Wook Jin

Bone bruises: MR characteristics and histological correlation in the young pig

PURPOSE To correlate magnetic resonance (MR) signal characteristics of bone bruises with histological findings. MATERIALS AND METHODS In 14 tibiae of young pigs, bone bruises were created in the proximal tibial metaphysis. The signal intensity seen on the MR images were correlated with histological findings. The following findings were evaluated: (a) changes of signal intensity on the tibiae; (b) changes of histology on the tibiae; and (c) changes of (a) and (b) on follow-up examinations. RESULTS We observed three types of injuries on T1-weighted images: focal or diffuse low signal, normal signal and linear low signal intensities. Severe hemorrhagic areas showed low signal intensities on all sequences of MR imaging. Fast spin-echo (FSE) T2-weighted images showed a more distinct low signal intensity than T1-weighted images. FSE short tau inversion recovery (STIR) and FSE fat saturated (FSE-FS) T2-weighted images showed similar signal intensities with FSE T2-weighted images. FS T1-weighted enhanced images showed low signal intensities with variable enhancements. Upon histological examination, hemorrhages and edemas were prominent at the subcortical areas of the contusion sites. The areas of dense, low signal intensities in all imaging sequences showed signs of severe hemorrhage. The areas of diffuse low signal and enhanced areas showed mixed areas of hemorrhages and edemas. Follow-up MR imaging showed evolution of the processes of hemorrhages and edemas with fatty marrow changes. CONCLUSIONS MR imaging can depict changes in the bone marrow resulting from direct injury to the bone. MR imaging is a useful tool for evaluating the evolution of bone bruises.

The various manifestations of ruptured hepatocellular carcinoma: CT imaging findings

Hepatocellular carcinoma (HCC) has a tendency to rupture spontaneously which leads to a life-threatening condition. Disruption of the tumor surface or a tear in a parasitic feeding artery can cause HCC rupture leading to hemoperitoneum. When evaluating patients with a ruptured HCC, CT can detect tumors, determine tumor extent, define the presence of tumor bleeding, and show serial hematoma density changes. Thus, familiarity with the various CT findings of ruptured HCCs is essential to ensure proper diagnosis and treatment. In this pictorial essay, the authors illustrate the usual and unusual manifestations of ruptured HCCs, as visualized by CT, and include some angiographic correlations. CT findings predictive of HCC rupture are also discussed.

Sonographic Findings of Groin Masses

The groin contents consist of the spermatic cord and its fascial coverings and vascular, nervous, and muscular structures. Abnormalities in the groin region are variable. The purpose of this image presentation is to describe the sonographic findings of the various kinds of groin lesions.

Acute retropharyngeal calcific tendinitis: a case report with unusual location of calcification

Retropharyngeal calcific tendinitis is an inflammatory process caused by calcium hydroxyapatite crystal deposition in the longus colli tendon of the prevertebral space, and it may mimic a retropharyngeal infection or abscess. The diagnosis of retropharyngeal calcific tendinitis will be made radiologically by the detection of calcifications anterior to C1–C3 and prevertebral soft tissue swelling. We present a case of acute retropharyngeal calcific tendinitis with an unusual location of calcification anterior to the C5–C6 disc.

Sonographic Evaluation of Anterosuperior Hip Labral Tears With Magnetic Resonance Arthrographic and Surgical Correlation

The purpose of this study was to retrospectively evaluate the sonographic findings compared with magnetic resonance (MR) arthrographic and arthroscopic findings in diagnosis of anterosuperior labral tears of the hip.

Recent Korean Perspective of Deep Vein Thrombosis After Total Knee Arthroplasty

This prospective study was performed on 311 consecutive knees in 227 patients for total knee arthroplasty. The aim was to assess the recent incidence of deep vein thrombosis (DVT) after total knee arthroplasty without chemoprophylaxis in Koreans, the efficacy of plasma d-dimer levels as a screening test, and the associated risk factors. Deep vein thrombosis was found in 79 knees (26.60%). There were 9 cases (3.03%) of proximal DVT, 70 cases (23.57%) of distal DVT, and no symptomatic pulmonary embolism. Although this cohort had limited number of patients by a single surgeon, there is still low incidence of proximal DVT in Koreans with rare pulmonary embolism occurrence compared with those of the Western. High postoperative d-dimer levels were correlative, but no appropriate cutoff value was found. Obesity was a significant associated risk factor.

What is the role of plain radiography in patients with foreign bodies in the gastrointestinal tract

Foreign bodies (FBs) in the gastrointestinal (GI) tract can show a wide range of clinical manifestations ranging from spontaneous evacuation to severe complication. Plain radiography is a straightforward and important initial imaging modality in cases of FB ingestion or insertion and is also helpful for follow-up purposes. Careful evaluations of the plain radiographs can determine the presence and nature of FBs, and help predict their precise locations and facilitate risk assessment. In this review, a wide variety of FBs in the GI tract are illustrated, and the role of plain radiography in patient management is discussed.

Diagnosis of acetabular labral tears: comparison of three-dimensional intermediate-weighted fast spin-echo MR arthrography with two-dimensional MR arthrography at 3.0 T

Background Magnetic resonance (MR) arthrography is the ideal imaging modality for the acetabular labrum. Three-dimensional (3D) fast spin-echo (FSE) sequences have similar diagnostic performance as two-dimensional (2D) conventional MR imaging for ligaments, menisci, or bone marrow edema in the knee. Purpose To compare the diagnostic accuracy and inter-observer reliability of 3D intermediate-weighted FSE sequence and 2D FSE sequences for the diagnosis of acetabular labral tears. Material and Methods Institutional review board approval was obtained and informed consent was waived for 45 patients (47 hips) who underwent 3D and 2D MR arthrography and subsequent arthroscopic surgery. The 3D sequences were performed using volumetric intermediate-weighted fast spin-echo imaging with fat suppression (voxel size, 0.6 × 0.6 × 1.2 mm; imaging time, 6 min 38 s). Labral tear was retrospectively and independently evaluated by two radiologists in four areas of the labrum (anterosuperior, posterosuperior, anteroinferior, and posteroinferior) on 3D and 2D FSE sequences. Statistical differences between the sensitivity and specificity of the methods were analyzed with the McNemar test, using arthroscopic findings as the reference standard. Inter-observer agreement was calculated using kappa statistics. Results Arthroscopic findings confirmed labral tears at 40 anterosuperior, 23 posterosuperior, 0 anteroinferior, and 2 posteroinferior quadrants. Sensitivity and specificity were 74% and 89% for 2D FSE sequences, and 78% and 92% for 3D FSE sequences, respectively. Sensitivities and specificities for the methods were not different statistically (P > 0.05). Inter-observer agreement for labral tear was substantial for 2D FSE sequences (k = 0.774) and almost perfect for 3D FSE sequences (k = 0.842). Conclusion 3D intermediate-weighted FSE MR arthrography is excellent for diagnosing acetabular labral tears. Sensitivity, specificity, and inter-observer reliability were similar to conventional 2D MR arthrography. For evaluation of the labrum, 3D FSE MR arthrography is more time-efficient than 2D FSE MR arthrography.

Bilateral asymmetric superficial soft tissue masses with extensive involvement of both upper extremities: demonstration of Kimura’s disease by US and MRI (2008: 12b)

Kimura’s disease is known as a rare chronic inflammatory disease occurring mainly in the head and neck regions of Asian male patients. We present a case of Kimura’s disease with extensive involvement of the bilateral upper extremities in a 20-year-old Korean man. Ultrasonography (US) and magnetic resonance imaging (MRI) demonstrated the presence of partially ill-defined, conglomerated soft tissue masses centered in the subcutaneous layer of both upper arms, with cranial extension along the cutaneous nerve in the right lesion. Medial epitrochlear, axillary and lower cervical lymphadenopathy accompanied the masses.

Leiomyosarcoma of the vagina: MR findings

We report the magnetic resonance imaging findings of a case of vaginal leiomyosarcoma. The lesion was demonstrated as a well-defined heterogeneously hyperintense mass within the vagina on T2-weighted images and was demonstrated as a hypointense mass on T1-weighted images. The mass showed irregular enhancement on fat-suppressed T1-weighted images after administration of gadopentate dimeglumine. On pathological specimen, the nonenhancing foci of the mass were seen as the necrotic portion of the lesion.