men, a longer and thicker MB-FD within the carpal tunnel increased the risk for CTS.

Ultrasonographic findings of Kimura’s disease presenting in the upper extremities

ObjectiveTo describe ultrasound findings of Kimura’s disease arising in the upper extremities.Materials and methodsFive patients with Kimura’s disease confirmed by surgical resection were retrospectively reviewed by two musculoskeletal radiologists and a pathologist.ResultsAll six lesions involved the epitrochlear area and appeared as partially (nxa0=xa05) or poorly (nxa0=xa01) marginated subcutaneous masses with the presence of curvilinear hyperechoic bands intermingled within the hypoechoic components by US. Moderate (nxa0=xa04) to severe (nxa0=xa02) vascular signals were observed in some proportion of the hyperechoic bands by color Doppler US. The associated findings were the increased echogenicity of surrounding subcutaneous fat (nxa0=xa06) and adjacent lymphadenopathy (nxa0=xa04). Microscopic examination showed proliferation of lymphoid follicles with prominent germinal centers and intervening fibrosis.ConclusionsIn this study, Kimura’s disease arising in the upper extremities showed a partially defined hypoechoic subcutaneous mass with internal hyperechoic bands and moderate-to-severe vascularities, increased echogenicity of the surrounding subcutaneous fat and adjacent lymphadenopathy on US. Thus, when these US features are observed in the typical epitrochlear region of an Asian individual, especially if accompanied by peripheral eosinophilia, Kimura’s disease should be considered as a possible diagnosis.

The location of the peroneus longus tendon in the cuboid groove: sonographic study in various positions of the ankle–foot in asymptomatic volunteers

ObjectiveTo evaluate the normal location of the peroneus longus tendon (PL) in the cuboid groove in various ankle–foot positions by ultrasonography in asymptomatic volunteers.Materials and methodsUltrasonographic assessment of the PL in the cuboid groove was performed in 20xa0feet of ten healthy volunteers. Each PL was examined in five ankle–foot positions (i.e., neutral, dorsiflexion, plantar-flexion, supination, and pronation). The PL location was qualitatively categorized as “inside” when the PL was entirely within the cuboid groove, as “overlying” when some part of the PL was perched on the cuboid tuberosity, and as “outside” when the PL was entirely on the cuboid tuberosity. For quantitative evaluation of the PL location, the distance between the PL and the cuboid groove was measured. The width of the cuboid groove was measured in the neutral position.ResultsThe PL location did not significantly change with changes in the ankle–foot position. Qualitatively, an “overlying” PL was the most common type, regardless of the ankle–foot position. “Inside” PLs were found in only 35, 20, 30, 25, and 35% of feet in neutral, dorsiflexion, plantar-flexion, supination, and pronation positions, respectively. The quantitative PL location was also not significantly different among all ankle–foot positions and it was significantly negatively correlated with the cuboid groove width.ConclusionsIn healthy volunteers, 65% or more of the PLs were partially or completely located outside of the cuboid groove, regardless of the ankle–foot position. The PL location relative to the cuboid groove was related to the cuboid groove width.

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.

Computed Tomography Features of Follicular Thyroid Adenoma and Carcinoma

Background: No previous study has investigated the computed tomography (CT) characteristics of follicular thyroid adenoma (FTA) and follicular thyroid carcinoma (FTC). This study aimed to compare the CT features of FTA and FTC. Methods: Eighty-seven consecutive patients with FTA or FTC that underwent preoperative neck CT from January 2006 to December 2013 were included. In each case, single radiologist retrospectively examined the corresponding neck CT under blinded conditions for the histopathological results. The CT features of FTA and FTC were evaluated, as well as the specific CT features for differentiating FTC from FTA. Results: After matching the CT and histopathological results, 55 FTAs and 25 FTCs in 80 patients were analyzed. No statistically significant differences were detected in patient age, gender, nodular size, or location between FTA and FTC patients. The most common CT features in both FTA and FTC included low attenuation, intraglandular configuration, smooth margin, round shape, absence of calcifications, and inhomogeneous enhancement. In particular, the prevalence of decreased, iso-, and increased enhancement was similar in both FTA and FTC. The prevalence of homogeneous attenuation in FTC was higher, whereas the prevalence of inhomogeneous attenuation in FTA was higher. The logistic regression analysis revealed no significant differences between FTA and FTC in any CT features, except for the pattern of attenuation (p = 0.002). Conclusion: No specific CT features of FTA and FTC were identified, and CT may be unhelpful for distinguishing FTC from FTA.