Bruno Vande Berg

Magnetic Resonance Imaging of the Axial Skeleton for Detecting Bone Metastases in Patients With High-Risk Prostate Cancer: Diagnostic and Cost-Effectiveness and Comparison With Current Detection Strategies

PURPOSE To evaluate the diagnostic performance, costs, and impact on therapy of one-step magnetic resonance imaging (MRI) of the axial skeleton (MRIas) for detecting bone metastases in patients with high-risk prostate cancer (PCa). PATIENTS AND METHODS Sixty-six consecutive patients with high-risk PCa prospectively underwent MRIas in addition to the standard sequential work-up (SW) of bone metastases (technetium-99m bone scintigraphy [BS] completed with targeted x-rays [TXR] in patients with equivocal BS findings and with MRI obtained on request [MRIor] in patients with inconclusive BS/TXR findings). Panel review of initial and 6-month follow-up MRI findings, BS/TXR, and all available baseline and follow-up clinical and biologic data were used as the best valuable comparator to define metastatic status. Diagnostic effectiveness of MRIas alone was compared with each step of the SW. Impact of MRIas screening on patient management and costs was evaluated. RESULTS On the basis of the best valuable comparator, 41 patients (62%) had bone metastases. Sensitivities were 46% for BS alone, 63% for BS/TXR, 83% for BS/TXR/MRIor, and 100% for MRIas; the corresponding specificities were 32%, 64%, 100%, and 88%, respectively. MRIas was significantly more sensitive than any other approach (P < .05, McNemar). MRIas identified metastases in seven (30%) of 23 patients considered negative and eight (47%) of 17 patients considered equivocal by other strategies, which altered the initially planned therapy. Economic impact was variable among countries, depending on reimbursement rates. CONCLUSION MRIas is more sensitive than the current SW of radiographically identified bone metastases in high-risk PCa patients, which impacts the clinical management of a significant proportion of patients.

Can Whole-body Magnetic Resonance Imaging with Diffusion-weighted Imaging Replace Tc 99m Bone Scanning and Computed Tomography for Single-step Detection of Metastases in Patients with High-risk Prostate Cancer?

BACKGROUND Technetium Tc 99m bone scintigraphy (BS) and contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) of the pelvis and abdomen are universally recommended for detecting prostate cancer (PCa) metastases in cancer of all stages. However, this two-step approach has limited sensitivity and specificity. OBJECTIVE Evaluate the diagnostic accuracy of whole-body MRI (WBMRI) as a one-step screening test for PCa metastases. DESIGN, SETTING, AND PARTICIPANTS One hundred consecutive PCa patients at high risk for metastases prospectively underwent WBMRI, CT, and BS completed with targeted x-rays (BS/TXR) in case of equivocal BS. Four independent reviewers reviewed the images. MEASUREMENTS This study compares the diagnostic performance of WBMRI, CT, BS, and BS/TXR in detecting PCa metastases using area under the curve (AUC) receiver operator characteristics. A best valuable comparator (BVC) approach was used to adjudicate final metastatic status in the absence of pathologic evaluation. RESULTS AND LIMITATIONS Based on the BVC, 68 patients had metastases. The sensitivity of BS/TXR and WBMRI for detecting bone metastases was 86% and 98-100%, respectively (p<0.04), and specificity was 98% and 98-100%, respectively. The first and second WBMRI readers respectively identified bone metastases in 7 and 8 of 55 patients with negative BS/TXR. The sensitivity of CT and WBMRI for detecting enlarged lymph nodes was similar, at 77-82% for both; specificity was 95-96% and 96-98%, respectively. The sensitivity of the combination of BS/TXR plus CT and WBMRI for detecting bone metastases and/or enlarged lymph nodes was 84% and 91-94%, respectively (p=0.03-0.10); specificities were 94-97% and 91-96%, respectively. The 95% confidence interval of the difference between the AUC of the worst WBMRI reading and the AUC of any of the BS/TXR plus CT lay within the noninferiority margin of ±10% AUC. CONCLUSIONS WBMRI outperforms BS/TXR in detecting bone metastases and performs as well as CT for enlarged lymph node evaluation. WBMRI can replace the current multimodality metastatic work-up for the concurrent evaluation of bones and lymph nodes in high-risk PCa patients.

Skeletal survey in advanced multiple myeloma: radiographic versus MR imaging survey

In an attempt to compare the sensitivity of bone radiographs and bone marrow magnetic resonance (MR) imaging for bone lesion detection in patients with stage III multiple myeloma (MM) and to evaluate the possible consequences of the replacement of the conventional radiographic skeletal survey (RSS) by an MR survey of the spinal and pelvic bone marrow in these patients, we obtained MR studies of the thoracic and lumbar spine, pelvis and proximal femurs in addition to the conventional RSS (including radiographs of the skull, entire spine, pelvis, ribs, humerus and femurs) in 80 consecutive patients with newly diagnosed stage III MM according to the Durie and Salmon staging system (based on blood tests and on the RSS). The performance of MR and radiographic studies to detect bone lesions in given anatomic areas and in given patients were compared. The consequences on MM staging following the substitution of the RSS by the MR survey were assessed.

Magnetic resonance imaging of the normal bone marrow

Abstract The bone marrow is a complex organ that contains fat and nonfat cells, the proportions of which vary greatly with age and in the different bones of the skeleton. Magnetic resonance (MR) imaging provides information on the composition of the medullary cavity of any given bone and on the distribution of red and yellow marrow in the skeleton. This article deals with the wide spectrum of appearances of the normal bone marrow at MR imaging.

Benign osteochondromas and exostotic chondrosarcomas: evaluation of cartilage cap thickness by ultrasound.

Ultrasonography (US) enables accurate assessment of the cartilage cap of exostoses. The cartilage cap appears as a hypoechoic layer covering the hyperechoic surface of the calcified part. Measurements of cap thickness with US were compared with measurements performed on pathological specimens in 22 resected exostoses and 2 exostotic chondrosarcomas. The US measurements proved to be very accurate, with a mean measurement error of less than 2 mm for cartilage caps less than 2 cm thick. The detection rate and measurement accuracy of US were higher than with computed tomography (CT) and comparable to magnetic resonance imaging (MRI), which were available in 14 and 10 cases, respectively. US appears to be a good procedure for evaluating the cartilage cap, which is usually thin for a benign exostosis and thick for a malignancy. In addition, other complications — such as bursa formation — are easily recognizable. The sole limitation is that US cannot visualize the cartilage cap when it is inwardly orientated or deeply located in soft tissues, which are both, however, relatively uncommon situations.

End plate marrow changes in the asymptomatic lumbosacral spine: frequency, distribution and correlation with age and degenerative changes.

PurposeTo investigate the frequency and distribution of end plate marrow signal intensity changes in an asymptomatic population and to correlate these findings with patient age and degenerative findings in the spine.Materials and methodsMR imaging studies of the lumbosacral (LS) spine in 59 asymptomatic subjects were retrospectively reviewed by 2 musculoskeletal radiologists to determine the presence and location of fat-like and edema-like marrow signal changes about the end plates of the L1-2 through L5-S1 levels. The presence of degenerative changes in the spine was recorded as was patient age. Descriptive statistics were utilized to determine the frequency and associations of end plate findings and degenerative changes in the spine. Interobserver variability was determined by a kappa score. Binomial probability was used to predict the prevalence of the end plate changes in a similar subject population. The Fisher exact test was performed to determine statistical significance of the relationship of end plate changes with degenerative changes in the spine, superior versus inferior location about the disc and age of the patient population.ResultsFocal fat-like signal intensity adjacent to the vertebral end-plate was noted in 15 out of 59 subjects by both readers, and involved 38 and 36 out of 590 end plates by readers 1 and 2, respectively. Focal edema-like signal intensity adjacent to the vertebral end plate was noted in 8 out of 59 subjects by both readers and involved 11 and 10 out of 590 end plates by readers 1 and 2, respectively. Either fat or edema signal intensity occurred most often at the anterior (p<.05) aspects of the mid-lumbar spine and was seen in an older sub-population of the study (p<.05).ConclusionEnd plate marrow signal intensity changes are present in the lumbar spine of some asymptomatic subjects with a characteristic location along the spine and in vertebral end plates.

Multidetector spiral CT arthrography of the shoulder. Clinical applications and limits, with MR arthrography and arthroscopic correlations

Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.

CT Arthrography, MR Arthrography, PET, and Scintigraphy in Osteoarthritis

CT arthrography and MR arthrography are accurate methods for the study of surface cartilage lesions and cartilage loss. They also provide information on subchondral bone and marrow changes, and ligaments and meniscal lesions that can be associated with osteoarthritis. Nuclear medicine also offers new insights in the assessment of the disease. This article discusses the strengths and limitations of CT arthrography and MR arthrography. It also highlights nuclear medicine methods that may be relevant to the study of osteoarthritis in research and clinical practice.

Necrotizing fasciitis: Contribution and limitations of diagnostic imaging

Necrotizing fasciitis is a rare, rapidly spreading, deep-seated infection causing thrombosis of the blood vessels located in the fascia. Necrotizing fasciitis is a surgical emergency. The diagnosis typically relies on clinical findings of severe sepsis and intense pain, although subacute forms may be difficult to recognize. Imaging studies can help to differentiate necrotizing fasciitis from infections located more superficially (dermohypodermitis). The presence of gas within the necrotized fasciae is characteristic but may be lacking. The main finding is thickening of the deep fasciae due to fluid accumulation and reactive hyperemia, which can be visualized using computed tomography and, above all, magnetic resonance imaging (high signal on contrast-enhanced T1 images and T2 images, best seen with fat saturation). These findings lack specificity, as they can be seen in non-necrotizing fasciitis and even in non-inflammatory conditions. Signs that support a diagnosis of necrotizing fasciitis include extensive involvement of the deep intermuscular fascias (high sensitivity but low specificity), thickening to more than 3mm, and partial or complete absence on post-gadolinium images of signal enhancement of the thickened fasciae (fairly high sensitivity and specificity). Ultrasonography is not recommended in adults, as the infiltration of the hypodermis blocks ultrasound transmission. Thus, imaging studies in patients with necrotizing fasciitis may be challenging to interpret. Although imaging may help to confirm deep tissue involvement and to evaluate lesion spread, it should never delay emergency surgical treatment in patients with established necrotizing fasciitis.

Idiopathic muscular infarction in a diabetic patient

Idiopathic or so-called spontaneous muscular infarction is an infrequent complication of diabetes melbitus. Only a few cases have been described . Typically, the infarction presents as localized pain and swelling and a limited active range of motion of the involved extremity. When these symptoms are present in a diabetic patient, the differential diagnosis should include diabetic muscular infarction. As far as we know, all reports of muscular infarction in diabetic patients have involved the quadriceps mechanism in the lower extremity exclusively. The following case report describes infarction of the semimembranosus and biceps femoris muscles in a patient who had diabetes mellitus.