Medullary impairment at early stage of non-traumatic osteonecrosis of the femoral head

Summary We found that a painful hip without radiological changes presented a modification of the magnetic resonance image of the femoral head and neck with diffuse low T1 weighted and high T2 weighted signal. Core biopsy showed that the bone marrow was replaced from the neck to the head of the femur by fibroblastic tissue and edema without detectable trabecular bone impairment. Classical radiographic, CT, and MRI abnormalities of osteonecrosis of the femoral head were present 14 months later. This report suggested that diffuse femoral head and neck medullary impairment with fat cell replacement by fibroblastic tissue without evidence of trabecular bone necrosis can be found at the early stages of idiopathic osteonecrosis.     

Transient osteoporosis of the hip, complete resolution after treatment with alendronate as observed by MRI description of eight cases and review of the literature

Transient osteoporosis of the hip (TOH), also referred to as transient bone marrow edema syndrome, is most common in middle-aged men and often after trivial trauma or sport-related injuries. Diagnosis is usually made by eliminating other possible causes of hip pain. Magnetic resonance imaging (MRI) plays an important role in diagnosis and demonstrates a typical pattern of bone marrow edema (BME) in the form of diffuse low signal on T1-weighted images and high signal on T2 fat-suppressed or short T1 inversion recovery images. No consensus exists about the management of TOH, as it may progress to avascular necrosis. We describe eight cases of TOH treated with alendronate resulting in improvement of pain and function and complete resolution of BME on MRI. The literature is reviewed regarding TOH and the relationship with bone marrow edema syndrome, avascular necrosis of the hip, and regional migratory osteoporosis. To our knowledge, this is the first report describing the improvement of this condition after of alendronate with documented radiological improvement on follow-up MRI.     

Two cases of lung metastasis of malignant melanoma]

We report 2 cases of lung metastasis of malignant melanoma. Patient 1 was a 71-year-old woman who had undergone an operation for enucleation of her left eye 13 years earlier. Chest magnetic resonance imaging (MRI) demonstrated intermediate intensity including partially high intensity on T 1 weighted images, and high intensity including partially low intensity on T 2 weighted images. Microscopic findings from a transbronchial lung biopsy specimen disclosed melanotic melanoma. Patient 2 was a 54-year-old man who had undergone surgery for malignant melanoma in the left upper arm 4 years earlier. Chest MRI films demonstrated low intensity on T 1 weighted images, and high intensity on T 2 weighted images. Microscopic findings from specimens of the primary lesion in the left upper arm revealed melanotic melanoma, but the findings from the lower right lobectomy disclosed amelanotic melanoma. It has been reported that MRI is useful in the diagnosis of malignant melanoma, and that melanin content reflects MRI signal intensity. The MRI findings were consistent with the histopathologic findings in each of the 2 cases we reported.     

Is transient hip osteoporosis a transient osteonecrosis?

A patient suffering from transient osteoporosis of the hip sustained a fracture of the ipsilateral collum femoris. Total hip replacement was performed. The complete specimen of the proximal femur was subjected to histological examination. The histological findings were consistent with the reparation stage of ischaemic bone necrosis of the femoral head. The authors discuss whether transient osteoporosis of the hip is a transient, i.e. self-recovering ischaemic necrosis of the femoral head.     

Transient osteoporosis of the hip: magnetic resonance imaging

We describe a 38-year-old male with abrupt onset of left hip pain. The diagnosis of transient osteoporosis of the hip was made on the basis of the clinical history and characteristic radiographic changes (osteopenia with indistinctness of the subchondral cortex). Magnetic resonance imaging demonstrated diffuse decreased signal in the proximal femur without localization to the femoral head and magnetic resonance findings were more obvious than those demonstrated by conventional radiographs. Radiographs and magnetic resonance imaging after cessation of symptoms were near normal. Magnetic resonance imaging may be helpful in evaluation of patients with acute hip pain.     

Relationship between magnetic resonance imaging and histologic findings by bone biopsy in nontraumatic osteonecrosis of the femoral head.

To attest the validity of magnetic resonance imaging (MRI) to evaluate the pathophysiology in nontraumatic osteonecrosis (ON) of the femoral head, we attempted to correlate the different MRI patterns with the histology in cases of early stages. We used not only the T1 and T2 pulse sequences, but also the T1 sequence after gadolinium-DTPA to demonstrate the presence of vascularization. Studying 24 core biopsies from 16 hips (9 patients), we explored the MRI presentations that corresponded to the main histologic findings of the different trabecular bone and bone marrow conditions. Histologic findings including trabecular bone necrosis and bone marrow necrosis represented by amorphous eosinophilic debris presented a low T1 signal intensity without enhancement after intravenous gadolinium injection and a low T2 signal intensity. Trabecular bone necrosis associated with mummified fat cells presented a normal T1 and T2 signal intensity. Trabecular bone necrosis with fibrosis filling the intertrabecular spaces had a low T1 signal intensity that was enhanced by gadolinium and had an intermediate T2 signal intensity. Bands of fibrosis without trabecular bone as seen in fracture zones showed a low T1 signal intensity that was enhanced by gadolinium with a high T2 signal intensity. Thickened trabecular bone with fibrosis as found in creeping substitution areas had also a low T1 signal enhanced by gadolinium, but the T2 signal intensity was low. Farther from the necrotic area, despite normal trabecular bone, we found some patchy necrosis of the bone marrow without any modification of the normal T1 and T2 MRI patterns.(ABSTRACT TRUNCATED AT 250 WORDS)     

Subchondral insufficiency fracture of the femoral head after total knee arthroplasty in a patient with rheumatoid arthritis

We report an 80-year-old woman with rheumatoid arthritis (RA) who was found to have subchondral insufficiency fracture of the right femoral head after total knee arthroplasty (TKA). Initially, plain radiographs showed no obvious changes, but magnetic resonance imaging (MRI) revealed an irregular, discontinuous, low-intensity band on T1-weighted images of the right hip. She underwent hemiarthroplasty of the hip. This report describes a rare case of subchondral insufficiency fracture of the femoral head after TKA in a patient with RA.     

The limbus in developmental dysplasia of the hip: An obstacle to reduction and its images changed by the femoral head position

This study aimed to describe the shape of the limbus arthroscopically and via arthrogram and magnetic resonance imaging (MRI), and to determine whether it prevents concentric reduction of the femoral head in developmental dysplasia of the hip (DDH).Twelve patients (mean age, 10.2 months; range, 3–31 months) who underwent arthroscopic-assisted reduction for DDH were retrospectively reviewed. Limbus shapes were captured on arthrogram before reduction, after closed reduction, and after arthroscopic-assisted reduction and categorized according to the Miyake classification.On arthrogram, the superior limbus was blocked in 2 hips, inverted in 2, intermediate in 5, and everted in 3 after attempted closed reduction. After arthroscopic-assisted reduction, the limbus was everted in 7 hips and normal in 5. On arthroscopy, in all cases, the limbus appeared as a whitish, cartilage-like ring with a variably blunted edge before reduction, without inversion or eversion. On postoperative MRI, 10 of 12 superior limbi showed hypertrophy or globular compression by the femoral head with intermediate or mixed MRI signal intensities and blunted edges. The remaining 2 hips had hypertrophied superior limbi with sharp edges. On transverse plane MRI, the posterior limbus of all hips showed sharp margins with low MRI signal intensity. Residual subluxation was observed in 7 of the 12 hips with interposition of the anteroinferior limbus.The appearance of the limbus varied according to the femoral head position, and it was neither inverted nor everted. Interposed anteroinferior limbi with residual subluxation suggest impeded concentric reduction in DDH.     

CT与MRI诊断鼻咽癌的对比研究

目的 探讨鼻咽癌向周围邻近结构侵犯的CT和MRI表现。并比较其诊断价值。方法 分析经病理证实的2l例NPC患者CT和MRI资料。结果 鼻咽癌瘤体T1WI等信号14例(66,7％),T2WI高信号18例(85．7％),增强T1WI高信号9例(100％)。CT、MRI显示鼻咽癌以下结构的浸润率有显著性差异：完全茎突后间隙、颅骨和海绵窦(P值分别为0．015,0.000和0．017)。副鼻窦检出率分别为14．3％和4．8％,但P值为0．143。其余结构两者检出无统计学差异。结论 以MRI为鼻咽癌患者首选影像学检查,可更准确了解肿瘤侵犯范围。     

Retrorectal tumors in adults: magnetic resonance imaging findings

AIM:To retrospectively evaluate the magnetic resonance imaging (MRI) features of adult retrorectal tumors and compare with histopathologic findings.METHODS:MRI features of 21 patients with preoperative suspicion of retrorectal tumors were analyzed based on the histopathological and clinical data.RESULTS:Fourteen benign cystic lesions appeared hypointense on T1-weighted images,and hyperintense on T2-weighted images with regular peripheral rim.Epidermoid or dermoid cysts were unilocular,and tailgut cysts were multilocular.Presence of intracystic intermediate signal intensity was observed in one case of tailgut cyst with a component of adenocarcinoma.Six solid tumors were malignant lesions and showed heterogeneous intensity on MRI.Mucinous adenocarcinomas showed high signal intensity on T2-weighted and mesh-like enhancing areas on fat-suppressed T2-weighted images.There was a fistula between the mass and anus with an internal opening in mucinous adenocarcinomas arising from anal fistula.Gastrointestinal stromal tumors displayed low signal intensity on T1-weighted images,and intermediate to high signal intensity on T2-weighted images.Central necrosis could be seen as a high signal on T2-weighted images.CONCLUSION:MRI is a helpful technique to define the extent of the retrorectal tumor and its relationship to the surrounding structures,and also to demonstrate possible complications so as to choose the best surgical approach.     

Subchondral insufficiency fracture of the femoral head: a differential diagnosis in acute onset of coxarthrosis in the elderly

OBJECTIVE: To document subchondral insufficiency fracture (SIF) of the femoral head and investigate its frequency. METHODS: The study was based on a retrospective review of 464 removed femoral heads (from 419 patients) with both radiologic and histologic evidence of subchondral collapse. Gross photographs, specimen radiographs, and histologic sections were reevaluated in all cases. Available clinical notes and imaging studies were also reviewed. RESULTS: Ten cases previously diagnosed as osteonecrosis were reinterpreted as SIF on a histopathologic basis. All of these patients were women over 65 years old (average age 75) with osteopenia. The initial symptom was acute onset of hip pain. Radiologically, a subchondral collapse, mainly in the superolateral segment of the femoral head, was noted. Magnetic resonance imaging, available in 3 cases, showed diffuse low intensity on T1-weighted images and high intensity on T2-weighted or fat-suppressed images. Bone scintigraphy, available in 4 cases, showed increased uptake in the femoral head. Histopathologically, a 1.0-2.5-cm long linear whitish gray zone, comprising fracture callus and granulation tissue, was found beneath the subchondral bone end plate. There was no evidence of antecedent osteonecrosis. CONCLUSION: The results of this study indicate that SIF should be included in the differential diagnosis of acute onset of coxarthrosis in the elderly.     

成人型肺结核磁共振表现初步观察

探讨磁共振对肺结核的诊断价值。方法回顾分析５５例成人型肺结核磁共振和Ｘ线片表现。结果磁共振和胸片在反映肺结核浸润性、增殖性病理变化和空洞、结核瘤、干酪性肺炎病变类型方面无明显差别。浸润性、增殖性病灶及干酪性肺炎Ｔ１、Ｔ２加权像均呈中等信号，空洞呈低信号，结核瘤Ｔ２加权像多呈不均信号。结论磁共振毋须做为肺结核诊断常规手段     

Magnetic resonance imaging of femoral marrow in patients with myelodysplastic syndromes or leukemia

We evaluated magnetic resonance imaging (MRI) of femoral marrow in 85 untreated adult patients with myelodysplastic syndromes (MDS) (N = 27), aplastic anemia (N = 9), and leukemia (N = 49). Images of femoral marrow were obtained using a T1-weighted spin-echo (SE) method and a short T1 inversion recovery (STIR) technique. In patients with MDS, the change in MRI pattern from a fatty or nodular pattern to a uniform pattern correlated with disease progression. Evolution to acute leukemia in MDS patients was associated with a higher signal intensity on STIR images (lower signal intensity on T1-weighted SE images) and an extended area of involvement. The femoral marrow in patients with de novo acute myeloid leukemia (AML) showed increased signal and varied patterns (scattered to uniform) on STIR images. However, the faint pattern (grade 4a) was characteristic of M2 AML. In patients with chronic myelogenous leukemia (CML) in the chronic phase, increased leukemic mass was represented by replacement of the femoral marrow with a region of abnormal signal intensity. The extent of involved areas in these CML patients correlated with the spleen size. This study indicates that MRI of femoral marrow is an important tool for the accurate diagnosis and management of patients with MDS and leukemia that may function as an adjunct to bone marrow aspiration and biopsy.     

The role of subchondral insufficiency fracture in rapid destruction of the hip joint: a preliminary report

OBJECTIVE: The pathophysiology of rapidly destructive arthrosis of the hip joint (RDA) is unknown. The purpose of this study was to document cases of subchondral insufficiency fracture of the femoral head, which has similar clinicoradiologic features to those of early-stage RDA. METHODS: This study was based on a retrospective review of 11 cases of subchondral insufficiency fracture of the femoral head that were confirmed histopathologically and for which radiographs both at the onset of hip pain and at the time of surgery were available. RESULTS: All patients were > 60 years of age (range 61-78 years, mean age 69), and 9 were women. On plain radiographs, the normal joint space had undergone rapid narrowing and/or disappeared within 9 months (mean 5.8 months). Magnetic resonance imaging, available in 2 cases, showed a pattern of bone marrow edema from the upper portion of the femoral head to the intertrochanteric region, with an associated focal low-intensity band on T1 paralleling the articular surface. In all cases, evidence of subchondral insufficiency fracture was confirmed histopathologically. In addition, in the marrow space, there were several round-to-oval granulomatous foci, which consisted of amorphous debris, fragmented bone, and articular cartilage surrounded by reactive histiocytes and giant cells. All 11 patients were osteopenic, as shown both radiologically and histopathologically. CONCLUSION: Subchondral insufficiency fracture resulting from osteopenia may lead to a rapid breakdown of the hip joint.     

Clinical and neuroimaging features of enterovirus71 related acute flaccid paralysis in patients with hand-foot-mouth disease

ObjectiveTo investigate clinical and neuroimaging features of enterovirus71 (EV71) related acute flaccid paralysis in patients with hand-foot-mouth disease.MethodsNine patients with acute flaccid paralysis met the criterion of EV71 induced hand-foot-mouth disease underwent spinal and brain MR imaging from May 2008 to Sep 2012.ResultsOne extremity flaccid was found in four cases (3 with lower limb, 1 with upper limb), two limbs flaccid in three cases (2 with lower limbs, 1 with upper limbs), and four limbs flaccid in two cases. Spinal MRI studies showed lesion with high signal in T2-weighted images (T2WI) and low signal T1-weighted images (T1WI) in the spinal cord of all nine cases, and the lesions were mainly in bilateral and unilateral anterior horn of cervical spinal cord and spinal cord below thoracic 9 (T9) level. In addition, the midbrain, pons, and medulla, which were involved in 3 cases with brainstem encephalitis, demonstrated abnormal signal. Moreover, spinal cord contrast MRI studies showed mild enhancement in corresponding anterior horn of the involved side, and strong enhancement in its ventral root.ConclusionsEV71 related acute flaccid paralysis in patients with hand-foot-mouth disease mainly affected the anterior horn regions and ventral root of cervical spinal cord and spinal cord below T9 level. MR imaging could efficiently show the characteristic pattern and extent of the lesions which correlated well with the clinical features.     

Initial change in transient osteoporosis of the hip on magnetic resonance images: a case report

We report the case of a 29-year-old Japanese man with transient osteoporosis of the left hip (TOH) following contralateral TOH, paying special attention to the initial changes on MRI. MR images showed no abnormal findings 6 weeks before the clinical manifestation, but the images just after the onset depicted a linear abnormality equivalent to a subchondral insufficiency fracture. Both radiological findings and clinical symptoms disappeared completely without any surgical intervention within 10 months.     

Factors associated with hip cartilage volume measured by magnetic resonance imaging: the Tasmanian Older Adult Cohort Study

OBJECTIVE: To compare associations between anthropometric and lifestyle factors and femoral head cartilage volume/thickness and radiographic features of osteoarthritis (OA) and to provide evidence of construct validity for magnetic resonance imaging (MRI) assessment of femoral cartilage volume and thickness. METHODS: We studied a cross-sectional sample of 151 randomly selected subjects (79 men, 72 women; mean age 63 years) from the Tasmanian Older Adult Cohort Study. A sagittal T1-weighted fat-suppression MRI scan of the right hip was performed to determine femoral head cartilage volume, cartilage thickness, and size. An anteroposterior radiograph of the pelvis with weight bearing was performed and scored for radiographic evidence of OA in the right hip. Other factors measured were height, weight, leg strength, serum vitamin D levels, and bone mineral density. RESULTS: Hip cartilage volume was significantly associated with female sex, body mass index, and femoral head size, whereas hip cartilage thickness was significantly associated only with the size of the femoral head. Only female sex was significantly associated with the total radiographic OA score and the joint space narrowing (JSN) score, but not the osteophyte score. Radiographic JSN of the hip, especially axial JSN (but not osteophytes), was significantly correlated with hip cartilage volume and thickness. CONCLUSION: Femoral head cartilage volume and thickness have modest but significant construct validity when correlated with radiographic findings. Furthermore, the generally stronger associations with volume compared with radiographic OA suggest that MRI may be superior at identifying risk factors for hip OA.     

Cystic mesothelioma of the peritoneum

We report a case of cystic mesothelioma of the peritoneum (CMP), a rare tumor. The magnetic resonance imaging (MRI) findings and the histochemical features were studied. The patient was an 18-year-old woman who presented with upper abdominal pain. Abdominal ultrasonography and computed tomography showed a well defined cystic mass with a solid papillary projection in its lumen. MRI of the cyst showed high intensity on T2- and proton weighted images and low intensity on T1-weighted images, and the solid projection showed low intensity on T2- and proton-weighted images and slight low intensity on T1-weighted images, on which it was well enhanced. The lesion was suspected to be a benign cyst, such as a hemangioma, lymphangioma, or a splenic or pancreatic cyst. Complete surgical resection was performed. The resected specimen consisted of a unilocular cystic mass, with a solid projection, weighing 260g and measuring 10 cm in diameter. The final diagnosis, arrived at by histopathological examination, was low-grade malignant CMP. The tumor cells were strongly positive for keratin, weakly positive for vimentin, and negative for epithelial membranous antigen. The patient is now well and symptom-free with no recurrence 19 months after operation. CMP is a rare tumor; only 12 cases have previously been reported in Japan.     

MRI features of pigmented villonodular synovitis (PVNS)

The aim of this study was to characterize the magnetic resonance imaging (MRI) features of PVNS. The radiographs and MR images of 23 pathologically proven cases of PVNS were retrospectively reviewed, with emphasis on MR images. There were 9 males and 14 females, mean age 36 years. Of 23 cases, 9 occurred in the hip, 8 in the knee, 3 in the ankle, 2 in the elbow and 1 in the wrist. Typical MRI findings included variable extent of nodular synovial proliferation, from mild proliferation to extensive masses, joint effusion in all cases, and multiple bony erosions in 15. Owing to the tight joint space, bone involvement was frequently seen in the hip, ankle, elbow and wrist. Although the knee joint had a loose capsule, bone involvement was rarely seen. Hemosiderin is a magnetic material, its deposit on proliferative synovial tissue resulting in a spotty low signal or extensive low signal area within the proliferative synovial masses on T₁- (T1WI) and T₂-weighted (T2WI) images, best seen on fast field echo (FFE) sequence MRI images. Fat-suppressed sequences obscured the deposit . This is diagnostic of PVNS. The MRI features of PVNS include variable extent of synovial proliferation, joint effusion and erosion of bone, and in particular the deposit of hemosiderin within the synovial masses. The deposit of hemosiderin, appearing as a low signal area best seen on FFE sequence, is diagnostic for PVNS.Abbreviations FFE Fast field echo - PVNS Pigmented villonodular synovitis     

Initial change in transient osteoporosis of the hip on magnetic resonance images: a case report

Abstract

We report the case of a 29-year-old Japanese man with transient osteoporosis of the left hip (TOH) following contralateral TOH, paying special attention to the initial changes on MRI. MR images showed no abnormal findings 6 weeks before the clinical manifestation, but the images just after the onset depicted a linear abnormality equivalent to a subchondral insufficiency fracture. Both radiological findings and clinical symptoms disappeared completely without any surgical intervention within 10 months.