imaging features of myositis ossificans have some characteristics. Misdiaguosis could be avoided when the disease was evaluated with the course.

Objective To analyze the clinical features of unilateral oculomotor nerve palsy caused by multiple myeloma(MM).Methods A 79-year-old female diagnosed MM for 3 years was admitted due to the disease relapse.The patient presented left oculomotor nerve palsy,bone marrow biopsy showed 4.5％ of myeloma cells,the serum level of λ light chain was up to 18 g/L,and brain CT/MRI scan revealed left parasphenoidsinus lesion.A diagnosis of relapsing intramedullary and extramedullary MM,IgGλ type,stage ⅢA was made.Ten cases were retrieved from literature since 1990,the clinical features of 11 cases were analyzed as follows.Results Among 11 cases of unilateral oculomotor nerve palsy caused by MM,7 were males and 4 females with a mean age of (60 ± 12) years (40-79 years).The sub-types of MM were IgG type (7 cases),IgA type (2 cases),biclonal of IgG and IgA type (1 case),and IgD type (1 case).Oculomotor nerve palsy was presented as the initial manifestation of MM in 9 cases,as a sign of relapse of MM in 1 case,and during MM treatment in 1 case.In 7 cases,oculomotor nerve was the only cranial nerve involved,while in other 4 cases,the Ⅳ,Ⅴ,Ⅵ cranial nerves were also involved.Neuroimaging revealed parasphenoid sinus lesions in 9 cases,and myeloma meningitis in 2 cases.Most of the reviewed cases achieved significant clinical improvement after chemotherapy and/or radiotherapy,except 2 cases with myeloma meningitis.The case in our department was improved significantly and rapidly after receiving chemotherapy with bortezomib.Conclusion MM should be considered when unilateral oculomotor nerve palsy is presented with or without the history of MM,the disease is sensitive to chemotherapy in most circumstances.

Objective To explore the findings of diaphysial osteosarcoma in long bone on X-ray,CT and MRI, and discuss their clinical features and manifestations for differential diagnosis. Methods Twenty-eight cases with diaphysial osteosarcoma in long bone proved by surgery and pathology were reviewed retrospectively. Eighteen tumors were located in the femur, 4 in fibula, 4 in humerus and 2 in tibia. All of the patients were examined by X-ray, CT and MRI. The imaging manifestations on X-ray, CT and MRI were analyzed, and the relationship of the imaging features with the pathological types was also observed. The imaging signs were correlated with the pathologic findings with a double blind method. Results Of the 28 cases, there were 16 cases with large bone destruction, 22 cases with periosteal reaction on X-ray and CT. On X-ray, 18 cases showed soft tissue mass and 12 cases with neoplastic bone and tumor calcification.While on CT, 22 cases showed soft tissue mass on plain scan and 2 more cases displayed soft tissue mass after the injection of contrast mediun. Sixteen cases showed neoplastic bone and tumor calcification on CT.On MRI, there were 10 cases with bone destruction and periosteal reaction with iso- and hypo-intense on T1WI and iso- signals on T2WI. Twenty-six cases showed soft tissue edema and bone marrow on MRI. The soft mass were iso-signals on T1 WI and iso-hyperintense signals on T2 WI or STIR. The soft tissue edema was found hyperintense signals on T2WI or STIR. The lesions had heterogeneous enhancement especially in bone marrow with edema and adjcent soft tissue. Conclusion The X-ray, CT and MRI can reflect the pathological changes of diaphysial osteosarcoma in long bone from different aspects. Lower incidence, large bone destruction and no pathological fracture were the features of diaphysial osteosarcoma. The osteogenic type is diagnosed easily, but the osteolytic lesion should be differentiated from Ewing sarcoma, malignant giant cell tumor of bone and so on.

ObjectiveTo evaluate the relationship between the proliferation of parathyroid cell in rabbit with primary hyperparathyroidism (PHPT) and the bone mineral density (BMD). MethodsEighty adult Chinese rabbits were randomly and equally divided into two groups. The contrast group was fed with normal diet ( Ca ∶ P, 1.0 ∶ 0. 7 ) and the experimental group was fed with high phosphate diet ( Ca ∶ P,1.0∶7.0) to establish the animal model of PHPT. At 3, 4, 5, and 6 months after the diet, bone mineral density of the rabbits was measured by the quantity CT (QCT). Then, the parathyroid and bone of the rabbits were removed for pathological examination. The number of parathyroid cell in PHPT was calculated.Proliferation was determined by immunohistochemistry of proliferation cell nuclear antigen ( PCNA ) and Bcl-2. The t test and Logistic regression was used to analyze the difference of data of two groups. ResultThe number of parathyroid cell in PHPT group was 1.61 times than that in the contrast group[ (673 ± 151 ) HP,(418 ± 25 ) HP,P ＜0. 01]. The rate of PCNA positive-cell was significantly increased in PHPT group than that in contrast group [(50.52 ± 11.62)％o, (26.70 ± 2. 78 )％, P ＜ 0.01], and so was Bcl-2[ (460. 37 ± 190. 05 )‰, (67. 02 ±:4. 38 )％‰,P ＜0. 05]. The value of BMD was significantly decreased in PHPT group than that in contrast group [ ( 152. 5 ± 34. 3 ), ( 188.6 ± 12. 2 ) g/cm3, P ＜ 0. 05]. There was a negative correlation between BMD and PCNA (r ＝ -0. 749, P ＜ 0. 05 ) and between BMD and Bcl-2 (r ＝-0.800, P ＜ 0. 05 ) in PHPT group. ConclusionThe BMD of PHPT is related to the parathyroid cells proliferation which provide a reliable method for early diagnosis of PHPT.

Objective To analyze the CT and magnetic resonance imaging (MRI) manifestations of the pelvic osteosarcoma. Methods The CT and MRI manifestations of 15 cases with pelvic osteosarcoma from January, 2013 to December, 2015 proved by histology were ret-rospectively analyzed. Results There were 10 males and 5 females in them. The median age was 27.0 years. Ilium was involved in 11 cases. A mixed lytic/sclerotic pattern of bone destruction was found in 11 cases, and the sclerotic type in 2 cases, the osteolytic type in 2 cases. Ra-dial periosteal reaction was found in 5 cases and immature bone formation in 8 cases. Soft tissue masses were seen in 13 cases. MRI showed enhancement in 15 cases and the CT showed no enhancement in 2 cases with sclerotic type. Conclusion The typical imaging manifestations of pelvic osteosarcomainclude mixed lytic/sclerotic appearance, radial periosteal reaction, soft tissue masses and immature bone formation.

Objective:To evaluate the application high-resolution 3.0-T magnetic resonance imaging (MRI) in diagnosis of ligament and tendon injuries of the forefeet.Methods:From September 2014 to August 2020, 40 patients with forefeet injury (40 forefoot) and 20 healthy subjects (40 forefoot) meeting the including and excluding criteria were enrolled into this retrospective study. All subjects underwent MRI T1-weighted image (T1WI) and fat suppression proton density-weighted imaging (PD-FS) scan on coronal planes, sagittal planes and axial planes, respectively. Then the MRI characteristics of tendons in forefoot of healthy subjects and patients with forefoot injuries were compared. In patients the MR features of ligament and tendons injury were compared with the surgical findings or follow-up results.Results:In 20 normal subjects the tendons and ligament of the forefoot showed homogeneous low-signal-intensity on T1WI and PD-FS images. In the 40 patients with forefoot injuries, 22 cases were confirmed by surgical findings and 18 cases were confirmed by follow-up results. There were 8 cases of collateral ligament injuries, including 2 cases with complete tear, 3 cases with partial tear and 3 cases with sprain; 2 cases of extensor tendon with partial tear; 8 cases of flexor tendon injuries, including 3 cases with complete tear, 3 cases with partial tear and 2 cases with sprain; 3 cases of abductor tendon with partial tear; 13 cases of plantar plate injuries; and 6 cases of Lisfranc ligament injuries including 5 cases with complete tear and 1 case with partial tear. The injured ligament and tendons presented thicker and discontinuity in T1WI; and demonstrated heterogeneously increased signal intensity with edema in the surrounding soft tissues in PD-FS. The partially torn ligament and tendons showed discontinuity and thickening; and the completely torn ligament and tendons showed that they were interrupted and retracted, fiber structure disappeared and was filled with liquid, and edema in the surrounding soft tissue.Conclusion:High resolution magnetic resonance imaging of the forefoot can demonstrate the anatomy and features of ligament and tendon injuries in forefoot accurately, which has clinical application value for the early diagnosis and accurate treatment of the injury.

Objective: To study the MRI manifestations of foot injuries in amateur marathoners and the diagnostic value of MRI for foot injuries. Methods: Forty-eight amateur marathoners were prospectively recruited from October 2018 to March 2019. Participants were grouped according to the FASS criteria. All participants underwent bilateral foot MRI examinations. The MRI features of foot in amateur marathoners with and without foot pain were analyzed.The association with gender, age, time to participate in marathon, amount of running per week, number of times to complete the whole marathon and the symptoms of foot pain was studied. Results: There were 28 sides in FASS in grade 0, including 8 males and 20 females, 8 hydrocele of the first metatarsophalangeal joint, 6 edema of bone marrow, 4 edema of soft tissue, 4 hydrocele of tendon sheath, and 6 without abnormal manifestations of MRI. There were 68 sides in FASS grade 1, including 42 males and 26 females, 38 Achilles tendinitis, 14 plantar fasciitis, 12 Achilles tendon bursitis and 4 posterior ankle impingement syndrome. The incidence of foot pain in amateur marathoners was related to gender (OR=1.060, P=0.043), unrelated to age (OR=0.248, P=0.078), number of marathons completed (OR=1.006, P=0.956), time to participate in marathon (OR=1.008, P=0.944), amount of running per week (OR=0.971, P=0.407). Conclusion Among amateur marathon runners, the foot pain is mainly caused by Achilles tendon and plantar fascia, while those without foot pain are mainly characterized by joint effusion, tendon sheath effusion and bone marrow edema. Gender is the only factor affecting the incidence of foot pain in amateur marathoners. MRI examination is an effective method to determine foot injury and has important clinical application value in the diagnosis and treatment of foot injury.

Objective To study the MRI manifestations of foot injuries in amateur marathoners and the diagnostic value of MRI for foot injuries. Methods Forty?eight amateur marathoners were prospectively recruited from October 2018 to March 2019. Participants were grouped according to the FASS criteria. All participants underwent bilateral foot MRI examinations. The MRI features of foot in amateur marathoners with and without foot pain were analyzed.The association with gender, age, time to participate in marathon, amount of running per week, number of times to complete the whole marathon and the symptoms of foot pain was studied. Results There were 28 sides in FASS in grade 0, including 8 males and 20 females, 8 hydrocele of the first metatarsophalangeal joint, 6 edema of bone marrow, 4 edema of soft tissue, 4 hydrocele of tendon sheath, and 6 without abnormal manifestations of MRI. There were 68 sides in FASS grade 1, including 42 males and 26 females, 38 Achilles tendinitis, 14 plantar fasciitis, 12 Achilles tendon bursitis and 4 posterior ankle impingement syndrome. The incidence of foot pain in amateur marathoners was related to gender(OR=1.060, P=0.043), unrelated to age(OR=0.248, P=0.078), number of marathons completed(OR=1.006, P=0.956), time to participate in marathon(OR=1.008,P=0.944), amount of running per week (OR=0.971,P=0.407). Conclusion Among amateur marathon runners, the foot pain is mainly caused by Achilles tendon and plantar fascia, while those without foot pain are mainly characterized by joint effusion, tendon sheath effusion and bone marrow edema. Gender is the only factor affecting the incidence of foot pain in amateur marathoners. MRI examination is an effective method to determine foot injury and has important clinical application value in the diagnosis and treatment of foot injury.

The flexor tendon and pulley system injuries of fingers are relatively common.Injuries to those structures may lead to different degrees of dysfunction,and some injuries may be missed or misdiagnosed in its early stage,resulting in delayed functional recovery,and reduced quality of life.The article is to describe the normal anatomic structure,mechanisms of injury and its imaging features,and the related research progress of the finger flexor tendon system.

Objective:To study the relationship between distal radioulnar joint (DRUJ) effusion and the integrity of triangular fibrcarotilage (TFC) in asymptomatic young adults.Methods:Thirty two asymptomatic young adults, 22 males and 10 females with a mean age of 25 year(20-30) were recruited in the study between September 2014 and October 2019. All subjects had no wrist pain, no wrist deformity or wrist mass, and had no history of wrist trauma or surgery. The DRUJ effusion was definedasfluid-like high signal intensityon fatsuppression proton density-weighted MRI.The presence of distal radioulnar joint effusion, the shape of the effusion, and the presence of triangular fibrocartilage abnormalities were documented.Results:Among 32 subjects, 25(78.1%, 15 males and 10 females) presented with distal radioulnar joint effusion on wrist MR images, including linear/tubular in 21 cases(84.0%) and saccular in 4 cases(16.0%).Twenty cases (62.5%) had distal radioulnar joint effusion while the TFC was intact, among whom, the effusion was confined to the proximal side of distal radioulnar jointin 17 cases, and reached the lower surface of TFC in 3 cases. In 5 cases (15.6%) with TFC tear, the effusion reached the lower surface of TFC in 4 cases. There were neutral, positive and negative variations of the ulna in 23, 6 and 3 cases, respectively, among whomthe distal radioulnar effusion was presented in 17, 5, 3 cases, and TFC tear in 1, 4 and 0 cases, respectively.The presence of distal radioulnar effusion was not significantly correlated with genders( P=0.069) or types of ulna variance( P=0.702). Conclusion:The distal radioulnar joint effusion maybe resent in asymptomatic young adults, and it maybe complicated with TFC tear.