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The purpose of this article is to present algorithms for the diagnostic management of solitary bone lesions incidentally encountered on computed tomography (CT) and magnetic resonance (MRI) in adults. Based on review of the current literature and expert opinion, the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology (SSR) proposes a bone reporting and data system (Bone-RADS) for incidentally encountered solitary bone lesions on CT and MRI with four possible diagnostic management recommendations (Bone-RADS1, leave alone; Bone-RADS2, perform different imaging modality; Bone-RADS3, perform follow-up imaging; Bone-RADS4, biopsy and/or oncologic referral). Two algorithms for CT based on lesion density (lucent or sclerotic/mixed) and two for MRI allow the user to arrive at a specific Bone-RADS management recommendation. Representative cases are provided to illustrate the usability of the algorithms.

Glenohumeral osteoarthritis has proven to be a major contributor to shoulder joint pain and dysfunction in the elderly. There are several conditions about the shoulder that contribute to the development of glenohumeral osteoarthritis, which includes traumatic injuries, rotator cuff pathology, glenohumeral instability, glenoid dysplasia, and osteonecrosis. When glenohumeral osteoarthritis pain is refractory to conservative treatment, intra-articular injections and surgery can be performed. The radiologist should be aware of the varying types of shoulder arthroplasties, what preoperative findings influence that decision and the expected postoperative appearance of the differing components.

To determine the frequency of non-diagnostic and discordant results from bone and soft tissue biopsies performed at our institution over a 3-year period and to investigate whether implementation of a weekly musculoskeletal radiology-pathology correlation conference decreased the time to appropriate patient management in cases of discordance. Consecutive image-guided core needle biopsy results obtained over a 12 month period of time were reviewed in a retrospective fashion. Following implementation of the correlation conference, subsequent consecutive image-guided core needle biopsy results obtained over a 26 month period of time were reviewed in a prospective fashion. For non-diagnostic and discordant cases, the time in days from date of availability of the biopsy result to date of documentation of a specific follow-up action plan was recorded. Diagnostic yield was 96.5% and 94.9% for the retrospective and prospective periods, respectively. There were four discordant results in the retrospective cohort (1.7%) and seven discordant results in the prospective cohort (2.1%). Following implementation of the weekly correlation conference, there was significant decrease (p

To determine the frequency of non-diagnostic and discordant results from bone and soft tissue biopsies performed at our institution over a 3-year period and to investigate whether implementation of a weekly musculoskeletal radiology-pathology correlation conference decreased the time to appropriate patient management in cases of discordance.Consecutive image-guided core needle biopsy results obtained over a 12 month period of time were reviewed in a retrospective fashion. Following implementation of the correlation conference, subsequent consecutive image-guided core needle biopsy results obtained over a 26 month period of time were reviewed in a prospective fashion. For non-diagnostic and discordant cases, the time in days from date of availability of the biopsy result to date of documentation of a specific follow-up action plan was recorded.Diagnostic yield was 96.5% and 94.9% for the retrospective and prospective periods, respectively. There were four discordant results in the retrospective cohort (1.7%) and seven discordant results in the prospective cohort (2.1%). Following implementation of the weekly correlation conference, there was significant decrease (p 0.05) in median time from a discordant biopsy result to follow-up action plan. There were no unnecessary surgeries, litigation, or other unfavorable consequences in either cohort.Image-guided core needle biopsies of bone and soft tissue provide high diagnostic yield, often with specific diagnoses. The statistically significant decrease in number of days to follow-up action plan for discordant results suggests radiology-pathology review has a positive impact on patient care. Subjective benefits from communication and educational standpoints are also noteworthy.

The development for equations of state both for polyimide and its reaction products is presented along with hydrody- namic simulations linking the two EOS through an Arrhenius rate law. The equations of state compare favorably to available data, and the hydrodynamic simulations are able to qualitatively reproduce many of the features seen in both legacy shock data and more modern embedded gauge data. However, quantitative agreement is not achieved, suggesting that new rate laws are needed to fully capture the effect of the reaction over a wide range of conditions.

To describe the technique of iodine125 (I125) seed deployment into nonpalpable soft tissue masses under direct ultrasound (US) or CT guidance for intraoperative localization. Patients considered candidates for radioactive seed localization (RSL) based on advanced imaging findings underwent an ultrasound examination of the area of concern to verify sonographic visualization of the targeted mass. If the mass was not visible sonographically, CT was used for guidance. Patients were scheduled for surgery 1–4 days after seed implantation. Intraoperative frozen section pathological analysis was performed on all patients. Operative time, specimen volume, intraoperative margin status, and final margin status were recorded. Following the surgery, patients and surgeons completed satisfaction surveys. Ten patients underwent seed placement between 1 and 4 days prior to surgery. All patients had successful surgical resection of the targeted mass with removal of all implanted radioactive seed(s). There was no seed migration. Intraoperative frozen-section margins were negative (>2 mm) in 6/10 patients. Final surgical margins were negative in 9/10 patients. The patient with a positive margin at final pathology did not undergo further resection due to the benign nature of the mass. Patient and surgeon satisfaction survey results were highly positive. All four surgeons reported a strong preference for seed localization over wire localization. RSL is an effective, reliable, and safe technique for preoperative localization of nonpalpable soft tissue masses and yields high patient and surgeon satisfaction.

The photocatalytic hydrogen (H2) production activity of various CdSe semiconductor nanoparticles was compared including CdSe and CdSe/CdS quantum dots (QDs), CdSe quantum rods (QRs), and CdSe/CdS dot-in-rods (DIRs). With equivalent photons absorbed, the H2 generation activity orders as CdSe QDs ≫ CdSe QRs > CdSe/CdS QDs > CdSe/CdS DIRs, which is surprisingly the opposite of the electron–hole separation efficiency. Calculations of photoexcited surface charge densities are positively correlated with the H2 production rate and suggest the size of the nanoparticle plays a critical role in determining the relative efficiency of H2 production.

We report the synthesis and optical characterization of core/shell CdSe/CdS quantum dots (QDs) with controlled surface composition. Using secondary phosphine chalcogenide and cadmium carboxylate precursors in an alternating layer-by-layer synthetic approach, the elemental surface composition of the quasi-type-I CdSe/CdS core/shell QDs can be repeatedly tuned from predominately cadmium to predominantly sulfur, as measured by X-ray photoelectron spectroscopy (XPS). Similar to CdS and CdSe core-only QDs, the surface composition has a significant effect on the photoluminescence (PL) quantum yield: sulfur terminated QDs exhibit quenched PL, while cadmium terminated QDs have relatively bright PL. Density-functional tight-binding calculations on CdSe/CdS core/shell clusters suggest that PL quenching for sulfur-rich surfaces is the result of a high density of hole surface states in the QD bandgap. Time-resolved PL measurements confirm the QDs’ nonradiative recombination rates are strongly sensitive to the surface composition.

Purpose To compare goniometric and visual assessments of angular hand joint and wrist joint positions measured by board-certified hand surgeons and certified hand therapists. We hypothesized that visual estimation would be similar to the goniometric measurement accuracy of digital and wrist joint positions. Methods The wrist, index finger metacarpophalangeal (MCP) joint, and index finger proximal interphalangeal (PIP) joint were evaluated in different positions by 40 observers: 20 board-certified hand surgeons and 20 certified hand therapists. Each observer estimated the position of the wrist, index MCP joint, and index PIP joint of the same volunteer, who was positioned in low-profile orthoses to reproduce predetermined positions. Following visual estimation, the participants measured the same joint positions using a goniometer. The control measurement was digitally determined by a radiologist who obtained radiographs of the hand and wrist positions in each orthosis. Observers were blinded to the results of control measurements. Results When considering all joints at all positions, neither visual assessments nor goniometer assessments were consistently within ± 5° of the measurements obtained on control radiographs. When considering individual joints, goniometer measurements were significantly closer to control radiograph measurements than the visual assessments for all 3 PIP joint positions. There was no difference for the measurements at the wrist or for 2 of the 3 MCP joint positions. Significant differences between surgeon and therapist joint angle measurements were not observed when comparing visual and goniometer assessments to radiograph controls. Conclusions Compared with radiograph measurements, neither visual nor goniometer assessment displayed high levels of accuracy. On average, visual assessment of the angular positions of the index MCP and wrist joint were as accurate as the goniometer assessment, whereas goniometer assessment of the angular position of the PIP joint was more accurate than visual assessment. There was a relatively high degree of between-observer variability in measurements, and therefore, no one person's measurements could be consistently relied upon to be accurate. Type of study/level of evidence Diagnostic II.

CdSe quantum dots (QDs) and simple aqueous Ni(2+) salts in the presence of a sacrificial electron donor form a highly efficient, active, and robust system for photochemical reduction of protons to molecular hydrogen in water. Using ultrafast transient absorption (TA) spectroscopy, the electron transfer (ET) processes from the QDs to the Ni catalysts have been characterized. CdSe QDs transfer photoexcited electrons to a Ni-dihydrolipoic acid (Ni-DHLA) catalyst complex extremely fast and with high efficiency: the amplitude-weighted average ET lifetime is 69 ± 2 ps, and ∼90% of the ultrafast TA signal is assigned to ET processes. The impacts of Auger recombination, QD size and shelling on ET are also reported. These results help clarify the reasons for the exceptional photocatalytic H2 activity of the CdSe QD/Ni-DHLA system and suggest direction for further improvements of the system.

Single and multiple exciton relaxation dynamics of CdSe/CdZnS nanocrystal quantum dots (QDs) monitored at the two lowest optical transitions, 1Se-1S3/2 and 1Se-2S3/2, have been examined using ultrafast transient absorption (TA) spectroscopy. For the CdSe/CdZnS QDs studied, the 1Se-1S3/2 and 1Se-2S3/2 transitions are widely separated (∼180 meV) compared to bare CdSe QDs (∼50-100 meV), allowing for clearly distinguishable TA signals attributable to hot hole relaxation. Holes depopulate from the 2S3/2 state with a lifetime of 7 ± 2 ps, which is consistent with the predictions for hole relaxation via a phonon coupling pathway to lower-energy hole states, with possible contributions from hole trapping as well. These results suggest that tuning the surface chemistry of semiconductor QDs is a viable route to measure and possibly control their hot hole relaxation dynamics.

The impact of pulsed versus continuous wave (cw) laser excitation on the photophysical properties of single quantum dots (QDs) has been investigated in an experiment in which all macroscopic variables are identical except the nature of laser excitation. Pulsed excitation exaggerates the effects of photobleaching, results in a lower probability of long ON fluorescence blinking events, and leads to shorter fluorescence lifetimes with respect to cw excitation at the same wavelength and average intensity. Spectral wandering, biexciton quantum yields, and power law exponents that describe fluorescence blinking are largely insensitive to the nature of laser excitation. These results explicitly illustrate important similarities and differences in fluorescence dynamics between pulsed and cw excitation, enabling more meaningful comparisons between literature reports and aiding in the design of new experiments to mitigate possible influences of high photon flux on QDs.

This Perspective describes recent progress and current challenges toward achieving a detailed understanding of fluorescence blinking in colloidal semiconductor nanocrystals (NCs). Many current mode...

Received August 26, 2008; accepted after revision November 21, 2008. 1Department of Radiology, Mayo Clinic, 5777 E Mayo Blvd., Phoenix, AZ 85054. Address correspondence to C. C. Roberts (roberts.catherine@mayo.edu). 2Department of Radiology, Mayo Clinic, Rochester, MN. 3Department of Radiology, University of Central Florida, Orlando, FL. 4Department of Diagnostic Radiology, Mayo Clinic, Jacksonville, FL. AJR 2009;193:S42–S45 0361–803X/09/1933–S42 © American Roentgen Ray Society ABSTRACT The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging spectrum of bites, stings, and their complications.

Arthrography has evolved during the last century from crude techniques with postprocedural radiographic imaging to modern CT and MR arthrographic techniques. Arthrography saw its widest use in the 1960s and 1970s, but indications for its use in many joints decreased significantly after the introduction of cross-sectional imaging modalities such as CT and MR imaging. Arthrography continues to provide valuable anatomic information about the joints and provides accurate depiction of internal derangement.

Three methods of harvesting Hawaiian freshwater prawn ponds are described: 1) Traditional (also called “Fuji,” after Fujimura, or “hukilau,” Hawaiian for community net fishing)-A seine is maneuvered around the pond by workers in the water who drag the net lead line with their feet as they encircle the catch. The seine is then closed into a bag and the prawns are removed. 2) Modified seining-A seine which spans the width of the pond is pulled from both ends simultaneously by tractors. The seine is pulled from one end of the pond to the other, concentrating the catch in the bag or live car enclosure. 3) Drain harvesting-Water is drained from the pond by gravity or by pumping, the screen is removed from the catch basin and a fish pump is used to pump the prawns into a dewatering box. The prawns are then transferred to holding tanks for sorting. The efficiencies and cost effectiveness of all three methods are discussed with recommendations relative to farm size.

Soft-tissue sarcoma requires aggressive treatment, often with a combination of radiation therapy, chemotherapy, and surgical resection. Even after multimodality treatment, local recurrence is common, and regular follow-up imaging at short intervals is required. Interpretation of posttreatment magnetic resonance (MR) images may be complicated by changes in the surgical bed or treatment field. The challenge of distinguishing posttreatment change from recurrent tumor may be minimized by using an organized, systematic approach to imaging, with emphasis on the patient's clinical and surgical history and a review of pretreatment images. Common changes that result from radiation therapy include soft-tissue trabeculation, increased fatty marrow, and focal marrow abnormalities. Rarely, radiation-induced malignancies may develop within the treatment field. Chemotherapy also influences posttreatment imaging appearance. Occasionally, it causes a substantial increase in tumor size that is a result of chemotherapy-induced hemorrhage. Although myocutaneous flaps used in reconstructive surgery may mimic a mass, they demonstrate time-dependent changes in size, signal intensity, and enhancement on MR images. Recurrent tumor is characterized by the presence of a discrete nodule or mass with signal characteristics that typically mirror those of the original tumor. MR imaging sequences such as unenhanced T1-weighted fat-suppressed and gradient-echo sequences may help differentiate posttreatment hemorrhage from local tumor recurrence. A consistent imaging approach combined with a detailed knowledge of the patient's history, familiarity with pretreatment images, and an understanding of the various posttreatment changes enables optimal monitoring of the treatment bed and maximizes accuracy in the detection of recurrence.

Promising results reported with currently available total ankle arthroplasty designs have led to an increased use of such devices as an alternative to ankle arthrodesis. Despite recent improvements in implant design and surgical technique, complications associated total ankle arthroplasty devices continue to be reported. Postoperative evaluation of total ankle arthroplasties relies on a combination of clinical and radiologic assessment. Familiarity with commonly used current total ankle arthroplasty devices and appropriate postoperative imaging techniques is imperative for effective characterization of the expected postoperative imaging appearances of such devices and facilitating detection of potential postoperative complications.

Differential diagnosis of soft tissue lesions of the foot can be narrowed with imaging. The cystic nature of ganglia, synovial cysts, and bursitis can be confirmed with MR imaging or sonography. Location and signal characteristics of noncystic lesions can suggest Morton's neuroma, giant cell tumor of tendon sheath, and plantar fibromatosis. Synovial-based lesions of the foot and ankle can be differentiated based on presence or absence of mineralization, lesion density, signal intensity, and enhancement pattern. Knowledge of the incidence of specific neoplasms of the foot and ankle based on patient age aids in providing a limited differential diagnosis.

OBJECTIVE. The purpose of this article is to review the basic design features of second-generation total ankle arthroplasty components and to illustrate the normal and abnormal postoperative imaging features associated with such devices. The usefulness of CT in postoperative evaluation will be highlighted.CONCLUSION. Postoperative evaluation of the total ankle arthroplasty necessitates a familiarity with the various designs currently in use. Radiography serves as an integral component in the postoperative evaluation of such devices, with CT offering further characterization of radiographic abnormalities.

MR imaging can be quite useful in the evaluation of pathologic processes related to the diabetic foot. The diagnosis of soft tissue processes such as callus formation, ulceration, foreign body granuloma, cellulitis, abscess, and gangrene can be made with the assistance of MR imaging. Osseous deformities such as hammertoe, rocker-bottom foot, neuropathic osteoarthropathy, and osteomyelitis can be detected and defined with MR imaging. Finally, although there are some overlapping features of neuropathic osteoarthropathy and osteomyelitis, the differentiation between the two entities is possible in most instances with the aid of MR imaging.

Idiopathic retroperitoneal fibrosis is an uncommon disease characterized by periaortic inflammation with gradual fibrosis and distortion of retroperitoneal structures such as the ureter. Several earlier case reports have documented hypermetabolic retroperitoneal activity on fluorodeoxyglucose positron emission tomography (FDG PET) in patients with active disease, and a decrease in the activity following immunosuppressive therapy. We report FDG PET positive findings in three patients presenting with active retroperitoneal fibrosis. In two cases, enhancing periaortic soft tissue seen on computed tomography (CT) markedly diminished following immunosuppressive therapy. In one patient, repeat FDG PET was performed following immunosuppressive therapy, with complete resolution of the retroperitoneal FDG avidity. We suggest that FDG PET may play a useful adjunct to anatomic imaging and serum inflammatory markers in assessing the severity of inflammation in retroperitoneal fibrosis, and in assessing the likelihood of response to immunosuppressive therapy. FDG PET may also be used in follow-up to assess therapeutic response if CT findings are unclear.

Cystic lesions around the knee comprise a diverse group of entities, ranging from benign cysts to complications of underlying diseases such as infection, arthritis, and malignancy. Their diverse causes result in varied prognoses and therapeutic options. Although the presentation of cystic masses may be similar, their management may differ, thus highlighting the importance of appropriate categorization. MR aids in the characterization of lesions by first localizing them, and then defining their relationship with adjacent structures and identifying any additional abnormalities. For the purpose of this article, the authors limit the scope of their discussion to benign cysts, ganglia, and bursae about the knee.

The knee joint remains the articulation most frequently assessed by MR imaging, and osseous tumor and tumor-like lesions are not uncommon incidental imaging findings. This article reviews the most commonly encountered incidental lesions, emphasizing the characteristic MR imaging features. It is intended not as a complete review of the imaging findings associated with these lesions but as a summary, highlighting the MR imaging features that are most useful in suggesting a specific diagnosis. The authors organize incidental lesions into the following broad categories: cartilaginous, fibro-osseous, and degenerative. They do not address those lesions that are typically symptomatic and, as a result, likely to be directly related to the patients' clinical presentation and subsequent imaging.

Infectious disease complicating surgery involving the musculoskeletal system is one of the most important causes of postoperative morbidity and mortality. Timely detection and accurate localization of infectious processes have important clinical implications and are critical to appropriate patient management. Imaging studies can play an important role in the detection of infection and can help guide appropriate clinical management. The diagnosis of postoperative infection can be made by a variety of imaging modalities. This article reviews the various methods and modalities available for the detection of postoperative infection.

Bone graft materials quickly are becoming a vital tool in reconstructive orthopedic surgery and demonstrate considerable variability in their imaging appearance. Functions of bone graft materials include promoting osseous ingrowth and bone healing, providing a structural substrate for these processes, and serving as a vehicle for direct antibiotic delivery. The three primary types of bone graft materials are allografts, autografts, and synthetic bone graft substitutes.

Bone graft materials are widely used in reconstructive orthopedic procedures to promote new bone formation and bone healing, provide a substrate and scaffolding for development of bone structure, and function as a means for direct antibiotic delivery. Bone graft materials include autografts, allografts, and synthetic substitutes. An autograft (from the patient's own bone) supplies both bone volume and osteogenic cells capable of new bone formation. The imaging appearance of an autograft depends on its type, composition, and age. Autografts often appear as osseous fragments at radiography. At computed tomography (CT), autografts appear similar to the adjacent cortical bone. At magnetic resonance (MR) imaging, however, autografts have a variable appearance as a consequence of the viable marrow inside them, a feature not present in other graft materials. An allograft (from cadaveric bone) has an appearance similar to that of cortical bone on radiographs and CT images. An allograft in the form of bone chips or morsels does not show those features on radiographs and CT images, but instead appears as a conglomerate with medium to high opacity and attenuation within the bone defect. In the immediate postoperative period, allografts appear hypointense on both T1- and T2-weighted MR images. Hematopoietic tissue replaces the normal fatty marrow in the later phases of graft incorporation. Synthetic bone substitutes are much more variable in imaging appearance. As the use of bone allografts and synthetic substitutes increases, familiarity with postoperative imaging features is essential for differentiation between grafts and residual or recurrent disease.

We report the observation of fluorescence from single PbS quantum dots (QDs) using confocal microscopy in an inert atmosphere. Single PbS QDs exhibit a narrowing of the fluorescence line width (relative to the ensemble) and fluorescence intermittency ("blinking"), consistent with the properties of other single QDs. However, single-particle line widths averaged 100 meV, indicating a significant homogeneous component to the ensemble line width. In addition, the duration of an on/off blinking event has a probability density that decays according to an inverse power law, indicating a broad distribution of kinetic rates to multiple on/off states.

Tumors involving the upper extremity are not uncommon. Although there is a wide variety of lesions that may occur in the hand and wrist, there are certain lesions which have a predilection for this location. This chapter will highlight the spectrum of imaging modalities available for the evaluation of upper extremity tumors, providing imaging guidelines for optimum selection of radiological examinations. It presents an overview of imaging of the hand and wrist, emphasizing the fundamental principles inherent to tumor imaging. Modalities reviewed include nuclear scintigraphy, positron emission tomography, sonography, computed tomography, arteriography, magnetic resonance imaging, and magnetic resonance angiography.

In conclusion, a wide variety of tumors and tumor-like conditions have a predilection for the hip. The imaging evaluation of these lesions begins with radiographs. Radiographs can depict the extent of disease; any characteristic calcifications; and osseous changes, such as remodeling,periosteal reaction, or destruction. MR imaging has emerged as the preferred imaging modality of choice for evaluating osseous and soft tissue masses of the hip by providing information for diagnosis and staging. The MR imaging signal characteristics and enhancement patterns of malignant and benign hip tumors permit specific diagnoses in some cases. Synovial-based tumor-like processes of the hip can be characterized by MR signal characteristics, such as the hemosiderin within PVNS or the cartilage within synovial chondromatosis. Finally, MR imaging can serve to exclude underlying osseous or soft tissue tumors when radiographs display aggressive features of tumor-like processes.

A rare case of neuroendocrine tumor of the uterus is presented. Magnetic resonance imaging (MRI) demonstrated diffuse enlargement of the uterus without a discrete mass. The vessels in the myometrium were not distorted. Histologically, tumor cells diffusely infiltrated the myometrium as well

Tumors involving the upper extremity are common. Although there are a wide variety of lesions that may occur in the hand and wrist, certain lesions have a predilection for this location. This article highlights the spectrum of imaging modalities available for the evaluation of upper extremity tumors, providing guidelines for optimum selection of radiologic examinations while emphasizing the fundamental principles inherent to tumor imaging.

Strained silicon germanium carbon (Si1-x-yGexCy or SiGeC) on silicon was oxidized using a novel photooxidation process. The growth rate of the oxide was investigated and found to depend heavily on the germanium and carbon concentrations. MOS capacitors were fabricated with the resulting oxide and electrical characterization was done. The SiGeC MOS capacitors proved to have high leakage current through the gate oxide. The leakage current was found to be highly dependent on carbon concentration, and to a lesser degree, on germanium concentration, as well. Fixed oxide charge and interface state density were found to increase by a factor of ten over photo-oxidized silicon.

OBJECTIVE. We sought to describe the radiographic and imaging features of cherubism.CONCLUSION. Cherubism is a rare osseous disorder of children and adolescents. Although the radiologic characteristics of cherubism are not pathognomonic, the diagnosis is strongly suggested by bilateral relatively symmetric jaw involvement that is limited to the maxilla and mandible. Imaging typically shows expansile remodeling of the involved bones, thinning of the cortexes, and multilocular radiolucencies with a coarse trabecular pattern.

OBJECTIVE. The objective of this article is to define the imaging characteristics of spindle cell lipoma on MRI and CT.CONCLUSION. The diagnosis of spindle cell lipoma should be suggested when a well-defined complex fatty mass is found in the subcutis of a middle-aged man, especially if the mass is localized to the posterior neck. Intense enhancement of the nonadipose component further supports this diagnosis.

Liposarcoma is a relatively common soft tissue malignancy with a wide spectrum of clinical presentations and imaging appearances. Several subtypes are described, ranging from lesions nearly entirely composed of mature adipose tissue, to tumors with very sparse adipose elements. The imaging appearance of these fatty masses is frequently sufficiently characteristic to allow a specific diagnosis, while in other cases, although a specific diagnosis is not achievable, a meaningful limited differential diagnosis can be established. The purpose of this paper is to review the spectrum of malignant fatty tumors, highlighting the current classification system, clinical presentation and behavior, treatment and spectrum of imaging appearances. The imaging review will emphasize CT scanning and MR imaging, and will stress differentiating radiologic features.

To document current postgraduate musculoskeletal training program (accredited and unaccredited) curricula and approaches to education. Questionnaires were sent to all musculoskeletal training programs. Responses regarding radiology residency and fellowship program sizes, types of imaging and invasive procedures included, and other program parameters were solicited. Features of accredited and unaccredited programs were compared. Teaching approaches, including the use of web-based or distance learning were evaluated. Twenty-nine (73%) of 40 musculoskeletal programs responded to the questionnaire. Twenty-eight percent of programs were accredited and 72% unaccredited. Radiology residencies were also present at all responding institutions (the majority had a class size of 4–8/year). Residency programs in related specialties included pathology 96%, orthopedics and rheumatology 90%, oncology 83% and pain management 69%. The majority (93–100%) provided training in radiography, MRI and CT. Spine MRI was included in 69% of programs, ultrasonography in 62% and positron emission tomography in 24%. Arthrography and diagnostic and therapeutic injections (100%) were included in all programs. Other invasive procedures, including spine and radiofrequency ablation, were offered less frequently. Teaching approaches included conferences (100%), journal clubs (62%), multidisciplinary conferences (45–90%), web-based learning (30%) and distance learning (7%). Forty-one percent of programs offered off-site rotations. The majority of musculoskeletal training programs prepared trainees for private or academic practice. There are inconsistencies that could be improved to better prepare trainees for careers in musculoskeletal imaging.

OBJECTIVE. Our purpose was to identify the characteristic imaging features of cystic adventitial disease of the peripheral arteries.CONCLUSION. Patients with cystic adventitial disease of the peripheral arteries often present for evaluation of soft-tissue masses involving the extremities. Noninvasive imaging reveals a characteristic appearance allowing confident diagnosis.

The key to adequate and accurate evaluation, diagnosis, and treatment of bone tumors is an organized and integrated approach involving the surgeon, radiologist, and pathologist. The radiologist plays not only a valuable role in the diagnosis and preoperative staging of bone tumors but may also play a role in biopsy and treatment. Despite the wide variety of imaging modalities available today, radiographs remain the mainstay in the evaluation of osseous neoplasms. Advanced imaging is. however. very useful for staging purposes and for characterization of the internal characteristics of tumors and may aid significantly in limiting the differential diagnosis. Although a detailed discussion of all ofthe various bone tumors of the lower extremities is beyond the scope of this article, an attempt is made to provide a framework for a rational and comprehensive approach to these complicated but relatively uncommon lesions. Certain lesions with unique characteristics are discussed to facilitate the diagnostic process.

MRI is the preferred modality for the evaluation of a soft tissue mass following radiography. The radiologic appearance of certain soft tissue tumors or tumor-like processes may be sufficiently unique to allow a strong presumptive radiologic diagnosis. It must be emphasized that one cannot differentiate reliably between benign and malignant lesions on radiologic imaging alone. When a specific diagnosis is not possible, knowledge of tumor prevalence by location and age, with appropriate clinical history and radiologic features, can be used to establish a suitably ordered differential diagnosis. Musculoskeletal tumors of the lower extremity are not uncommon, and although there are a wide variety of lesions that may occur in the lower extremity, there are certain lesions that have a predilection for this location. This article highlights the imaging of the most common tumors of the lower extremity. It is not intended as a comprehensive review, but as an overview, emphasizing the use of MRI in the evaluation of these lesions and highlighting those diagnoses that may be suggested by MRI. It is difficult to determine the true prevalence of soft tissue tumors of the lower extremity. Such data are typically acquired from large referral populations, and consequently incorporate a significant referral bias. The situation is made more complex for the practicing radiologist in that referral studies are invariably based on surgical series. Such series include large numbers of superficial subcutaneous masses that are only infrequently imaged. With these caveats in mind the prevalence data from a large retrospective analysis of over 7000 lower-extremity soft tissue tumors seen in consultation by the Department of Soft Tissue Pathology, Armed Forces Institute of Pathology, is presented to determine the most commonly encountered soft tissue tumors of the lower extremity [1,2]. Because of the increased number of malignancies inherent in any referral population, benign and malignant lesions are considered separately, to reflect more accurately their relative prevalence. The foot and ankle are separated from the remainder of the lower extremity in that these lesions account for only one quarter of all lower-extremity lesions and show a somewhat different tumor population (Table 1).

The purpose of this study was to identify the characteristic imaging features of wooden foreign bodies.The imaging studies of 12 patients with surgically confirmed wooden foreign bodies were retrospectively reviewed. The study group consisted of seven females and five males, 10-65 years old (mean age, 36 years). All patients underwent radiography. Nine patients were evaluated with sonography, eight with MR imaging, three with CT, and one with CT arthrography. Gadolinium-enhanced MR imaging was performed in six patients. Three patients presented with a draining sinus and nine with painful swelling. Only three patients presented with a history of penetrating injury.Lesions were located in the foot (n = 4), hand (n = 3), thigh (n = 2), calf (n = 2), and elbow (n = 1). Radiographs failed to reveal the retained foreign bodies in all patients. With MR imaging, wooden foreign bodies displayed a variable signal intensity that was equal to or less than that of skeletal muscle on both T1- and T2-weighted images. MR imaging showed the surrounding inflammatory response in all patients. CT showed the retained wood as linear cylindric foci of increased attenuation. Wood was highly echogenic and revealed pronounced acoustic shadowing on sonography. Arthrography in one patient showed an associated reactive synovitis.The imaging appearance of wooden foreign bodies is variable; however, imaging can be quite specific, and when taken in the appropriate clinical setting, the imaging should reliably suggest the diagnosis. Sonography is frequently underused but proved most useful for the evaluation of retained wooden foreign bodies.

The photo- and cathodoluminescence properties of epitaxial lithium-doped zinc gallate thin-film phosphors grown on (100) MgO single crystal substrates using pulsed laser ablation were investigated. The addition of lithium to both undoped and Mn-doped ZnGa2O4 films significantly enhanced the photo- and low-voltage cathodoluminescent intensity. Cathodoluminescent efficiencies for as-deposited undoped and Mn-doped lithium zinc gallate films as high as 0.21 lm/W and 0.29 lm/W, respectively, were achieved for 1 kV and 2.26 μA/cm2. Based on these results, lithium-doped zinc gallate thin-film phosphors appear to be attractive for applications in low-voltage field emission display devices.

No accepted description of luminescent blinking in quantum dots is currently available. Now, experiments probing the connection between charge and fluorescence intensity fluctuations unveil an unexpected source of blinking, significantly advancing our fundamental understanding of this baffling phenomenon.