[Magnetic resonance imaging manifestation of foot injury in amateur half marathon athletes].

Eighty-four amateur half marathon athletes (168 side feet) in Beijing from October 2018 to May 2021 were recruited, and their age, gender and whether they have foot pain were collected, including 44 males and 40 females, aged from 21 to 60 (40.7±9.3) years. All participants underwent bipedal magnetic resonance imaging (MRI) examinations, and the degree of foot pain was graded by foot ankle injury scale (FASS scale). The relationship between MRI features and the foot pain of amateur half marathon athletes were analyzed. The study found that the proportion of foot pain symptoms among amateur half marathon athletes in Beijing was high(122/168), and the MRI manifestations were mainly heel tendinitis and plantar fasciitis, which accounted for about 59.5% of all cases.

[Magnetic resonance imaging of normal anatomy and injury of the peroneal tendon].

Objective: To explore the MR characteristics of normal anatomy and injured peroneal tendon and the diagnostic value of MR in the peroneal tendon injuries. Methods: From February 2018 to December 2018, a total of 20 healthy volunteers (40 ankle joints) were selected, 10 males and 10 females, with an age range of 20-30 (26±3) years. Retrospective analyzed 62 patients with ankle sprain and peroneal tendon injuries confirmed by operation, 34 males and 28 females, with an age range of 14-78(41±14) years. All volunteers and patients underwent MR examination. The MRI characteristics of the normal anatomy of peroneal tendon were analyzed. The patients were classified according to the MR diagnostic criteria of injury. Then the MRI features of different types of injured peroneus longus tendon and peroneus brevis tendon were analyzed. At last, imaging findings were compared with surgical results. Results: The peroneal tendon of 20 healthy volunteers showed oval and elliptical band-like structures on T(1)WI and PD-FS sequences, with natural alignment, clear boundary and uniform low signal. The whole length of the peroneal tendon can't be displayed completely on the same imaging plane. It needed multi-dimensional observation combined with axial, coronal and sagittal directions. There were 62 cases of peroneal tendon injury, including 46 cases of peroneal tendon tear (7 cases of partial-thickness tear, 11.3% of the total injuries, 39 cases of full-thickness tear, 62.9% of the total injuries), 16 cases of peroneal tendon dislocation (15 cases of intrathecal dislocation, 24.2% of the total injuries, 1 case of extrathecal dislocation, 1.6% of the total injuries). In 7 cases of partial-thickness tear (4 cases of peroneus brevis tendon tear, 3 cases of peroneus longus tendon tear), MR showed irregular tendon shape and local continuity interruption. In 39 cases of full-thickness tear (31 cases of peroneus brevis tendon tear, 8 cases of peroneus longus tendon tear), MR showed that the tear was penetrated through the whole layer of tendon from dorsolateral side to plantar side of foot, and the range of tear was different. The torn tendon could be accompanied by tendinitis or effusion of tendon sheath; 15 cases of intrathecal dislocation (3 cases of type A, 12 cases of type B), MR findings of type A dislocation showed that the peroneus longus tendon was located in the deep part of the peroneus brevis tendon, MR findings of type B dislocation showed that the peroneus longus tendon was displaced into the longitudinal tear of peroneus brevis tendon. In 1 case of extrathecal dislocation (type Ⅲ), MR showed that the SPR and the attached cortex of lateral malleolus were avulsed together, and the peroneal tendon was displaced under the avulsed fracture piece. Conclusion: MR can accurately demonstrate the fine anatomical structure of peroneal tendon and the imaging features of injuries. It has important clinical application value for the early diagnosis and accurate treatment of peroneal tendon injuries.

[Magnetic resonance imaging of the elbow joint tendon: imaging technique and clinical application].

Objective: To explore the magnetic resonance imaging (MRI) imaging technique and the clinical application in ligament and tendons of elbow. Methods: The study was reviewed and approved by an institutional review board of Beijing Jishuitan Hospital. A total of 20 normal volunteers with 40 elbows including 12 males and 8 females, aged from 20 to 55 years, with an average age of 35 years and 38 patients with 38 elbows who complained elbow pain with elbow injuries including 23 males and 15 females, ranged in age from 9 to 77 years, with an average age of 41 years old were chosen to undergo magnetic resonance examination between May 2013 and October 2018.All subjects underwent examination on coronal T(1)WI scan and PD-FS on three planes respectively in a prone position. Then the MRI characteristics of tendons in elbow of healthy volunteers and patients with elbow injuries were studied and the MRI features of tendon injury were compared with the surgical results and confirmed by double-blind method. Results: Twenty normal volunteers without tendons or ligament injures showed homogeneous low-signal-intensity on T(1)-weighted and proton fat saturation sequence (PD-FS) images.In the 38 patients with elbow injuries, there were 44 tendon injuries, including 14 cases of common extensor tendon injuries, 10 cases of common flexor tendon injuries, 3 cases of biceps tendon injuries, 7 cases of brachialis tendon injuries and 10 cases of triceps tendon injuries. The injuried tendons became thicker and discontinuity in T(1)WI and demonstrated heterogeneously increased signal intensity with effusion of tendon sheath in PD-FS. Partial tear showed discontinuity and thickening of tendons and the complete tear showed that the tendons were interrupted, retracted, the fiber structure disappeared and was filled with liquid, and the surrounding soft tissue edema was found. Conclusions: MRI can demonstrate the anatomy and injuries features of tendons in elbow joint accurately. It is significance for the early diagnosis and treatment protocols of the tendons injuries.

[The classification and MR imaging of scapholunate ligament injuries].

Objective: To explore the MRI characteristics of injuries of scapholunate ligament (SLL), and provide imaging basis for the early diagnosis and treatment of the injuries. Methods: A total of 20 healthy volunteers without wrist injuries and 30 patients who complained dorsoradial-sided wrist pain and were highly suspected as the injury of SLL underwent the wrist magnetic resonance examination and X-ray examination in Beijing Jishuitan Hospital from January 2013 to September 2017.All subjects underwent anterior and lateral radiographs of the wrist joint and examination on coronal T(1)WI scan and PD-FS on 3 planes respectively in a prone position.Then the MRI characteristics of 20 healthy volunteers and 30 patients with SLL injuries that confirmed by operation were analyzed.According to the comparative analysis of normal anatomy and Geissler grades, the injuries were graded and MRI features of different types of injuries were analyzed.At last, imaging findings were compared with surgical results. Results: Twenty healthy volunteers without injuries showed mainly in low signal intensity on T(1)WI and PD-FS images.According to Geissler grades, there were 11 GradeⅠ injuries (5 had triangular fibrocartilage complex (TFCC) and SLL injuries and 1 had fracture of scaphoid and SLL injuries simultaneously), 8 GradeⅡ injuries (2 had TFCC and SLL injuries, 1 had TFCC, lunotriquetral ligament (LTL) and SLL injuries and 1 had distal radius fracture, TFCC and SLL injuries simultaneously), 7 Grade Ⅲ injuries (3 had TFCC and SLL injuries, 2 had fracture of scaphoid and SLL injuries and 1 had TFCC, LTL and SLL injuries simultaneously) and 4 Grade Ⅳ injuries (2 had TFCC and SLL injuries and 1 had fracture of scaphoid and SLL injuries simultaneously) among 30 patients.A tear can be confidently diagnosed when the ligament segment was absent or there was a fluidfilled discontinuity.A tear that involves 1 or 2 of the 3 segments (volar, proximal, or dorsal) of either the SLL was considered a partial tear, whereas a tear of all 3 segments was a complete tear. Conclusion: MRI can demonstrate the anatomy of interosseous ligaments accurately, evaluate and make the general grades of injuries.It is of significance for the early diagnosis and treatment protocols of the interosseous ligaments injuries.

[MR imaging of flexor tendon and pulley system of the fingers: normal anatomy and injury].

Objective: To explore the magnetic resonance imaging (MRI) features of the anatomy and injuries of flexor tendon and pulley system of the fingers. Methods: Clinical and imaging data of 20 healthy volunteers without injuries and 36 patients from Beijing Jishuitan Hospital with flexor tendon and pulley system injuries in the fingers between March 2013 and March 2016 were retrospectively analyzed. All subjects underwent magnetic resonance imaging (MRI) examination. The MRI findings of patients were compared with healthy volunteers. In addition, imaging findings of patients were compared with the surgical results and confirmed by double-blinded method. Results: Twenty volunteers without flexor tendon and pulley system injures showed homogeneous hypointensity on both T1-weighted and Proton Density-weighted images with fat saturation (PD-FS). There were 36 patients with finger injures, including 21 cases of flexor tendon injury, 10 cases of pulley system injury, 5 cases of compound injury, which demonstrated unclear signal, discontinuity on T1-weighted images and heterogeneously increased signal intensity of the involved structures on PD-FS images. Edema was detected in the soft tissues surrounding the injured sites. Conclusions: MRI is an accurate method for evaluation of the anatomy and pathologic conditions of flexor tendon and pulley system of the fingers and a useful tool for diagnosis and treatment of flexor tendon and pulley system injuries.

[MRI anatomy and injury of the lateral collateral ligaments of ankle].

Objective: To explore the MRI features of the lateral collateral ligament injuries of the ankle and determine the value MRI in diagnosing the ligament injuries of the ankle. Methods: The study was reviewed and approved by an institutional review board of hospital. Retrospective analysised 10 healthy volunteers and 26 ankle injury cases underwent surgery since January 2013 to September 2016, the MR imaging findings of patients were compared with volunteers' and operative documents, to analysis the MRI feature of the ligament injuries of the ankle. Results: The normal anterior talofibular ligament and posterior talofibular ligament can be manifest in 3-4 layers of MRI, and can be fully displayed in 1 layer. The normal calcaneofibular ligament can be manifest in 3 layers of MRI, but can not be fully displayed in 1 layer. 26 cases of lateral ligament injury (including 1 case of ATFL injury, 1 case of CFL injury, 3 cases of ATFL conjunction with CFL injury, 3 cases of ATFL conjunction with CFL and PTFL injury) manifested the heterogeneous signal of the T(1)-weighted image, the ligament disruption, the increased signal intensity on fat-suppression PD-weighted image , the surrounding soft tissue edema and bone marrow edema. Conclusion: MR imaging is an accurate method for evaluation of the ligament injuries of the ankle, and it is a useful tool for diagnosis and treatment.

[MRI of the finger ligament and tendon injuries: imaging technique and clinical application].

Objective: To explore the MRI technique and the clinical application in ligament and tendons of fingers. Methods: The study was reviewed and approved by an institutional review board of hospital.A total of 20 normal volunteers and 50 patients from Beijing Jishuitan Hospital between May 2012 and May 2015 with finger injuries were chosen to undergo magnetic resonance examination by using Achieva 3.0 T MR produced by Philips.Scanning from coronal, sagittal and axial view in T(1)-weighted and proton fat saturation sequence (PD-FS), choosing suitable parameters, in order to get clear images of finger tendons and ligaments. Results: Twenty normal volunteers without tendons or ligament injuries showed homogeneous low-signal-intensity on T(1)-weighted and proton fat saturation sequence (PD-FS) images.In the 50 patients with finger injuries, there were 33 cases of ligament injuries, 10 cases of extensor tendon injuries and 7 cases of flexor tendon injuries. There were 8 cases of all the 50 cases combined with bone fracture.The injured ligaments and tendons became thicker and discontinued in T(1)WI and demonstrated heterogeneously increased signal intensity with edema in the soft tissues surrounding the injured sites in PD-FS. Conclusion: MRI can demonstrate the anatomy and injuries features of ligament and tendons in fingers accurately.It is significance for the early diagnosis and treatment protocols of the ligament and tendons injuries.

[Focal periphyseal edema zone on MRI and clinical significance of the adolescent knee].

OBJECTIVE: To investigate the MR image characteristics and clinical significance of focal periphyseal edema (FOPE) zone of the adolescent knee which was with or without trauma history, and provide the basis for the correct diagnosis and treatment. METHOD: A total of 12 patients (9 boys, age range 12-16 years, average age 14 years old, 3 girls, age range 12-15 years, average age 13 years )who had pain of the knee without the traumatic history and 16 patients (12 boys, age range 10-15 years, average age 14 years; 4 girls, age range 11-13 years, average age 12 years) who were painful in the knee after trauma were included in this study. The knee MR examinations were performed in all the patients. The characteristics of MRI between painful knee without trauma and painful knee after trauma were compared and analyzed, and the average vertical distances from the farthest of the edema area to the epiphyseal plate were measured. The vertical distances were measured respectively in sagittal view and coronal view in PD-FS and in sagittal view in T1WI, and the average for the three were calculated. At last, the images with the results of operation or follow-up examinations were compared and confirmed by double blind method. RESULTS: The MRI characteristics of FOPE zone in the 12 adolescent who complained painful knee but had no trauma showed low signal intensity in T1WI and high signal intensity in PD-FS. The edema centered at the physis and extended into both the adjacent epiphysis and metaphysic.In addition, it shaped like patches and thread, and edema range(14.5±6.6)mm.The MRI findings of the 16 adolescent had pain of the knee after injury characterized by a wide range of low T1WI signal intensity and increased PD-FS signal intensity involving the articular surface of the epiphysis.The range of edema was (26.2±8.8)mm.There was statistically significant difference between non-traumatic edema and the edema caused by trauma (t=4.346, P<0.05). CONCLUSION: A FOPE zone of the adolescent knee is likely to be related to pain in the adolescent growth period and physiologic physeal fusion, and should not be mistaken for an abnormality, while the larger range of edema surrounding the epiphyseal plate may be associated with the trauma of the knee.

[Classification and MR imaging of triangular fibrocartilage complex lesions].

OBJECTIVE: To explore the MRI characteristics of injuries of triangular fibrocartilage complex (TFCC), and provide imaging basis for the early diagnosis and treatment of the injuries. METHODS: A total of 10 healthy volunteers without wrist injuries and 200 patients from Beijing Jishuitan Hospital who complained ulnar-sided wrist pain and were highly suspected as the injury of TFCC underwent the wrist magnetic resonance examination. All subjects were in a prone position and underwent examination on coronal T1WI scan and PD-FS on 3 planes respectively. Then the MRI characteristics of 3 healthy volunteers and 67 patients with TFCC injuries that confirmed by operation were analyzed. According to the comparative analysis of normal anatomy and Palmer classification, the injuries were classified and MRI features of different types of injuries were analyzed. At last, imaging findings were compared with surgical results. RESULTS: Three healthy volunteers without injuries showed mainly in low signal intensity on T1WI and PD-FS images. According to Palmer classification, there were 52 traumatic injuries (ⅠA 9, ⅠB 25, ⅠC 3, ⅠD 13, In addition, 1 has central perforation and ulnar avulsion and 1 has ulnar and radial injuries simultaneously) and 15 degenerative injuries (ⅡA 5, ⅡB 1, ⅡC 2 , ⅡD 1 , ⅡE 6) among 67 patients. The central perforation mainly demonstrated as linear high signal perpendicular to the disk, and run in a sagittal line. The ulnar, distal, and radial avulsion mainly showed the injuries were irregular, the structures were ambiguous, and there was high signal intensity in the injured structures on PD-FS. Degenerative injuries demonstrated the irregularity of TFC and heterogeneous signals on PD-FS. There were mixed intermediate-high signals and changes in the articular cartilage of lunate and ulna, high signal in the lunotriquetral ligament and ulnocarpal or radioulnar arthritis. CONCLUSION: MRI can demonstrate the anatomy of TFCC accurately, evaluate and make the general classification of injuries. It is of significance for the early diagnosis and treatment protocols of the TFCC injuries.

Rabbit model of primary hyperparathyroidism induced by high-phosphate diet.

The objective of this study is to establish a new rabbit model of primary hyperparathyroidism (PHPT) induced by high-phosphate diet. One hundred twenty rabbits were divided into two groups of 60 each. The treatment group was fed a high-phosphate diet (Ca:P = 1:7) and the control group was given a normal animal diet (Ca:P = 1:0.7) for 1 to 6 mo. Serologic examinations, including parathyroid hormone (PTH), calcium and phosphorus levels, blood urea nitrogen, creatinine, and uric acid, and the histologic examination, including parathyroid, kidney, and bones, were performed at the end of each month for 6 mo. Compared with the control, serum PTH levels in the treatment groups were elevated at all six time points, whereas serum calcium levels were reduced, and serum phosphorus levels remain unchanged over the course of the first 3 mo. Serum calcium levels were increased, whereas serum phosphorus levels were reduced at 4, 5, and 6 mo. Parathyroid histopathological examination showed no change during the first month, whereas 60% of the animals exhibited mild hyperplasia starting at 2 mo, and 90% of the animals in the treatment group exhibited mild-to-moderate hyperplasia with gland enlargement starting from 3 mo through the end of the study. Histopathological examination of the kidneys showed no change at 1 mo, but focal parenchymal inflammation with calcium deposition was observed in the treatment groups at 2 to 6 mo. Fibrous tissue of the bone extended toward the cortex, and fibrosis was evident at the third month. The fibrous cells were found to be concentrated mainly on the inner and outer membranes of the bone cortex, and the amount of fibrous tissue increased as the disease progressed. We conclude that a new rabbit animal model of PHPT can be successfully created by the administration of a high-phosphate diet. This animal model can be used in various future studies related to PHPT.

[3D solid model of mandible with dental arch via LOM method].

OBJECTIVE: Based on 3D reconstruction data from CT scanning, a solid model of mandible with dental arch is obtained via a rapid prototype machine using LOM method. METHODS: 3D reconstruction data is transferred to STL file using software of Delcam(UK),which will be fed to Magics RP software for detection and rebuilding. Reproduction of the papery model of mandible with dental arch is then performed with highly geometric similarity. RESULTS: The RP model of mandible with dental arch is obtained. CONCLUSION: Accuracy of the reproduction model meets the demands of students in prosthetic dentistry,which gives the possibility of computer aided design of prosthetic dentistry based on 3D solid model.

Dynamic CT scan of intracranial tumors.

Of ninety-eight patients with intracranial tumors examined by dynamic CT scanning, 66 were confirmed operatively and pathologically. Our study showed that: 1) Dynamic CT can be performed safely and easily in outpatients; 2) Acoustic neurinoma, meningioma, pituitary chromophobe adenoma, astrocytoma and metastatic tumor have varying levels of time-density curves; 3) The tissue-blood ratio (TBR) at peak time (TBRp) is a useful indicator of the vascularity of tumoral tissues, and analysis of the time-density curve combining with TBRp is helpful to the differential diagnosis of tumors; 4) Differential diagnosis between tumors and vascular abnormalities such as aneurysm and arteriovenous malformation could be made easily with dynamic CT.

CT in diagnosis of acoustic neuromas.

A detailed analysis of the CT findings in 75 cases of acoustic neuroma is presented. The method of examination included plain and enhanced CT, metrizamide CT cisternography (M-CTC), and gas CT cisternography (gas-CTC). The common CT appearances of acoustic neuromas were as follows: 93.6% appeared as isodense or hypodense on precontrast scan; homogeneous enhancement was observed in 53.8% on postcontrast scan; the tumor center, mostly located at the level of the internal acoustic canal, was spherical in shape with an acute angle between the lateral tumor border and petrous bone; and there was widening of the internal acoustic canal or destruction of petrous bone. However, the presence of an acoustic neuroma could not be excluded if widening of the internal acoustic canal was absent. It was not certain whether contrast filling of the internal acoustic canal occurred at M-CTC in the four cases so examined. One case of intracanalicular neuroma was diagnosed by gas-CTC, which is the most sensitive and reliable technique for detecting and excluding small tumors. The significance of various CT appearances, early diagnosis, and differential diagnosis of acoustic neuroma from other cerebellopontine-angle tumors, particularly meningioma, are discussed.