Characterization Of Adrenal Masses Research Articles

Comparative Analysis of FSE T2 Weighted, Chemical Shift and Dynamic Contrast-Enhanced MR Imaging in the Characterization of Adrenal Masses Based on Qualitative and Quantitative Parameters.

The purpose of our study was to investigate the role of different magnetic resonance imaging (MRI) parameters in the characterization of adrenal masses. A total of 150 patients who presented with 186 adrenal tumors were retrospectively evaluated in this study. Final patient cohort consisted of 17 pheochromocytomas, 3 adrenocortical carcinomas, 24 metastases, 31 lipid-poor adenomas and 111 lipid-rich adenomas. We carried out a visual assessment on FSE (Fast spin echo)T2 weighted images and also calculated T2 signal intensity ratio of all adrenal masses and also performed a qualitative assessment on chemical shift imaging (CSI) together with quantitative calculation using Adrenal to spleen signal intensity (si) ratio and Adrenal si index formulas. On dynamic contrast-enhanced sequences, visual assessment based on enhancement patterns on late-arterial phase images was performed and also mean signal intensity measurements were carried out. All examinations were interpreted by two abdominal radiologists in consensus who were blinded to the clinical and pathological findings. Statistical analysis was performed. On FSE T2 weighted imaging, isointense to liver and slightly hyperintense than liver was found higher in benign cases, however, in malignant cases moderately and strikingly hyperintense than liver was higher than in benign cases (p=0.001, p<0.01). There was a statistically significant difference between the T2 signal intensity ratio values of adrenal tumor groups (p=0.001, p<0.01). In lipid-rich and lipid-poor adenoma groups, T2 signal intensity ratio values was significantly lower than in pheochromocytoma and metastasis cases. In malignant group, T2 signal intensity ratio values were found statistically significantly higher than in the benign group (p=0.001, p<0.01). There was a statistically significant difference between CSI visual assessment of adrenal tumor groups (p=0.001, p<0.01). Although moderate and significant signal intensity loss was usually detected in lipid-rich adenoma group, never detected in other tumor groups. There was also a statistically significant difference between benign and malignant adrenal tumor groups (p=0.001, p<0.01). In the malignant group, Adrenal to spleen si ratio values were found significantly higher whereas, Adrenal si index values were significantly lower compared to benign tumors (p=0.001, p<0.01). Based on malignancy, there was a statistically significant difference between adrenal tumor groups (p=0.001, p<0.01). Although capillary blush and homogenous type enhancement were more common in benign cases than in malignant ones, peripheral-patchy and strikingly capillary blush type enhancement was more frequent in malignant tumors. Based on malignancy, mean arterial signal intensity values of malignant tumors were statistically higher than benign tumors (p=0.001; p<0.01). Dynamic contrast-enhanced MRI protocol including CSI aids in the characterization of indeterminate adrenal masses. Herein, the combined use of qualitative and quantitative parameters enables more tumors to be recognized that otherwise would be indeterminate.

THU604 Characterization Of Adrenal Masses In Young Adults At A Tertiary Academic Medical Center

Abstract Disclosure: S.A. Jacob: None. M. Itani: None. M.J. Hoegger: None. D. Ludwig: None. T. Pandian: None. T.C. Brown: None. L.M. Brunt: None. I. Bancos: None. N. Genere: None. Introduction: Adrenal mass incidence has increased tenfold over the last two decades, with most masses detected in individuals over 40 years of age. The majority of these adrenal masses are benign (&amp;gt;80%), and few are malignant (8%) or hormonally active (4%); most are incidentally detected. Studies suggest higher rates of hormonally active and malignant adrenal masses in younger patients, however, evidence for this age group is scarce. In two recent large cohort studies of adrenal masses, young adults (18-40 years) represented only 0.2-7.1% of individuals studied. This study aimed to characterize clinical, imaging, and biochemical presentation of young adults diagnosed with adrenal masses. Methods: This is a retrospective cohort study of young adults (18-40 years) with adrenal masses detected based on a radiology report text database search between January 2015 and December 2021 at a tertiary medical center. Exclusion criteria included pre-existing adrenal masses before 2015, hyperplasia, or masses &amp;lt;1cm. Images were reviewed by abdominal radiologists, and clinical data were obtained through review of electronic medical records. Results: A total of 255 young adults (56% women, 61% white) were diagnosed with adrenal masses with median age 35 (IQR 30-39) years. Genetic predisposition syndrome was present in 6%. Comorbidities included: BMI &amp;gt;30 kg/m2 in 48%, hypertension in 35%, and diabetes in 10%. Adrenal masses were detected incidentally in 72% and during cancer staging in 16%. Median mass size was 1.9cm (IQR 1.4-2.7cm) and 49% (39/79) were lipid poor (Hounsfield units &amp;gt;10). Only 22% of patients underwent hormonal evaluation. Final diagnoses included 16% malignancy, 9% benign adenoma with overt hormone excess, 40% benign adenoma with incomplete hormonal evaluation and 24% radiographically indeterminate masses. Subgroup analysis showed that adrenal masses in those &amp;lt;30 years old compared to 31-40 year-olds were more frequently associated with tumor predisposition syndrome (15% vs 3%, p&amp;lt;0.01) and more often lipid poor (76% vs 40%, p&amp;lt;0.01); but, no differences in frequency of malignancy or overt hormone excess were identified. Discussion: We found a higher frequency of malignancy and overt hormonal excess in our cohort of young adults compared to previously published studies, though direct comparisons are limited by differences in methodology. These findings, in addition to high frequencies of metabolic disease in our cohort, would suggest the need for hormonal assessment in young adults; yet, this was completed in only a minority of patients. Additional areas of research may include studying hormonal status of adrenal masses in young adults in a multi-center cohort to overcome issues of selection bias and increase the rates of those with complete hormonal evaluation. Presentation: Thursday, June 15, 2023

CECT IN THE ADRENOCORTICAL CARCINOMAS: RECOGNIZING THE TYPICAL MORPHOLOGICAL FEATURES

Objectives: This study was characterization of adrenal masses on computer tomography (CT) using shape, size, and enhancement patterns. Methods: It is a retrospective study of 86 adrenal masses with morphological differences in the appearance and enhancement patterns (histopathologically proven 36 pheochromocytoma [PCCs], 26 adrenal cortical carcinoma [ACCs], one lymphoma, 22 metastases, and one schwannoma). Two experienced radiologists who were unaware of the histopathological diagnosis reviewed the computed tomography scans, morphological parameters had been noted, along with attenuations measured in Hounsfield units for all the phases of contrast-enhanced computed tomography. Results: Necrosis had been seen in all the cases of ACCs with a loss of adeniform shape. ACCs were significantly less enhancing in arterial phase and venous phase than PCC; however, no significant difference was seen with lymphomas, metastasis, and schwannoma. 25/33 (75.5%) ACC showed heterogeneous enhancement (due to the presence of necrosis) in the VP. Conclusion: Heterogenous architecture with a size of more than 5 cm is relatively specific for diagnosing ACC. No specific enhancement pattern could well differentiate ACC from lymphoma, metastases, and schwannoma.

A SPECTRUM OF ADRENAL LESIONS AND THEIR CT WASHOUT CHARACTERSTICS

Background: The adrenal gland is involved in several pathologic conditions, including hyperplasia, hemorrhage, and benign and malignant masses. Most of the adrenal masses are discovered incidentally. Cross-sectional imaging plays a vital role not only in detection of adrenal abnormalities, but also in the characterization of the adrenal lesions. The most common lesion detected is incidental benign adrenal adenoma. Materials And Methods: Patients with suspected adrenal masses who presented to SMS hospital were referred to the Department of Radiodiagnosis for evaluation. CECT with adrenal protocol (non-contrast study, contrast study at 80 seconds and delayed study at 15 min) was done. Biopsy of selective lesions was performed. A total of 43 patients were s Results: ubjected to the study. The anomalies detected were- 30 adrenal adenoma, 3 adrenal metastasis, 2 adrenocortical carcinoma, 4 myelolipoma, 2 pheochromocytoma, 1 adrenal lymphoma and 1 adrenal tuberculosis. Adrenal adenoma is the most common adrenal mass and metast Conclusion: asis is the most common malignant adrenal mass. Multidetector CT is the primary modality for detection and characterization of adrenal masses.

Contrast-enhanced ultrasound in evaluation of adrenal lesions with CT/MRI correlation

Most of the adrenal masses are incidentally detected. Multiphasic CT forms the mainstay for diagnosis and characterization of adrenal masses. MRI can further be used if the masses are indeterminate on CT scan. But as these investigations are expensive with risk of radiation exposure, contrast-enhanced ultrasound (CEUS) is currently under evaluation to assess its utility to act as a screening modality to differentiate benign vs malignant adrenal masses This investigative modality is relatively safe and can be used in patients having renal dysfunction or allergy to CT contrast. We, hereby, present a pictorial review of imaging appearance of various adrenal lesions on CEUS with CT and MRI correlation.

EP020 - Characterization of adrenal masses using CT histogram analysis, dual energy CT and chemical shift MRI: Methods comparison, first results

EP020 - Characterization of adrenal masses using CT histogram analysis, dual energy CT and chemical shift MRI: Methods comparison, first results

MDCT combined parameters in characterization of adrenal masses in cancer patients; A prospective study in South Egypt Cancer Institute

MDCT combined parameters in characterization of adrenal masses in cancer patients; A prospective study in South Egypt Cancer Institute

Diagnostic accuracy of 18F-FDG PET or PET/CT for the characterization of adrenal masses: a systematic review and meta-analysis.

We aimed to explore the role of the diagnostic accuracy of 18F fluodeoxyglucose PET (18F-FDG PET) or PET/CT for characterization of adrenal lesions through a systematic review and meta-analysis. The MEDLINE, EMBASE, and Cochrane Library database, from the earliest available date of indexing through 30 April 2017, were searched for studies evaluating the diagnostic performance of 18F-FDG PET or PET/CT for characterization of adrenal lesions. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR + and LR-), and constructed summary receiver operating characteristic curves. Across 29 studies (2421 patients), the pooled sensitivity for 18F-FDG PET or PET/CT was 0.91 [95% CI (0.88-0.94)] with heterogeneity (χ2 = 141.8, p = 0.00) and a pooled specificity of 0.91 [95% CI (0.87-0.93)] with heterogeneity (χ2 = 113.7, p = 0.00). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 9.9 [95% CI (7.1-13.7)] and negative likelihood ratio (LR-) of 0.09 [95% CI (0.07-0.13)]. The pooled diagnostic odds ratio was 105 [95% CI (63-176)]. In metaregression analysis, study design, publication year, study location (western vs others), interpretation criteria of PET or PET/CT images, quantification of PET or PET/CT [SUVmax (maximum standardized uptake value) vs SUV (standardized uptake value) ratio], patient group, and analysis method (patient-based vs lesion-based) were the sources of the study heterogeneity. However, in multivariate metaregression, no definite variable was the source of the study heterogeneity. 18F-FDG PET or PET/CT demonstrated good sensitivity and specificity for the characterization of adrenal masses. At present, the literature regarding the use of 18F-FDG PET or PET/CT for the characterization of adrenal masses remains still limited; thus, further large multicenter studies would be necessary to substantiate the diagnostic accuracy of 18F-FDG PET or PET/CT characterization of adrenal masses. Advances in knowledge: 18F- FDG PET or PET/CT showed good sensitivity and specificity for the characterization of adrenal masses and could provide additional information for that purpose.

Characterization of adrenal masses with non-enhanced CT and 18F FDG-PET in patients with primary malignancies

Background: Characterizing adrenal lesions in patients with a known primary malignancy has a vital role in treatment and prognostication. A study by Gufler et al proposed a scoring system based on density, contour, homogeneity and size and found a high accuracy in differentiating adrenal adenomas from metastasis in patients with a known malignancy. This study evaluates the sensitivity and specificity of this NECT scoring system and comparing it with that of 18F FDG PET.Methods: The study was conducted on patients with diagnosed malignancies with adrenal mass, referred for 18F-FDG PET-CT scanning as a part of work up or follows up between October 2014 and March 2016. Whole-body CT and PET images were obtained using standard protocol. NECT scoring and quantitative analysis of FDG uptake in the adrenal lesions (SUVavg analysis) is done separately.Results: Of the 50 patients studied, 33 patients had benign adrenal lesions and the rest had metastatic lesions. Most common site of primary was lung. NECT score yielded a sensitivity of 88.2%, specificity of 100% and positive predictive value of 100%. SUVavg analysis yielded a 100% sensitivity, specificity and positive predictive value. Comparison of the predictive power of the two tests showed a z score of 2.5 and p value of 0.0124.Conclusions: 18-FDG PET can be considered as a gold standard for differentiating between metastasis and benign lesions of adrenal glands in patients with known primary. NECT has a comparable specificity as that of FDG PET, however with lower sensitivity.

Performance of 18F-FDG PET/CT in the Characterization of Adrenal Masses in Noncancer Patients: A Prospective Study.

Few prospective studies have evaluated the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the characterization of adrenal masses. To assess the performance of 18F-FDG PET/CT in the malignancy diagnosis of adrenal masses in noncancer patients. Prospective multicenter study. The study population consisted of 87 patients (87 adrenal masses) referred to endocrine surgeons: 56 with mass diameter ≥40 mm and 31 with a diameter <40 mm and of indeterminate nature based on unenhanced and washout CT attenuation densities. Fourteen patients had hypercortisolism. Adrenal masses were characterized by 18F-FDG PET/CT. Histology was the gold standard for the diagnosis of malignancy. In the absence of pathological proof (n = 23), the nature of the lesion was based on the 12-month imaging follow-up. Fifteen adrenal masses were classified as malignant (including 11 adrenocortical carcinomas) and 72 as benign. Compared with benign lesions, malignant lesions were larger in size (P = 0.003), had higher unenhanced densities (P = 0.002), lower relative washout values (P = 0.007), and higher 18F-FDG uptake parameters (P < 10-3). The optimal threshold value of (Tumor SUVmax:Liver SUVmax) the ratio for malignancy was >1.5 with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 86.7%, 86.1%, 56.5%, 96.9%, and 86.2%, respectively. Our results show that 18F-FDG PET/CT complements adrenal washout CT in the evaluation of adrenal masses and should be recommended in the evaluation of large and/or indeterminate adrenal masses.

Dynamic perfusion CT parameters and delayed contrast washout CT in characterization of adrenal tumors: A comparative study

PurposeThe study aims to compare the accuracy of washout and perfusion CT techniques in diagnosis of adrenal tumors. Patients and methodsA prospective study included 38 patients with incidentally detected adrenal masses on conventional abdominal CT studies performed for unrelated reasons were subjected to full medical history, physical examinations, serum creatinine assessment, dynamic perfusion CT using 64 MDCT scanner with Absolute washout (APW), Relative washout (RPW) assessment and CT perfusion parameters calculation [perfusion, Peak enhancement intensity (PEI), Time to peak (TTP) & Blood volume (BV)]. Time density curves (TDCs) for all adrenal masses were done. The gold standard was either follow up or histopathological examination after fine needle biopsy or surgical resection. ResultsWashout CT differentiated between adenomas and non-adenomas using APW (≥55%) with sensitivity 73.3%, specificity 90% and accuracy 82.8%, and using RPW (≥36%) with sensitivity 53.3%, specificity 85% and accuracy 81.8%. Perfusion CT differentiated between adenomas and nonadenomas using BV (≥15ml/100g) with sensitivity 80%, specificity 75% and accuracy 77.1%. TDC curves of adenomas show slow-rise platform pattern. ConclusionPerfusion CT can distinguish between adrenal adenomas and non-adenomas using the BV, however washout CT was more accurate than perfusion CT in characterization of adrenal masses using the APW and RPW.

Use of 18F-FDG-positron emission tomography in presurgical evaluation of nonspecific or suspectious adrenal masses in non-oncologic patients

Background and objectiveOur purpose was to assess the utility of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in pre-surgical characterization of adrenal masses. These masses were incidentally discovered in non-oncologic patients or during the study of endocrine hormone overproduction. These nodular lesions showed nonspecific or suspicious radiological features in the imaging tests routinely performed (CT and/or MRI). Patients and methodsThis is a cross-sectional and prospective study in 12 patients with adrenal masses which were radiologically non-specific or suspicious for malignancy before adrenalectomy. An 18F-FDG-PET was made and quantitative FDG uptake (SUVmax) in the adrenal region (adrenal SUVmax) and liver (liver SUVmax), and the ratio SUVmax adrenal/liver was calculated. These parameters were related to the pathological findings. We evaluated the accuracy of the test by receive operating curves (ROC). ResultsThe ROC to discriminate between benign and malignant lesions showed that the SUVmax was a better parameter than size or SUVmax adrenal/liver ratio. Using a SUVmax cutoff value ≥3.1, sensitivity, specificity, positive and negative predictive value of the test were 100, 67, 50 and 100%, while a SUVmax adrenal/liver ratio ≥1.8 showed a sensitivity, specificity, positive and negative predictive value of 67, 100, 100 and 90%, respectively. The presence of a SUVmax adrenal/liver ratio ≥1.8 showed a statistically significant association with carcinoma occurrence. Conclusion18F-FDG-PET may be useful in the characterization of nonspecific or suspicious adrenal masses discovered in patients without a previous history of cancer. Its use in some cases could avoid unnecessary interventions.

Utilidad de la tomografía de emisión de positrones con 18F-fluorodesoxiglucosa en la evaluación prequirúrgica de masas adrenales con características radiológicas inespecíficas o sospechosas de malignidad en pacientes sin cáncer

Background and objectiveOur purpose was to assess the utility of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in pre-surgical characterization of adrenal masses. These masses were incidentally discovered in non-oncologic patients or during the study of endocrine hormone overproduction. These nodular lesions showed nonspecific or suspicious radiological features in the imaging tests routinely performed (CT and/or MRI). Patients and methodsThis is a cross-sectional and prospective study in 12 patients with adrenal masses which were radiologically non-specific or suspicious for malignancy before adrenalectomy. An 18F-FDG-PET was made and quantitative FDG uptake (SUVmax) in the adrenal region (adrenal SUVmax) and liver (liver SUVmax), and the ratio SUVmax adrenal/liver was calculated. These parameters were related to the pathological findings. We evaluated the accuracy of the test by receive operating curves (ROC). ResultsThe ROC to discriminate between benign and malignant lesions showed that the SUVmax was a better parameter than size or SUVmax adrenal/liver ratio. Using a SUVmax cutoff value≥3.1, sensitivity, specificity, positive and negative predictive value of the test were 100, 67, 50 and 100%, while a SUVmax adrenal/liver ratio≥1.8 showed a sensitivity, specificity, positive and negative predictive value of 67, 100, 100 and 90%, respectively. The presence of a SUVmax adrenal/liver ratio≥1.8 showed a statistically significant association with carcinoma occurrence. Conclusion18F-FDG-PET may be useful in the characterization of nonspecific or suspicious adrenal masses discovered in patients without a previous history of cancer. Its use in some cases could avoid unnecessary interventions.

Should we use CT or MRI for detection and characterization of benign adrenal lesions?

ObjectivesComputed tomography (CT) and magnetic resonance imaging (MRI) are the main imaging modalities used for analysis of adrenal lesions. We compared the ability of CT and MRI to detect and characterize benign adrenal lesions. Patients and methodsUnenhanced abdominal CT and MRI were performed in 16 patients (age range 39–77), and reviewed by a radiologist with 6years of experience in abdominal imaging. The presence, number, size and structure of each mass were analyzed and compared between the two modalities. ResultsThere were 18 adrenal masses in 11 patients, four patients had adrenal hyperplasia (AH), whereas one patient had left-sided AH and right-sided adenoma. Ten masses were≥2cm in diameter, and were perfectly depicted using CT and all MRI techniques. There were nine masses with diameter<2cm detected by CT, three of them were missed using MRI. AH was detected in five patients using CT, but its mild form was missed in one patient using MRI. Four masses with attenuation values of>10Hounsfield units could not be characterized using unenhanced CT, but three of them were characterized using MRI. ConclusionCT has higher sensitivity for detection of small adrenal tumours and adrenal hyperplasia than MRI. MRI is an important tool in characterization of adrenal masses that could not be characterized using unenhanced CT.

Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas—Initial study

ObjectivesTo evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging. Patients and Methods34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination. ResultsThe study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas. ConclusionsParametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients.

Adrenal masses in oncology patients

In the general population, adrenal masses are demonstrated in 2-9% of CT scans. Eighty per cent of these are benign cortical adenomas. However, in patients with cancer, over 50% of detected adrenal masses prove to be metastases. Despite this the techniques for the evaluation of adrenal masses in patients with cancer should be similar to patients without cancer and incidentally discovered adrenal masses. Extensive published material is now available on the diagnostic performance of CT, MRI and PET in the characterization of adrenal masses. It must be borne in mind, however, that these techniques are usually evaluated for their ability to positively identify adenomas. Other adrenal pathology also occurs incidentally and it is essential that the radiologist should be familiar with the range of appearances of this pathology. Examples of this include phaeochromocytomas, cysts, myelolipomas, haemorrhage and granulomatous infections. Furthermore, although cross-sectional imaging techniques, particularly when modified specifically to evaluate indeterminate adrenal masses, can prove to have an excellent diagnostic performance (with remarkably high specificity), all have limitations. It is a consideration of the relative comparative strengths and weaknesses of each of these imaging modalities that informs the choice of technique and interpretation of the findings. This short presentation outlines the key points relating to the most widely used techniques for evaluating the adrenal mass in patients with cancer and the evidence for their role in patient management.

Nouveautés en imagerie surrénalienne

Subclinical adrenocortical adenomas are the most frequent cause of adrenal incidentalomas that are present in 5 % of adult abdominal imaging. Pheochromocytomas and adrenocortical carcinomas, less often encountered tumors, should be diagnosed at an early stage. Unenhanced density with computed tomography below 10 Hounsfield Units (HU) is in favor of an adrenocortical adenoma. Higher unenhanced density should lead to a characterization of the vascularization with contrast-enhanced washout study. Some adrenal masses remain indeterminate after computed tomography scanning. Further diagnostic imaging performed by a multidisciplinary team is required. Progress has been made recently in the characterization of adrenal mass with nuclear medicine imaging. Flurodeoxyglucose positron emission tomography scan is a useful tool to suspect malignancy. Up-to-date imaging allows in the majority of cases to properly diagnose an adrenal tumor.

PET and PET/CT imaging in thyroid and adrenal diseases: an update

Positron emission tomography (PET) and PET/computed tomography (PET/CT) with different tracers are imaging methods increasingly used in patients with thyroid and adrenal diseases. The aim of this article is to provide an overview based on literature data about the usefulness of PET imaging in this setting. PET and PET/CT with different tracers have been used in patients with thyroid diseases including differentiated thyroid carcinoma, medullary thyroid carcinoma, and poorly differentiated and anaplastic thyroid carcinoma. The usefulness of 18F-FDG-PET and PET/CT in assessing indeterminate thyroid nodules at fine needle aspiration biopsy and the clinical relevance of thyroid incidental 18F-FDG uptake has also been evaluated. Currently, great interest is being shown in a variety of PET tracers that target specific characteristics of adrenal gland function, allowing a more accurate characterization of adrenal masses and staging of adrenal tumors. Since PET/CT using different tracers is an expensive diagnostic tool which necessitates ionizing radiation exposure, cost-effectiveness studies are needed in order to define the appropriate use of this diagnostic method in various endocrine disorders.

Multiparametric PET/CT in oncology

The standardized uptake value (SUV) and other measurements of tumour uptake of fluorodeoxyglucose (FDG) on positron emission tomography (PET) can potentially be supplemented by additional imaging parameters derived either from the PET images or from the computed tomography (CT) component of integrated PET/CT examinations including tumour size, CT attenuation, texture (reflecting tumour heterogeneity) and blood flow. This article illustrates the emerging benefits of such a multiparametric approach. Example benefits include greater diagnostic accuracy in characterization of adrenal masses achieved by using both the SUV and measured CT attenuation. Tumour size combined with the SUV can potentially improve the prognostic information available from PET/CT in oesophageal and lung cancer. However, greater improvements may be realized through using CT measurements of texture instead of size. Studies in breast and lung cancer suggest that combined PET/CT measurements of glucose metabolism and blood flow provide correlates for tumour proliferation and angiogenesis, respectively. These combined measurements can be utilized to determine vascular-metabolic phenotypes, which vary with tumour type. Uncoupling of blood flow and metabolism suggests a poor prognosis for larger more advanced tumours, high-grade lesions and tumours responding poorly to treatment. Vascular-metabolic imaging also has the potential to subclassify tumour response to treatment. The additional biomarkers described can be readily incorporated in existing FDG-PET examinations thereby improving the ability of PET/CT to depict tumour biology, characterize potentially malignant lesions, and assess prognosis and therapeutic response.

Characterization of adrenal masses with diffusion-weighted imaging

OBJECTIVE. The purpose of this article is to assess the role of diffusion-weighted MRI in characterizing adrenal masses. MATERIALS AND METHODS. A retrospective review of the MRI database from August 2007 to July 2009 was performed. The MRI examinations of 48 patients, with 49 lesions, were reviewed independently and blindly by two experienced abdominal radiologists who measured the signal intensities on in-phase and opposed-phase T1-weighted imaging and apparent diffusion coefficient (ADC). ADC measurements and quantitative parameters of chemical shift imaging (signal intensity index and adrenal-to-spleen ratio) were assessed separately and in combination. Lesions with indeterminate signal intensity index (< 16.5%) were considered benign if ADC was greater than or equal to 1.0 × 10–3 mm2/s and malignant if ADC was less than 1.0 × 10–3 mm2/s. Stepwise logistic regression analysis and receiver operating characteristic curves analysis were performed. RESULTS. There were 12 malignant and 37 benign lesions. On...