Radiology of the Mesentery.

The recent description and re-classification of the mesentery as an organ prompted renewed interest in its role in physiological and pathological processes. With an improved understanding of its anatomy, accurately and reliably assessing the mesentery with non-invasive radiological investigation becomes more feasible. Multi-detector computed tomography is the main radiological modality employed to assess the mesentery due to its speed, widespread availability, and diagnostic accuracy. Pathologies affecting the mesentery can be classified as primary or secondary mesenteropathies. Primary mesenteropathies originate in the mesentery and subsequently progress to involve other organ systems (e.g., mesenteric ischemia or mesenteric volvulus). Secondary mesenteropathies describe disease processes that originate elsewhere and progress to involve the mesentery with varying degrees of severity (e.g., lymphoma). The implementation of standardized radiological imaging protocols, nomenclature, and reporting format with regard to the mesentery will be essential in improving the assessment of mesenteric anatomy and various mesenteropathies. In this article, we describe and illustrate the current state of art in respect of the radiological assessment of the mesentery.

The development and structure of the mesentery.

The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of abdominal anatomy, there are multiple mesenteries. Recent findings point to an alternative model in which digestive organs are connected to a single mesentery. Given that direct evidence of this is currently lacking, we investigated the development and shape of the entire mesentery. Here we confirm that, within the abdomen, there is one mesentery in which all abdominal digestive organs develop and remain connected to. We show that all abdominopelvic organs are organised into two, discrete anatomical domains, the mesenteric and non-mesenteric domain. A similar organisation occurs across a range of animal species. The findings clarify the anatomical foundation of the abdomen; at the foundation level, the abdomen comprises a visceral (i.e. mesenteric) and somatic (i.e. musculoskeletal) frame. The organisation at that level is a fundamental order that explains the positional anatomy of all abdominopelvic organs, vasculature and peritoneum. Collectively, the findings provide a novel start point from which to systemically characterise the abdomen and its contents.

Unusual Sites of High-Grade Neuroendocrine Carcinomas: A Case Series and Review of the Literature.

BACKGROUND Neuroendocrine tumors (NETs) encompass a diverse group of varying clinicopathological entities arising from cells of the endocrine and nervous systems. The presentation of these unique tumors can range from occult disease discovered incidentally to hyperactive, metastatic secretory tumors. NETs most commonly originate in the gastrointestinal and respiratory tract, although they may occur at any site in the body due to the wide distribution of neuroendocrine cells. Their classification system is complex and continues to evolve, and the current system uses histological grade in defining these subtypes. Neuroendocrine carcinomas (NECs), or high-grade, poorly-differentiated NETs, are the most aggressive subtype. Surgical resection remains the primary treatment modality and may be curative, thus early diagnosis is paramount. Management of advanced NETs remains both a diagnostic and therapeutic challenge; however, advances in our understanding of these unique neoplasms as well as an evolving classification system has led to the development of adjunctive therapeutic approaches aimed to minimize morbidity and improve patient outcomes. CASE REPORT We present 6 cases of unusual sites of high-grade neuroendocrine carcinomas involving the cervix, gallbladder, oesophagus, ovary, prostate, and urinary bladder. CONCLUSIONS Our case series highlights the heterogenous and aggressive nature of this subtype of NETs as well as their diagnostic and therapeutic difficulties. We also review the evolution of the NET classification system and its impact on the management of these malignancies.

Palliative gastrostomy in the setting of voluminous ascites.

OBJECTIVE: We report the indications, methods, and complications of percutaneous gastrostomy/gastrojejunostomy (G/GJ) in patients with voluminous ascites. METHODS: Following institutional review board approval, 69 patients (14 male, 55 female, mean age 58±12 years, range 32-89 years) who underwent percutaneous G/GJ with paracentesis were identified from a prospectively acquired database. Electronic medical record data extracted included diagnosis, method of G/GJ insertion, clinical course, and complications, which were graded by The Society of Interventional Radiology (SIR) criteria. Statistics were performed using Graphpad Instat. RESULTS: Sixty-six G and three GJ catheters were placed in 62 patients with malignant and 7 patients with benign disease; 47 procedures were conducted using fluoroscopy and 22 using computed tomography (CT; 10 patients had failed fluoroscopy). Sixty-six patients had 1980±1371 mL (range, 20-5000 mL) ascites drained (more in males, p=0.01) 0.8±1.6 days (range, 0-5 days) prior to placement. Forty-one patients had significantly less ascites (1895±1426 mL; range, 100-5400 mL) drained after G/GJ (p>0.0.5). Mean survival after insertion was 43±57 days (range, 1-252 days) among 38 patients for whom data were available. Fifty-six patients had a mean postprocedure hospital stay of 8.6±8.4 days (range, 0-45 days); 3 were outpatients and 10 patients died in the hospital. Successful gastropexy was confirmed on subsequent cross-sectional imaging in 22 of 25 patients. There were 25 tube maintenance issues that included catheter displacement and leakage, one patient experienced hemorrhage, and there were two deaths. All except one patient had satisfactory gastrostomy function. CONCLUSION: Effective G/GJ placement is possible in most patients with voluminous ascites provided ascites is drained and gastrocutaneous fistula formation occurs. Caution is advised; placement is generally for fragile terminal patients, and fluoroscopy or CT guidance is required.

Percutaneous biopsy of focal lesions of the gastrointestinal tract.

PURPOSE: To evaluate the technical success and diagnostic accuracy of image-guided percutaneous biopsy of the gastrointestinal (GI) tract. MATERIALS AND METHODS: An interventional radiology database was used to retrospectively identify patients who underwent image-guided percutaneous biopsy of the GI tract. The medical and imaging records were reviewed to assess biopsy results and complications. RESULTS: Twenty-nine patients (M:F = 19:10, mean age 65 years) were identified who underwent image-guided (CT/US) percutaneous biopsies of the GI tract. All biopsies were performed using coaxial technique with 18 g core and 22 g FNA needles. Twenty-two biopsies (76 %) were for circumferential or segmental wall thickening; the remaining were wall thickening with exophytic mass. Mean tumor diameter was 7.4 cm (SD = 3.4 cm), average wall thickening was 2.1 cm (SD 7.2), and exophytic mass was 10.0 cm (SD = 4.2). Tumor locations included stomach (n = 5), small bowel (n = 8), and colon (n = 16). Malignancy was confirmed in 22 patients, 12 of whom underwent excision, with 3 false positive samples. Benign disease was diagnosed in 7 patients, including 3 with pathology confirmation, with one false negative sample. The overall sensitivity was 83 % and accuracy was 84 %. There was one complication presenting as bleeding at the biopsy site, treated conservatively. CONCLUSION: Percutaneous biopsy of the GI tract is an uncommon procedure. The results of this study suggest that it is a safe and sensitive procedure that may be considered for small bowel lesions in which endoscopy is not feasible, for submucosal lesions, or in the setting of patients with previously negative endoscopic biopsies.

Role of positron emission tomography--computed tomography in head and neck cancer.

Head and neck squamous cell carcinoma (HNC) is the sixth most common cancer worldwide. In the United States, it accounts for approximately 2% of all cancers and 2% of cancer deaths. The introduction of integrated positron emission tomography and computed tomography (PET/CT) has revolutionized imaging by permitting improved and more accurate anatomic localization of functional abnormalities in the complex territory of the head and neck region, and PET/CT has become a standard clinical imaging modality in patients with HNC. The main indications for PET/CT in HNC are in pretherapy staging, detection of unknown primaries, and monitoring of therapy response or disease surveillance. Although PET/CT is a promising tool in diagnosis and surveillance of HNC, there is lack of consensus as to its use, accuracy, and implications for patient management. The existing literature on the role of PET/CT in the management of HNC is reviewed, and a summary of the current debate is provided. Second primary cancers are the main cause of death among HNC patients with early disease, and the presence of distant metastases greatly impairs the survival of patients with advanced HNC. Therefore, early detection of second primary and metastatic tumors is imperative for optimizing survival outcome. However, given the lack of randomized, prospective trials addressing the role of PET/CT after chemoradiotherapy, the ideal function of PET/CT in disease surveillance has yet to be defined.

An imbalance in progenitor cell populations reflects tumour progression in breast cancer primary culture models.

BACKGROUND: Many factors influence breast cancer progression, including the ability of progenitor cells to sustain or increase net tumour cell numbers. Our aim was to define whether alterations in putative progenitor populations could predict clinicopathological factors of prognostic importance for cancer progression. METHODS: Primary cultures were established from human breast tumour and adjacent non-tumour tissue. Putative progenitor cell populations were isolated based on co-expression or concomitant absence of the epithelial and myoepithelial markers EPCAM and CALLA respectively. RESULTS: Significant reductions in cellular senescence were observed in tumour versus non-tumour cultures, accompanied by a stepwise increase in proliferation:senescence ratios. A novel correlation between tumour aggressiveness and an imbalance of putative progenitor subpopulations was also observed. Specifically, an increased double-negative (DN) to double-positive (DP) ratio distinguished aggressive tumours of high grade, estrogen receptor-negativity or HER2-positivity. The DN:DP ratio was also higher in malignant MDA-MB-231 cells relative to non-tumorigenic MCF-10A cells. Ultrastructural analysis of the DN subpopulation in an invasive tumour culture revealed enrichment in lipofuscin bodies, markers of ageing or senescent cells. CONCLUSIONS: Our results suggest that an imbalance in tumour progenitor subpopulations imbalances the functional relationship between proliferation and senescence, creating a microenvironment favouring tumour progression.

Assessment of a new undergraduate module in musculoskeletal medicine.

BACKGROUND: Despite the high prevalence of musculoskeletal disorders seen by primary care physicians, numerous studies have demonstrated deficiencies in the adequacy of musculoskeletal education at multiple stages of medical education. The aim of this study was to assess a newly developed module in musculoskeletal medicine for use at European undergraduate level (i.e., the medical-school level). METHODS: A two-week module in musculoskeletal medicine was designed to cover common musculoskeletal disorders that are typically seen in primary care. The module incorporated an integrated approach, including core lectures, bedside clinical examination, and demonstration of basic practical procedures. A previously validated examination in musculoskeletal medicine was used to assess the cognitive knowledge of ninety-two students on completion of the module. A historical control group (seventy-two students) from a prior course was used for comparison. RESULTS: The new module group (2009) performed significantly better than the historical (2006) control group in terms of score (62.3% versus 54.3%, respectively; p < 0.001) and pass rate (38.4% versus 12.5%, respectively; p = 0.0002). In a subgroup analysis of the new module group, students who enrolled in the graduate entry program (an accelerated four-year curriculum consisting of students who have already completed an undergraduate university degree) were more likely to perform better in terms of average score (72.2% versus 57%, respectively; p < 0.001) and pass rates (70.9% versus 21.4%, respectively; p < 0.001) compared with students who had enrolled via the traditional undergraduate route. In terms of satisfaction rates, the new module group reported a significantly higher satisfaction rate than that reported by the historical control group (63% versus 15%, respectively; p < 0.001). CONCLUSIONS: In conclusion, the musculoskeletal module described in this paper represents an educational advance at undergraduate (i.e., medical-school) level as demonstrated by the improvement in scores in a validated examination. As pressure on medical curricula grows to accommodate advancing medical knowledge, it is important to continue to improve, assess, and consolidate the position of musculoskeletal medicine in contemporary medical education.

Whole-body magnetic resonance imaging in skeletal muscle disease.

The evaluation of muscle diseases has traditionally integrated clinical with biochemical findings, occasionally resorting to muscle biopsy. This article reviews the role and imaging appearances of muscle diseases at MRI, specifically emphasising the role of WBMRI in global assessment of muscle abnormality, and in particular its role in determining distribution and extent of muscle abnormality.

Whole-body magnetic resonance imaging: emerging applications.

Beyond established roles in the assessment of skeletal metastatic disease, in muscle diseases and in myeloma, WBMRI has the potential to offer many further valuable clinical applications. This article presents an overview of emerging clinical applications of WBMRI emphasizing its role in the assessment of musculoskeletal ailments, ranging from the assessment of arthropathy through to body composition research.

Whole-body imaging modalities in oncology.

This article outlines the expanding approaches to whole-body imaging in oncology focusing on whole-body MRI and comparing it to emerging applications of whole-body CT, scintigraphy, and above all PET CT imaging. Whole-body MRI is widely available, non-ionizing and rapidly acquired, and inexpensive relative to PET CT. While it has many advantages, WBMRI is non-specific and, when compared to PET CT, is less sensitive. This article expands each of these issues comparing individual modalities as they refer to specific cancers.

Imaging of groin pain.

Groin pain is a commonly encountered problem in musculoskeletal radiology. The diagnosis can be difficult to establish, based on the complex interconnected anatomy at the pubic symphysis and surrounding structures. The differential diagnosis is therefore broad, and diagnostic imaging is crucial in reaching the correct diagnosis, thus allowing appropriate therapy to be instituted. This article reviews the relevant anatomy and differential diagnoses encountered in overuse injuries of the groin. The common mechanisms of injury, presenting symptoms, and imaging findings for each diagnosis are addressed.

MR imaging of overuse injuries of the hip.

The aim of this article is to emphasize the importance of MR imaging in the evaluation of chronic hip pain and overuse injuries. Image interpretation of the hip can be difficult because of the complex anatomy and the varied pathology that athletes can present with, such as labral and cartilaginous injuries, surrounding soft tissue derangement involving muscles or tendons, and osseous abnormalities. The differential diagnosis in adults is diverse and includes such common entities as stress fracture, avulsive injuries, snapping-hip syndrome, iliopsoas bursitis, femoroacetabular impingement syndrome, tendinosis, and tears of the gluteal musculature.

MR imaging of muscle injury.

Although most muscle injuries in the athlete are diagnosed clinically, MR imaging is an excellent noninvasive diagnostic adjunct to clinical examination, which allows the site and severity of muscle injury to be assessed accurately, influencing therapy and overall outcome. There has been a rapid expansion in the clinical use of MR imaging during the past decade. MR imaging conveys unparalleled anatomic resolution and high sensitivity in the detection of acute and chronic muscle abnormalities. This article discusses the spectrum of muscle injuries, emphasizing the important role of MR imaging in their diagnosis and management.

Molecular and magnetic resonance imaging: The value of immunoliposomes.

Molecular imaging has the potential to transform the field of diagnostic imaging through enabling far more detailed investigation and characterisation of disease processes than is currently possible. Magnetic resonance imaging (MRI) is capable of three-dimensional non-invasive imaging of opaque tissues at near cellular resolution. Among the imaging techniques available today, MRI has, perhaps, the greatest potential to exploit the possibilities that molecular imaging presents. Nanoparticles are the focus of intense research, due to a wide variety of potential applications in the biomedical, optical, and electronic fields. In this article we examine the progress made in the development of nanoparticles as targeted contrast agents for molecular magnetic resonance imaging. In particular, we will examine the potential of antibody-targeted liposomes (immunoliposomes) as vehicles for delivering MRI contrast agents to cellular biomarkers, thus enabling visualisation of structures and processes at the molecular level. We will address some of the challenges that must be faced by researchers in this field before the progress made in the laboratory can be translated into improved clinical diagnostics and therapeutics.

Prophylactic stabilization of proximal femoral metastatic bone disease: reconstruction intramedullary nail fracture.

Pathological fracture is an unfortunate manifestation of metastatic bone disease and whenever possible, prophylactic stabilization is preferable to fixation of fracture. The Russell-Taylor reconstruction intramedullary nail (Smith & Nephew Richards, Inc., Memphis, Tennessee) provides a stable construct for the prophylactic management of impending pathological fracture. Implant failure with this system typically involves distal locking screws. Cases of proximal screw cut-out and pullout have been reported as has breakage of both proximal locking screws. We present a case of failure of the Russell-Taylor delta reconstruction nail implant, just distal to the point of insertion of the proximal locking screws.

Nontuberculous pyogenic spinal infection in adults: a 12-year experience from a tertiary referral center.

STUDY DESIGN: We performed a retrospective review of 48 cases of pyogenic spinal infection presenting over a 12-year period to the National Spinal Injuries Unit (NSIU) of the Republic of Ireland. The NSIU is the tertiary referral center for all adult spinal injuries and diseases of the spine warranting surgical intervention in the Republic of Ireland. OBJECTIVES: The objective of this study was to analyze the presentation, etiology, management, and outcome of nontuberculous pyogenic spinal infection in adults. SUMMARY OF BACKGROUND DATA: Pyogenic spinal infection encompasses a broad range of clinical entities, including spondylodiscitis, septic discitis, vertebral osteomyelitis, and epidural abscess. Management of pyogenic spinal infection can involve conservative methods and surgical intervention. METHODS: The medical records, radiologic imaging, and bacteriology results of 48 patients with pyogenic vertebral osteomyelitis from 1992 through 2004 were reviewed. The Hospital Inpatient Enquiry (HIPE) System and the NSIU Database were used to identify our study cohort. RESULTS: The average age of presentation was 59 years with an even distribution between males and females. Most patients (21 of 48) were symptomatic for between 2 and 6 weeks before presenting to hospital. The most frequently isolated pathogen was Staphylococcus aureus, in 23 of 48 cases (48%); 35 of 48 cases (73%) were managed by conservative measures alone, including antibiotic therapy and spinal bracing. However, in 13 of 48 cases (27%), surgical intervention was required because of neurologic compromise or mechanical instability. CONCLUSIONS: In the majority of cases, conservative management of pyogenic spinal infection with antibiotic therapy and spinal bracing is very successful. However, in a minority of cases, surgical intervention is warranted and referral to a specialist center is appropriate.