Stephen Eustace

Contribution of meniscal extrusion and cartilage loss to joint space narrowing in osteoarthritis.

OBJECTIVE This study was undertaken to determine the contribution of meniscal extrusion and cartilage loss to joint space narrowing on conventional radiographs by correlation with magnetic resonance imaging (MRI). SUBJECTS AND METHODS Sixty-two consecutive patients, 32 patients with osteoarthritis and 30 without osteoarthritis, over the age of 60 years that were referred for both radiographic and MRI of the knee were included in the study. In each case, relative joint space narrowing on conventional AP radiographs was assessed utilizing the Kellgren-Lawrence scoring system. Subsequently, the degree of meniscal extrusion and the integrity of articular cartilage were evaluated from MR in the same patients. RESULTS Each of 30 patients with normal joint space (Kellgren Grade 0) were noted to have normal articular cartilage, grade 1 meniscal extrusion was identified in only three of these patients. In comparison, meniscal extrusion was identified in all 32 patients with joint space narrowing (Kellgren Grades 1-4). Definite thinning or loss of articular cartilage was identified in only 15 of the 32 cases. In 17 patients with radiographic joint space narrowing (Kellgren Grades 1-3) and meniscal extrusion, no loss of articular cartilage was observed. A statistically significant correlation (P<0.001) was observed between Kellgren Grade and degree of meniscal extrusion and cartilage thinning on MRI. CONCLUSION Conventional radiographs are an unreliable method of evaluating for articular cartilage loss in patients with early osteoarthritis. Initial joint space narrowing on conventional radiographs is secondary to meniscal extrusion rather than thinning of articular cartilage in most cases.

Turbo STIR magnetic resonance imaging as a whole‐body screening tool for metastases in patients with breast carcinoma: Preliminary clinical experience

This study was undertaken to assess the utility of whole‐body turbo short tau inversion recovery (STIR) magnetic resonance imaging (MRI) to detect metastases to liver, brain, and bone as a single examination in women with breast cancer. Seventeen patients with biopsy‐proven breast cancer and suspected metastatic disease attending over a 12‐month period referred for both conventional imaging and whole‐body MRI were included in the study. Three patients were found to be free of metastases at both conventional and MR imaging. Appendicular or axial skeletal metastases were identified in 11 of 17 patients, with correlation between findings at whole‐body MRI and scintigraphy in 15 of the 17 patients. Five patients had evidence of hepatic metastases on whole‐body MRI, of which metastases were identified in only three patients at CT despite contrast enhancement. Four patients had brain abnormalities (metastases in three patients, meningioma in one patient) detected on both whole‐body and dedicated brain MRI. Preliminary clinical experience suggests that turbo STIR whole‐body MRI may represent a convenient and cost‐effective method of total body screening for metastases in patients with breast carcinoma. J. Magn. Reson. Imaging 2000;11:343–350.

Postmortem whole-body magnetic resonance imaging as an adjunct to autopsy: Preliminary clinical experience

The purpose of this study was to evaluate whole‐body magnetic resonance imaging (MRI) of cadavers as an adjunct to autopsy. Eight consecutive patients underwent both whole‐body MRI and autopsy [either conventional (six), limited (one), or percutaneous (one)] within 24 hours of death. Comparison was made of major and minor abnormalities and predicted cause of death recorded by independent readers at both MRI and autopsy. Major discrepancies between the recorded primary cause of death at imaging and autopsy occurred in five (5) patients. These included a myocardial infarction found at autopsy alone, bowel infarction and portal venous gas found at MRI alone, and aortic dissection and occipital infarct found at MRI alone in a patient on whom only limited autopsy was performed. Postmortem MRI may represent a useful adjunct to autopsy, particularly in patients in whom autopsy is limited due to patient/family consent, inoculation risks, and ethnic doctrines. J. Magn. Reson. Imaging 2001;13:277–287.

Whole-Body MRI versus PET in assessment of multiple myeloma disease activity.

OBJECTIVE The purpose of this study was to compare FDG PET; whole-body MRI; and the reference standard, bone marrow aspiration and biopsy, to determine the best imaging technique for assessment of disease activity in multiple myeloma. SUBJECTS AND METHODS Twenty-four patients (13 women, 11 men; mean age, 67.1 years; range, 44-83 years) with bone marrow biopsy-proven multiple myeloma were included in the study. All patients underwent PET/CT and whole-body MRI within 10 days of each other. Eight patients underwent more than one follow-up PET/CT and whole-body MRI examination, for a total of 34 pairs of images. Activity was defined as lesions with a maximum standardized uptake value greater than 2.5 at PET and as evidence of marrow packing at whole-body MRI. PET and whole-body MRI results were correlated with findings at bone marrow aspiration biopsy. RESULTS PET had a sensitivity of 59%, specificity of 75%, positive predictive value of 81%, and negative predictive value of 50% (p = 0.08). Whole-body MRI had a sensitivity of 68%, specificity of 83%, positive predictive value of 88%, and negative predictive value of 59% (p = 0.01). In 62% of cases, PET and whole-body MRI findings were concordant. When PET and whole-body MRI findings were concordant and positive, no false-positive results were found, yielding a specificity and a positive predictive value of 100% (p = 0.04). CONCLUSION Whole-body MRI performed better than PET in the assessment of disease activity, having a higher sensitivity and specificity. The positive predictive value of whole-body MRI in the assessment of active disease was high at 88%. When used in combination and with concordant findings, PET and whole-body MRI were found to have a specificity and positive predictive value of 100%, which may be of value to clinicians assessing the effectiveness of aggressive and expensive treatment regimens.

Injectable Corticosteroid and Local Anesthetic Preparations: A Review for Radiologists

Corticosteroids and local anesthetics are some of the most commonly administered medications in radiology departments. These medications have marked variability in their formulations, which may increase their adverse event profile for specific procedures. In particular, certain corticosteroid preparations are associated with adverse central nervous system (CNS) sequelae. This is most likely due to distal embolization by particulate formulations. Nonparticulate steroid formulations are not associated with such events. Local anesthetics have severe CNS and cardiac adverse effects if injected intravascularly and have recently been associated with intraarticular chondrolysis if used in large doses. This review discusses these medications with particular emphasis on their established and postulated adverse effects. The administering radiologist should be aware of these potential effects and how best to reduce their occurrence.

Radiographic features that enable assessment of first metatarsal rotation: the role of pronation in hallux valgus.

This study describes a method of detecting first metatarsal pronation on the basis of the movement of the inferior tuberosity of the base of 20 cadaveric first metatarsals at 0°, 10°, 20° and 30° pronation. On pronation, the inferior tuberosity of the base of the first metatarsal moved lateral to the mid-line axis. At 10°, the tuberosity pointed to the junction of the inner third and outer two-thirds of a line between the midpoint and lateral tubercle of the base. At 20°, it pointed to the junction of the inner two-thirds and outer third of that line. At 30°, it pointed to the outer margin of the lateral third. Using these features, the amount of first metatarsal pronation in 100 consecutive weight-bearing views of feet was recorded and plotted against the corresponding intermetatarsal angles in those feet. Four of 43 patients with an intermetatarsal angle of less than 9° had pronation greater than 10°, 48 of 57 patients with an intermetatarsal angle greater than 9° had pronation greater than 10° (P<0.001). As intermetatarsal angles increase, the amount of first metatarsal pronation increases (r= 0.69). Pronation and varus deviation of the first metatarsal are linked; both alter the tendon balance maintaining proximal phalanx alignment and lead to the development of hallux valgus.

Radiofrequency ablation of osteoid osteoma with cooled probes and impedance-control energy delivery

OBJECTIVE Our objective was to evaluate the efficacy of percutaneous radiofrequency ablation of osteoid osteoma with cooled radiofrequency probes and impedance control energy delivery from a 200-W generator. We also compared the outcome to published data for therapy with a 5-mm noncooled probe and temperature-controlled short-duration therapy protocols. SUBJECTS AND METHODS Radiofrequency ablation was performed on 11 patients with a clinical and radiologic diagnosis of osteoid osteoma. A cooled radiofrequency probe was introduced into the lesion under CT guidance. Twelve minutes of radiofrequency energy was delivered from a 200-W generator under impedance control. Postprocedural pain, function, and satisfaction were evaluated by means of an interview and questionnaire. RESULTS All procedures were technically successful. No serious complication occurred. Postoperative pain was scored at a mean of 6.9 +/- 3.06 (95% confidence interval) on a numeric rating scale. Postoperative pain was rated as similar to night pain. By 1 week after therapy, all patients had resolution of pain and returned to normal activity. There was no recurrence during the follow-up period (range, 6-27 months; mean, 14.4 months). Patients rated their satisfaction as high. CONCLUSION Radiofrequency ablation of osteoid osteoma with a high-energy delivery technique is safe and has a high success rate. When compared with patients in a published series using 5-mm probes and manual energy control from lower-output generators, our cohort showed increased postoperative pain scores and an increased interval to symptom resolution.

MRI findings in bipartite patella

PurposeBipartite patella is a known cause of anterior knee pain. Our purpose was to detail the magnetic resonance imaging (MRI) features of bipartite patella in a retrospective cohort of patients imaged at our institution.Materials and methodsMRI exams from 53 patients with findings of bipartite patella were evaluated to assess for the presence of bone marrow edema within the bipartite fragment and for the presence of abnormal signal across the synchondrosis or pseudarthrosis. Any other significant knee pathology seen at MRI was also recorded. We also reviewed 400 consecutive knee MRI studies to determine the MRI prevalence of bipartite patella.ResultsOf the 53 patients with bipartite patella 40 (75%) were male; 35 (66%) had edema within the bipartite fragment. Of the 18 with no edema an alternative explanation for knee pain was found in 13 (72%). Edema within the bipartite fragment was the sole finding in 26 of 53 (49%) patients. Bipartite patella was seen in 3 (0.7%) of 400 patients.ConclusionIn patients with bipartite patella at knee MRI, bone marrow edema within the bipartite fragment was the sole finding on knee MRI in almost half of the patients in our series.

Hallux valgus, first metatarsal pronation and collapse of the medial longitudinal arch--a radiological correlation.

In a previous study we developed a model to assess first metatarsal pronation based on the position of the inferior tuberosity of its base and showed a significant relationship between first metatarsal pronation and the intermetatarsal angle (r=0.69, p<0.001). The present study was undertaken to correlate first metatarsal pronation with the height of the medial longitudinal arch in an attempt to define the clinical significance of this new finding. The weight-bearing anteroposterior and lateral radiographs of the feet of 50 patients (100 feet; 36 females patients of mean age 38 years, 14 males patients of mean age 40 years) were reviewed, and in each case, the patients age, sex, intermetatarsal angle, amount of first metatarsal pronation and medial longitudinal arch angle were recorded by independent observers. A significant relationship was demonstrated between first metatarsal pronation and the height of the medial longitudinal arch (r=0.93, p<0.0001). Less marked association was observed between intermetatarsal angles and first metatarsal pronation (r=0.71, p<0.001). Multivariate analysis of patient age, sex, intermetatarsal angle and medial longitudinal arch angle against metatarsal pronation showed that the single most dominant variable affecting metatarsal pronation was the height of the medial longitudinal arch.

Whole-body turbo STIR MR imaging: controversies and avenues for development

Abstract.The idea of a non-ionizing high-resolution technique to screen the entire body for occult disease is immensely appealing. This article outlines an evolving technique, controversies and clinical application of whole-body scanning using MRI with turbo short tau inversion recovery tissue excitation.