Pterygoid venous plexus anastomosis in trigeminal percutaneous glycerol rhizotomy: illustrative case

BACKGROUND

Percutaneous glycerol rhizotomy (PGR) is a common, effective, and relatively safe treatment for trigeminal neuralgia that is refractory to medical management. Anastomotic skull base venous anatomy should be considered when delivering percutaneous agents.

OBSERVATIONS

The authors report an anastomotic connection, not previously described in the literature, between the bilateral pterygoid venous plexuses upon air injection during PGR with computed tomography (CT) guidance for trigeminal neuralgia. Pertinent microsurgical and skull base venous anatomy is reviewed.

LESSONS

Anastomoses between the pterygoid venous plexuses present a potential passage for materials used during PGR to reach unintended contralateral neurovascular structures. The use of CT guidance may identify this anastomotic connection and decrease the likelihood of an aberrant flow of materials used during the PGR.

Health Justice Standards in Graduate Medical Education: Moving from Performative to Concrete Change

BACKGROUND

Inadequate support for underrepresented-in-medicine physicians, lack of physician knowledge about structural drivers of health, and biased patient care and research widen US health disparities. Despite stating the importance of health equity and diversity, national physician education organizations have not yet prioritized these goals.

AIM

To develop a comprehensive set of Health Justice Standards within our residency program to address structural drivers of inequity.

SETTING

The J. Willis Hurst Internal Medicine Residency Program of Emory University is an academic internal medicine residency program located in Atlanta, Georgia.

PARTICIPANTS

This initiative was led by the resident-founded Churchwell Diversity and Inclusion Collective, modified by Emory IM leadership, and presented to Emory IM residents.

PROGRAM DESCRIPTION

We used an iterative process to develop and implement these Standards and shared our progress with our coresidents to evaluate impact.

PROGRAM EVALUATION

In the year since their development, we have made demonstrable progress in each domain. Presentation of our work significantly correlated with increased resident interest in advocacy (p<0.001).

DISCUSSION

A visionary, actionable health justice framework can be used to generate changes in residency programs' policies and should be developed on a national level.

Designing a Cancer Prevention Collaborative Goal-Setting Mobile App for Non-Hispanic Black Primary Care Patients: An Iterative, Qualitative Patient-Led Process

BACKGROUND

There remains a need to engage at-risk primary care populations in cancer prevention behaviors, yet primary care physicians often lack the time or resources to discuss these behaviors with their patients.

OBJECTIVE

The objective of this study is to evaluate the content, usability, and acceptability of a mobile app that leverages insights from goal-setting and social network literature to facilitate cancer prevention goal setting, tracking, and sharing between non-Hispanic Black primary care patients and their social ties.

METHODS

We recruited eligible non-Hispanic Black primary care patients (aged ≥18 years) from 2 practice sites in West Philadelphia, using nonprobabilistic purposive sampling. We conducted semistructured interviews with 5 to 7 participants over 3 weeks to solicit feedback on paper mock-ups of the app, iteratively adapting these mock-ups after each set of interviews. Thereafter, and informed by initial feedback, we created an electronic beta version of the app and sought acceptability and usability feedback from a different set of participants. Then, we conducted content analysis of all user responses to search for unifying themes on acceptability and usability of both the initial mock-ups and beta version of the app. We further assessed app usability using questions derived from the System Usability Scale.

RESULTS

A total of 33 non-Hispanic Black primary care patients participated in this study. The mean age was 49 (SD 13) years, and 26 (79%) out of 33 participants identified as female. Semistructured interviews revealed three primary generalizable insights from our target population: the framing of each goal and its relevance to cancer impacted the likelihood that the goal would be chosen, participants thought that sharing health goals with others facilitates health behaviors, and most participants found it motivating to see other users' goal progress, while still collaborating with these users on their health goals. An overarching insight that permeated across each theme was the participants' desire to customize and personalize the app. Usability testing revealed that 100% (33/33) of participants found the app easy to use, and 76% (25/33) of participants reported that they would like to use this app frequently.

CONCLUSIONS

Cancer prevention in the modern era must include options that are accessible to all, but this does not mean that all options must be universal. This study's iterative process led to the development of a cancer prevention mobile app that non-Hispanic Black primary care patients deemed usable and acceptable and yielded noteworthy insights about what intended end users value in setting and accomplishing health goals.

"I Think That I Have a Good Understanding of How to Protect Myself": A Qualitative Study About HIV Risk Perceptions Among Men and Gender Diverse Individuals Who Have Sex With Men

This qualitative study aimed to determine how men and gender diverse individuals who have sex with men describe their perceived risk of HIV and what factors influence this risk assessment. We conducted in-depth, virtual interviews with 18 HIV-negative individuals from Philadelphia, eligible for or taking PrEP. The interviews assessed the participants' understanding of their HIV risk, using thematic analysis to deductively code and extract themes. Three themes emerged: (1) participants expressed both deliberative and affective risk perception before and after sexual encounters; (2) participants linked HIV knowledge to risk perception and stigma; (3) participants connected intrinsic and extrinsic factors to risk perception differently. Participants endorsed low overall risk perception, while also describing moments of high affective risk perception after sexual encounters in which they were not able to implement their preferred prevention strategies. Future research should explore helping individuals transform affective risk perception into empowerment around sexual health.

Management of degenerative spondylolisthesis: development of appropriate use criteria

BACKGROUND CONTEXT

Outcomes of treatment in care of patients with spinal disorders are directly related to patient selection and treatment indications. However, for many disorders, there is absence of consensus for precise indications. With the increasing emphasis on quality and value in spine care, it is essential that treatment recommendations and decisions are optimized.

PURPOSE

The purpose of the North American Spine Society Appropriate Use Criteria was to determine the appropriate (ie reasonable) multidisciplinary treatment recommendations for patients with degenerative spondylolisthesis across a spectrum of more common clinical scenarios.

STUDY DESIGN

A Modified Delphi process was used.

METHODS

The methodology was based on the Appropriate Use Criteria development process established by the Research AND Development Corporation. The topic of degenerative spondylolisthesis was selected by the committee, key modifiers determined, and consensus reached on standard definitions. A literature search and evidence analysis were completed by one work group simultaneously as scenarios were written, reviewed, and finalized by another work group. A separate multidisciplinary rating group was assembled. Based on the literature, provider experience, and group discussion, each scenario was scored on a nine-point scale on two separate occasions, once without discussion and then a second time following discussion based on the initial responses. The median rating for each scenario was then used to determine if indications were rarely appropriate (1 - 3), uncertain (4-6), or appropriate (7-9). Consensus was not mandatory.

RESULTS

There were 131 discrete scenarios. These addressed questions on bone grafting, imaging, mechanical instability, radiculopathy with or without neurological deficits, obesity, and yellow flags consisting of psychosocial and medical comorbidities. For most of these, appropriateness was established for physical therapy, injections, and various forms of surgical intervention. The diagnosis of spondylolisthesis should be determined by an upright x-ray. Scenarios pertaining to bone grafting suggested that patients should quit smoking prior to surgery, and that use of BMP should be reserved for patients who had risk factors for non-union. Across all clinical scenarios, physical therapy (PT) had an adjusted mean of 7.66, epidural steroid injections 5.76, and surgery 4.52. Physical therapy was appropriate in most scenarios, and most appropriate in patients with back pain and no neurological deficits. Epidural steroid injections were most appropriate in patients with radiculopathy. Surgery was generally more appropriate for patients with neurological deficits, higher disability scores, and dynamic spondylolisthesis. Mechanical back pain and presence of yellow flags tended to be less appropriate, and obesity in general had relatively little influence on decision making. Decompression alone was more strongly considered in the presence of static versus dynamic spondylolisthesis. On average, posterior fusion with or without interbody fusion was similarly appropriate, and generally more appropriate than stand-alone interbody fusion which was in turn more appropriate than interspinous spacers.

CONCLUSIONS

Multidisciplinary appropriate treatment criteria were generated based on the Research AND Development methodology. While there were consistent and significant differences between surgeons and non-surgeons, these differences were generally very small. This document provides comprehensive evidence-based recommendations for evaluation and treatment of degenerative spondylolisthesis. The document in its entirety will be found on the North American Spine Society website (https://www.spine.org/Research-Clinical-Care/Quality-Improvement/Appropriate-Use-Criteria).

Promoting Collaborative Goal Setting for Cancer Prevention Among Primary Care Patients Through mHealth: Mixed Methods Evaluation of a New App

BACKGROUND

Many newly diagnosed cancers are associated with modifiable lifestyle behaviors, such as diet, exercise, smoking cessation, and maintaining a healthy weight. However, primary care providers rarely discuss cancer prevention behaviors with their patients.

OBJECTIVE

This study aims to assess the usability, acceptability, and user engagement of the Healthier Together mobile app, which is designed to promote cancer prevention behaviors among non-Hispanic Black primary care patients, by using social networks and goal-setting theories of behavior change.

METHODS

In an 8-week pilot study, we enrolled primary care patients (N=41) and provided them with a cancer prevention mobile app that allowed them to select, track, and share progress on cancer prevention goals with other users. App usability was assessed using the System Usability Scale. We assessed the app's acceptability by qualitatively analyzing open-ended responses regarding participants' overall experience with the app. We assessed participants' engagement by analyzing the built-in data capture device, which included the number of times participants checked in (out of a maximum of 8) during the study.

RESULTS

The mean age of the 41 participants was 51 years (SD 12), and 76% (31/41) were women. App use data were captured from all participants, and 83% (34/41) completed the exit survey and interview. The mean System Usability Scale score was 87 (SD 12; median 90; IQR 78-95). The analysis of open-ended responses revealed several key themes, and participants complemented the app's ease of use and health behavior-promoting features while also commenting on the need for more feedback and social interactions through the app. On average, participants checked in 5.7 times (SD 2.7) out of 8 possible opportunities. Of the 41 participants, 76% (31/41) checked in during at least 4 of the 8 weeks. Secondary analyses revealed that participants often accomplished their set goals (mean 5.1, SD 2.7) for each week. The qualitative analysis of comments given by participants within the app after each weekly check-in revealed several themes on how the app assisted participants in behavioral change, highlighting that some participants created exercise programs, ate healthier foods, lost a significant amount of weight, and stopped smoking during this study.

CONCLUSIONS

The implementation of a mobile cancer prevention goal-setting app in a primary care setting was feasible, and the app achieved high usability, acceptability, and engagement among participants. User feedback revealed an influence on health behaviors. These findings suggest the promise of the Healthier Together app in facilitating behavioral change to reduce cancer risk among non-Hispanic Black primary care patients.

Prior Sexually Transmitted Infection and Human Immunodeficiency Virus Risk Perception in a Diverse At-Risk Population of Men Who Have Sex with Men and Transgender Individuals

Prior sexually transmitted infections (STIs) are associated with higher rates of subsequent human immunodeficiency virus (HIV) infection, but the influence of prior STIs on perceived vulnerability to HIV remains unclear. We aimed to assess this relationship, hypothesizing that a prior STI diagnosis is associated with higher self-assessed vulnerability to HIV. We performed a cross-sectional study of men and transgender individuals who have sex with men screening for HIV prevention trials in Philadelphia. An unadjusted regression analysis found no significant association between prior STI and HIV risk perception (p = 0.71) or HIV anxiety (p = 0.32). Multivariate logistic regression models that controlled for predetermined potential cofounders known to impact HIV risk-such as condom use, preexposure prophylaxis use, and demographics-also failed to show statistically significant associations between prior STI and HIV risk perception (p = 0.87) or HIV anxiety (p = 0.10). Furthermore, there was no effect modification by HIV preventive behaviors on the relationship between prior STI and HIV vulnerability. These data suggest that a gap exists between how clinicians may attribute individual HIV risk and how individuals view their own vulnerability at a given moment in time. Future research should focus on the dynamic relationship between perceived HIV vulnerability, STI diagnosis, and adoption of preventive behavior to determine better, individualized targets for HIV prevention interventions.

MR imaging of the neural foramina of the cervical spine: Comparison of 3D-DESS and 3D-FISP sequences

Purpose: To assess whether a single three-dimensional double-echo steady state (3D-DESS) sequence can produce equivalent results when compared to a 3D free induction with steady precession (3D-FISP) sequence for the evaluation of the neural foraminal diameter and structures.

Material and Methods: Five phantoms were imaged on CT with 3-mm axial slices followed by reformatted axial 3D-DESS and 3D-FISP sequences. In addition, 3D-DESS and 3D-FISP sequences of 20 healthy subjects were compared with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural foramina, and differentiation between vertebrae and neural foramina.

Results: Compared with CT, 3D-DESS and 3D-FISP sequences consistently underestimated the diameters of the neural foramina. The mean difference values for the 3D-DESS was 12.8%, compared to 9.5% for the 3D-FISP sequence. Concerning the in vivo studies, the 3D-DESS sequence was superior but not statistical significant to the 3D-FISP sequence with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural formina, and identification of the nerve roots.

Conclusion: The 3D-DESS sequence is moderately accurate in the evaluation of the neural foraminal size. Compared to the 3D-FISP sequence, the 3D-DESS sequence is compatible concerning the image quality, differentiation between the cervical vertebrae and discs, and between the discs and neural foramina.

Degenerative Changes of the Menisci of the Knee

Increased meniscal MR signal attributable to meniscal degeneration is a common finding. The role of different MR sequences in the analysis of the extent and distribution of meniscal degeneration in middle-aged and elderly patients has not been thoroughly evaluated. We retrospectively studied the role of different MR sequences in 175 anatomic meniscal sections originating from 20 freshly frozen knees from 10 cadavers using MR-anatomic correlation. T1-weighted and proton-density spin-echo images as well as postprocessed meniscal windows based on T1-weighted spin-echo images proved to be the most reliable in this diagnosis (53.7%, 54.9%, and 53.1% correctly diagnosed meniscal sections, respectively). T2-weighted spin-echo images and gradient-echo images proved to be less reliable (37.1%) and 40.0% correctly diagnosed meniscal sections). While the T2-weighted spin-echo images commonly underestimated the extent of meniscal degeneration, gradient-echo images commonly overestimated the extent of such changes. These last two types of sequences should not be used alone in the description of meniscal degeneration.

The role of surgery for treatment of low back pain: insights from the randomized controlled Spine Patient Outcomes Research Trials

Low back pain (LBP) is a common medical problem with high morbidity and healthcare costs. The optimal management strategy, including the role of surgical intervention, remains controversial. The Spine Patient Outcomes Research Trials were randomized controlled studies conducted to assess the effectiveness of surgery for three of the most common conditions implicated in LBP: Intervertebral disc herniation, degenerative spondylolisthesis, and spinal stenosis. Despite challenges in data interpretation related to patient cross over, these studies support the efficacy of surgery as treatment for these three common conditions.

Spinal cord injury induced neuropathic pain: Molecular targets and therapeutic approaches

Neuropathic pain, especially that resulting from spinal cord injury, is a tremendous clinical challenge. A myriad of biological changes have been implicated in producing these pain states including cellular interactions, extracellular proteins, ion channel expression, and epigenetic influences. Physiological consequences of these changes are varied and include functional deficits and pain responses. Developing therapies that effectively address the cause of these symptoms require a deeper knowledge of alterations in the molecular pathways. Matrix metalloproteinases and tissue inhibitors of metalloproteinases are two promising therapeutic targets. Matrix metalloproteinases interact with and influence many of the studied pain pathways. Gene expression of ion channels and inflammatory mediators clearly contributes to neuropathic pain. Localized and time dependent targeting of these proteins could alleviate and even prevent neuropathic pain from developing. Current therapeutic options for neuropathic pain are limited primarily to analgesics targeting the opioid pathway. Therapies directed at molecular targets are highly desirable and in early stages of development. These include transplantation of exogenously engineered cell populations and targeted gene manipulation. This review describes specific molecular targets amenable to therapeutic intervention using currently available delivery systems.

Repeat treatment of acute hereditary angioedema attacks with open-label icatibant in the FAST-1 trial

Hereditary angioedema (HAE) is characterized by potentially life-threatening recurrent episodes of oedema. The open-label extension (OLE) phase of the For Angioedema Subcutaneous Treatment (FAST)-1 trial (NCT00097695) evaluated the efficacy and safety of repeated icatibant exposure in adults with multiple HAE attacks. Following completion of the randomized, controlled phase, patients could receive open-label icatibant (30 mg subcutaneously) for subsequent attacks. The primary end-point was time to onset of primary symptom relief, as assessed by visual analogue scale (VAS). Descriptive statistics were reported for cutaneous/abdominal attacks 1-10 treated in the OLE phase and individual laryngeal attacks. Post-hoc analyses were conducted in patients with ≥ 5 attacks across the controlled and OLE phases. Safety was evaluated throughout. During the OLE phase, 72 patients received icatibant for 340 attacks. For cutaneous/abdominal attacks 1-10, the median time to onset of primary symptom relief was 1·0-2·0 h. For laryngeal attacks 1-12, patient-assessed median time to initial symptom improvement was 0·3-1·2 h. Post-hoc analyses showed the time to onset of symptom relief based on composite VAS was consistent across repeated treatments with icatibant. One injection of icatibant was sufficient to treat 88·2% of attacks; rescue medication was required in 5·3% of attacks. No icatibant-related serious adverse events were reported. Icatibant provided consistent efficacy and was well tolerated for repeated treatment of HAE attacks.

Role of NKCC1 and KCC2 in the development of chronic neuropathic pain following spinal cord injury

Neuropathic pain is a common problem following spinal cord injury (SCI). Effective analgesic therapy has been hampered by the lack of knowledge about the mechanisms underlying post-SCI neuropathic pain. Current evidence suggests GABAergic spinal nociceptive processing is a critical functional node in this complex phenotype, representing a potential target for therapeutic intervention. Normal GABA neurotransmission is dependent on precise regulation of the level of intracellular chloride, which is determined by the coordinated activities of two cation/chloride cotransporters (CCCs) in the SLC12 family: the inwardly directed Na(+)-K(+)-Cl(-) cotransporter isoform 1 (NKCC1) and outwardly directed K(+)-Cl(-) cotransporter isoform 2 (KCC2). Inhibition of NKCC1 with its potent antagonist bumetanide reduces pain behavior in rats following SCI. Moreover, the injured spinal cord tissues exhibit a significant transient upregulation of NKCC1 protein and a concurrent downregulation of KCC2 protein. Thus, imbalanced function of NKCC1 and KCC2 may contribute to the induction and maintenance of the chronic neuropathic pain following SCI.

North American Spine Society: Newly released vertebroplasty randomized controlled trials: a tale of two trials

This commentary is a product of the North American Spine Society (NASS). It was approved by the NASS Board of Directors and accepted for publication outside The Spine Journal's peer review process.

Preoperative patient selection with magnetic resonance imaging, computed tomography, and electroencephalography: does the test predict outcome after cervical surgery?

OBJECT

The objective of this systematic review was to use evidence-based medicine to assess whether preoperative imaging or electromyography (EMG) predicts surgical outcomes in patients undergoing cervical surgery.

METHODS

The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to the preoperative imaging and EMG. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.

RESULTS

Preoperative MR imaging and CT myelography are successful in confirming clinical radiculopathy (Class II). Multilevel T2 hyperintensity, T1 focal hypointensity combined with T2 focal hyperintensity, and spinal cord atrophy each convey a poor prognosis (Class III). There is conflicting data concerning whether focal T2 hyperintensity or cervical stenosis are associated with a worse outcome. Electromyography has mixed utility in predicting outcome (Class III).

CONCLUSIONS

Magnetic resonance imaging or CT myelography are important for preoperative assessment. Magnetic resonance imaging may be helpful in assessing prognosis, whereas EMG has mixed utility in assessing outcome.

The role of cation-dependent chloride transporters in neuropathic pain following spinal cord injury

BACKGROUND

Altered Cl- homeostasis and GABAergic function are associated with nociceptive input hypersensitivity. This study investigated the role of two major intracellular Cl- regulatory proteins, Na+-K+-Cl- cotransporter 1 (NKCC1) and K+-Cl- cotransporter 2 (KCC2), in neuropathic pain following spinal cord injury (SCI).

RESULTS

Sprague-Dawley rats underwent a contusive SCI at T9 using the MASCIS impactor. The rats developed hyperalgesia between days 21 and 42 post-SCI. Thermal hyperalgesia (TH) was determined by a decrease in hindpaw thermal withdrawal latency time (WLT) between days 21 and 42 post-SCI. Rats with TH were then treated with either vehicle (saline containing 0.25% NaOH) or NKCC1 inhibitor bumetanide (BU, 30 mg/kg, i.p.) in vehicle. TH was then re-measured at 1 h post-injection. Administration of BU significantly increased the mean WLT in rats (p < 0.05). The group administered with the vehicle alone showed no anti-hyperalgesic effects. Moreover, an increase in NKCC1 protein expression occurred in the lesion epicenter of the spinal cord during day 2-14 post-SCI and peaked on day 14 post-SCI (p < 0.05). Concurrently, a down-regulation of KCC2 protein was detected during day 2-14 post-SCI. The rats with TH exhibited a sustained loss of KCC2 protein during post-SCI days 21-42. No significant changes of these proteins were detected in the rostral region of the spinal cord.

CONCLUSION

Taken together, expression of NKCC1 and KCC2 proteins was differentially altered following SCI. The anti-hyperalgesic effect of NKCC1 inhibition suggests that normal or elevated NKCC1 function and loss of KCC2 function play a role in the development and maintenance of SCI-induced neuropathic pain.

Pattern of osteophytes and enthesophytes in the proximal ulna: an anatomic, paleopathologic, and radiologic study

OBJECTIVE

To develop a schematic segmentation of the proximal ulna in order to detect, assess the frequency, and characterize the bony outgrowths arising from the trochlea and from the radial notch of the ulna, to enable differentiation of osteophytes from enthesophytes.

MATERIALS AND METHODS

Eighty well-preserved ulna specimens from the collection of the San Diego Museum of Man were analyzed by two musculoskeletal radiologists. The trochlea and the radial notch of the ulna simulate the shape of a clock quadrant. The proximal ulna was divided into 24 anatomic areas. The relationships of the joint capsule and insertions of tendons and ligaments onto these area were assessed by the two readers, and the resulting appearances of bony outgrowths were compared at visual inspection and on Radiographs.

RESULTS

The interobserver visual comparison was good in 17 areas out of 24, but poor correlation was found in 7 areas. In one case, difficulties in differentiating osteophytes originating from the brachialis muscle/ tendon (area 9) from an enthesophyte originating from the capsule insertion on the coronoid process (areas 2 or 3) occurredand between two different enthesophytes in a further case. Five cases had difficulties in defining differences in the grading system of the outgrowths. The percentage of outgrowths observed in each of the areas was globally high, especially in areas 9 and 10. On radiographs it was possible to observe irregularities in ten areas; in eight at a threshold of height of 2 mm (areas 1-4, 9, 10, 11, 14) and in two at a threshold of height of 3 mm (areas 5, 6). The two readers had the same difficulties in differentiating enthesophytes from osteophytes at radiographic and visual examination.

CONCLUSION

Our segmentation scheme is reproducible and objective, and permitted the differentiation of the bony outgrowths arising from the proximal ulna into osteophytes and enthesophytes, which may be particularly useful for the in vivo assessment of abnormalities seen in elbow overuse syndromes.

Hyperplastic callus formation in osteogenesis imperfecta type V mimicking osteosarcoma: 4-year follow-up with resolution

We report a case of hyperplastic callus formation that occurred in both femurs in a patient with type V osteogenesis imperfecta (OI), with 4-year follow-up and resolution. The clinical, histological and imaging aspects of this condition are discussed. Recognition of the hyperplastic callus formation in this particular type of OI is important in order to avoid misdiagnosis.

Imaging findings in symptomatic patients with femoral diaphyseal stress injuries

PURPOSE

To assess the imaging findings seen in symptomatic patients with stress injuries of the femoral diaphysis.

MATERIAL AND METHODS

Seven patients (5 F, 2 M, age range 16 to 56 years, mean 38 years) underwent imaging evaluation of the symptomatic lower extremity due to an insidious onset of thigh or groin pain unrelated to trauma. Imaging studies included radiography and magnetic resonance imaging (MRI) in seven patients, bone scintigraphy in five, and computed tomography (CT) in three.

RESULTS

Radiographs depicted three frank fractures in two patients, and revealed findings of stress injury in six patients. Available scintigraphic and CT findings were abnormal. On MR images, a solitary fracture was seen in two patients; two patients presented with bilateral stress fractures of the femoral diaphysis; and all seven patients had the imaging features of stress injury. Femoral diaphyseal stress fractures (n = 6) appeared as linear regions of T1- and T2-weighted low signal intensity, surrounded by diffuse bone marrow edema. Three of the six frank fractures, with an evident fracture line, were longitudinal and parallel to the cortical surface.

CONCLUSION

Femoral diaphyseal stress fractures are often inconspicuous with conventional radiography. MRI depicts the changes of stress injury in the femoral diaphysis, and is particularly useful in documenting the presence, morphology, and extent of fracture(s), information valuable for definitive diagnosis and appropriate management.

Magnetic resonance imaging of para-acetabular insufficiency fractures in patients with malignancy

AIM

To describe the characteristic magnetic resonance imaging (MRI) findings of para-acetabular insufficiency fractures in patients with malignancy, and compare the MRI appearance of these fractures with that of metastatic bone disease.

MATERIALS AND METHODS

MRI examinations were reviewed in 16 patients with a known malignant tumour and severe hip pain that raised the possibility of local recurrence or metastatic disease. Six patients had received pelvic irradiation, and three patients were receiving steroid medication.

RESULTS

The total number of fractures detected was 21: a solitary fracture was present in 11 patients and five patients had bilateral para-acetabular fractures. Two patients had associated sacral insufficiency fractures, and one of them had stress fractures involving both acetabular columns. Conventional radiography allowed the diagnosis of 14 (67%) fractures; six (28%) radiographic examinations were negative; and one (5%) examination was equivocal for fracture. Available scintigraphic and computed tomography (CT) studies revealed typical findings of fracture. Using MRI, insufficiency fractures appeared as linear regions of low signal intensity on T1- and T2-weighted images. Marked marrow oedema was evident in all cases. Fractures characteristically were parallel to the superior acetabulum in a curvilinear fashion in 18 (86%) instances, and were oblique in three (14%) instances. The fractures demonstrated considerable enhancement after intravenous gadolinium administration. No associated soft tissue masses were documented.

CONCLUSION

Para-acetabular insufficiency fractures are a cause of hip pain, which may mimic skeletal metastasis in the patient with malignancy and pelvic irradiation. Recognition of the characteristic MRI findings of these fractures can preclude misdiagnosis and unnecessary bone biopsy.

Posterolateral complex knee injuries: magnetic resonance imaging with surgical correlation

PURPOSE

To describe the magnetic resonance imaging (MRI) findings of injuries of the posterolateral aspect of the knee and to evaluate the diagnostic capabilities of MRI in the assessment of these injuries.

MATERIAL AND METHODS

The MRI studies of 14 patients (mean age 33 years) with trauma to the posterolateral aspect of the knee were retrospectively reviewed, and the imaging findings were correlated with those of surgery.

RESULTS

In all patients, MRI showed an intact iliotibial (ITB) band. MRI showed injury to the biceps tendon in 11 (79%), the gastrocnemius tendon in 1 (7%)), the popliteus tendon in 5 (36%), and the lateral collateral ligament (LCL) in 14 (100%) patients. Tear of the anterior cruciate ligament (ACL) was seen in 11 (79%) patients and tear of the posterior cruciate ligament (PCL) in 4 (29%) patients. With routine MRI, visualization of the popliteofibular or fabellofibular ligaments was incomplete. On MRI, the lateral meniscus and the medial meniscus were torn with equal frequency (n = 4; 29%). Osteochondral defects were seen in 5 (36%) cases and joint effusion in all 14 (100%) cases on MRI. Using surgical findings as the standard for diagnosis, MRI proved 86% accurate in the detection of injury to the ITB band, the biceps tendon (93%), the gastrocnemius tendon (100%), the popliteus tendon (86%), the LCL (100%), the ACL (79%), the PCL (86%), the lateral meniscus (90%), the medial meniscus (82%), and the osteochondral structures (79%). Surgical correlation confirmed the MRI findings of joint effusion in all cases.

CONCLUSION

MRI is well suited for demonstrating the presence and extent of injuries of the major structures of the posterolateral complex of the knee, allowing characterization of the severity of injury.

Posttraumatic pseudolipoma: MRI appearances

The goal of this study was to describe the MRI characteristics of posttraumatic pseudolipomas. Ten patients with previous history of blunt trauma or local surgery were investigated with MRI at the level of their deformity. The etiology was blunt trauma in eight patients and postoperative trauma in two. For all patients medical documentation, in the form of clinical history and physical examination, confirmed that a visible hematoma was present acutely at the same location following the injury and that the contour deformity subsequently appeared. All patients underwent liposuction. Preoperative bilateral MRI examinations were performed on all patients. The mean clinical follow-up was 17.8 months. MRI examinations were interpreted in consensus by two experienced musculoskeletal radiologists with attention to fatty extension (subcutaneous fatty thickness and anatomical extension), asymmetry compared with the asymptomatic side, the presence or absence of fibrous septae or nonfatty components, and patterns of contrast enhancement. Ten posttraumatic pseudolipomas were identified. Clinically, they showed as subcutaneous masses with the consistency of normal adipose tissue. Their locations were the abdomen (n=1), hip (n=1), the upper thigh (n=6), the knee (n=1), and the ankle (n=1). On MRI examinations, using the contralateral side as a control, pseudolipomas appeared as focal fatty masses without a capsule or contrast enhancement. Posttraumatic pseudolipomas may develop at a site of blunt trauma or surgical procedures often antedated by a soft tissue hematoma. Characteristic MRI findings are unencapsulated subcutaneous fatty masses without contrast enhancement.

Contrast-enhanced MRI of the menisci of the knee using ultrashort echo time (UTE) pulse sequences: imaging of the red and white zones

The objective of this study was to demonstrate the red and white zones of the meniscus of the knee using MRI. Ultrashort echo time (UTE) pulse sequences with an initial TE of 0.08 ms and later echoes at 5.95 ms, 11.08 ms and 17.70 ms were used to image the meniscus of the knee in two normal subjects before and after intravenous administration of gadodiamide. Difference images were formed by subtraction of later echo images from the first. The difference images showed obvious enhancement in an area consistent in location and dimensions with the red zone of the meniscus. Regions of interest placed within this area, central to it (corresponding to the white zone), and peripheral to it (corresponding to perimeniscal tissue) all showed increases in signal intensity after intravenous contrast administration. The greatest change in signal intensity in these regions of interest was seen with the shortest TE and in perimeniscal tissue on the original images. The increase in signal intensity was greatest in the red zone on the difference images. Using UTE pulse sequences and difference images derived from them, it is possible to visualize enhancement selectively in the red zone of the meniscus. Less obvious but significant changes in signal intensity were also present in the white zone.

Folic acid supplementation enhances repair of the adult central nervous system

Folic acid supplementation has proved to be extremely effective in reducing the occurrence of neural tube defects (NTDs) and other congenital abnormalities in humans, suggesting that folic acid can modulate key mechanisms for growth and differentiation in the central nervous system (CNS). To prevent NTDs, however, supplemental folate must be provided early in gestation. This suggests that the ability of folic acid to activate growth and differentiation mechanisms may be confined to the early embryonic period. Here, we show that folic acid can enhance growth and repair mechanisms even in the adult CNS. Using lesion models of CNS injury, we found that intraperitoneal treatment of adult rats with folic acid significantly improves the regrowth of sensory spinal axons into a grafted segment of peripheral nerve in vivo. Regrowth of retinal ganglion cell (RGC) axons into a similar graft also was enhanced, although to a smaller extent than spinal axons. Furthermore, folic acid supplementation enhances neurological recovery from a spinal cord contusion injury, showing its potential clinical impact. The results show that the effects of folic acid supplementation on CNS growth processes are not restricted to the embryonic period, but can also be effective for enhancing growth, repair, and recovery in the injured adult CNS.

Calcification in calcium pyrophosphate dihydrate (CPPD) crystalline deposits in the knee: anatomic, radiographic, MR imaging, and histologic study in cadavers

OBJECTIVE

To demonstrate and determine the frequency and location of calcification within cadaveric knees with or without calcification typical of calcium pyrophosphate dihydrate (CPPD), utilizing histologic, radiographic and MR imaging techniques.

DESIGN AND PATIENTS

Ten cadaveric knees of elderly individuals that demonstrated no radiographic evidence of prior surgery or trauma were studied with MR imaging and subsequently sectioned in planes corresponding to those obtained with MR imaging. The slices were imaged with high-resolution radiography. Two musculoskeletal radiologists correlated the anatomic, MR and radiographic findings. Three of the knees, which did not demonstrate calcifications, were utilized as controls. Histologic sections were obtained from four knees that contained calcifications and from the three controls, and analyzed with special histologic stains that demonstrate phosphorus and calcium.

RESULTS

Radiographic imaging and histologic analysis demonstrated widespread CPPD crystal deposition in four of the 10 knee specimens (40%). MR imaging demonstrated some calcifications only within the articular cartilage of the femoral condyles in three of the four (75%) specimens that had CPPD deposits. In all four specimens radiographs and histologic analysis were more sensitive than MR imaging. Histologic analysis demonstrated no evidence of CPPD crystals in the control specimens.

CONCLUSION

MR imaging is insensitive to the presence of CPPD deposits in the knee, even when such deposits are widespread. Our study suggests that the sensitivity of MR imaging was significantly better in detecting CPPD deposits in the hyaline cartilage of the femoral condyles when compared with other internal structures, even when such structures contained a higher amount of calcification.

MR imaging evaluation of myocardial viability in the setting of equivocal SPECT results with (99m)Tc sestamibi

PURPOSE

To determine if contrast material-enhanced magnetic resonance (MR) imaging is useful for assessment of myocardial viability in patients with equivocal stress-rest results from single photon emission computed tomographic (SPECT) examination with technetium 99m sestamibi.

MATERIALS AND METHODS

Twenty patients underwent stress-rest SPECT examinations with sestamibi. Results were considered equivocal for assessment of myocardial infarct on the basis of fixed perfusion defects that either had normal wall motion or exceeded any wall motion abnormalities. Patients then underwent (a). contrast-enhanced MR imaging for assessment of myocardial infarct and (b). cine MR imaging for assessment of wall motion. For image analyses, the left ventricle was divided into 14 segments. Wall motion and extent of infarct were assessed independently and compared.

RESULTS

Forty-one segments were equivocal for infarct at SPECT, and most (21 of 41 [51%]) involved the posterior or inferior wall. Infarct was confirmed with MR imaging in 10 of 41 (24%) equivocal segments in eight patients (40%). An additional 29 segments in eight patients had infarct at MR imaging that was not suspected at SPECT, including segments in three patients with no clinical history of myocardial infarct prior to imaging. All cases of infarct except one that were equivocal or undetected with sestamibi at SPECT were nontransmural at MR imaging, and most of the unsuspected subendocardial infarcts (15 of 28 [54%]) had no associated wall motion abnormalities.

CONCLUSION

Patients with radionuclide examination findings that are equivocal for infarct may benefit from contrast-enhanced MR imaging, particularly in the setting of nontransmural infarct.

Avulsion fractures of the medial and lateral malleoli of the ankle in cadavers: new radiographic projections for improved diagnosis

The malleolar attachment sites of the tibionavicular (TN), tibiocalcaneal (TC), posterior tibiotalar (PTT), anterior talofibular (ATF), and calcaneofibular (CF) ligaments of 3 cadaveric ankles were dissected. Standard and new radiographic projections of the ankle were obtained with the foot in different positions and various degrees of beam angulation. Simulated avulsion injuries related to these ligaments were created, and the visibility of these structures was assessed. Avulsion injuries of the TN ligament were better assessed in the plantar-flexed radiographs with lateral beam angulation. Standard projections were found to adequately depict avulsion fractures related to the TC and CF ligaments. Radiographs in external ankle rotation were best for evaluating injuries of the PTT ligament. Avulsion injuries related to the ATF ligament were best visualized in the plantar-flexed views with medial beam angulation. Modified radiographic projections of the ankle improve visualization of ligamentous structures of the malleoli and avulsion injuries related to those.

Plantar calcaneal enthesophytes: new observations regarding sites of origin based on radiographic, MR imaging, anatomic, and paleopathologic analysis

OBJECTIVE

To determine the relationship between sites of calcaneal plantar enthesophytes and surrounding fascial and soft tissue structures using routine radiography, MR imaging, and data derived from cadaveric and paleopathologic specimens.

DESIGN AND PATIENTS

Two observers analyzed the MR imaging studies of 40 ankles in 38 patients (35 males, 3 females; mean age 48.3 years) with plantar calcaneal enthesophytes that were selected from all the ankle MR examinations performed during the past year. Data derived from these MR examinations were the following: the size of the enthesophyte; its location in relation to the plantar fascia (PF) and flexor muscles; and the thickness and signal of the PF. The corresponding radiographs of the ankles were evaluated at a different time by the same observers for the presence or absence of plantar enthesophytes and, when present, their measurements. A third observer reviewed all the discordant observations of MR imaging and radiographic examinations. Two observers analyzed 22 calcaneal specimens with plantar enthesophytes at an anthropology museum to determine the orientation of each plantar enthesophyte. MR imaging of a cadaveric foot with a plantar enthesophyte with subsequent sagittal sectioning was performed to provide further anatomic understanding.

RESULTS

With regard to MR imaging, the mean size of the plantar enthesophytes was 4.41 mm (SD 2.4). Twenty (50%) enthesophytes were located above the PF, 16 (40%) between the fascia and abductor digiti minimi, flexor digitorum brevis and abductor hallucis muscles, and only one (3%) was located within the PF. In three (8%) cases the location was not determined. The size of enthesophytes seen with MR imaging and radiographs was highly correlated (P<0.01). The interobserver agreement for all measurements was good (Pearson >0.8, kappa >0.9). Eleven of the 22 bone specimens had plantar enthesophytes oriented in the direction of the abductor digiti minimi and 11 oriented in the direction of the flexor digitorum brevis and PF. The cadaveric sections revealed different types of enthesophytes.

CONCLUSIONS

Plantar calcaneal enthesophytes arise in five different locations: at the insertion sites of abductor digiti minimi and flexor digitorum brevis muscles; between the PF and these muscles; and, less frequently, within the PF and at the insertion site of the short plantar ligament.

Do patients with primary sclerosing cholangitis have a greater frequency of pancreatic abnormalities at MRI than patients with other liver diseases?

PURPOSE

It has been proposed that there is an increased frequency of pancreatic abnormalities in patients with primary sclerosing cholangitis (PSC). Our purpose is to compare the frequency of pancreatic abnormalities detected at MRI in patients with PSC and to compare these findings with those found in a matched cohort with other liver diseases.

METHOD

We identified 29 patients who had either a histologic or an endoscopic retrograde cholangiopancreatography diagnosis of PSC and 29 age- and gender-matched patients with liver disease without PSC who underwent MRI at 1.5 T. The protocol included breath-hold T1-weighted gradient echo, echo train, fast spin echo, T2-weighted images and dynamic gadolinium-enhanced MRI. Two blinded readers retrospectively evaluated the MR images for abnormalities of pancreatic size and morphology, T1 and T2 signal intensity, duct size and irregularities, arterial-phase contrast enhancement, focal pancreatic masses, cystic lesions, peripancreatic fluid/edema, ascites, and capsular-like rim surrounding the pancreas.

RESULTS

The prevalence of pancreatic and peripancreatic abnormalities was 10 of 29 (35%) in PSC patients and 14 of 29 (48%) in control patients. MR findings included ascites (9 PSC, 12 controls), peripancreatic edema (7 PSC, 11 controls), atrophy (4 PSC, 3 control), increased T2 signal (3 PSC, 4 controls), cystic lesions (2 PSC, 3 controls), abnormal T1 signal (1 PSC, 2 controls), and dilated pancreatic ducts (3 PSC, 2 controls). Quantitative parameters were not significantly different between PSC patients and the control subjects with pancreatic findings.

CONCLUSION

There is no significant difference in pancreatic abnormalities detected on MRI between patients with PSC and those with other liver diseases.

The hamatolunate facet: characterization and association with cartilage lesions--magnetic resonance arthrography and anatomic correlation in cadaveric wrists

The objective of this study was to characterize the appearance of the hamatolunate facet using high-resolution magnetic resonance (MR) arthrography in cadavers and to correlate the presence of this anatomic variant with the presence of osteoarthritis in the wrist. High-resolution MR images of 22 cadaveric wrist specimens were obtained after tri-compartmental arthrography. Two readers in consensus analyzed the MR images and recoded the presence or absence of a hamatolunate facet. Geometric characteristics and cartilage and ligament integrity were analyzed. A third reader, who was blinded to the purpose of the study, recorded cartilage lesions of all the bones of the proximal and distal carpal rows. A hamatolunate facet was present in 11 of 22 wrists (50%). The mean coronal size of the lunate facet at the lunate (type II lunate) was 4.5 mm (range, 2-6 mm). The highest frequencies of cartilage lesions were seen in the scapho-trapezio-trapezoid joint (45.5%) and at the proximal pole of the hamate (54.4% and 40.9% for consensus reading/blinded reading, respectively). In cases with a hamatolunate facet, the frequency of cartilage lesions in the proximal pole of the hamate was 81.8% and 63.6% versus 27.3% and 18.2% without such a facet (chi-squared, P=0.01/ P=0.03). No correlation of the presence of a hamatolunate facet with interosseous ligament tears or lesions of the triangular fibrocartilage was seen. In conclusion, the hamatolunate facet is a very common anatomic variant. The presence of a hamatolunate facet is associated with cartilage damage in the proximal pole of the hamate.

Colorectal neoplasms: prospective comparison of thin-section low-dose multi-detector row CT colonography and conventional colonoscopy for detection

PURPOSE

To prospectively compare thin-section low-dose multi-detector row computed tomographic (CT) colonography with conventional colonoscopy for the detection of colorectal neoplasms.

MATERIALS AND METHODS

One hundred five patients underwent CT colonography immediately before colonoscopy. Supine and prone CT colonographic acquisitions to image the region during a 30-second breath hold were performed. CT colonographic images were prospectively interpreted for the presence, location, size, and morphologic features of polyps. The time of image interpretation was noted. Sensitivity, specificity, and positive and negative predictive values of CT colonography were calculated, with 95% CIs, by using colonoscopic findings as the reference standard. The weighted CT dose index was calculated on the basis of measurements in a standard body phantom. Effective dose was calculated by using commercially available software.

RESULTS

Median CT data interpretation time was 12 minutes. One hundred thirty-two polyps in 59 patients were identified at colonoscopy; no polyps were detected in 46 patients. Sensitivities for detection of polyps smaller than 5 mm, 6-9 mm, and larger than 10 mm in diameter were 12% (11 of 91 polyps), 70% (19 of 27 polyps), and 93% (13 of 14 polyps), respectively. Estimated overall specificity was 97.7% (515 of 527 imaging results). The total weighted CT dose index for combined supine and prone CT colonography was 11.4 mGy. The effective doses for combined CT colonography were 5.0 mSv and 7.8 mSv for men and women, respectively.

CONCLUSION

Low-dose multi-detector row CT colonography has excellent sensitivity and specificity for detection of colorectal neoplasms 10 mm and larger.

The role of angiostatin in the spontaneous bone and prostate cancers of pet dogs

Angiostatin is a potent inhibitor of angiogenesis generated in cancer-bearing hosts by tumor-derived proteases. Because the naturally occurring bone and prostate cancers of pet dogs provide unique model systems to study factors that regulate cancer progression and tumor dormancy, we investigated the capacity of these tumors to generate angiostatin. We determined that angiostatin fragments are present in urine of dogs with bone cancer. The identity of these fragments was confirmed by comparison of the experimentally determined protein sequence to that of a clone of canine angiostatin. Importantly, these fragments were absent in urine collected from the same dogs after complete surgical removal of the primary tumor. We also demonstrate that canine prostate cancer cells are capable of processing plasminogen to angiostatin in vitro. These findings provide rationale for using spontaneous canine tumor models to isolate endogenous angiogenesis inhibitors and to investigate their therapeutic use against cancer.

Cardiac function: MR evaluation in one breath hold with real-time true fast imaging with steady-state precession

In 12 healthy volunteers and eight patients with cardiac disease, cine magnetic resonance (MR) imaging in the heart was performed with real-time true fast imaging with steady-state precession (FISP), which permitted evaluation of the entire left ventricle in one breath hold (91 msec per frame, 13 frames per section position, nine short-axis section positions per breath hold). Contrast-to-noise ratios (CNRs) and left ventricular mass and function measurements with this technique were compared in all subjects with single-section true FISP imaging and, in the volunteers only, with segmented fast low-angle shot (FLASH) MR imaging. Myocardium-to-blood CNR was significantly higher for both true FISP sequences compared with the FLASH sequence. Measurements of resting left ventricular function with real-time true FISP imaging were comparable with those derived from a series of separate breath-hold single-section true FISP acquisitions.

Intraarticular osteoid osteoma: sonographic findings in three patients with radiographic, CT, and MR imaging correlation

OBJECTIVE

Intraarticular osteoid osteoma often has subtle radiographic findings and nonspecific clinical features; further diagnostic workup of unexplained joint pain may involve musculoskeletal sonography. We describe the sonographic features of intraarticular osteoid osteoma in three consecutive patients with radiographic, CT, and MR imaging correlation.

CONCLUSION

The sonographic findings of painful cortical irregularity and focal synovitis should raise the possibility of intraarticular osteoid osteoma, prompting the search for characteristic findings on correlative imaging studies.

Patellar tendon-lateral femoral condyle friction syndrome: MR imaging in 42 patients

OBJECTIVE

To demonstrate the MR imaging findings that occur between the posterior inferolateral patellar tendon and the lateral femoral condyle in patients with chronic anterior and or lateral knee pain.

PATIENTS AND DESIGN

A retrospective review of the MR images in 42 patients who presented with chronic anterior or lateral knee pain was performed by two musculoskeletal radiologists. In 15 patients, post-contrast images were available.

RESULTS

Sagittal and axial imaging planes best demonstrated the patellar tendon and its relationship with the lateral femoral condyle. In 40 patients, there was obliteration of the fat planes and abnormal signal intensity in the lateral soft tissues of the inferior patellofemoral joint. Enhancement after administration of gadolinium was noted in all cases in which contrast was administered. Eighteen patients showed cystic changes in the soft tissues adjacent to the lateral femoral condyle in addition to fat plane obliteration. In two patients, only cystic changes were noted in the lateral soft tissues. Abnormal patellar alignment was noted in 37 patients. Patellar tendon pathology was seen in nine patients.

CONCLUSION

In evaluating anterior knee symptoms, MR imaging allows identification of changes that may be related to patellar tendon-lateral femoral condyle friction syndrome and that should be distinguished from other causes of anterior or lateral knee pain.

Selective nerve root blocks for the treatment of sciatica: evaluation of injection site and effectiveness--a study with patients and cadavers

PURPOSE

To relate different types of radiographic contrast material distributions to anatomic compartments by using cadaveric specimens and to relate the injection site to treatment-induced discomfort and therapeutic effect.

MATERIALS AND METHODS

The contrast material distributions of selective nerve root blocks (SNRBs) in 36 patients (13 women, 23 men; mean age, 52 years; age range, 22-88 years) were graded by two radiologists in conference as type 1 (tubular appearance), type 2 (nerve root visible as filling defect), or type 3 (nerve root not visible). These patterns were correlated with pain reduction after 15 minutes and 2 weeks (with a visual analogue scale of 100-mm length). In addition, 30 nerve roots were injected with iodine-containing contrast material and blue dye in three cadaveric specimens. Radiographs were compared with anatomic sections.

RESULTS

After 15 minutes and 2 weeks, 75% and 86% of the patients, respectively, reported pain relief. Mean pain relief length after 15 minutes for type 1 distribution was 60 mm; for type 2, 44 mm; and for type 3, 22 mm; and after 2 weeks, it was 34 mm for type 1, 31 mm for type 2, and 57 mm for type 3. There was no correlation between early and late response. Pain during intervention was less pronounced in type 2 injection, compared with type 1 (P = .002). On the basis of anatomic sections, type 1 injection was intraepineural; type 2, extraepineural; and type 3, paraneural.

CONCLUSION

Therapeutic SNRB is effective in sciatica, but early response does not predict the effect after 2 weeks. Type 1 injections are more painful than type 2 injections.

What happens to the triangular fibrocartilage complex during pronation and supination of the forearm? Analysis of its morphology and diagnostic assessment with MR arthrography

OBJECTIVE

To evaluate the dynamic morphologic changes of the triangular fibrocartilage complex (TFCC) during pronation and supination of the forearm using high-resolution MR arthrography in cadavers and to evaluate the impact of these changes on the diagnostic assessment of the normal and abnormal TFCC. DESIGN AND SPECIMENS: High-resolution MR arthrography of 10 wrists of cadaveric specimens was obtained in maximum pronation, in the neutral position, and in maximum supination of the forearm. The structures of the TFCC were evaluated by two musculoskeletal radiologists and correlated with anatomic sections. The position of the forearm that allowed the best visualization of normal structures and lesions of the TFCC was determined.

RESULTS

The shape and extent of the articular disc as well as the radial portions of the radioulnar ligaments did not change with pronation and supination. The articular disc was horizontal in the neutral position and tilted more distally to align with the proximal carpal row in pronation and supination. The fibers of the ulnar part of the radioulnar ligaments (ulnar attachment of the articular disc) revealed the most significant changes: their orientation was coronal in the neutral position and sagittal in positions of pronation and supination. The ulnomeniscal homologue was largest in the neutral position and was reduced in size during pronation and supination. The extensor carpi ulnaris tendon was centered in its groove in the neutral position and pronation. In supination this tendon revealed subluxation from this groove. The dorsal capsule of the distal radioulnar joint was taut in pronation, and the palmar capsule was taut in supination. The preferred forearm position for analysis of most of the structures of the TFCC was the neutral position, followed by the pronated position. The neutral position was rated best for the detection of ulnar and radial detachments of the TFCC, followed by the pronated position, except for two central perforations of the TFCC which were best seen with supination.

CONCLUSION

The articular disc and the surrounding radial portions of the radioulnar ligaments form a rigid, unified complex with the radius without change in their shape in positions of pronation and supination of the forearm, while the ulnar attachment of the TFCC shows important dynamic changes. The neutral forearm position is the best position to analyze both the normal and the abnormal TFCC.

Greater trochanter of the hip: attachment of the abductor mechanism and a complex of three bursae--MR imaging and MR bursography in cadavers and MR imaging in asymptomatic volunteers

PURPOSE

To evaluate trochanteric anatomy with magnetic resonance (MR) imaging, bursography, MR bursography, and anatomic analysis.

MATERIALS AND METHODS

T1-weighted and fat-saturated T2-weighted (transverse, sagittal, coronal, and coronal oblique planes) MR imaging of the greater trochanter was performed in 10 cadaveric hips and 12 hips of asymptomatic volunteers. Three bursae comprising the trochanteric bursa complex were injected, and conventional radiography and MR imaging were performed. The specimens were sectioned for anatomic analysis, corresponding to the MR imaging planes. Tendon attachments and bursal localization were related to the facets of the greater trochanter.

RESULTS

The bony surface of the greater trochanter consists of four facets: anterior, lateral, posterior, and superoposterior. The gluteus medius muscle attaches to the superoposterior and lateral facets. The gluteus minimus muscle attaches to the anterior facet. The trochanteric bursa covered the posterior facet and the lateral insertion of the gluteus medius muscle. The subgluteus medius bursa was located in the superior part of the lateral facet, underneath the gluteus medius tendon. The subgluteus minimus bursa lies in the area of the anterior facet, underneath the gluteus minimus tendon, medial and cranial to its insertion, and extends medially covering the distal anterior part of the hip joint capsule. The trochanteric bursa is delineated with fat on both sides and can be seen on transverse nonenhanced T1-weighted images as a fine line curving around the posterior part of the trochanter.

CONCLUSION

MR imaging and bursography provide detailed information about the anatomy of tendinous attachments of the abductor muscles and the bursal complex of the greater trochanter.

Intermetatarsal spaces: analysis with MR bursography, anatomic correlation, and histopathology in cadavers

PURPOSE

To describe the normal magnetic resonance (MR) imaging-depicted anatomy of the intermetatarsal spaces, with emphasis on the MR imaging appearance of the intermetatarsal bursae, and to correlate the MR findings with those seen in anatomic sections and at histopathologic analysis.

MATERIALS AND METHODS

Conventional radiography and pre- and postcontrast T1-weighted and fat-saturated T1-weighted spin-echo MR imaging were performed in 32 intermetatarsal spaces in eight human cadaveric feet. The cadaveric specimens were sectioned in planes corresponding to those at MR imaging for anatomic correlation. The intermetatarsal space anatomy was analyzed. Histopathologic examinations of the bursae were performed.

RESULTS

The intermetatarsal spaces were located in the forefoot between two metatarsal heads, below and above the deep transverse metatarsal ligament (DTML) that separated the spaces into two levels. The superior level contained the synovial bursa, the plantar and dorsal interosseous muscles and tendons, and the collateral ligament complexes of the metatarsophalangeal joints. The inferior level contained lumbrical muscles and neurovascular bundles. The bursae extended distally to the DTML in the second and third spaces close to the neurovascular bundles and did not extend beyond the DTML in the first and fourth spaces. In the first intermetatarsal space, the bursa had a specific appearance as it coursed along the adductor hallucis tendon as a tendon sheath. Histopathologic examination of the bursae revealed a single layer of attenuated cells.

CONCLUSION

MR bursography provided detailed information about the intermetatarsal anatomy, especially the intermetatarsal bursae.

Cervical spine: postmortem assessment of accident injuries--comparison of radiographic, MR imaging, anatomic, and pathologic findings

PURPOSE

To assess the ability of postmortem radiography and magnetic resonance (MR) imaging to depict occult cervical spine injuries as compared with anatomic and pathologic findings.

MATERIALS AND METHODS

The cervical spines of 10 adult accident victims underwent radiography and MR imaging, with T1-weighted, fast spin-echo T2-weighted, and four gradient-echo pulse sequences. The frozen specimens were cut into 3-mm-thick slices (sagittal plane) and photographed, and microfocus radiographs were obtained. Imaging findings were compared with the anatomic and pathologic findings.

RESULTS

Eight of the 10 specimens had 28 posttraumatic lesions: three fractures (two missed at the initial MR imaging reading), 10 facet joint capsule lesions with bleeding, five soft-tissue and ligament lesions, eight disk lesions, and two spinal cord lesions. Radiography depicted one lesion (4%). Two partial ruptures of the anterior annulus fibrosus were depicted at only MR imaging. Initially, 11 of 28 lesions were detected on MR images; retrospectively, 17 of 28 lesions were correlated with anatomic findings.

CONCLUSION

Soft-tissue and intervertebral disk and ligament injuries account for 89% (25 of 28) of posttraumatic cervical spine lesions detected on postmortem images. Occult lesions, including apophyseal joint injuries, were found in clinically noninjured cervical spines. MR imaging was limited in the depiction of discrete lesions when T1-weighted non-fat-saturated, fast spin-echo T2-weighted, and gradient-echo pulse sequences were used.

Assessment of the position of the distal portion of the ulna in lateral projection radiographs of the wrist: analysis of the influence of pronation-supination and flexion-extension on the pisoscaphoid and the ulnotriquetral distances: a cadaver study

RATIONALE AND OBJECTIVES

Accurate assessment of the distal radioulnar joint is of paramount importance for the detection of possible dislocation or subluxation. Using a cadaveric model, the authors attempted to establish a quantitative method that would allow identification of normal and abnormal distal radioulnar joint anatomy on well-positioned and rotated conventional radiographs.

METHODS

Four cadaveric wrists, in which subsequent sectioning confirmed the absence of disease, and one cadaveric wrist with a circumscribed lesion of the triangular fibrocartilaginous complex were studied. Defined movements in flexion and extension (+/- 10 degrees, 20 degrees, 30 degrees ) and in pronation and supination (+/- 10 degrees, 20 degrees, 30 degrees ) as well as combined flexion/extension and pronation/supination were performed. The ulnotriquetral and the pisoscaphoid distances were assessed in each position. Correlation with cryosections was achieved.

RESULTS

A strong linear correlation between the degree of pronation or supination and the pisoscaphoid and ulnotriquetral distances was noted. Flexion and extension produced no significant effect on the pisoscaphoid distance, but a defined shift of the ulnotriquetral distance occurred with increasing flexion and extension.

CONCLUSIONS

If all parameters are taken into account, this correlation aids in estimating the degree of possible malpositioning of the wrist during radiography and the degree of subluxation of the distal radioulnar joint. Tabular data with parameters to correct for instances of malrotated images and to estimate the extent of dislocation or malrotation of the distal radioulnar joint are provided.

In vivo changes after mechanical injury

Chondrocytes undergo apoptosis in response to mechanical injury in vitro. The current clinical study correlates arthroscopic and magnetic resonance imaging results with biopsy specimens of cartilage from patients with knee injury. Twenty patients were evaluated at a mean 2.7 months after acute knee injury. The mean age of the patients was 32 years and the mean weight was 83 kg. Cartilage lesions were graded separately on magnetic resonance images and arthroscopy in a blinded manner. During arthroscopy, a 1.8 mm diameter biopsy specimen was obtained from the edge of cartilage lesion. The biopsy specimen underwent histologic examination by safranin O staining and detection of chondrocyte apoptosis by the presence of deoxyribonucleic acid fragmentation. There was a positive correlation in 50% (10 of 20) when the presence or absence of cartilage lesions by magnetic resonance imaging was correlated with arthroscopy. All cases of partial thickness or full-thickness cartilage loss that were seen by arthroscopy also were detected by magnetic resonance images. Apoptotic cells were significantly more numerous in biopsy specimens from lesions compared with control biopsy specimens. The findings of reduced cell viability attributable to apoptosis may have profound implications for cartilage repair. This opens potential therapeutic avenues for the treatment of posttraumatic cartilage lesions through apoptosis prevention.

Cartilage imaging techniques: current clinical applications and state of the art imaging

The high incidence of cartilage lesions, coupled with the recent advances for their surgical and nonsurgical treatment, have necessitated the development of techniques for accurate diagnosis and monitoring of these lesions. Although arthroscopy has been the standard for cartilage evaluation, magnetic resonance imaging has emerged as the imaging method of choice, allowing analysis of its infrastructure and surface abnormalities. The authors will focus on current clinical applications for articular cartilage analysis and advances and the future direction of the imaging of articular cartilage.