Imaging of the head and neck

Imaging is increasingly being used in the evaluation of patients presenting with a neck mass or with a ‘hot’ neck and has an established role in the staging of head and neck cancer. Plain radiographs have a very limited role and the workhorses of neck imaging are ultrasound, computed tomography (CT) and magnetic resonance imaging with an increased demand, more recently, for positron emission tomography-CT. Contrast studies, videofluoroscopy, angiography and nuclear medicine have a limited but important role in selected cases. This article will discuss the role of some of these imaging modalities in evaluating the soft tissues of the neck.     

原位肝移植术后并发症的影像学评价

目的：对评价原位肝移植(orthotopic liver transplantation，OLT)术后并发症的影像学检查方法进行评价。方法：对OLT术后并发症的影像学检查结果进行分析，并对各类并发症的相关影像学表现加以总结。结果：B超可用作OLT术后并发症的早期筛查；彩色多谱勒超声能早期发现血管性并发症；螺旋CT和MRI对术后血管性和(或)胆管性并发症、肝实质本身异常以及肝外转移性并发症有很高的诊断价值；对排斥反应．目前影像学检查还无特征性表现。结论：影像学检查(特别是超声、螺旋CT和MRD在OLT术后各类并发症的诊断中具有重要的作用。     

Update on functional imaging in the evaluation of diabetic foot infection

Diabetic foot infection is a preventable complication of diabetes mellitus. It is an essential component of diabetic foot disease, which is characterised by a triad of neuropathy, ischaemia and infection. These factors may lead to foot ulceration, sepsis and amputation resulting in increased morbidity and poor quality of life. Confirming or excluding infection can be difficult especially when routine laboratory tests and plain radiographs are inconclusive. Early diagnosis and localization of diabetic foot infection is extremely important to institute timely, appropriate therapy. Structural imaging using computed tomography and magnetic resonance imaging all have individual applications towards the diagnostic workup of this condition but have their own limitations. Scintigraphic detection is based on physiochemical changes and hence provides a functional evaluation of bone pathology.We describe the evolution of functional nuclear medicine imaging including immunoscintigraphy in diabetic foot infection and highlight current applications of physiological 18-Fluoro-deoxyglucose positron emission tomography (18-FDG-PET) and computed tomography (18-FDG-PET/CT) in such patients.18-FDG-PET/CT is a promising modality for imaging diabetic foot infection. Future studies will allow standardisation of technological details and options of 18-FDG-PET/CT interpretation in diabetic foot infection.     

Imaging of the distal radioulnar joint

The distal radioulnar joint can be evaluated by many different imaging techniques, including plain radiography, arthrography, tomography, nuclear medicine bone scanning, computed tomography, and magnetic resonance imaging. Each of these techniques has advantages and disadvantages that must be considered when determining the appropriate diagnostic evaluation for a particular patient.     

Cross-Sectional Imaging in Evaluation of Soft Tissue Reactions Secondary to Metal Debris

An integral component of systematic treatment algorithms to optimize evaluation and management of patients with MoM hip arthroplasty recommend the use of cross-sectional imaging to diagnose the presence of adverse local tissue reactions. Cross-sectional imaging studies such as ultrasound is a useful screening tool to detect the presence of a soft-tissue mass adjacent to a MoM implant. MARS MRI is a useful diagnostic test for assessing MoM hip arthroplasty and modular taper corrosion for adverse tissue reactions. Each cross-sectional imaging modality has unique utility and limitations. As metal artifact reduction technique continues to be refined, the utility of MARS MRI in evaluating patients with MoM hip arthroplasty and modular taper corrosion is likely to have an increased role in the clinical decision making process. However, over-reliance on any single investigative tool in the clinical decision-making process should be avoided.     

Imaging of the diabetic foot diagnostic dilemmas

Multiple diagnostic imaging modalities are available and beneficial for the evaluation of the diabetic foot. There is not yet "one best test" for sorting out the diagnostic dilemmas commonly encountered. The differentiation of cellulitis alone from underlying osteomyelitis and the early detection of abscesses remain important diagnostic goals. Equally important, differentiation of osteomyelitis and neuroarthropathy remains a difficult job. This is often compounded by postoperative diabetic foot states status after reconstruction. Diagnostic evaluation often involves multiple studies that are complementary and that include conventional radiography, computed tomography, nuclear medicine scintigraphy, magnetic resonance imaging, ultrasonography, and positron emission tomography.     

Imaging of the thyroid and parathyroid glands

Current multimodal imaging techniques offer practicing providers the adequate framework to plan and accomplish care for patients with thyroid and parathyroid disorders. Available imaging modalities include ultrasonography (US), nuclear scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI). US remains the most cost-effective and the safest approach for the initial evaluation of the thyroid gland. Parathyroid subtraction scintigraphy provides localization of pathologic parathyroid glands with the greatest sensitivity. Localizing imaging studies allow for surgical planning with minimal risk and morbidity to the patient. CT scan and MRI play an adjunctive role in the further characterization of neck pathology.     

Imaging of postoperative shoulder instability

Postoperative imaging in shoulder instability is still a challenge for radiologists due to various postsurgical anatomical findings that could be considered pathologic in treated shoulder. For this reason is very important a deep knowledge about surgical procedures, anatomical changes after surgery and the appropriate diagnostic imaging modalities to work up the symptomatic postoperative shoulder. Postoperative imaging options include use conventional radiography, magnetic resonance imaging (MRI), MRI arthrography, computed tomography (CT) and CT arthrography. The purpose of our review is to explain the different surgical procedures and to describe postoperative changes detected with radiological imaging.     

医学影像检查方法的选择在诊断椎管内肿瘤中的意义

目的：医学影像检查方法的选择及其结果的评价对早期诊断椎管内肿瘤十分重要。本文就医学影像检查在诊断椎管内肿瘤中的作用提出讨论,试图寻找一个较为合理的选择方案。方法：将７３例经手术治疗,病理证实的原发性椎管内肿瘤的临床资料、医学影像检查结果进行分析。结果：椎管造影,ＣＴＭ,ＭＲＩ确诊率高,Ｘ线平片和ＣＴ则较低。结论：Ｘ线平片作为一般性鉴别诊断是必要的,在神经系统定位体征不明显时首选椎管造影,否则选用ＭＲＩ,ＣＴ作为首选方法应慎重。结果的评价应结合临床,不应唯影像学为是。     

Medical imaging of the diabetic foot

Medical imaging of the diabetic foot entails a variety of imaging modalities. The diagnostic evaluation often includes a gamut of studies that include conventional radiography, CT, nuclear medicine scintigraphy, MRI, ultrasonography, and a newcomer, positron emission tomography combined with CT and leukocyte labeling. There is not yet "one best test" for sorting out the diagnostic dilemmas that are commonly encountered. Confirmation or exclusion of the frequent diagnosis of osteomyelitis often requires multiple studies, which are complementary to one another.     

Advanced Renal Mass Imaging: Diffusion and Perfusion MRI

Computed tomography (CT) is considered the imaging modality of choice in evaluation of renal lesions. The advantages of magnetic resonance imaging (MRI) compared to CT include superior soft tissue contrast, avoidance of ionizing radiation and iodinated contrast media, and the possibility of performing functional and advanced imaging techniques such as diffusion-weighted (DWI) and perfusion–weighted imaging (PWI). Although the traditional role of MRI in the evaluation of renal mass is primarily that of a problem-solving tool, DWI and PWI are expanding the role of MRI in management of renal cell cancers. DWI and PWI have shown considerable promise not only in renal lesion detection and characterization as benign or malignant, but also in assessment of renal cell cancer subtype and nuclear grade. Furthermore, these techniques have the potential to assist with tailoring patient- and disease-specific management by providing surgical planning in patients with localized renal cell cancer and assessing treatment response in patients with advanced renal cell cancer undergoing targeted chemotherapy.     

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??Imageology features and assessment of gallbladder carcinoma HUANG Sui-qiao. Department of Radiation, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou 510120, China
Abstract There are many imaging methods in detecting gallbladder carcinoma. Ultrasonography is the most common imaging method now, but the applications of CT and MRI are increased gradually and shown very important in diagnosing gallbladder carcinoma in clinical practice. 18F-FDG PET-CT has very high specificity and can be used in diagnosing difficult cases. It is not difficult for diagnosing typical gallbladder carcinoma, but it is not easy to diagnose early stage of gallbladder carcinoma. The applications of CDFI, contrast-enhanced ultrasound, dynamic CT and MRI scanning, DWIBS technique and 18F-FDG PET-CT will hopefully increase correct diagnosing level for early stage of gallbladder carcinoma. CT and MRI are better in demonstrating invasion of near structures and lymph node involvement due to gallbladder carcinoma. But lymph node involvement can easily get missed diagnosis just based on the size of lymph node. The shortages would be improved by 18F-FDG PET-CT and DWIBS technique.     

Contemporary Imaging of the Renal Mass

Renal masses increasingly are detected incidentally in asymptomatic individuals. Accurate characterization of these lesions is important for clinical management, planning intervention, and avoiding unnecessary procedures. Ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) are the mainstays of renal mass detection and characterization. Ultrasonography is useful for distinguishing cystic from solid lesions and can detect lesion vascularity, especially with use of ultrasound contrast agents, but is less sensitive, less specific, and less reproducible than CT and MRI. CT, with and without intravenous contrast, is the primary imaging test for characterization and staging of renal lesions, and is utilized more often than MRI. Current multidetector CT technology provides near isotropic acquisition, with three-dimensional reformatting capabilities. Due to lack of exposure to iodinated contrast and ionizing radiation and superior soft tissue contrast, MRI is being increasingly utilized as a problem-solving tool for diagnosis, staging, and preoperative planning for renal malignancies. Future directions for imaging of primary renal neoplasm include accurate characterization of renal cell cancer subtype, assistance with treatment planning, and evaluation of treatment response.     

Intraoperative imaging using a mobile computed tomography scanner.

OBJECTIVE: The radicality of tumour removal in patients suffering from glioma is discussed to be an important factor for longer survival times. Therefore intraoperative imaging modalities like magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) are tested in many neurosurgical facilities for clinical use. In our department a mobile CT for intraoperative applications is used for this purpose since 1999. The handling and useful application of the mobile CT scanner as well as results without intraoperative imaging are discussed. MATERIAL AND METHODS: 470 CT scans with the mobile CT were accomplished, including 270 cases of neuronavigation planning, 76 cases of intraoperative scans, 48 cases of postoperative scans, 69 CT scans for stereotactic biopsy planning and control as well as 3 cases of emergency scanning in trauma patients and 4 spine applications. The results of the intraoperative CT scans are compared with those of the postoperative MRI scans. Additionally 87 patients with glioma were evaluated. These patients underwent surgery without intraoperative imaging. RESULTS: In 27 out of 43 patients with glioma residual tumour was detected with intraoperative CT. In 13 cases the surgery was resumed to complete resection, in 14 cases the operation was not continued due to close vicinity to eloquent areas or difficulties in image interpretation. In 44 cases the results of intraoperative CT and postoperative MRI were compared. In 6 cases the MRI demonstrated residual tumour in contrast to the results of the CT scans. In 3 cases the tumour removal could have been more complete (6.8 %). In 87 cases glioma surgery was performed without intraoperative CT. In 6 cases a more complete tumour removal could have been performed (6.9 %) according to the results of postoperative MRI. CONCLUSION: Intraoperative imaging with a mobile CT scanner is a good method for detection of residual tumour. The CT scanner can be integrated in an operative setting without problems. Although intraoperative imaging can be helpful in some selected cases, most of the neurosurgical procedures can be well performed with proper neuronavigation planning.     

Imaging molecular and cellular events in transplantation

Imaging methods such as nuclear medicine (including positron emission tomography), magnetic resonance imaging, ultrasound, and optical imaging can be used to provide information about the expression of genes, and the location of molecules and cells in intact animals or patients. In the setting of transplantation, this will allow monitoring of inflammatory responses, as well as the state of the graft. In this review, the advantages and disadvantages of different approaches to imaging will be discussed, as well as their potential application to transplantation.     

Imaging Prostate Cancer: An Update on Positron Emission Tomography and Magnetic Resonance Imaging

Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an essential role in the clinical management of patients. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI allows functional assessment with techniques such as diffusion-weighted MRI, MR spectroscopy, and dynamic contrast-enhanced MRI. The most common PET radiotracer, ¹⁸F-fluorodeoxyglucose, is not very useful in prostate cancer. However, in recent years other PET tracers have improved the accuracy of PET/CT imaging of prostate cancer. Among these, choline (labeled with ¹⁸F or ¹¹C), ¹¹C-acetate, and ¹⁸F-fluoride have demonstrated promising results, and other new radiopharmaceuticals are currently under evaluation in preclinical and clinical studies.     

Preoperative Imaging of Colorectal Liver Metastases After Neoadjuvant Chemotherapy: A Meta-Analysis

Background

Chemotherapy treatment induces parenchymal changes that potentially affect imaging of CRLM. The purpose of this meta-analysis was to provide values of diagnostic performance of magnetic resonance imaging (MRI), computed tomography (CT), fluorodeoxyglucose positron emission tomography (FDG-PET), and FDG-PET/CT for preoperative detection of colorectal liver metastases (CRLM) in patients treated with neoadjuvant chemotherapy.

Methods

A comprehensive search was performed for original articles published from inception to 2011 assessing diagnostic performance of MRI, CT, FDG-PET, or FDG-PET/CT for preoperative evaluation of CRLM following chemotherapy. Intraoperative findings and/or histology were used as reference standard. For each imaging modality we calculated pooled sensitivities for patients who received neoadjuvant chemotherapy as well as for chemonaive patients, defined as number of malignant lesions detected divided by number of malignant lesions as confirmed by the reference standard.

Results

A total of 11 papers, comprising 223 patients with 906 lesions, were included. Substantial variation in study design, patient characteristics, imaging features, and reference tests was observed. Pooled sensitivity estimates of MRI, CT, FDG-PET, and FDG-PET/CT were 85.7% (69.7?C94.0%), 69.9% (65.6?C73.9%), 54.5% (46.7?C62.1%), and 51.7% (37.8?C65.4%), respectively. In chemonaive patients, sensitivity rates were 80.5% (67.0?C89.4%) for CT, 81.3% (64.1?C91.4%) for FDG-PET, and 71.0% (64.3?C76.9%) for FDG-PET/CT. Specificity could not be calculated because of non-reporting of ??true negative lesions.??

Conclusion

In the neoadjuvant setting, MRI appears to be the most appropriate imaging modality for preoperative assessment of patients with CRLM. CT is the second-best diagnostic modality and should be used in the absence of MRI. Diagnostic accuracy of FDG-PET and PET-CT is strongly affected by chemotherapy.     

Imaging techniques for the patient with renal cell carcinoma

The imaging of renal cell carcinoma continues to evolve from radiographic tomography to state-of-the-art three-dimensional imagery using computed tomography (CT) or magnetic resonance imaging (MRI). This article reviews the current techniques of imaging the patient with renal cell carcinoma. Careful and accurate imaging of these patients allows for the appropriate diagnosis, treatment planning, and follow-up care. At each point in the care of these patients, imaging plays an important role. In particular, the diagnosis and staging of renal cell carcinoma can be accomplished with CT and MRI, with each modality having strengths and weaknesses that are contrasted. Intraoperative ultrasound is used during laparoscopic or conventional partial nephrectomies, whereas ultrasound, CT, and MRI can be used for guiding ablative technologies. Imaging also plays an important role in the follow-up care of these patients. The particular follow-up care is dependent on the stage and grade of the lesion and the treatment modality used. In summary, this article reviews the current imaging approaches for the diagnosis, staging, treatment, and follow-up care of patients with renal cell carcinoma.     

Advanced Imaging Technology in Surgical Innovation

ABSTRACT

Advanced imaging technologies including computed tomography (CT) and magnetic resonance imaging (MRI) have immensely expanded possibilities in imaging and surgery. The accurate visualization of bones and soft tissue has transformed the surgical management of numerous diseases, including middle ear disease, orthopedic and reconstructive cases, and cancer. In fact, in surgical subspecialties such as neurosurgery, CT and MRI are the diagnostic modalities of choice for preoperative evaluation of patients. Furthermore, the ongoing development of the newer imaging technologies continues to expand image-guided surgical treatments. The development of new radiological modalities combined with the modern training of surgeons will provide an exciting landscape for future practicing physicians.