[Skeletal manifestations of systemic hematologic disorders]. / Skelettveränderungen bei hämatologischen Systemerkrankungen.

BACKGROUND: Bone marrow consists of connective tissue and stem cells, which generate blood cells. This includes erythropoiesis, leukopoiesis and thrombopoiesis. Thus, hematologic disorders first affect the bone marrow and secondarily the blood. METHODS: Bone marrow changes can be sensitively detected using magnetic resonance imaging (MRI) and often represent the initial manifestation of the underlying disease. With longer duration of disease, changes can also be found on X­ray or computed tomography (CT). RESULTS: The findings on MRI and X­ray/CT are often nonspecific and can only be interpreted in the context of clinical information. CONCLUSION: In the following article, we provide a brief overview of the clinical manifestations and imaging changes to be expected in leukemia, anemia, and chronic myeloproliferative disorders.

[Posttherapeutic changes in bone marrow]. / Posttherapeutische Veränderungen am Knochenmark.

The bone marrow basically consists of red blood-forming bone marrow and yellow fat. In the skeleton, there is an age-dependent distribution of these two parts. In the context of medical interventions or therapies, bone marrow changes can occur, whereby the normal bone marrow can basically be replaced by fat, edema, or fibrosis/sclerosis. Here, specific signal intensities and patterns are shown in imaging. After irradiation therapies, edematous changes, hemorrhages, and osteoradionecroses are observed. Likewise, insufficiency fractures, impairment of the growth gaps, or the development of tumors is possible. In patients on dialysis, deposit of protein in the bone marrow is possible in the case of the so-called amyloidosis osteoarthropathy. Postoperative bone marrow edema, insufficiency fractures, or osteonecrosis can be observed after arthroscopy. Changes in the distribution of fat markers and blood-forming bone marrow can be observed after stem cell transplants. In the therapy with cortisone, insufficiency fractures and osteonecroses are possible. Depending on their effect on the hematopoietic system, chemotherapyies can first lead to edematous changes and then to fatty bone marrow, which is reversible after therapy. Angiogenesis inhibitors in combination with other chemotherapeutic agents often lead to mixed images of stimulated and fatty bone marrow.

[Differentiation between acute osteoporotic and metastatic vertebral body fractures by imaging]. / Unterscheidung akuter osteoporotischer und metastasenbedingter Wirbelkörperfrakturen in der Bildgebung.

OBJECTIVES: This article discusses the morphological criteria for the differentiation between acute osteoporotic and metastatic vertebral body fractures and new imaging methods, such as diffusion-weighted and chemical shift magnetic resonance imaging (MRI) are presented. BACKGROUND: The differential diagnostics of osteoporotic and metastatic vertebral body fractures can be difficult in some cases. Both entities normally occur without adequate trauma and predominantly in elderly patients. IMAGING: Conventional X-ray examination is the initial imaging method of choice but is not able to reliably differentiate between the osteoporotic or metastatic etiology of a fracture. Computed tomography (CT) clearly depicts osseous destruction in metastatic fractures but lacks specificity. Magnetic resonance imaging (MRI) shows a higher sensitivity and specificity in differentiating osteoporotic and metastatic fractures. DIFFERENTIAL DIAGNOSTICS: The combination CT and MRI allows an accurate diagnosis with respect to an osteoprorotic or metastatic etiology in most of cases but bone marrow edema in acute fractures sometimes leads to ambiguous results and differential diagnostic problems.

Early detection of metastatic disease in asymptomatic breast cancer patients with whole-body imaging and defined tumour marker increase.

BACKGROUND: Follow-up care in breast cancer is still an issue of debate. Diagnostic methods are more sensitive, and more effective therapeutic options are now available. The risk of recurrence is not only influenced by tumour stage but also by the different molecular subtypes. This study was performed to evaluate the use of whole-body imaging combined with tumour marker monitoring for the early detection of asymptomatic metastatic breast cancer (MBC). METHODS: This analysis was performed as part of a follow-up study evaluating 813 patients with a median follow-up of 63 months. After primary therapy, all patients underwent tumour marker monitoring for CEA, CA 15-3 and CA 125 at 6-week intervals within an intensified diagnostic aftercare algorithm. A reproducible previously defined increase was considered as a strong indicator of MBC. From 2007 to 2010, 44 patients with tumour marker increase underwent whole-body magnetic resonance imaging and/or an FDG-PET/CT scan. Histological clarification and/or imaging follow-up were done. RESULTS: Metastases were detected in 65.9% (29/44) of patients, 13.6% (6/44) had secondary malignancies besides breast cancer and 20.5% (9/44) had no detectable malignancy. Limited disease was found in 24.1% (7/29) of patients. Median progression-free survival of MBC was 9.2 months and median overall survival was 41.1 months. The 3- and 5-year survival rates were 64.2% and 40.0%, respectively. CONCLUSIONS: A reproducible tumour marker increase followed by whole-body imaging is highly effective for early detection. By consequence, patients might benefit from earlier detection and improved therapeutic options with a prolonged survival.

[Radiological diagnostics of multiple myeloma]. / Radiologische Diagnostik des multiplen Myeloms.

CLINICAL/METHODICAL ISSUE: Robust and reliable imaging methods are required to estimate the skeletal tumor load in multiple myeloma, as well as for the diagnosis of extraskeletal manifestations. Imaging also plays an essential role in the assessment of fracture risk and of vertebral fractures. STANDARD RADIOLOGICAL METHODS: The conventional skeletal survey has been the gold standard in the imaging of multiple myeloma for many years. METHODICAL INNOVATIONS: Other modalities which have been investigated and are in use are whole-body computed tomography (WBCT), 18F-fluorodeoxyglucose positron emission tomography computed tomography (FDG PET-CT) and whole-body magnetic resonance imaging (WBMRI). These techniques are able to depict both mineralized bone and the bone marrow with a high sensitivity for myeloma lesions. PERFORMANCE: Several studies have shown that cross-sectional imaging is superior to the skeletal survey in the detection of myeloma lesions and WBMRI has been shown to be significantly more sensitive than WBCT for the detection of focal myeloma lesions as well as for diffuse infiltration. The FDG PET-CT technique has a sensitivity comparable to WBMRI. ACHIEVEMENTS: Due to the higher sensitivity in the detection of myeloma lesions WBCT and WBMRI should replace the skeletal survey. PRACTICAL RECOMMENDATIONS: A WBCT should be performed if there is suspicion of multiple myeloma. If no focal lesions are found WBMRI or at least MRI of the spine and pelvis should be additionally performed if available. If WBMRI has been initially performed and focal lesions are present, an additional WBCT may be performed to assess the extent of bone destruction and fracture risk. In cases of monoclonal gammopathy of undetermined significance (MGUS), solitary and smoldering myeloma, a WBMRI, if available, should be performed in addition to WBCT.

FDG-PET-CT and whole-body MRI for triage in patients planned for radioembolisation therapy.

PURPOSE: The purpose was to evaluate the potential of FDG-PET-CT and whole-body MRI (WB-MRI) as diagnostic triage methods for patients planned for radioembolisation of metastatic liver disease. MATERIALS AND METHODS: 135 patients with multifocal liver metastases were evaluated for potential palliative therapy with radioembolisation using 90-Yttrium microspheres. All patients were examined consecutively with FDG-PET-CT and WB-MRI for exclusion of relevant extra-hepatic tumor manifestations. All patients underwent 99mTc-albumine angiography followed by scintigraphy to exclude significant hepato-pulmonary shunting. RESULTS: Out of the 135 patients included into the pre-therapeutic diagnostic algorithm, 56% were eligible and received radioembolisation, while 44% could not be treated. In 91% the exclusion criteria was diagnosis of significant extra-hepatic metastatic disease. In 85% exclusion diagnosis was made concordantly by both FDG-PET-CT and WB-MRI, in 9% diagnosis was provided by PET-CT, in 6% by WB-MRI alone. Patient-based sensitivity for detection of extra-hepatic disease was 94% for PET-CT and 91% for WB-MRI. False-positive diagnosis of extrahepatic disease leading to exclusion for radioembolisation therapy was made in 2% of patients, in one patient by PET-CT and in one patient by WB-MRI alone. Overall, specificity for inclusion of radioembolisation therapy by combining both modalities was 99%. In 9% of patients angiographic diagnosis made radioembolisation impossible, in 7% solely the angiographic findings were decisive. CONCLUSION: Both FDG-PET-CT and WB-MRI are efficient diagnostic triage methods for patients planned for radioembolisation of liver metastases. Overall, FDG-PET-CT shows a trend to higher diagnostic accuracy compared to WB-MRI and may be used as imaging method of choice as a standalone examination. In combination, both modalities exhibited high sensitivity for the diagnosis of extra-hepatic tumor manifestations and result in high specificity.

The influence of adjuvants on local recurrence rate in giant cell tumour of the bone.

INTRODUCTION: Intralesional surgery of giant cell tumour of the bone (GCT) may result in a high rate of local recurrence. The introduction of local adjuvants, such as cementation, cryosurgery or phenolization, has proved to be successful in the reduction of recurrence rates. This study presents the results of a single institution in surgery of GCT with an evolution in treatment strategies. MATERIAL & METHODS: Forty primary and 25 recurrent surgical procedures in 46 patients with GCT of the bone with a median follow-up of 72 months were reviewed retrospectively. The mean age was 32.6 years (range 13.6-57.9 years). Forty-seven curettages and 18 resections were performed. For the curettages, a large bone window was cut followed by high speed burring and bone grafting or cementation. In 34 of 47 curettages and 7 of 18 resections, phenol was additionally applied. RESULTS: Two patients showed pulmonary metastasis, one died due to metastatic disease. In total, a third of the patients developed local recurrence (32.3%). This was evenly spread among primary and recurrent diesease (32.5% vs. 32%). Seven of 13 curettages without adjuvant recurred (53.9%), compared to 11 of 34 curettages with adjuvant phenol (32.4%). Three of 18 resections developed a recurrence (16.7%). No complications in respect to the use of phenol were seen. DISCUSSION: Phenolization is a safe local adjuvant therapy for GCT. Although the recurrence rate was lower with the use of phenol, this drop was not significant. The comparable high recurrence rate in our study, even if phenol was used, might be due to the fact that curettage was our favoured treatment, even in cases with an extensive juxta-articular tumour. We recommend adjuvant phenolization in the treatment of GCT of the bone after thorough curettage in applicable cases, including where cementation is used for defect filling.

Dysplasia epiphysealis hemimelica of the distal ulna: a case report and review of the literature.

Dysplasia epiphysealis hemimelica (DEH) or Trevor's Disease is a very rare disease with an estimated incidence of one in 1.000.000. The majority of cases reported affect the lower limb and only 25 case reports of 33 cases with affection of the upper limb have been published. Here we present a case of DEH affecting the distal ulnar epiphysis and the lunate in an eleven-year-old girl, a DEH location described extremely rarely before. We firstly do not only present clinical and radiological findings (plane radiographs, CT, MRI), but also the surgical approach and the histopathological results of DEH in this uncommon location. Although extremely rare, DEH should be considered also in non-typical locations.

Whole-body MRI at 1.5 T and 3 T compared with FDG-PET-CT for the detection of tumour recurrence in patients with colorectal cancer.

The purpose of this study was to assess the diagnostic accuracy of whole-body MRI (WB-MRI) at 1.5 T or 3 T compared with FDG-PET-CT in the follow-up of patients suffering from colorectal cancer. In a retrospective study, 24 patients with a history of colorectal cancer and suspected tumour recurrence underwent FDG-PET-CT and WB-MRI with the use of parallel imaging (PAT) for follow-up. High resolution coronal T1w-TSE and STIR sequences at four body levels, HASTE imaging of the lungs, contrast-enhanced T1w- and T2w-TSE sequences of the liver, brain, abdomen and pelvis were performed, using WB-MRI at either 1.5 T (n = 14) or 3 T (n = 10). Presence of local recurrent tumour, lymph node involvement and distant metastatic disease was confirmed using radiological follow-up within at least 5 months as a standard of reference. Seventy seven malignant foci in 17 of 24 patients (71%) were detected with both WB-MRI and PET-CT. Both investigations concordantly revealed two local recurrent tumours. PET-CT detected significantly more lymph node metastases (sensitivity 93%, n = 27/29) than WB-MRI (sensitivity 63%, n = 18/29). PET-CT and WB-MRI achieved a similar sensitivity for the detection of organ metastases with 80% and 78%, respectively (37/46 and 36/46). WB-MRI detected brain metastases in one patient. One false-positive local tumour recurrence was indicated by PET-CT. Overall diagnostic accuracy for PET-CT was 91% (sensitivity 86%, specificity 96%) and 83% for WB-MRI (sensitivity 72%, specificity 93%), respectively. Examination time for WB-MRI at 1.5 T and 3 T was 52 min and 43 min, respectively; examination time for PET-CT was 103 min. Initial results suggest that differences in accuracy for local and distant metastases detection using FDG-PET-CT and WB-MRI for integrated screening of tumour recurrence in colorectal cancer depend on the location of the malignant focus. Our results show that nodal disease is better detected using PET-CT, whereas organ disease is depicted equally well by both investigations.

Feasibility of a RARE-based sequence for quantitative diffusion-weighted MRI of the spine.

The feasibility of a diffusion-weighted single-shot fast-spin-echo sequence for the diagnostic work-up of bone marrow diseases was assessed. Twenty healthy controls and 16 patients with various bone marrow pathologies of the spine (bone marrow edema, tumor and inflammation) were examined with a diffusion-weighted single-shot sequence based on a modified rapid acquisition with relaxation enhancement (mRARE) technique; four diffusion weightings (b-values: 50, 250, 500 and 750 s/mm(2)) in three orthogonal orientations were applied. Apparent diffusion coefficients (ADCs) were determined in the bone marrow and in the intervertebral discs of healthy volunteers and in diseased bone marrow. Ten of the 20 volunteers were repeatedly scanned within 30 min to examine short-time reproducibility. Spatial reproducibility was assessed by measuring ADCs in two different slices including the same lesion in 12 patients. The ADCs of the lesions exhibited significantly higher values, (1.27 +/- 0.32)x10(-3) mm(2)/s, compared with healthy bone marrow, (0.21 +/- 0.10)x10(-3) mm(2)/s. Short-time and spatial reproducibility had a mean coefficient of variation of 2.1% and 6.4%, respectively. The diffusion-weighted mRARE sequence provides a reliable tool for determining quantitative ADCs in vertebral bone marrow with adequate image quality.

[Degenerative diseases of the spine: Rare and often unrecognized causes of pain syndromes]. / Degenerative Erkrankungen der Wirbelsäule: Seltene und oft verkannte Ursachen von Schmerzsyndromen.

GOAL: The aim of this article is to describe rare and often unrecognized causes of spinal pain syndromes. METHOD: Intervertebral disc degeneration frequently appears in early adulthood and can have a symptomatic or asymptomatic course. This article discusses incidence, pathophysiology, imaging, and pain symptomatology involved in the origin of back pain. RESULTS: Anulus tears are often found in asymptomatic individuals but could be implicated in lumbar pain symptomatology in correlation with the provocative discography. Transient disorders can lead to pseudarthrosis of the iliac bone and to degeneration or to a reactive hypermobility with intervertebral disc degeneration in the level above. Modic type 1 erosive osteochondrosis is characterized by bone marrow edema near the hyaline cartilage end plate, which mostly elicits severe pain and results in serious limitations in everyday activities. The most important differential diagnosis is spondylodiscitis. Schmorl's nodes can exhibit considerable surrounding bone marrow edema that can be mistaken for metastases. A combination of MRI and CT should be employed for the diagnostic work-up of fatigue fracture of the interarticular portion, which is often overlooked due to its location. Synovial cysts of the facet joints can lead to radicular symptoms. Insufficiency fracture of the sacrum is frequently mistaken for metastasis due to intense scintigraphic enhancement and its signal behavior in MRI. CT provides instructive information. CONCLUSION: Differential diagnosis should include less common causes such as anulus tears, transient disorders, activated Schmorl's nodes, synovial cysts of the facet joints, fatigue fractures of the interarticular portion of the spine and the sacrum and distinguish from metastases in particular.

[Lumbar disc arthroplasty: indications, biomechanics, types, and radiological criteria]. / Lumbale Bandscheibenendoprothesen: Indikationen, Biomechanik, Typen und radiologische Kriterien.

Lumbar total disc replacement (TDR) was developed to treat a painful degenerative lumbar motion segment while avoiding the disadvantages of fusion surgery, such as adjacent segment instabilities. Early clinical results with TDR have shown a significant reduction in low back pain and a significant improvement in disability scores. When compared to fusion, the results with TDR tend to be superior in the short-term follow-up and initial rehabilitation is faster. The radiological assessment is an integral part of the preoperative work-up. Plain X-rays of the lumbar spine should be complemented by flexion - extension views in order to assess residual segmental mobility. Computed tomography is used to exclude osteoarthritis of the zygapophyseal joints, Baastrup's disease (kissing spines) and other sources of low back pain. Magnetic resonance imaging is useful to exclude substantial disc protrusions; it allows for the detection of disc dehydration and bone marrow edema in the case of activated spondylochondrosis. If osteoporosis is suspected, an osteodensitometry of the lumbar spine should be performed. Postoperative plain X-rays should include antero-posterior and lateral views as well as flexion - extension views in the later postoperative course. Measurements should determine the disc space height in the lateral view, the segmental and total lumbar lordosis as well as the segmental mobility in the flexion - extension views. The ideal position of a TDR is exactly central in the ap-view and close to the dorsal border of the vertebral endplates in the lateral view. Malpositioning may cause segmental hyperlordosis and unbalanced loading of the endplates with the risk of implant subsidence and migration.

Whole-body MR imaging of bone marrow.

In clinical routine, multimodality algorithms, including X-ray, computed tomography, scintigraphy and MRI, are used in case of suspected bone marrow malignancy. Skeletal scintigraphy is widely used to asses metastatic disease to the bone, CT is the technique of choice to assess criteria of osseous destruction and bone stability. MRI is the only imaging technique that allows direct visualization of bone marrow and its components with high spatial resolution. The combination of unenhanced T1-weighted-spin echo- and turbo-STIR-sequences have shown to be most useful for the detection of bone marrow abnormalities and are able to discriminate benign from malignant bone marrow changes. Originally, whole-body MRI bone marrow screening was performed in sequential scanning techniques of five body levels with time consuming coil rearrangement and repositioning of the patient. The introduction of a rolling platform mounted on top of a conventional MRI examination table facilitated whole-body MR imaging and, with the use of fast gradient echo, T1-weighted and STIR-imaging techniques, for the first time allowed whole-body imaging within less than one hour. With the development of parallel imaging techniques (PAT) in combination with global matrix coil concepts, acquisition time could be reduced substantially without compromises in spatial resolution, enabling the implementation of more complex and flexible examination protocols. Whole-body MRI represents a new alternative to the stepwise multimodality concept for the detection of metastatic disease, multiple myeloma and lymphoma of the bone with high diagnostic accuracy.

Techniques for diffusion-weighted imaging of bone marrow.

Diffusion-weighted magnetic resonance imaging (DWI) is an imaging technique which is sensitive to random water movements in spatial scales far below those typically accessible by magnetic resonance imaging (MRI). This property makes DWI a powerful tool for diagnosis of diseases which involve alterations in water mobility, such as acute stroke. In bone marrow, DWI has been proven to be a highly useful method for the differential diagnosis of benign and malignant compression fractures. Unfortunately, the application of DWI sequences to the bone marrow frequently suffers from artifacts, which in some cases seriously restrict the diagnostic utility of the image. This requires the introduction of additional correction techniques, or even the development of new sequences. Thus, the selection of an adequate imaging technique for DWI of the bone marrow is a very important issue. In this article the most important sequences for DWI of the bone marrow are reviewed. Special attention is paid to the problems associated with these sequences, as well as their possible solutions.

[Staging of multiple myeloma with MRI: comparison to MSCT and conventional radiography]. / Staging des multiplen Myeloms mit der MRT: Vergleich zur MSCT und zur konventionellen Röntgendiagnostik.

The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. "salt and pepper" pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse infiltration. Multidetector computed tomography and especially 16- and 64-detector row scanners allow fast imaging with thin slice collimation and multiplanar reconstructions. With low-dose protocols, effective dose reduction can be achieved, so that radiation exposure is only slightly higher than that of a whole-body skeletal x-ray exam. Sensitivity of MSCT is markedly superior to conventional radiography. Due to the direct visualization of the bone marrow with MRI, MRI is superior in detecting early infiltrations with myeloma cells without osteolyses. In advanced multiple myeloma, CT on the other hand, enables for more precise assessment of bony destructions and fracture risk.

[Comparison of high resolution whole-body MRI using parallel imaging and PET-CT. First experiences with a 32-channel MRI system]. / Hochauflösendes Ganzkörpertumorstaging unter Verwendung paralleler Bildgebung im Vergleich zur PET-CT. Erste Erfahrungen auf einem 32-Kanal-MRT-System.

PURPOSE: To compare the accuracy in the detection and staging of various malignant tumors with high resolution whole-body MRI using parallel imaging with whole-body dual-modality PET-CT. PATIENTS AND METHODS: Preliminary results of an interim analysis from a prospective, blinded study are presented, in which 20 patients (mean age 59 years, range 27-77 years) with different oncological diseases underwent whole-body dual modality FDG-PET-CT screening for tumor search or staging in case of confirmed or suspected metastatic disease. All patients also underwent whole-body MRI imaging with the use of parallel imaging (iPAT). High-resolution coronal T1w- and STIR-sequences of 5 body levels with 512 x 512 matrix, axial fast T2w imaging of lung and abdomen (HASTE), contrast-enhanced dynamic and static T1w-sequences of liver, brain, abdomen, and pelvis were performed. Using a 32-channel whole-body MRI scanner (Magnetom Avanto, Siemens Medical Solutions) with a total field of view of 205 cm and free table movement, all patients could be covered from head to toe within one examination. With this technique, high spatial resolution and acceptable scanning times could be obtained. Two experienced radiologists read the MRI-scans, one radiologist and one nuclear scientist read PET-CT scans, each in consensus in a clinical setting. Delineation of the primary tumor (T-stage) or recurrent tumor, pathologic lymph node involvement, as well as degree and localization of metastatic disease, was assessed using PET-CT as standard of reference. RESULTS: Metastases from gastrointestinal tumor (25%) and breast cancer (25%), genitourinary tumor (15%) and malignant melanoma (15%) were detected. In 4/20 patients the primary tumor was identified, 2/20 patients showed recurrent tumor. Of 140 malignant lesions detected by PET-CT, 124 lesions were detected with MRI, resulting in a sensitivity of 89% at a specificity of 86%. In malignant lymph node detection, sensitivity of MRI was 83% and specificity 85%. CONCLUSION: Whole-body MRI is a promising technique in the detection of primary tumor and metastatic disease. Sensitivity in the assessment of lymph node metastases seems to be limited. With the use of parallel imaging (iPAT), dedicated high-resolution whole-body MRI is possible within acceptable scanning times.