The Retro Superior Costotransverse Ligament Space as a New Target for Ultrasound-Guided Intertransverse Process Block: A Report of 2 Cases.

An intertransverse process block (ITPB) is a paraspinal thoracic nerve block technique, where the local anesthetic (LA) is injected into the thoracic intertransverse tissue complex posterior to the superior costotransverse ligament (SCTL). Although an ITPB can be ultrasound-guided, it is performed using surrogate bony landmarks without even identifying the SCTL. This report describes a transverse ultrasound imaging technique to identify the retro-SCTL space and perform an ITPB with a retro-SCTL space injection, in 2 patients undergoing video-assisted thoracoscopic surgery. The resultant bilateral, symmetrical, thoracolumbar anesthesia was consistent with epidural spread of the LA and effective for perioperative analgesia.

Texture analysis of bone marrow in knee MRI for classification of subjects with bone marrow lesion - data from the Osteoarthritis Initiative.

Visualization of bone marrow lesion (BML) can improve the diagnosis of many bone disorders that are associated with it. A quantitative approach in detecting BML could increase the accuracy and efficiency of diagnosing those bone disorders. In this paper, we investigated the feasibility of using magnetic resonance imaging (MRI)-based texture to (a) identify slices and (b) classify subjects with and without BML. A total of 58 subjects were studied; 29 of them were affected by BML. The ages of subjects ranged from 45 to 74years with a mean age of 59. Texture parameters were calculated for the weight-bearing region of distal femur. The parameters were then analyzed using Mann-Whitney U test and individual feature selection methods to identify potentially discriminantive parameters. Forward feature selection was applied to select features subset for classification. Classification results from eight classifiers were studied. Results show that 98 of the 147 parameters studied are statistically significantly different between the normal and affected marrows: parameters based on co-occurrence matrix are ranked highest in their separability. The classification of subjects achieved an area under the receiver operating characteristic curve (AUC) of 0.914, and the classification of slices achieved an AUC of 0.780. The results show that MRI-texture-based classification can effectively classify subjects/slices with and without BML.

Automating the tracking of lymph nodes in follow-up studies of thoracic CT images.

The study of lymph node features over time is of great clinical significance. Tracking of the same lymph node in CT images over time is done manually in the current clinical practice, which is tedious and lack of consistency. In this paper, we propose a search scheme to automate the process. Regions of interest (ROIs) are located by mapping the center point of lymph node based on the transformation found in the rigid registration. Similarity values between ROI of the template image and ROIs of repository images are compared, the highest of which decides the best match. Our method generated a success rate of 82% in determining the corresponding image in follow-up scan with the same lymph node as in baseline. The location of the lymph node in the corresponding image is tracked and estimated by mapping the lymph node center at baseline image using the transformation obtained from both affine and free-form deformation (FFD) registration. FFD performs better than affine registration in tracking the lymph node location. All lymph nodes in our study are tracked successfully by the suggested points which fall within the boundary of the same node in the corresponding follow-up images using FFD registration.

Security protection of DICOM medical images using dual-layer reversible watermarking with tamper detection capability.

Teleradiology applications and universal availability of patient records using web-based technology are rapidly gaining importance. Consequently, digital medical image security has become an important issue when images and their pertinent patient information are transmitted across public networks, such as the Internet. Health mandates such as the Health Insurance Portability and Accountability Act require healthcare providers to adhere to security measures in order to protect sensitive patient information. This paper presents a fully reversible, dual-layer watermarking scheme with tamper detection capability for medical images. The scheme utilizes concepts of public-key cryptography and reversible data-hiding technique. The scheme was tested using medical images in DICOM format. The results show that the scheme is able to ensure image authenticity and integrity, and to locate tampered regions in the images.

Investigation on the use of deformable registrations in lymph node tracking over time.

Evolutionary features of lymph nodes such as change in size over time are decisive descriptors to assess disease progression in cancer patient. Other than study at one point in time, it is more useful to derive temporal analysis on structures of interest. The paper presents the use of deformable registration in lymph node tracking, particularly in the context of disease progression. We found that the extent of disease progression plays an important role in determining the performance of deformable registration in aligning up small anatomic structures, such as lymph node. Both Demons and B-spline registrations have their own advantages in different medical context.

Quantitative texture analysis of MRI images for detection of cartilage-related bone marrow edema.

This paper presents a study that investigated the potential of texture analysis using Fluid Sensitive Fat Suppressed MRI images for the use in detection of bone marrow edema. A total of 168 slices of knee MRI from 10 subjects were involved. Six histogram-based textures (mean intensity, standard deviation, smoothness, third moment, uniformity and entropy) were calculated in both 2D and 3D, and were compared between healthy group and group affected by bone marrow edema. Two-sample t-tests were performed to assess the difference between healthy group and group affected by edema. The intensity third moment in 2D showed significant difference between the slices of healthy subjects and the slices affected by edema (p<0.05). Smoothness and standard deviation in 2D showed a modest significance between healthy and affected groups. No significant difference was found in the 3D textures of healthy group and group affected by edema.

Iron-based ferritin nanocore as a contrast agent.

Self-assembling protein cages have been exploited as templates for nanoparticle synthesis. The ferritin molecule, a protein cage present in most living systems, stores excess soluble ferrous iron in the form of an insoluble ferric complex within its cavity. Magnetic nanocores formed by loading excess iron within an engineered ferritin from Archaeoglobus fulgidus (AfFtn-AA) were studied as a potential magnetic resonance (MR) imaging contrast agent. The self-assembly characteristics of the AfFtn-AA were investigated using dynamic light scattering technique and size exclusion chromatography. Homogeneous size distribution of the assembled nanoparticles was observed using transmission electron microscopy. The magnetic properties of iron-loaded AfFtn-AA were studied using vibrating sample magnetometry. Images obtained from a 3.0 T whole-body MRI scanner showed significant brightening of T(1) images and signal loss of T(2) images with increased concentrations of iron-loaded AfFtn-AA. The analysis of the MR image intensities showed extremely high R(2) values (5300 mM(-1) s(-1)) for the iron-loaded AfFtn-AA confirming its potential as a T(2) contrast agent.

Transverse thickening along the articular surface of the rotator cuff consistent with the rotator cable: identification with MR arthrography and relevance in rotator cuff evaluation.

OBJECTIVE: The purposes of this study were to describe the imaging appearance of transverse thickening along the articular surface of the supraspinatus and infraspinatus tendons presumed to represent the rotator cable on MR arthrographic images obtained with the shoulder in abduction and external rotation (ABER) and in the non-ABER position and to assess the role of the rotator cable in the diagnosis of rotator cuff tears. MATERIALS AND METHODS: The study group comprised 54 patients who underwent arthroscopy of the shoulder and preoperative MR arthrography in which ABER images were obtained. Two blinded reviewers independently examined the ABER and non-ABER images for the presence of the rotator cable and rotator cuff tears. RESULTS: In intact rotator cuffs, the presumed rotator cable was not well visualized on non-ABER images. In one case of prominent rotator cable, MR arthrography showed no tear on non-ABER images, but at arthroscopy, a partial-thickness undersurface tear was found. On non-ABER images, both readers readily visualized the rotator cable in eight and 10 of 18 cases (44% and 56%) of partial-thickness undersurface tear and four of five cases (80%) of full-thickness tear. On ABER images, both readers readily visualized the rotator cable in 15 and 17 of 31 cases (48% and 55%) of intact cuff, 14 and 15 of 18 cases (78% and 83%) of undersurface tear, and four and five cases (80% and 100%) of full-thickness tear. Interobserver agreement on cable visualization was almost perfect (kappa = 0.86). CONCLUSION: On non-ABER MR arthrographic images, thickening along the articular side of the supraspinatus and infraspinatus tendons presumed to represent the rotator cable suggests the presence of a partial-thickness rotator cuff tear. On ABER images, the cable is well defined in intact and torn rotator cuffs.

Metastatic myxoid liposarcomas: imaging and histopathologic findings.

OBJECTIVE: The objective was to describe the imaging and histopathologic characteristics of metastatic myxoid liposarcomas. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and complied with HIPAA guidelines. The study group comprised 12 patients with metastatic myxoid liposarcoma who underwent MRI, CT, or FDG-PET. The location and imaging characteristics of the metastatic lesions were recorded, and the histopathology of all metastatic lesions was reviewed. RESULTS: There were 23 histologically proven metastases in 12 patients. Based on imaging criteria, there were 41 metastases. The mean time from the diagnosis of primary tumor to the first metastasis was 4.4 years. Sixty-seven percent of patients had bone and soft tissue metastases, 33% had pulmonary metastases, 33% had liver metastases, 25% had intra-abdominal, and 16% retroperitoneal metastases. CT demonstrated well-defined lobulated masses with soft tissue attenuation in all cases, without macroscopic fat component. In cases of osseous metastases, CT showed mixed lytic and sclerotic foci, with bone destruction in advanced cases. MRI demonstrated fluid-like signal intensity with mild heterogeneous enhancement in cases of soft tissue metastases. In osseous metastases, MRI showed avid heterogeneous enhancement. FDG-PET showed no significant FDG uptake for all metastases. MRI was the most useful imaging modality for osseous and soft tissue metastases. CONCLUSION: Myxoid liposarcomas are soft tissue sarcomas, with a high prevalence of extrapulmonary metastases. The bones and soft tissues were the most common site of involvement, followed by the lungs and liver. MRI was the most sensitive modality in the detection of osseous and soft tissue metastases, and is the recommended modality for the diagnosis and follow-up of bone and soft tissue involvement.

Spectrum of shoulder injuries in the baseball pitcher.

This review describes a range of shoulder injuries experienced by baseball pitchers. It is estimated that more than 57% of pitchers suffer some form of shoulder injury during a playing season. Knowledge of the overhead throwing cycle is crucial for our understanding of these shoulder injuries. Baseball pitchers are prone to rotator cuff tears from tensile overload and impingement. Glenoid labrum degeneration or tears are also common, due to overuse syndrome (micro-instability), internal impingement and microtrauma. An understanding of the lesions involved in overhead throwing is crucial in baseball pitchers, as long-term disability can result from these injuries, sometimes with severe financial consequences to the player.

Perioperative endovascular internal iliac artery occlusion balloon placement in management of placenta accreta.

OBJECTIVE: The purpose of our study was to evaluate the efficacy of the perioperative placement of occlusion balloons within the internal iliac arteries in reducing intraoperative blood loss and transfusion requirements during cesarean delivery for women with placenta accreta or its variants. MATERIALS AND METHODS: Over a 30-month period, 11 patients with placenta accreta or its variants underwent cesarean delivery after bilateral internal iliac artery occlusion balloon placement (study group). The intraoperative blood loss and transfusion volumes, immediate postoperative change in hemoglobin levels, duration of surgery, and length of ICU stay and hospitalization of this study group were compared with 14 similar patients who underwent cesarean delivery without occlusion balloon placement over a 36-month period (control group). RESULTS: The mean intraoperative blood loss in the study group (2,011 mL; range, 400-5,000 mL) was 39.4% less than in the control group (3,316 mL; range, 1,000-4,000 mL) (p = 0.042). The mean volume of blood transfused was 52.1% less in the study group (1,058 mL; range, 0-3,600 mL) than in the control group (2,211 mL; range, 1,190-3,980 mL) (p = 0.005). There was no significant difference in the immediate postoperative change in hemoglobin levels (p = 0.44), length of hospitalization (p = 0.203), or ICU admission (p = 0.614). The duration of the surgery was significantly less in the study group (p = 0.046). CONCLUSION: Perioperative internal iliac artery occlusion balloon placement is a safe and minimally invasive technique that reduces intraoperative blood loss and transfusion requirements in patients with placenta accreta and its variants undergoing cesarean delivery.

A 16-year-old boy with back pain.

This case is presented to illustrate the imaging and clinical findings of a condition of interest to orthopaedic surgeons. The initial findings are noted on this page. The clinical and imaging diagnoses are presented on the following pages.