Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Correlative study between insulin-like growth factor-Ⅰ and histologic findings and MR imaging in steroid-induced osteonecrosis of the rabbit femoral head

大量激素引起股骨头坏死(osteonecrosis of femoral head,ONFH)的发病机制为股骨头骨髓脂肪化,髓腔内脂肪细胞增多、增大,压迫窦状细血管,血管床面积减少,引起局部缺血、缺氧[1-2].     

Effects of hyperbaric oxygen on TF、TNF-α in the rabbit model of steroid-induced avascular osteonecrosis of femoral head

Objective To investigate dynamic changes in serum TF and TNF-α in the rabbit model of steroid-induced avascular osteonecrosis of femoral head ( SANFH) and also to explore the mechanism of SANFH, as well as effects of hyperbaric oxygen ( HBO) on SANFH. Methods Seventy-eight New Zealand male rabbits were randomly divided into 3 groups:the normal control (group N) (7 animals), the model group (group M) (41 animals) and the HBO group (group H) (30 animals). The model group was subdivided into the immediate model group (the M0 group) (10 animals), the two-week model group (the M2 group) (10 animals), the four-week model group (the M4 group) (10 animals) and the six-week model group (the M6 group) (11 animals). The HBO group was further divided into the 2-week HBO therapy group (HBO2) (7 animals), the 4-week HBO therapy group (HBO4) (11 animals) and the 6-week HBO therapy group (HBO6) (12 animals). Through injection of endotoxin and methyl-prednisolone, rabbits in the group HBO2, HBO4 and HBO6 received HBO therapy 1 hour daily from the second day of the experiment. The durations of HBO therapy were 2 weeks ( HBO2), and 4 weeks respectively. The animals were sacrificed after blood samples were taken at respective blood collection time. Then, levels of TF, TNF-α in the serum were measured and the histological changes in the femoral heads were observed. Results Levels of TF and TNF-α in group M0 increased significantly, when compared with those of group N (P ＜0. 05 or P ＜0.01), while for the HBO subgroups the expression of TF and TNF-α measured at the same time points all decreased, when compared with that of the model subgroups (P＜0. 05 or P ＜0.01). To elaborate, TF levels in group M2 and M4 were much higher than those in group HBO2 and HBO4 ( P＜0. 01 ). TF level in group M6 was higher than that in group HB06 ( P ＜ 0.05). TNF-α in group M0 also increased significantly, when compared with that in group N( P ＜0.01). TNF-α levels in group M2 and M6 were also much higher than those in group HBO2 and HBO6 ( both P ＜0. 01 ). TNF-α in group M4 was higher than that in group HBO4 (P＜0.01). Histological examination revealed that tissues of the femoral heads in group N were normal, osteonecrosis and thrombus could be noted in group M2 and M4, hyperplasia fibrosis could be found in group M6, and osteonecrosis in HBO2 and HB04 groups seemed less severer than that in M2 and M4 groups, no thrombi in HBO2, HBO4 groups were noted, and growth of new bones were detected in HBO4 and HBO6. Conclusions The levels of TF and TNF-α levels increased in the rabbit model of SANFH, inducing blood coagulation. Thrombosis at the femoral heads was one of the causes of SANFH. HBO therapy could inhibit the release of TF and TNF-α, thus improving the abnormality of blood coagulation and enhancing treatment of osteonecrosis.     

Bipositional MR imaging vs arthrography for the evaluation of femoral head sphericity and containment in Legg-Calvé-Perthes disease

Eleven hips of 10 patients with Legg-Calvé-Perthes disease (LCPD) were examined by arthrography and magnetic resonance (MR) imaging. Arthrogram and MR images were obtained with the hips in neutral position and in 20 degrees flexion-abduction and internal rotation. Modified arthrographic index (AI) was used for the evaluation of sphericity and acetabulum head index (AHI) was used for the assessment of containment. According to AI, there is no significant difference between the arthrograms and coronal MR imaging, but the difference between the coronal and sagittal MR imaging was significant. There was no statistical difference between the arthrograms and MR measurements in terms of AHI. Anterior flattening of the femoral head and the effect of hip flexion in the containment at the sagittal plane could be demonstrated clearly in sagittal MR imaging. Even if there was significant flattening in coronal plane, the sphericity of the head was preserved in the sagittal plane. Bipositional MR imaging is comparable to arthrography for the demonstration of sphericity and containment of the femoral head in both coronal and sagittal planes in LCPD.     

Ultrasound imaging features of the Achilles tendon in dancers. Is there a correlation between the imaging and clinical findings? A cross-sectional study

ObjectivesTo analyze the prevalence of tendon pathology and performance associated in pre-professional classic dancers with no history of Achilles tendon (AT) pain. Design: A cross-sectional study was conducted.ParticipantsTwenty-nine classic ballet dancers without AT pain (58 tendons) were recruited. The tendons were classified (normal, abnormal) using ultrasound imaging (USI). Cross-sectional area (CSA) and thickness of flexor hallucis longus (FHL) muscle were measured using USI. Range of movement (ROM) of the first metatarsophalangeal join, balance test, endurance test and vertical jump were measured (bilaterally) as performance variables.ResultsMore than a half (62%) of the participants had at least one abnormal tendon, with 45% of the dancers in the abnormal group having bilateral abnormalities. Dancers with AT pathology had significantly more years of dancing and number of weekly pointe hours than those with no pathology on US imaging. No significant differences between the groups were identified for the rest of the variables. Dancing years were moderately correlated with AT thickness.ConclusionsAsymptomatic classic dancers had a high incidence of tendon pathology. Increased dancing years was associated with pathology in the AT. Nevertheless, these abnormalities may not affect dance performance.     

Contrast-enhanced MR imaging of the spine: when, why and how? How to optimize contrast protocols in MR imaging of the spine

The optimal protocols and the role of contrast agents in spinal MR imaging are controversial. Although the diagnosis of many common spinal diseases can be reliably achieved by means of unenhanced images, contrast use is often necessary to improve lesion detection and differential diagnosis. The heterogeneity of the different spinal compartments and the wide variety of spinal pathology require tailored imaging strategies. Thus, the rules to achieve optimization of contrast protocols for MR imaging of the spine are frequently very different to those for brain imaging, and depend on the location and site of origin of the lesions in a specific spinal compartment, on the findings of unenhanced imaging, and on the concomitant use of fat-suppression techniques. Furthermore, in most cases, the small size of the examined structures requires a meticulous technique, and the administration of a contrast agent with high relaxivity, such as MultiHance, is advisable to enable the detection of tiny areas of contrast enhancement. The applications and clinical utility of post-contrast MR imaging are discussed with regard to different spinal diseases.     

Complications of loco-regional therapy in the liver—spectrum of imaging findings by CT and MRI

The aim of this study was to discuss the appearance of common complications from loco-regional therapy of primary and secondary malignant liver neoplasms on cross-sectional imaging. Knowledge of common complications is important for the safe performance of loco-regional therapy (LRT) and for the interpretation of post-LRT follow-up imaging. With careful patient selection, LRT represents an effective and safe treatment of primary and secondary hepatic malignancies; however, complications related to LRT methods infrequently lead to additional morbidity.     

MR imaging and proton MR spectroscopic studies in Sjögren-Larsson syndrome: characterization of the leukoencephalopathy

BACKGROUND AND PURPOSE: Sj?gren-Larsson syndrome (SLS) is a neurocutaneous syndrome caused by a genetic enzyme deficiency in lipid metabolism. Our purpose was to characterize the nature of the cerebral involvement in SLS. METHODS: MR imaging was performed in 18 patients (aged 5 months to 45 years) and repeated in 14. Single-voxel proton MR spectra were acquired from cerebral white matter and gray matter in 16 patients, with follow-up studies in 11. LCModel fits were used to determine brain metabolite levels. RESULTS: MR imaging showed retardation of myelination and a mild persistent myelin deficit. A zone of increased signal intensity was seen in the periventricular white matter on T2-weighted images. Proton MR spectroscopy of white matter revealed a prominent peak at 1.3 ppm, normal levels of N-acetylaspartate, and elevated levels of creatine (+14%), choline (+18%), and myo-inositol (+54%). MR imaging and proton MR spectroscopy of gray matter were normal. In the two patients examined during the first years of life, abnormalities on MR imaging and proton MR spectroscopy gradually emerged and then stabilized, as in all other patients. CONCLUSION: Abnormalities on MR imaging and proton MR spectroscopy emerge during the first years of life and are similar in all patients with SLS, but the severity varies. The changes are confined to cerebral white matter and suggest an accumulation of lipids, periventricular gliosis, delayed myelination, and a mild permanent myelin deficit.     

Usefulness of diffusion-weighted MR imaging for differentiating between Warthin’s tumor and oncocytoma of the parotid gland

Purpose

To assess the efficacy of diffusion-weighted (DW) MR imaging for differentiating between Warthin’s tumor and oncocytoma of the parotid gland.

Methods

Forty-five histopathologically confirmed parotid gland tumors (41 Warthin’s tumors and 4 oncocytomas) were examined by MR imaging including DW imaging. ¹⁸F-fluorodeoxyglucose PET/CT was also performed in 9 Warthin’s tumors and 3 oncocytomas. We retrospectively reviewed the images and compared the MR signal intensities, apparent diffusion coefficients (ADCs), and maximum standardized uptake values (SUVmax) of the solid components between the two pathologies.

Results

The signal intensity ratios (SIRs) on both T2-weighted images (0.92 ± 0.18 vs 0.65 ± 0.13, p < 0.01) and DW images (1.24 ± 0.42 vs 0.43 ± 0.16, p < 0.001) were higher in Warthin’s tumors than in oncocytomas. ADCs (0.79 ± 0.11 vs 1.06 ± 0.06 × 10^?3 mm²/s, p < 0.001) were lower in Warthin’s tumors than in oncocytomas. No significant differences in the SIRs on T1-weighted images (1.09 ± 0.12 vs. 0.99 ± 0.07, p = 0.051) and SUVmax (8.22 ± 3.86 vs. 8.11 ± 1.33, p = 0.864) were found between Warthin’s tumor and oncocytoma.

Conclusion

DW imaging with ADC measurements is useful for the differentiation of Warthin’s tumor from oncocytoma of the parotid gland.

     

A comparative study between MR sialography and salivary gland scintigraphy in the diagnosis of Sjögren syndrome

PURPOSE: The purpose of this work was to compare the diagnostic accuracy of MR sialography with that of salivary gland scintigraphy in Sj?gren syndrome. METHOD: One hundred thirty patients clinically suspected of having Sj?gren syndrome were examined by MR sialography and salivary gland scintigraphy. A labial gland biopsy was performed in all patients. Imaging findings of MR sialography and salivary gland scintigraphy were compared with the results of labial gland biopsy. RESULTS: From the results of labial gland biopsy, the diagnosis of Sj?gren syndrome was established in 80 patients. Abnormally high T2 signal intensity areas on MR sialography and decreased uptake and delayed excretion of [(99m)Tc]pertechnetate on salivary gland scintigraphy were well seen in patients with Sj?gren syndrome. For the diagnosis of Sj?gren syndrome, salivary gland scintigraphy showed higher sensitivity than MR sialography. On the other hand, MR sialography showed higher specificity and positive predictive value (PPV) than salivary gland scintigraphy. Overall diagnostic accuracy was 83% for MR sialography and 72% for salivary gland scintigraphy. CONCLUSION: The high PPV of MR sialography suggests that MR sialography is the preferred imaging modality in patients suspected of having Sj?gren syndrome.     

CT and MR imaging of the “target sign” in metastatic brain disease

The “target sign” is a common finding in granulomatous infection. A case with the target sign in metastatic brain tumor from small cell lung carcinoma is reported. Received: 28 September 1998; Revised: 15 March 1999; Accepted: 15 April 1999