Neurolymphomatosis of the Ulnar Nerve Presenting as Cubital Tunnel Syndrome: A Case Report.

Lymphoma is a malignant tumour of the lymphatic system. Neurolymphomatosis occurs when lymphoma cells invade the peripheral nervous system (PNS). Neurolymphomatosis has been reported involving the sciatic nerve, nerve roots and within the axilla and the upper arm. It can cause nerve dysfunction depending on the involved nerve. Neurolymphomatosis involving the ulnar nerve is rare. We report a patient with neurolymphomatosis of the ulnar nerve around the elbow that presented with features of cubital tunnel syndrome. A high index of suspicion is necessary in patients with cubital tunnel syndrome that present with uncommon symptoms such as sudden onset, rapid progression and/or severe pain. Level of Evidence: Level V (Therapeutic).

Diagnostic performance of dual-energy computed tomography for detection of acute spinal fractures.

OBJECTIVE: To assess the diagnostic performance of dual-energy computed tomography (DECT) with the color-coded virtual non-calcium (VNC) technique for detecting acute fractures in patients after acute spine trauma, especially in an emergency clinical setting. MATERIALS AND METHODS: Our retrospective study included 31 patients presented to emergency department with suspected spine trauma. All patients underwent both DECT (80 kVp and 140 kVp) and MRI. Post-processing was performed using color-coded VNC technique. Two independent radiologists visually assessed color-coded VNC images in a random order, and one of the two readers re-assessed the images in 4 weeks after the initial assessment. They were allowed to read only color-coded VNC images and asked to determine the presence of acute fracture. To determine the standard reference point, the other two experienced radiologists made consensus readings on both grayscale CT and MRI. Sensitivity, specificity, PPV, NPV, and accuracy analyses were determined. Both intra- and inter-observer agreements were also calculated. RESULTS: A total of 217 vertebral bodies (65 thoracic and 152 lumbar vertebrae) were included in our study. Sensitivity was 83.3% and 76.7% for first and second readers, respectively. Specificity of 99.5% and 98.9%, PPV of 96.1% and 96.3%, NPV of 97.3% and 96.3%, and accuracy of 97.2% and 95.8%, respectively, were noted. Both intra-observer and inter-observer agreements indicated excellent agreement (κ = 0.86 and κ = 0.84, respectively). CONCLUSION: In spite of the relatively low sensitivity, DECT-based detection of acute spinal fractures showed good specificity, positive predictive value, negative predictive value, accuracy, and inter-/intra-observer agreements.

CT imaging biomarker for evaluation of emodin as a potential drug on LPS-mediated osteoporosis mice.

RATIONALE AND OBJECTIVES: To identify micro-computed tomography (CT) imaging biomarkers for evaluating the effects of emodin, a potential drug to treat osteoporosis, in the mouse model of lipopolysaccharide (LPS)-mediated osteoporosis. MATERIALS AND METHODS: Forty male imprinting control region (ICR) mice with LPS-induced bone resorption were equally divided into four experimental groups: phosphate-buffered saline-treated (control), emodin-treated, LPS-treated, and LPS + emodin-treated groups. Emodin (50 mg/kg) was administered orally on alternate days for 8 days, and LPS (5 mg/kg) was injected intraperitoneally on days 1 and 4. After 8 days, the mice were sacrificed, and micro-CT images of the left proximal femurs were obtained. Three-dimensional images were analyzed by using commercial software to measure the bone volume to total volume fraction (BV/TV), trabecular number (Tb-N), trabecular thickness (Tb-Th), and trabecular separation (Tb-Sp) as CT imaging biomarkers. Histologic analyses of the femurs were performed using hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) immunohistochemical staining. RESULTS: The LPS + emodin-treated group demonstrated marked suppression of LPS-induced bone resorption compared to the LPS-treated group (BV/TV, 28.84% vs. 40.76%; Tb-N, 2.65 vs. 3.45 mm(-1); Tb-Sp, 300.81 vs. 212.31 µm; Tb-Th, 116.94 vs. 131.25 µm). TRAP immunohistochemical analysis showed fewer osteoclasts per field of tissue in the LPS + emodin-treated group than in the LPS-treated group (27.8 vs. 41.8). The BV/TV, Tb-N, and Tb-Sp data correlated well with the histomorphometric findings. CONCLUSIONS: The findings reveal a novel effect of emodin on bone remodeling in the LPS-mediated osteoporotic mouse model. The ex vivo micro-CT imaging is a promising tool for assessing the therapeutic effects of potential drugs on osteoporosis.

Micro-CT measurements of tumoral vessels supplied by portal circulation in hepatic colorectal metastasis mouse model.

The purpose of this study was to elucidate the micro CT findings of tumoral vessels supplied by portal circulation during establishment of hepatic metastasis of colorectal cancer in a mouse model. Hepatic metastases were induced in 15 BALB/c mice through the injection of murine colonic adenocarcinoma tumor cells into the mesenteric vein. Micro-CT imaging of the tumoral vessels was obtained to clarify the microvascular architecture. We evaluated the sinusoidal structure, diameter of the tumoral vessels (DTV) and blood vessel density (BVD) according to tumor sizes ranging from 201 to 3,000 µm in diameter. A total of 116 tumors were observed on day 15 after cell injection. The mean diameter of a normal hepatic sinusoid was 11.7 ± 2.0 µm on micro CT. The DTV supplied by the portal vein of tumors measuring 1,001-1,500 µm in diameter was greater than that of tumors 200-1,000 µm in diameter. The mean BVD from the portal vein gradually decrease according to size of tumor from 201 to 3,000 µm in diameter (r(2) = -0.584, P < 0.01). The characteristics of tumoral vessels supplied by portal circulation during establishment of hepatic colorectal metastases were well visualized with micro-CT imaging.

Imaging findings of desmoplastic fibroma rarely involving the clavicle: case report.

Desmoplastic fibroma of bone is a rare locally aggressive, but non-metastatic tumor. In this case report, we present a desmoplastic fibroma in an unusual location, the clavicle. Desmoplastic fibroma involving the clavicle is extremely rare, with only 2 reported cases before 1985. We report the imaging findings of a desmoplastic fibroma of the clavicle with a review of the relevant literature.

TCL-SPION-enhanced MRI for the detection of lymph node metastasis in murine experimental model.

RATIONALE AND OBJECTIVES: The aim of this study was to assess the feasibility of thermally cross-linked superparamagnetic iron oxide nanoparticle contrast (TCL-SPION) in magnetic resonance (MR) imaging (MRI) for the detection of lymph node metastasis in experimental model. MATERIALS AND METHODS: B16F1 human melanoma cells were subcutaneously injected into the thighs of C57BL/6 mice (n = 10). MRI was performed 21 days after tumor injection using a 4.7-T MR scanner. In vivo MRI was performed before and after the intravenous administration of TCL-SPION using T2 fast spin-echo and T2 gradient-echo pulse sequences. Then, ex vivo MR images were obtained for resected inguinal lymph nodes (n = 18) using the same pulse sequences as for in vivo imaging. On the basis of hematoxylin and eosin staining results, the lymph nodes were classified into three groups: group 1, nonmetastatic; group 2, tumor volume <50% of the resected sample; and group 3, tumor volume >50% of the resected sample. Size, signal-to-background ratio, and enhancement pattern were evaluated in each of the three groups on ex vivo images. RESULTS: The findings observed on ex vivo MR images of 18 inguinal lymph nodes were compared with histopathologic findings. All nodes were classified into three groups: group 1, n = 6; group 2, n = 5; and group 3, n = 7. The sizes of the lymph nodes in group 1 were significantly different from the sizes of those in group 3 (P = .014), but there was no significant difference in lymph node sizes between groups 1 and 2 (P = .792). Signal-to-background ratios of samples in groups 2 and 3 were significantly higher than those of samples in group 1 (P = .045 and P = .007, respectively). Each group of lymph nodes showed characteristic enhancement patterns that were well correlated between the images and pathology, except for one node. CONCLUSIONS: The features and extent of metastasis in the lymph nodes corresponded to those observed on TCL-SPION-enhanced MR images. TCL-SPION-enhanced MRI is useful for the detection and estimation of lymph node metastasis.

Risedronate directly inhibits osteoclast differentiation and inflammatory bone loss.

Risedronate, a nitrogen-containing bisphosphonate, is widely used in the clinical field for the treatment of osteoporosis. Risedronate is known to exert its effects through binding to hydroxyapatite in bone tissue, inhibiting osteoclastic activity, and inducing apoptosis of osteoclasts. The purpose of this study was to determine the effects of risedronate on osteoclast differentiation in vitro and on an inflammatory bone loss model in vivo. Risedronate inhibited osteoclast differentiation in co-culture of bone marrow cells (BMCs) and osteoblasts, and suppressed receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-mediated osteoclast differentiation from bone marrow-derived macrophages (BMMs) in a dose-dependent manner without toxicity. Risedronate significantly inhibited expression of c-Fos and nuclear factor of activated T cells (NFAT) c1 induced by RANKL. To examine the effect of risedronate on bone loss in vivo, we used a mouse model of lipopolysaccharide (LPS)-mediated bone loss. Micro-CT analysis of the femurs showed that LPS treatment caused bone loss. However, bone loss was significantly attenuated in mice administered with risedronate. Taken together, we conclude that risedronate exerts beneficial effects on osteoporosis by inhibiting osteoclast differentiation both directly and indirectly. In infectious conditions, the inhibitory effect of risedronate on bone erosion was excellent. Thus risedronate could be a treatment option for osteoporosis caused by inflammatory and infectious conditions.

Colloidal gold nanoparticles as a blood-pool contrast agent for X-ray computed tomography in mice.

OBJECTIVES: To present the pharmacokinetics and computed tomographic imaging efficacy of colloidal gold nanoparticles (AuNPs) as a blood-pool agent for x-ray computed tomography (CT). METHODS AND MATERIALS: To prepare the colloidal AuNPs, gold nanocrystals were modified using sulfhydrated polyethylene glycol (PEG). Cytotoxicity and histopathologic tests were carried out for toxicity evaluation. Six adult Balb/c mice underwent microcomputed tomography scans after injection of colloidal AuNPs (2.5 micromol Au/g body weight). Four mice with HT-1080 tumors were imaged for visualization of the tumor vasculature. RESULTS: The PEG coated colloidal AuNPs appeared as spherical nanoparticles with 38-nm diameters. The AuNPs-PEG showed a biocompatibility without toxicity in the mice. We identified a stable imaging window for visualizing the vasculature system, immediately to 24 hours after injection. Microcomputed tomography imaging using AuNPs-PEG clearly visualized the tumor vascular structures. CONCLUSION: Colloidal AuNPs show potential as a blood-pool agent for x-ray CT imaging.

Peliosis hepatis with hemorrhagic necrosis and rupture: a case report with emphasis on the multi-detector CT findings.

We report here on an uncommon case of peliosis hepatis with hemorrhagic necrosis that was complicated by massive intrahepatic bleeding and rupture, and treated by emergent right lobectomy. We demonstrate the imaging findings, with emphasis on the triphasic, contrast-enhanced multidetector CT findings, as well as reporting the clinical outcome in a case of peliosis hepatis with fatal hemorrhage.

Imaging findings of hepatic paragonimiasis : a case report.

Hepatic paragonimiasis is a rare form of ectopic infestation caused by Paragonimus. We experienced a case of hepatic paragonimiasis that showed characteristic imaging findings. CT and MR images showed a cluster of small cysts with rim enhancement in the subcapsular area of the liver. This finding seems to be characteristic for hepatic paragonimiasis, considering imaging findings in paragonimiasis involving other organs.

Mucoepidermoid carcinoma of the thymus: a case report.

Mucoepidermoid carcinoma of the thymus is an extremely rare malignant mediastinal neoplasm, and to our knowledge, only 13 cases have been reported. We report a case of mucoepidermoid carcinoma of the thymus that was seen in a 53-yr-old man with right chest pain. Chest CT scan showed a huge, cystic mass having a focal solid portion with direct invasion of the adjacent anterior chest wall and pericardium in the anterior mediastinum. Mucoepidermoid carcinoma of the thymus should be included in the differential diagnosis for masses of the anterior mediastinum associated with extensive cystic changes, although the carcinoma is exceedingly rare.

A case of primary pericardial undifferentiated sarcoma.

Primary pericardial sarcomas are extremely rare. The authors report a case of a 46-yr-old woman in whom a large mediastinal mass was discovered. The patient presented with cough, dyspnea, and orthopnea. Diagnostic investigations, such as echocardiography, computed tomography, and exploratory thoracotomy provided the evidence of a large mass in the mediastinum, attached by a broad base to the superior portion of the pericardium. A excisional biopsy was performed, and histologic examination of a biopsy specimen showed undifferentiated sarcoma. However, the complete removal of the mass was impossible due to adhesion to the adjacent great vessels. After the completion of the chemotherapy the patient was completely asymptomatic. However, follow-up transesophageal echocardiography showed a residual 3 x 4 cm-sized mass. The patient received the radiotherapy with a total dose of 55 Gy over 6 weeks. At present, there is no evidence of disease progression.

Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent.

OBJECTIVE: To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. MATERIALS AND METHODS: We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. RESULTS: Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. CONCLUSION: Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

MR evaluation of the "arcuate" sign of posterolateral knee instability.

OBJECTIVE: The purpose of this study was to evaluate associated knee injuries using MR imaging in patients with the "arcuate" sign, a term referring to avulsion fracture of the proximal fibula on conventional radiographs. MATERIAL AND METHODS: MR imaging of 18 cases (17 patients, both knees in one patient) with the arcuate sign on conventional radiographs was retrospectively interpreted to evaluate the associated meniscal, ligamentous, and bony injuries. In 12 cases, MR findings were correlated with surgical results. RESULTS: In all cases, avulsed bony fragments from the proximal pole of the fibula were attached to the fibular collateral ligament, the biceps femoris tendon, or both. Tear of the posterolateral capsule was seen in 12 cases (67%). Injury of the cruciate ligaments was noted in 16 cases (89%): injury to both the anterior cruciate ligament and posterior cruciate ligament was seen in nine cases (50%), injury to only the anterior cruciate ligament was seen in four, and injury to the posterior cruciate ligament only was noted in three. Bone bruises or gross fractures were seen in all cases: bone bruises on the anteromedial femoral condyle were noted in nine cases (50%) and were seen on the anteromedial tibial condyle in five cases (28%). Tear of the medial meniscus was seen in five cases (28%) and tear of the lateral meniscus in four cases (22%). Injury to the popliteus was seen in six cases (33%). Joint effusion was associated in all cases. CONCLUSION: MR imaging is useful for evaluation of associated soft-tissue injuries in patients with the arcuate sign on conventional radiographs. Avulsion injury to the proximal fibula is an important indicator of the internal derangement of the knee and for predicting the mechanism of an injury with varus stress. Cruciate ligament tear and bone bruises on the anteromedial condyle of the femur and tibia are common associated findings.

Prognostic value of CT before thrombolytic therapy in iliofemoral deep venous thrombosis.

PURPOSE: To prospectively assess the computed tomographic (CT) findings of iliofemoral deep venous thrombosis (DVT) and evaluate their relevance to the treatment of DVT with catheter-directed thrombolysis. MATERIALS AND METHODS: Twenty-four consecutive patients with symptomatic iliofemoral DVT were studied with both nonenhanced and contrast-enhanced CT before thrombolytic therapy. Mean duration of clinical symptom was 15.8 days +/- 20.8 (range, 1-90 d). Selected CT findings were prospectively evaluated and correlated with duration of symptoms and outcome of thrombolytic therapy, including attenuation number of the thrombus on nonenhanced CT (in HU), presence of venous distention (distention ratio: vein diameter divided by the diameter of corresponding normal contralateral vein), and poor venous wall demarcation. The following threshold variables were also evaluated: attenuation > or =60 HU and distention ratio > or =1.5. RESULTS: CT was suggestive of DVT in all patients, although different patterns were present. Higher attenuation on noncontrast CT was seen in patients who had favorable outcome of thrombolytic therapy compared to poor responders (66.1 +/- 8.7 vs 45.9 +/- 9.6; P <.0001). Distention ratio was also significantly higher in the good response group (2.6 +/- 1.4 vs 1.4 +/- 0.7; P <.05). Recent onset of clinical symptoms was associated with better outcome (9.4 d +/- 8.9 vs 28.6 d +/- 31.2; P <.03). Multiple-stepwise regression analysis of these variable produce the results of "attenuation >60" as the most predictive variable of favorable outcome of thrombolysis, followed by "distention ratio >1.5" and poor demarcation. CONCLUSION: Selected CT findings are better predictors of a favorable outcome of thrombolytic therapy than duration of clinical symptoms alone.