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Image-guided needle biopsies are commonly used to diagnose musculoskeletal tumors, but nondiagnostic (ND) results can delay diagnosis and treatment. It is important to understand which factors or diagnoses predispose to a ND result so that appropriate patient education or a possible change in the clinical plan can be made. Currently it is unclear which factors or specific lesions are more likely to lead to a ND result after image-guided needle biopsy.We therefore identified specific factors and diagnoses most likely to yield ND results. We also asked whether an image-guided needle biopsy of bone and soft tissue lesions is an accurate and clinically useful tool.We retrospectively reviewed data from a prospectively collected database for a case-control study of 508 image-guided needle biopsies of patients with suspected musculoskeletal tumors between 2003 and 2008.The interpretations of 453 of the 508 (89%) needle biopsies were accurate and clinically useful. Forty-five biopsies (9%) were ND and 10 (2%) were incorrect (IC). Bone lesions had a higher ND rate than soft tissue lesions (13% vs. 4%). The specific diagnosis with the highest ND rate was histiocytosis. Elbow and forearm locations had higher ND rates than average. Malignant tumors had a higher IC rate than benign tumors (5% vs. 0%); fibromyxoid sarcoma and rare subtypes of osteosarcoma had higher IC rates than other diagnoses. Repeat needle or open biopsies were performed in 71 (14%) patients. Bone lesions were more likely than soft tissue lesions to require repeat biopsies (18% vs. 9%).A high rate of accuracy and clinical usefulness is possible with image-guided needle biopsies of musculoskeletal lesions. We believe these biopsies appropriate in selected circumstances but a key factor for appropriate use is an experienced musculoskeletal tumor team with frequent communication to correlate clinical, radiographic, and histologic information for each patient.

OBJECTIVE. Conventional CT of the postoperative patient with metal hardware is frequently limited by beam-hardening artifacts. With the evolution of 3D CT, CT is an increasingly effective means of examining the postsurgical patient for the integrity of their hardware and the course of their healing.CONCLUSION. Potential postsurgical complications such as nonunion, osteolysis, infection, and heterotopic ossification are all well assessed by 3D CT.

OBJECTIVE. Musculoskeletal functional imaging should encompass the real-time (dynamic) depiction of joints in motion (kinematic). Our goal was to determine the technical feasibility of performing dynamic–kinematic imaging of the knee and wrist joints using a new technique, 256-MDCT.CONCLUSION. Dynamic–kinematic imaging of the wrist and knee using 256-MDCT is feasible to depict anatomic and functional information, warranting further study of diagnostic efficacy, and could augment the current repertoire of joint dysfunction diagnostic testing.

Intramedullary or intraosseous osteosarcomas are the most common subtype of osteosarcoma, followed in frequency by parosteal and periosteal osteosarcomas, with intracortical osteosarcomas representing the rarest type. The diagnosis and classification of osteosarcomas can be complicated or delayed when these lesions masquerade as benign bone lesions. This article presents a case of a low-grade osteosarcoma arising in the tibia of a 19-year-old man, which had radiographic features most suggestive of a benign entity.

OBJECTIVES: To determine the prevalence of atraumatic lateral collateral ligament complex (LCLC) abnormalities by magnetic resonance imaging (MRI) in patients with osteoarthrosis (OA) of the knee. METHODS: Magnetic resonance imaging scans in 96 subjects (25 with OA and 71 without OA) were retrospectively reviewed for the presence and severity of LCLC signal abnormalities. Abnormalities in the MRI scans of subjects with OA were compared with those of subjects without OA using chi2 test and the Mantel-Haenszel test for trend. RESULTS: Lateral compartment OA (23 of 25) was associated with abnormalities of the LCLC in 96% (22 of 23 subjects had fibular collateral ligament abnormalities, P < 0.0001). Medial compartment OA (25 of 25) was associated with abnormalities of the LCLC in 88% (22 of 25 subjects had fibular collateral ligament abnormalities, P < 0.0001). There was a positive trend for severity of MRI abnormalities with severity of OA (P < 0.0001 to P = 0.04). CONCLUSIONS: Lateral collateral ligament complex MRI signal abnormalities are common in patients with OA, in the absence of trauma.

Intramedullary or intraosseous osteosarcomas are the most common subtype of osteosarcoma, followed in frequency by parosteal and periosteal osteosarcomas, with intracortical osteosarcomas representing the rarest type. The diagnosis and classification of osteosarcomas can be complicated or delayed when these lesions masquerade as benign bone lesions. This article presents a case of a low-grade osteosarcoma arising in the tibia of a 19-year-old man, which had radiographic features most suggestive of a benign entity.

There is a diversity of modalities available for the imaging of soft tissue and skeletal sarcomas. However, conventional radiography remains the first line imaging modality in the diagnostic work-up, as it provides superior spatial resolution for the evaluation of bone trabecular detail. This article focuses on the advanced imaging modalities of computer tomography, magnetic resonance imaging, and positron emission tomography in the evaluation of sarcomas.

This case report details the diagnosis and treatment of a previously unreported complication of a congenital chest wall anomaly. Our patient presented with a painful anterior sternoclavicular joint subluxation secondary to a bicipital rib. Thoracic magnetic resonance and computed tomographic imaging provided the diagnosis. Complete resolution of symptoms was achieved after resection of the bicipital rib.

Although conventional magnetic resonance (MR) imaging with T1, T2, and gadolinium enhancement is the primary modality used for characterizing musculoskeletal lesions, its specificity for distinguishing malignancy from nonmalignant tissue remains low. Proton MR spectroscopy (MRS) is a new approach to the evaluation of musculoskeletal lesions that offers a method of metabolic imaging with MR. With proton MRS, a footprint of metabolite concentration in a region of interest can be obtained and markers for malignancy can be detected, such as elevated concentrations of the metabolite choline. Proton MRS is one of the most promising noninvasive techniques available for molecular identification of malignant tumor markers. However, the role of MRS in the assessment of musculoskeletal tumors remains in its infancy. In this article, we discuss the technical aspects of performing proton MRS, including differences between single voxel and multivoxel technique and its advantages and limitations. We demonstrate its potential utility in the evaluation of musculoskeletal lesions through a series of examples.

Publisher Summary Magnetic resonance cholangiopancreatography (MRCP) plays an important role in the diagnosis of abnormalities of the pancreatic and biliary tract. This chapter discusses the basic principles, techniques, and pitfalls encountered in performing and reading MRCP. MRCP is a relatively recent advance in pancreaticobiliary tract imaging, and now it is also used in oncologic imaging. MRCP supplants endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) in the initial diagnostic evaluation and follow-up of diseases of the pancreas, gallbladder, and biliary tract. This is largely due to its noninvasive nature. MRCP does not utilize ionizing X-ray radiation like ERCP or PTC and does not require the same degree of operator skill or patient preparation. It has become the technique of choice in patients with factors contributing to a high failure rate for ERCP. MRCP is especially excellent at depicting ductal anatomy beyond an obstructing lesion, which is impossible to demonstrate by ERCP. MRCP takes advantage of the inherent T2-weighted contrast that exists between intra-abdominal slow-flow fluid-containing structures and the background organs and soft tissues. Current techniques usually include use of ultrafast breath-hold pulse sequences such as single-shot fast spin-echo and half-Fourier acquisition short TE. When combined with the use of intravenous gadolinium-chelate contrast agents, MRCP serves as a comprehensive modality for the detection and evaluation of malignancy. MRCP is also very helpful as a guidance modality prior to tissue sampling via ERCP, endoscopic ultrasonography (EUS), or percutaneous CT or ultrasound-guided biopsy.

Although the primary imaging modality for the evaluation of inflammatory arthritis of the foot and ankle is currently magnetic resonance imaging, computed tomography may be performed in some patients and can aid in diagnosis. This article reviews a number of inflammatory arthritic conditions that involve the feet. Computed tomographic findings and the role of computed tomography in diagnosing infection, gout, and rheumatoid arthritis of the foot are discussed.

Musculoskeletal infection is commonly encountered in the emergency department and can take many forms, depending on the involvement of the various soft-tissue layers, bones, and joints. Infection may manifest as superficial cellulitis, necrotizing or nonnecrotizing fasciitis, myositis, a soft-tissue abscess, osteomyelitis, or septic arthritis. Because clinical parameters for the detection of musculoskeletal infection generally lack sensitivity and specificity, computed tomography (CT) plays an important role in the assessment of potential musculoskeletal infections in the emergency department. CT provides an analysis of compartmental anatomy, thereby helping to distinguish among the various types of musculoskeletal infection and to guide treatment options. Specific imaging features exist that help identify the numerous forms of infection in the bones and soft tissues, and CT is invaluable for detecting deep complications of cellulitis and pinpointing the anatomic compartment that is involved by an infection. Although all patients with musculoskeletal infection will require treatment with antibiotics, CT helps guide therapy toward emergency surgical debridement in cases of necrotizing fasciitis and toward percutaneous drainage in cases of abscess formation.

After publishing the paper, ‘A nomogram to estimate the proportion of patients at hemoglobin A1c target\7 % with noninsulin antidiabetic drugs in type 2 diabetes: a systematic review of 137 randomized controlled trials with 39,845 patients’ by Esposito et al. [1], it was brought to our journal’s attention that the article contained some redundancies with an earlier article published in Diabetes, Obesity and Metabolism entitled, ‘Proportion of patients at HbA1c target\7 % with eight classes of antidiabetic drugs in type 2 diabetes: systematic review of 218 randomized controlled trials with 78,945 patients’ by Esposito et al. [2]. The later article, by Esposito et al. [1], neither mentioned nor referenced the earlier published work. References

The reverse shoulder prosthesis is a prosthesis that has been in clinical use in Europe since 1985 and was approved for use in the United States in 2004. This unique prosthesis has a baseplate attached to the glenoid, which holds a spherical component, while the humeral component includes a polyethylene insert that is flat. This design is the "reverse" configuration of that seen with a conventional arthroplasty, in which the spherical component is part of the humeral component. The indications for the reverse prosthesis are: (1) painful arthritis associated with irreparable rotator cuff tears (cuff tear arthropathy), (2) failed hemiarthroplasty with irreparable rotator cuff tears, (3) pseudoparalysis due to massive, irreparable rotator cuff tears, (4) some reconstructions after tumor resection, and (5) some fractures of the shoulder not repairable or reconstructable with other techniques. This prosthesis can produce a significant reduction in pain and some improvement in function for most of the indications mentioned. However, the unique configuration and the challenge of its insertion can result in a high incidence of a wide variety of unusual complications. Some of these complications, such as dislocation of the components, are similar to conventional shoulder replacement. Other complications, such as notching of the scapula and acromial stress fractures, are unique to this prosthesis.The configuration of the reverse prosthesis, its normal radiographic appearance and potential complications associated with its use are reviewed.

Purpose To determine the value of multivoxel proton magnetic resonance spectroscopic imaging (MRSI) in distinguishing malignant skeletal tumors from benign tumors and normal bone marrow using the metabolite choline (Cho) as a marker for malignancy. Materials and Methods Pathologic specimens obtained from 13 patients who had undergone wide resection for skeletal tumors underwent evaluation by MRSI at 1.5 T. Coronal T1-weighted gradient-echo sequence obtained for localization purposes (TR/TE = 250/1.8 msec, field of view [FOV] = 18 × 18), and single-slice MRSI (TR/TE = 2000/272 msec, FOV = 18 × 18, 10-mm slice-thickness) were performed. Water, lipid, and Cho images were reconstructed from MRSI data. Cho signal was measured in each specimen and expressed relative to background noise level (signal-to-noise ratio [SNR]) where noise was measured between 7.0 and 9.0 ppm. Cho SNRs were compared between areas containing malignant tumor and nonmalignant tissue (benign lesion or normal bone marrow) as determined by histopathology. Results Specimens included 13 skeletal sarcomas (seven osteosarcomas, three chondrosarcomas, one malignant fibrous histiocytoma, one fibrosarcoma, and one leiomyosarcoma). All specimens included a sample of normal bone marrow and two specimens also contained benign lesions. All sarcomas demonstrated a signal at 3.2 ppm assigned to Cho-containing metabolites in areas of malignancy. Peak Cho SNR was significantly different for areas containing histologically-proven malignancy compared to nonmalignant tissue (9.8 ± 5.1 vs. 2.7 ± 1.4, respectively, P < 0.002). Conclusion These preliminary results indicate that MRSI at 1.5 T is a promising noninvasive method of differentiating malignant skeletal tumors from nonmalignant tissue. Using MRSI, Cho can be detected in skeletal tumors and may serve as a marker for malignancy. J. Magn. Reson. Imaging 2006. © 2005 Wiley-Liss, Inc.

The radiograph is indispensable for characterizing pediatric skeletal lesions. However, cross-sectional imaging with CT and MRI can provide additional information and augment or confirm an impression obtained from the initial radiographic findings. This review will highlight the role of CT and MRI in characterizing pediatric skeletal tumors and tumor-like conditions. Focus will be given to the contributions of each modality to the process of characterizing skeletal lesions, recalling that cross-sectional imaging is more commonly obtained for the purpose of determining extent of disease rather than for characterization.

The objectives of our study were to define CT and MRI features that distinguish pathologic fractures from stress fractures and to compare the performance of CT and MRI with radiography.Two reviewers retrospectively reviewed 45 MR images, 37 CT scans, and 43 radiographs in 59 patients (30 biopsy-proven pathologic fractures and 29 stress fractures followed to resolution). The features observed on MRI were abnormal bone marrow (well-defined, ill-defined); intracortical, periosteal, or muscle T1 or T2 signal; endosteal scalloping; and a soft-tissue mass. The features seen on CT were marrow abnormality and character (well-defined, ill-defined, permeative, moth-eaten), endosteal scalloping, periosteal reaction (benign, aggressive), and a soft-tissue mass. Reviewers rated their confidence for diagnosing a pathologic fracture on a 1-3 scale (50%, 50-95%,95% sure, respectively) with each technique. Performance of each technique was defined by reviewer accuracy and area under the receiver operating characteristic curve (Az); the frequency with which the MRI and CT features were associated with pathologic and stress fractures was calculated.For both reviewers, accuracy for differentiating pathologic from stress fractures was highest on MRI (accuracy/Az: reviewer 1, 98%/0.97; reviewer 2, 93%/0.99); CT (reviewer 1, 88%/0.83; reviewer 2, 82%/0.90) was less accurate than radiography (reviewer 1, 94%/0.98; reviewer 2, 88%/0.96). On MRI, pathologic fractures compared with stress fractures exhibited well-defined T1 marrow signal (83% vs 7%, respectively; p0.001), endosteal scalloping (58% vs 0%, p0.001), muscle signal (83% vs 48%, p = 0.026), and a soft-tissue mass (67% vs 0%, p0.001). On CT, pathologic fractures compared with stress fractures exhibited marrow abnormality (84% vs 17%, respectively; p = 0.001), endosteal scalloping (44% vs 0%, p = 0.006), and aggressive periosteal reaction (36% vs 0%, p = 0.04).MRI is useful for distinguishing pathologic from stress fractures, especially after inconclusive radiographic findings. Specifically, pathologic fractures exhibit well-defined T1 marrow alterations, endosteal scalloping, and adjacent soft-tissue abnormalities.

An image overlay system is presented to assist needle placement in conventional CT scanners. The device consists of a flat LCD display and a half mirror and is mounted on the gantry. Looking at the patient through the mirror, the CT image appears to be floating inside the patient with correct size and position, thereby providing the physician with two-dimensional “X-ray vision” to guide needle placement procedures. The physician inserts the needle following the optimal path identified in the CT image that is rendered on the LCD and thereby reflected in the mirror. The system promises to increase needle placement accuracy and also to reduce X-ray dose, patient discomfort, and procedure time by eliminating faulty insertion attempts. We report cadaver experiments in several clinical applications with a clinically applicable device.

OBJECTIVE. Positron emission tomography (PET) with FDG is useful for tumor imaging, but false-positive results can occur. The purpose of this study is to describe three oncology patients with sacral fractures in whom FDG uptake in the sacrum increased on PET.CONCLUSION. Sacral fractures can show increased uptake of FDG on PET. Therefore, correlative cross-sectional imaging is necessary to avoid the erroneous diagnosis of sacral metastases on PET and prevent inappropriate treatment of patients.

Purpose To determine the diagnostic performance of functional magnetic resonance cholangiography (fMRC) for the evaluation of anatomic and functional biliary disorders. Materials and Methods At 1.5 T, 39 MR examinations with conventional MRC and mangafodipir trisodium-enhanced fMRC were retrospectively reviewed by three observers who recorded anatomic (duct dilation, stricture, filling defects) and functional (cholecystitis, obstruction) abnormalities in three modes: MRC alone, fMRC alone, and MRC and fMRC images together (combined-MRC). Performance was determined by comparing findings with each mode to findings of invasive cholangiography (IC) and surgery. Results Among 75 biliary segments (correlated with IC), the sensitivity/specificity for diagnosing dilation (N = 41) with MRC was 95%/97%; with fMRC, 90%/100%; with combined-MRC, 100%/97%. For stricture (N = 7), the sensitivity/specificity of MRC was 86%/98%; of fMRC, 43%/100%; of combined-MRC, 86%/100%. For filling defects (N = 9), the sensitivity/specificity of MRC was 91%/98%; of fMRC, 82%/100%; of combined-MRC, 91%/100%. For diagnosing obstruction (N = 9), the sensitivity/specificity of MRC, fMRC, and combined-MRC were 89%/100%, 100%/100%, and 100%/100%, respectively. For surgically proven cholecystitis (N = 13), positive predictive values for diagnosing acute/chronic cholecystitis for MRC were 33%/40%; for fMRC, 100%/50%; for combined-MRC, 100%/50%. Conclusion Although single-shot fast spin echo (SSFSE)-MRC is valuable, the addition of fMRC increased diagnostic performance for functional biliary disorders. J. Magn. Reson. Imaging 2003;18:449–460. © 2003 Wiley-Liss, Inc.

Multiscale adaptive histogram equalization (MAHE), a wavelet-based algorithm, was investigated as a method of automatic simultaneous display of the full dynamic contrast range of a computed tomographic image. Interpretation times were significantly lower for MAHE-enhanced images compared with those for conventionally displayed images. Diagnostic accuracy, however, was insufficient in this pilot study to allow recommendation of MAHE as a replacement for conventional window display.

An approach for contrast enhancement utilizing multi-scale analysis is introduced. Sub-band coefficients were modified by the method of adaptive histogram equalization. To achieve optimal contrast enhancement, the sizes of sub-regions were chosen with consideration to the support of the analysis filters. The enhanced images provided subtle details of tissues that are only visible with tedious contrast/brightness windowing methods currently used in clinical reading. We present results on chest CT data, which shows significant improvement over existing state-of-the-art methods: unsharp masking, adaptive histogram equalization (AHE), and the contrast limited adaptive histogram equalization (CLAHE). A systematic study on 109 clinical chest CT images by three radiologists suggests the promise of this method in terms of both interpretation time and diagnostic performance on different pathological cases. In addition, radiologists observed no noticeable artifacts or amplification of noise that usually appears in traditional adaptive histogram equalization and its variations.

Vascular malformations can be classified into high-flow arteriovenous malformations (AVM) and low-flow venous or lymphatic malformations (VM/LM). VMs and LMs have the ability to cross multiple tissue boundaries. Not only is subcutaneous tissue often involved, but multiple muscle groups, tendons, bone cortex and bone marrow are also not uncommonly violated. Magnetic resonance imaging (MRI) provides valuable information for the assessment and treatment of malformations. Firstly, MRI can characterize the flow pattern of these malformations to guide treatment towards trans-arterial embolization for AVMs and percutaneous embolization for low flow malformations. MRI is essential to define the anatomic extent and in-volvement of various tissue layers (a distinct advantage over ultrasound), and to correlate treatable components of the malformation with patient symptoms. Treatment is decided by the need to alleviate clinical symptoms, and is dependent on the extent of the malformation as defined by MRI. We present MRI features of vascular malformations to demonstrate the potential spectrum of in-volvement of these lesions, illustrating the value of MRI in treatment planning.