BACKGROUNDThe imaging evaluation of pain in patients who have had a hip arthroplasty (HA) is challenging, and traditional imaging techniques, including magnetic resonance imaging (MRI) and computerized tomography (CT), are limited by metallic artifact. The purpose of the present study was to investigate the use of modified MRI techniques to visualize periprosthetic soft tissues and the bone-implant interface, and to evaluate the value of MRI for the assessment of patients with painful hip arthroplasty.

METHODSFifty-six painful hips in fifty-six patients following primary HA were assessed using optimized MRI, CT and standardized radiographs. The diagnosis of MRI was correlated with intraoperative findings as well as with microbiological and histological examinations (when available). The sensitivity and the specificity of MRI diagnosis were determined according to final diagnosis. The chi-square test was performed to detect a difference between MRI and final diagnosis.

RESULTSForty-eight patients have received revision surgery and final diagnosis were established. MRI was demonstrated high sensitivity and specificity in detecting aseptic loosening (93% and 95%), periprosthetic infection (94% and 97%), adverse local tissue reaction (100% and 100%) and periprosthetic fracture (100% and 100%). MRI was determined to be the most sensitive technique in detecting implant loosening for any reason, with a sensitivity of 93.8% for acetabular shell and 97.1% for femoral stem, compared to 81.3% and 80.0% on CT, 75.0% and 77.1% on radiographs.

CONCLUSIONSOptimized MRI was effective for the assessment of the periprosthetic soft tissues and bone. The use of modified magnetic resonance imaging parameters provided a useful adjunct to conventional examinations for the evaluation of patients with painful hip arthroplasty.

Arthroplasty, Replacement, Hip ; adverse effects ; Hip Prosthesis ; adverse effects ; Humans ; Magnetic Resonance Imaging ; methods ; Pain ; diagnosis ; etiology ; Prospective Studies

Acrylic Resins ; adverse effects ; Adult ; Breast Implantation ; adverse effects ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Middle Aged

OBJECTIVETo investigate the effective diagnostic method for the patients with polyacrylamide hydrogen injection for augmentation mammaplasty.

METHODSMRI scanning (layer thickness 1mm, t2 _ ps3d_ cor alignment) was performed on 23 patients with polyacrylamide hydrogen injection for augmentation mammaplasty. The data were imported into computer and processed. 3D reconstruction and analysis modules were run subsequently to do the volume reconstruction and surface reconstruction to obtain stereoscopic images of the gel and adjacent structures in virtual reality, and to calculate the volume of the hydrogel.

RESULTSAmong the 23 patients (46 breasts), the injected hydrogel with integrity capsule existed in retromammary space with no malposition in 5 cases (10 breasts). The capsule was not integrally formed and hydrogel was separately distributed with irregular edge in 6 patients (12 breasts). The pectoris major space, subcutaneous and gland invasion was found in 11 patients (22 breasts). Small amount of hydrogel sparsely distributed in mammary gland and degenerative muscular tissue in 1 patient (2 breasts) who had received extracting surgery before. The volume of hydrogel ranged from 220.309 ml to 372.371 ml (mean: 306.328 ml) in 22 untreated patients (44 breasts).

CONCLUSIONSThe volume and distribution of hydrogel can be known clearly by 3D MRI reconstruction technique. This feasible technique is helpful in removing the hydrogel completely.

Acrylic Resins ; Adolescent ; Adult ; Breast Implants ; adverse effects ; Female ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; methods ; Mammaplasty ; adverse effects ; methods ; Postoperative Period ; Treatment Outcome ; Young Adult

OBJECTIVE: An ex vivo study found a copper-containing intrauterine device (IUD) to be safe for women undergoing an MRI examination at a 3.0-T field. No significant artifacts caused by the metallic implant were detected. However, there are still no in vivo data about these concerns. The aim of this study was to evaluate 3.0-T magnetic field interactions of copper-containing IUDs in vivo. MATERIALS AND METHODS: Magnetic field interactions and potential adverse events were evaluated in 33 women using a questionnaire-based telephone survey. Two experienced radiologists performed artifact evaluation on MR images of the pelvis. RESULTS: Eighteen patients were eligible for the survey. One patient reported a dislocation of the IUD after the MR examination. All other patients had no signs of field interactions. No IUD-related artifacts were found. CONCLUSION: MRI at 3.0-T is possible for women with copper-containing IUDs. However, consulting a gynecologist to check the correct position of the IUD and exclude complications after an MR examination is highly recommended. High-quality clinical imaging of the female pelvis can be performed without a loss in image quality.
Adult ; Artifacts ; *Copper ; Female ; Hot Temperature ; Humans ; *Intrauterine Devices, Copper/adverse effects ; Magnetic Fields ; Magnetic Resonance Imaging/adverse effects/*methods ; Middle Aged ; Pelvis

OBJECTIVE: Device- or technique-related air embolism is a drawback of various neuro-endovascular procedures. Detachable aneurysm embolization coils can be sources of such air bubbles. We therefore assessed the formation of air bubbles during in vitro delivery of various detachable coils. MATERIALS AND METHODS: A closed circuit simulating a typical endovascular coiling procedure was primed with saline solution degassed by a sonification device. Thirty commercially available detachable coils (7 Axium, 4 GDCs, 5 MicroPlex, 7 Target, and 7 Trufill coils) were tested by using the standard coil flushing and delivery techniques suggested by each manufacturer. The emergence of any air bubbles was monitored with a digital microscope and the images were captured to measure total volumes of air bubbles during coil insertion and detachment and after coil pusher removal. RESULTS: Air bubbles were seen during insertion or removal of 23 of 30 coils (76.7%), with volumes ranging from 0 to 23.42 mm3 (median: 0.16 mm3). Air bubbles were observed most frequently after removal of the coil pusher. Significantly larger amounts of air bubbles were observed in Target coils. CONCLUSION: Variable volumes of air bubbles are observed while delivering detachable embolization coils, particularly after removal of the coil pusher and especially with Target coils.
Embolism, Air/*etiology ; Embolization, Therapeutic/*adverse effects/*instrumentation ; Intracranial Embolism/*etiology ; Magnetic Resonance Imaging/methods ; Microscopy ; Risk Assessment ; Statistics, Nonparametric

The present study was aimed to investigate the pathological changes after magnetic resonance imaging (MRI) guided high intensity focused ultrasound (MRgHIFU) therapy for ablating the liver tissue adjacent to goat portal vein. Fifty goats were involved in this study. Normal liver tissues at 0, 5, and 10 mm distance from portal vein, respectively, were ablated with MRgHIFU. Among the 50 tested subjects, 40 goats were sacrificed immediately after the operations, and the other 10 were sacrificed 7 days after the procedure for pathological examination of the targeted areas and the contiguous portal veins. Coagulation necrosis was observed in all the treated liver tissues. Collagen swelling (CS) and vessel wall fracture (VWF) emerged more frequently in the 0 mm group than that in the 5mm group: CS [0 mm group VS 5mm group = 27/40 (67.5%) VS 7/40 (17.5%), P < 0.05], VWF [0 mm group VS 5mm group = 8/40 (20%) VS 0/40 (0%), P < 0.05]. Seven days after ablation, no portal vein damages (CS and VWF) were observed under light microscope. The results indicated that MRgHIFU could be used to ablate the liver tissue adjacent to goat portal vein effectively, which may cause blood vessel damage when the focus is on the wall of blood vessels (0 mm). However, the pathological results indicated that these damages are reversible.
Animals ; Female ; Goats ; High-Intensity Focused Ultrasound Ablation ; adverse effects ; methods ; Liver ; pathology ; Magnetic Resonance Imaging ; Male ; Portal Vein ; pathology

BACKGROUNDNicotine is primarily rsponsible for the highly addictive properties of cigarettes. Similar to other substances, nicotine dependence is related to many important brain regions, particular in mesolimbic reward circuit. This study was to further reveal the alteration of brain function activity during resting state in chronic smokers by fractional amplitude of low frequency fluctuation (fALFF) based on functional magnetic resonance imaging (fMRI), in order to provide the evidence of neurobiological mechanism of smoking.

METHODSThis case control study involved twenty healthy smokers and nineteen healthy nonsmokers recruited by advertisement. Sociodemographic, smoking related characteristics and fMRI images were collected and the data analyzed.

RESULTSCompared with nonsmokers, smokers showed fALFF increased significantly in the left middle occipital gyrus, left limbic lobe and left cerebellum posterior lobe but decreases in the right middle frontal gyrus, right superior temporal gyrus, right extra nuclear, left postcentral gyrus and left cerebellum anterior lobe (cluster size >100 voxels). Compared with light smokers (pack years ≤ 20), heavy smokers (pack years >20) showed fALFF increased significantly in the right superior temporal gyrus, right precentral gyrus, and right occipital lobe/cuneus but decreased in the right/left limbic lobe/cingulate gyrus, right/left frontal lobe/sub gyral, right/left cerebellum posterior lobe (cluster size >50 voxels). Compared with nonsevere nicotine dependent smokers (Fagerstrőm test for nicotine dependence, score ≤ 6), severe nicotine dependent smokers (score >6) showed fALFF increased significantly in the right/left middle frontal gyrus, right superior frontal gyrus and left inferior parietal lobule but decreased in the left limbic lobe/cingulate gyrus (cluster size >25 voxels).

CONCLUSIONSIn smokers during rest, the activity of addiction related regions were increased and the activity of smoking feeling, memory, related regions were also changed. The resting state activity changes in many regions were associated with the cumulative amount of nicotine intake and the severity of nicotine dependence.

Adult ; Brain ; physiology ; Case-Control Studies ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Smoking ; adverse effects ; Young Adult

OBJECTIVE: Constructing a predictive model for urinary incontinence after laparoscopic radical prostatectomy (LRP) based on prostatic gland related MRI parameters. METHODS: In this study, 202 cases were included. All the patients were diagnosed with prostate cancer by prostate biopsy and underwent LRP surgery in Peking University Third Hospital. The preoperative MRI examination of all the patients was completed within 1 week before the prostate biopsy. Prostatic gland related parameters included prostate length, width, height, prostatic volume, intravesical prostatic protrusion length (IPPL), prostate apex shape, etc. From the first month after the operation, the recovery of urinary continence was followed up every month, and the recovery of urinary continence was based on the need not to use the urine pad all day long. Logistic multivariate regression analysis was used to analyze the influence of early postoperative recovery of urinary continence. Risk factors were used to draw the receiver operator characteristic (ROC) curves of each model to predict the recovery of postoperative urinary continence, and the difference of the area under the curve (AUC) was compared by DeLong test, and the clinical net benefit of the model was evaluated by decision curve analysis (DCA). RESULTS: The average age of 202 patients was 69.0 (64.0, 75.5) years, the average prostate specific antigen (PSA) before puncture was 12.12 (7.36, 20.06) μg/L, and the Gleason score < 7 points and ≥ 7 points were 73 cases (36.2%) and 129 cases (63.9%) respectively, with 100 cases (49.5%) at T1/T2 clinical stage, and 102 cases (50.5%) at T3 stage. The prostatic volume measured by preoperative MRI was 35.4 (26.2, 51.1) mL, the ratio of the height to the width was 0.91 (0.77, 1.07), the membranous urethral length (MUL) was 15 (11, 16) mm, and the IPPL was 2 (0, 6) mm. The prostatic apex A-D subtypes were 67 cases (33.2%), 80 cases (39.6%), 24 cases (11.9%) and 31 cases (15.3%), respectively. The training set and validation set were 141 cases and 61 cases, respectively. The operations of all the patients were successfully completed, and the urinary continence rate was 59.4% (120/202) in the 3 months follow-up. The results of multivariate analysis of the training set showed that the MUL (P < 0.001), IPPL (P=0.017) and clinical stage (P=0.022) were independent risk factors for urinary incontinence in the early postoperative period (3 months). The nomogram and clinical decision curve were made according to the results of multivariate analysis. The AUC value of the training set was 0.885 (0.826, 0.944), and the AUC value of the validation set was 0.854 (0.757, 0.950). In the verification set, the Hosmer-Lemeshow goodness-of-fit test was performed on the model, and the Chi-square value was 5.426 (P=0.711). CONCLUSION Preoperative MUL, IPPL, and clinical stage are indepen-dent risk factors for incontinence after LRP. The nomogram developed based on the relevant parameters of MRI glands can effectively predict the recovery of early urinary continence after LRP. The results of this study require further large-scale clinical research to confirm.
Male ; Humans ; Prostate/surgery* ; Prostatectomy/adverse effects* ; Prostatic Neoplasms/pathology* ; Urinary Incontinence/etiology* ; Laparoscopy/methods* ; Magnetic Resonance Imaging/adverse effects* ; Recovery of Function ; Retrospective Studies

BACKGROUNDNasopharygeal fibroangioma (NPF) can be approached through lateral rhinotomy, the middle skull fossa approach and the transcranial-facial combined approach. It is complicated and thus results in more insults, and when adopted, the total resection rate of tumor is still low. The nasal endoscope is minimally invasive, the dead angles of a craniotomy, such as sphenoid sinus, maxillary sinus, and nasopharynx are easily approached by an endoscope. Lateral rhinotomy have to make facial incision and affects maxillary bone development. We combined the craniotomy and endoscopic approach intending to take advantages of the two approaches.

METHODSTwelve NPF patients who underwent craniotomy with endoscopic assistance from March 2002 to July 2008 at the Beijing Tongren Hospital were selected. All patients were male. Their ages ranged from 11 to 33 years. The main symptoms were visual deterioration, exophthalmos, nasal obstruction, epistaxis and pharynx nasalis neoplasm. The diagnosis was based on CT, MRI and digital subtraction angiography (DSA). All patients had intracranial encroachment and all underwent DSA and embolism treatment were taken before surgery. Seven patients had a pterional craniotomy, five had a frontal-temporal-orbital-zygomatic craniotomy. Most of the tumor was resected piecemeal, then removed through the sphenoidal sinus. Finally, using an endoscope in the nasal cavity, tumor in nasal cavity was resected and removed through the sphenoidal sinus, observing the dead angle of the craniotomy and confirming that sinus drainage was unobstructed.

RESULTSThe tumor was removed completely in 11 patients and partially resected in one patient because of hemorrhage. One patient had an infection after the operation and one patient had cerebrospinal rhinorrhea 3 years after surgery that was remediated by endoscopic repair.

CONCLUSIONCraniotomy with endoscopic assistance in the treatment of NPF was minimally invasive, safe and efficient, and avoided facial incision.

Adolescent ; Adult ; Child ; Child, Preschool ; Craniotomy ; adverse effects ; methods ; Endoscopy ; adverse effects ; methods ; Fibroma ; diagnostic imaging ; pathology ; surgery ; Humans ; Magnetic Resonance Imaging ; Male ; Nasopharyngeal Neoplasms ; diagnostic imaging ; pathology ; surgery ; Radiography ; Young Adult

The anterior cruciate ligament (ACL) is an important stabiliser of the knee and is commonly torn in sports injuries. Common indications for imaging after ACL reconstruction include persistent symptoms, limitation of motion and re-injury. Important postoperative complications include graft failure, impingement, arthrofibrosis and graft degeneration. This article aimed to familiarise the radiologist with magnetic resonance (MR) imaging appearances of properly positioned intact ACL grafts and to provide a comprehensive review of MR imaging features of complications following ACL reconstruction.
Anterior Cruciate Ligament ; diagnostic imaging ; surgery ; Anterior Cruciate Ligament Reconstruction ; adverse effects ; methods ; Humans ; Knee Joint ; diagnostic imaging ; surgery ; Magnetic Resonance Imaging ; Postoperative Complications ; diagnostic imaging ; Transplants ; diagnostic imaging ; Wound Healing