Advanced Imaging Procedures Research Articles

Long‐term prognosis of medullary thyroid carcinoma

The clinical course of patients with medullary thyroid carcinoma (MTC) is variable, even in the subgroup of patients after surgery with curative intent and postoperatively persistent elevated calcitonin levels. This study aimed to evaluate the long-term prognosis of survival in patients with MTC. Long-term survival was analysed in 32 patients with MTC being treated in an endocrine centre over a 40-year period. Patients were classified as having sporadic MTC, familial MTC (FMTC), multiple endocrine neoplasia (MEN) IIA or MEN IIB. Seventeen patients had sporadic MTC (53.1%), eight had MEN IIA (25%) and three had MEN IIB (9.4%); the remaining four patients (12.5%) had not undergone genetic analysis until now. The overall average age at diagnosis was 42.0 years, and the median follow-up time was 9.5 years (range 0.5-39 years). Mortality due to progressive MTC was 15.6%. The 5-year survival rate was 96% (95% CI 89-100), the 10-year survival rate 91% (95% CI 79-100), and the 15-year survival rate 85% (95% CI 78-100). The estimated mean survival time after initial diagnosis was 31 years (95% CI 26.7-37.0). There is a significant difference in survival time between patients achieving complete remission compared with patients with biochemical persistent disease (P = 0.038) or metastasis (P = 0.0003). In five patients, advanced imaging with positron emission tomography/computed tomography (PET/CT) identified additional sites of tumour load. Eight more lymph node metastases were found in four patients and one local tumour recurrence in one patient by PET/CT. The overall prognosis of MTC is favourable, even if the rate of biochemical cure is lower in MTC than in differentiated types of thyroid cancer. This is also true for patients with biochemically persistent disease. Whether the identification of further tumour sites by advanced imaging procedures such as PET/CT translates into a better prognosis in patients with persistently elevated calcitonin levels remains to be investigated.

Utilization Trends for Advanced Imaging Procedures

Recent reports by the Medicare Payment Advisory Commission have highlighted sharp increases in the use of advanced diagnostic imaging procedures among the Medicare fee-for-service population. Little research has examined whether such trends also exist among persons with generous private insurance coverage. Moreover, research documenting changes in the share of utilization linked to self-referral is nonexistent. Using data from a large private insurer in California, we document trends in utilization for magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET) scans over the time period 2000-2004. We collected data that enable us to calculate relative changes in use rates by provider type (self-referral physicians, radiologists, hospitals, and independent diagnostic testing facilities). Examining trends in the share of utilization performed by provider type can offer insights as to the effects of self-referral on rates of use. Rates of use for the 3 advanced imaging modalities examined-MRI, CT, and PET-increased rapidly between 2000 and 2004. PET utilization increased by almost 400%, whereas the corresponding increases for MRI and CT exceeded 50%. Findings suggest that physician self-referral arrangements and independent diagnostic testing facilities seem to be contributing to this greater use of advanced imaging, especially for MRI and PET. In contrast, relative changes in use of advanced imaging performed at hospitals were small. Use rates for all 3 modalities were much higher in southern California compared with the northern region of the state. Use of highly reimbursed advanced imaging, a major driver of higher health care costs, should be based on clear clinical practice guidelines to ensure appropriate use.

Virtual colonoscopy: Good results and not so good results—why the difference?

Virtual colonoscopy: Good results and not so good results—why the difference?

Advanced brain imaging procedures and human memory disorder.

The impact of advanced brain imaging procedures in the field of human memory disorder is reviewed, with particular emphasis on current and potential applications that may impact upon the diagnosis and management of memory-disordered patients. While both advanced structural, resting physiological and functional physiological brain imaging procedures have been applied to conditions where memory disorder is a major feature, the specific implications of research findings for diagnosis and treatment in routine clinical practice remain tentative and promising, but not yet substantive enough to inform clinical decisions to a significant degree. In terms of diagnostic applications, several promising areas include dementia, epilepsy, and transient amnesic states. In the case of applications in treatment settings, advanced brain imaging procedures may help to monitor neural correlates of spontaneous recovery or progression of memory function, and may also help in the planning and monitoring of therapeutic intervention.

Benign hepatic tumours.

Benign hepatic tumours include a broad spectrum of regenerative and true neoplastic processes. Due to advances in imaging procedures like MRI, Cf-scan and ultrasound as well as progress in immunohistochemistry, the appropriate diagnosis is made ina high percentage of patients without laparotomy and resection. Most important in clinical practice is the differential diagnosis of focal nodular hyperplasia and hepatocellular adenoma because of the risk of rupture and bleeding in the latter. Cavernous haemangioma, the most common benign hepatic tumour, rarely needs treatment. The diagnosis of nodular regenerative hyperplasia is often missed and patients present with secondary complications and signs of portal hypertension that necessitate treatment. The main problem in angiomyolipoma is to distinguish it from malignant processes which do require treatment. Because of its clinical presentation, inflammatory pseudotumour is also sometimes confused with a malignant tumour. Therapeutic options are drug therapy or surgical resection. Benign haemangioendothelioma of the infant is rare but may cause life-threatening complications. Bile duct adenoma is an incidental finding that is not known to cause any symptoms whereas biliary cystadenoma is often symptomatic and may progress to cystadenocarcinoma and therefore needs resection.

Role of tumor markers in the diagnosis of cystic and intraductal neoplasms.

Despite recent advances in imaging procedures, the correct diagnosis of cystic lesions of the pancreas is lacking in about one third of cases. Cyst fluid analysis can help in the differential diagnosis, particularly in patients with unilocular or paucilocular lesions, thus precluding unjustified resection in patients with benign cystic lesions of the pancreas. Although use of cystic fluid marker analysis is helpful in several situations, it is crucial to carefully evaluate the clinical context with appraisal of patient's demographics, clinical symptoms, and morphologic data. A multidisciplinary approach is advised and should improve the overall diagnostic performance and lead to better management strategies in patients presenting with such tumors of the pancreas.

New strategies for embedding, orientation and sectioning of tissue from small laboratory animals, and its correlation to advanced brain imaging or stereologic procedures

New strategies for embedding, orientation and sectioning of tissue from small laboratory animals, and its correlation to advanced brain imaging or stereologic procedures

Pathologic features of primary and metastatic hepatic malignancies.

In the mammalian liver, 60% of the cells are hepatocytes while the remainder (35%) include biliary epithelium, Kupffer cells, endothelial cells, fat storing cells and connective tissue cells. Although, neoplasms of hepatocytes are the most common liver tumors in humans, a significant number of other neoplasms including tumors of bile duct epithelium can develop. Not too long ago, liver tumors were left untreated because liver was considered as a complex and mysterious organ inaccessible to surgery. Advances in imaging procedures and surgical techniques over the past 30 years have revolutionized the approaches to the treatment of benign and malignant liver tumors. Subsegmentectomy, segmentectomy, lobectomy and transplantation are routinely performed for treatment of primary and metastatic liver tumors with minimal morbidity and mortality rates. Since accurate diagnosis remains the key to sound management, the emphasis of this article is on classification, morphological features and differential diagnosis of malignant neoplasms of liver.KeywordsCholedochal CystFocal Nodular HyperplasiaGiant Cell TumorBile Duct CarcinomaExtramedullary HematopoiesisThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Diagnostic Imaging of Lameness in Small Animals

The demand for advanced diagnostic imaging procedures such as nuclear scintigraphy, ultrasonography, computed tomography, and magnetic resonance imaging has increased dramatically over the past 10 years. Veterinarians, seeking to improve their diagnostic capabilities and clients willing to pursue "best medicine" have driven this demand, resulting in installation of advanced imaging facilities at most academic and private referral practices. Knowledge of potential benefits of various modalities will allow the veterinarian to optimize his or her use of diagnostic imaging in his or her own practice or in a referral practice.

Contrast agents

Contrast agents

Workbook to Accompany Radiographic Positioning and Procedures, Volume II: Advanced Imaging Procedures

Department of Radiation Oncology; Allegheny University Hospitals, Hahnemann; Philadelphia, PA, U.S.A.

Squamous cell carcinoma of the canine nasal planum: eight cases (1988-1994).

Squamous cell carcinoma of the nasal planum was diagnosed in eight dogs between March 1988 and January 1994. Epistaxis, sneezing, and ulceration or swelling of the nasal planum were the most common presenting complaints. Although no evidence of metastasis was identified, the primary tumor in all cases was locally invasive with extensive involvement of underlying tissues. Advanced imaging procedures performed in three cases indicated that physical examination may underestimate the local extent of the neoplasm. Euthanasia was performed in six cases due to progressive neoplastic disease with worsening epistaxis and sneezing; the mean survival time in these cases was 5.4 months.

Bringing Geophysics into the Mine: Radio Attenuation Imaging and Mine Geology

Recent work using radio wave frequencies to define ore shape between boreholes shows promise for changing the way mine geologists evaluate a deposit. Traditionally, orebody evaluation at an advanced exploration site or a mine involves three distinct tiers of information, exploration drilling (>200 m borehole separation), follow-up drilling (40 m to 100 m separation), and in-fill drilling (<20 m). The inexact nature of ore definition at the follow-up and in-fill stages inevitably results in poor mine design or dilution. This has been shown to have a significant cost to any operation. The clear incentive is to improve evaluation techniques by using high resolution sensing methods between physical intersections. A new geophysical technique using comparative radio wave attentuation values from cross-borehole measurements and advanced tomographic imaging procedures has been applied at a number of mine sites in Australia. Radio wave attentuation is a function of the host medium conductivity. Conductive ore will attenuate the signal more than resistive host rock. These variations in signal attenuation may be expressed in the form of a tomographic image for analysis. This paper evaluates results from controlled experimentation at the Broken Hill and Osborne deposits and reviews the likely future role for radio imaging at metalliferous mine sites. It is suggested that the clear role for radio scanning is particularly in the follow-up stage of drilling (40 m to 100 m). The integration of the images into mine planning packages, as an input to geostatistics and as a visualisation aid for mine planners and geologists is likely to improve the accuracy of ore definition and overall metal recovery at individual mine sites.