SAR user guide to the rectal MR synoptic report (primary staging).

Rectal MR is the key diagnostic exam at initial presentation for rectal cancer patients. It is the primary determinant in establishing clinical stage for the patient and greatly impacts the clinical decision-making process. Consequently, structured reporting for MR is critically important to ensure that all required information is provided to the clinical care team. The SAR initial staging reporting template has been constructed to address these important items, including locoregional extent and factors impacting the surgical approach and management of the patient. Potential outputs to each item are defined, requiring the radiologist to commit to a result. This provides essential information to the surgeon or oncologist to make specific treatment deisions for the patient. The SAR Initial Staging MR reporting template has now been officially adopted by the NAPRC (National Accreditation Program for Rectal Cancer) under the American College of Surgery. With the recent revisions to the reporting template, this user guide has been revamped to improve its practicality and support to the radiologist to complete the structured report. Each line item of the report is supplemented with clinical perspectives, images, and illustrations to help the radiologist understand the potential implications for a given finding. Common errors and pitfalls to avoid are highlighted. Ideally, rectal MR interpretation should not occur in a vacuum but in the context of a multi-disciplinary tumor board to ensure that healthcare providers use common terminology and share a solid understanding of the strengths and weaknesses of MR.

Advances in radiological staging of colorectal cancer.

The role of imaging in clinically staging colorectal cancer has grown substantially in the 21st century with more widespread availability of multi-row detector computed tomography (CT), high-resolution magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI), and integrated positron-emission tomography (PET)/CT. In contrast to staging many other cancers, increasing colorectal cancer stage does not highly correlate with survival. As has been the case previously, clinical practice incorporates advances in staging and it is used to guide therapy before adoption into international staging guidelines. Emerging imaging techniques show promise to become part of future staging standards.

Prostatitis: imaging appearances and diagnostic considerations.

Acute and chronic inflammation of the prostate gland can be attributed to several underlying aetiologies, including but not limited to, bacterial prostatitis, granulomatous prostatitis, and Immunoglobulin G4-related prostatitis. In this review, we provide an overview of the general imaging appearances of the different types of prostatitis, their distinguishing features and characteristic appearances at cross-sectional imaging. Common imaging pitfalls are presented and illustrated with examples.

Tumour markers and their utility in imaging of abdominal and pelvic malignancies.

The utility of tumour biomarkers has increased considerably in the era of personalised medicine and individualised therapy in oncology. Biomarkers may be prognostic or predictive, and only a handful of markers are currently US Food and Drug Administration (FDA)-approved for clinical use. Tumour markers have a wide array of uses such as screening, establishing a differential diagnosis, assessing risk, prognosis, and treatment response, as well as monitoring disease status. Major overlap exists between biomarkers and their associated pathologies; therefore, despite suggestive imaging features, establishing a differential diagnosis may be challenging for the radiologist. We review common biomarkers that are of interest to radiologists such as carcinoembryonic antigen (CEA), lactate dehydrogenase (LDH), prostate-specific antigen (PSA), beta human chorionic gonadotropin (ß-hCG), carbohydrate antigen 19-9 (CA 19-9), alpha fetoprotein (AFP), and carbohydrate or cancer antigen 125 (CA 125), as well as their associated malignant and non-malignant pathologies. We also present relevant case examples from our practice.

Aetiology, imaging features, and evolution of spontaneous perirenal haemorrhage.

AIM: To evaluate the aetiology, imaging features, and the evolution of spontaneous perirenal haemorrhage detected by imaging. MATERIALS AND METHODS: In this retrospective study, the hospital database was searched for all cases of spontaneous perinephric haemorrhage detected by imaging between January 2000 and December 2012. Imaging examinations were reviewed and the following parameters were recorded: the location, extension, and total volume of the haematoma, presence of active extravasation, the haematocrit effect, and highest density. The resolution time was calculated using follow-up imaging. The final aetiology for all cases was assessed via clinical, radiological, and histopathological data. Differences in imaging features of haemorrhage according to aetiology group were analysed with independent samples test and Fisher's exact test. RESULTS: Eighty-one haematomas were identified in 78 patients during this 13-year period. Causes of perirenal haemorrhage included coagulation disorders (22/81, 27.1%), ruptured renal cyst (11/81, 13.6%), rupture of abdominal aortic aneurysm (9/81, 11.1%), renal cell carcinoma (9/81, 11.1%), adrenal masses (9/81, 11.1%), polycystic kidney disease (7/81, 8.6%), angiomyolipoma (6/81, 7.4%), renal vascular diseases (2/81, 2.4%), and recurrent pyelonephritis (1/81, 1.2%). Haematomas associated with coagulation abnormalities and vascular diseases presented with larger volumes and were more likely to extent to the pararenal space more so than other groups; ruptured renal cyst and renal cell carcinomas tended to be more associated with subcapsular haematomas. The haematocrit effect and haemorrhage involving renal parenchyma were more often observed in the group with coagulation abnormalities. CONCLUSION: Imaging features, such as location and extension, could help radiologists identify possible aetiologies of spontaneous perirenal haemorrhage.

Apparent diffusion coefficient as a non-invasive predictor of treatment response and recurrence in locally advanced rectal cancer.

AIM: To evaluate the role of pretreatment apparent diffusion coefficient (ADC) as a predictor of treatment response and local recurrence in patients with locally advanced rectal cancer who underwent neoadjuvant therapy. MATERIALS AND METHODS: Forty-nine patients who underwent preoperative diffusion-weighted magnetic resonance imaging (MRI) followed by neoadjuvant chemoradiation and surgery were enrolled in the study. The mean tumour ADC was measured independently from multiple, non-overlapping regions of interest (ROIs) to cover the entire tumour area on a single section by two radiologists and patients were followed postoperatively for a median of 16.4 months. Diagnostic accuracy of ADC for predicting treatment response and recurrence was evaluated using the area under the receiver-operating characteristic (ROC) curve, sensitivity, specificity, and predictive values. Univariate and multivariate analyses including clinical tumour (cT) staging, carcinoembryonic antigen (CEA) level, lymph-node involvement, tumour grade, surgical margin, vascular involvement, and ADC were performed with respect to recurrence. Interobserver agreement of ADC values was assessed. RESULTS: Twenty patients showed response to neoadjuvant therapy and recurrence was noted in 17 patients. Low pretreatment ADC, MRI findings of cT4 staging, and node involvement were significantly related to poor treatment response. Sensitivity and specificity of ADC = 0.833 × 10(-3) mm(2)/s for prediction of treatment response was 75 and 48% for reader 1 and 65 and 52% for reader 2, respectively. Univariate and multivariate analyses identified pretreatment tumour ADC as the only predictive factor for recurrence. Sensitivity and specificity of ADC = 0.833 × 10(-3) mm(2)/s for prediction of recurrence was 86 and 77% for reader 1 and 80 and 69% for reader 2, respectively. Interobserver agreement for measuring ADC was good with a kappa value of 0.70. CONCLUSION: Pretreatment rectal tumour ADC values may be an early biomarker for predicting treatment response and local recurrence in patients who underwent neoadjuvant chemoradiation.

Hepatic manifestations of tuberous sclerosis complex: a genotypic and phenotypic analysis.

Hepatic manifestations of tuberous sclerosis complex: a genotypic and phenotypic analysis. A retrospective review of the clinical records and radiological images of 205 patients with tuberous sclerosis complex (TSC) was performed to evaluate the prevalence and progression of hepatic lesions; examine the association of hepatic phenotype with genotype, age, and gender; and investigate the relationships between hepatic, renal, and pulmonary involvement. Hepatic angiomyolipomas (AML), cysts, and other benign lesions were identified in 30% of the cohort, and some lesions grew significantly over time. However, no patient had clinical symptoms or complications from hepatic lesions. TSC2 patients exhibited a higher frequency of AML compared to TSC1 patients (p = 0.037), and patients with no mutation identified exhibited a higher frequency of cysts compared to TSC2 patients (p = 0.023). Age was positively correlated with frequency of hepatic involvement (p < 0.001), whereas hepatic phenotype was independent of gender. Presence of hepatic AML was associated with presence of renal AML (p = 0.001). These findings confirm a high rate of asymptomatic hepatic lesions in TSC and further characterize the TSC phenotype.

Pancreatic neuroendocrine tumors in patients with tuberous sclerosis complex.

We explored pancreatic neuroendocrine tumors (PanNETs) associated with tuberous sclerosis complex (TSC) to determine their incidence in the TSC population; define their clinical, radiological, and pathological characteristics; and investigate their association with underlying genotypes. Retrospectively reviewed abdominal imaging of 219 patients with TSC, evaluating the incidence, size, and architecture of pancreatic lesions. Pathology records at Massachusetts General Hospital (MGH) were reviewed for all PanNET diagnoses in patients with TSC. Literature was reviewed for TSC-related PanNET cases. Nine patients with TSC were found to have a pancreatic lesion(s) on abdominal imaging and six patients have been diagnosed with a PanNET by pathology at MGH. Twelve cases of TSC-associated PanNETs have been reported in the literature. Of these 18 PanNET cases, one third were cystic, and the average age at resection was 26 years. Germline TSC2 mutations were found in all patients for whom genetic data were available (n = 3). We did not identify pancreatic angiomyolipomas in this series. Our results suggest that PanNETs are the most common pancreatic lesion in patients with TSC. Focal pancreatic mass lesions, solid or cystic, in patients with TSC should be considered possible PanNETs, and resection of the lesion may be clinically indicated.

Focal therapy in prostate cancer-report from a consensus panel.

PURPOSE: To establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer. MATERIAL AND METHODS: Urologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted. RESULTS: Candidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage

Nodal staging in genitourinary cancers.

In patients with genitourinary cancers nodal staging is an integral part of the pretreatment evaluation. The presence of nodal metastatic disease plays an important role in predicting prognosis and treatment planning. Although some nodal groups can be evaluated clinically, most patients undergo various imaging studies for nodal staging. Each modality has its own unique attributes and applications. This article reviews various imaging modalities, namely, contrast enhanced computerized tomography, magnetic resonance imaging (MRI), and positron emission tomography, used for nodal staging in patients with genitourinary cancers and highlights their strengths and weaknesses. Emerging novel techniques such as lymphotropic nanoparticle enhanced MRI are also highlighted.

Lymphotrophic nanoparticle enhanced MR imaging (LNMRI) for lymph node imaging.

Nodal staging is an integral part of the pretreatment staging of any patient with malignancy and has therapeutic and prognostic implications. Currently used imaging techniques used for nodal evaluation are limited in accuracy because they rely on size criteria for the detection of metastases. This has led to the emergence of lymphotropic nanoparticle enhanced magnetic resonance imaging as a promising tool for nodal characterization. This article reviews the properties of lymphotropic iron oxide nanoparticles and the technique, image interpretation, and initial clinical experience with lymphotropic nanoparticle enhanced magnetic resonance imaging.

Case report. Hepatic portal venous gas: transient radiographic finding associated with colchicine toxicity.

Hepatic portal venous gas has traditionally been associated with a grave prognosis and high mortality. However, with the advent of ultrasound and CT, numerous less serious causes have been associated with this dramatic radiological finding. We present a previously unreported association with colchicine toxicity. The patient ingested a large dose of colchicine and was subsequently found to have portal venous gas on CT. The source of gas was felt to be intestinal gas penetrating through the demonstrated bowel injury. No surgical intervention was deemed necessary and the finding resolved spontaneously.

Halo sign: useful CT sign for differentiating benign from malignant colonic disease.

AIM: To evaluate the halo sign for accurately distinguishing benign from malignant colonic wall thickening. MATERIALS AND METHODS: Computed tomography (CT) examinations of 92 patients (70 men; 22 women; mean age 57 years) with pathologically proven colonic wall thickening (51 benign and 41 malignant) were retrospectively reviewed in a blinded fashion. The affected segment was assessed for presence of the halo sign, degree and uniformity of thickness and density of the intramural stratum. RESULTS: The halo sign was present in 74.5% (38/51) patients with benign and 7.3% (3/41) patients with malignant bowel disease. The presence of the halo sign was 75.4% sensitive and 92.5% specific for benign bowel wall thickening. All 38 benign halos showed uniform, continuous stratification; only one of three malignant halos met the strict criteria for benign halo. CONCLUSION: The halo sign is a moderately sensitive and highly specific sign for distinguishing benign from malignant bowel wall thickening. However, it is not pathognomonic for benign disease. Detailed analysis of halo characteristics is necessary to improve the usefulness of this finding.

Predictive value of benign percutaneous adrenal biopsies in oncology patients.

PURPOSE: Percutaneous CT guided biopsy is accepted as a safe procedure for the diagnosis of indeterminate adrenal masses in oncologic patients. The purpose of this study was to evaluate the accuracy of a 'negative for tumour' adrenal biopsy in the oncologic patient population by assessing subsequent outcome including clinical course, size and imaging characteristics of the adrenal lesions on follow-up imaging studies and pathological findings at re-biopsy or following adrenal mass resection. MATERIALS AND METHODS: Retrospective analysis of 225 oncological patients (FM, 128;87; age range 33-87 years, mean age 66 years) who had undergone CT guided biopsies of an adrenal mass over a 5-year period was performed. Those patients with a report consistent with 'negative for malignancy' were evaluated by reviewing the medical records for patient demographics, primary malignancy, histology of adrenal tumour, subsequent surgical interventions, repeat adrenal biopsy under image guidance, by open surgery or at autopsy, subsequent abdominal imaging in which the adrenal gland was imaged, and long-term outcome including hospital admissions, or death. RESULTS: Of the 225 CT-guided adrenal biopsies performed, 41 (18%) were negative for neoplasm. The primary neoplasm in these 41 patients included lung cancer (n=32), breast (n=5), renal cell carcinoma (n=2), bladder (n=1), and prostate (n=1). The size of the adrenal lesions ranged from 2.8-5 cm. Of the 41 biopsies, which were negative for tumour; 10 were identified as adenomas and the rest showed benign adrenal cortical cells or hyperplasia on cytopathology and histopathology. Repeat biopsies were obtained in 13/41 (31%) patients; whereas 2/41 (5%) had their adrenal gland analyzed on post mortem examination. None of these 15 repeat evaluations yielded tumour. CONCLUSION: In oncological patients, pathological analysis of tissue samples obtained by CT-guided percutaneous biopsy, suggesting benign aetiology, is reliable and predicts a benign course on long-term follow-up. A negative or benign pathology result for a CT guided percutaneous adrenal biopsy can be regarded as a true negative evaluation in oncological patients with no necessity to repeat the biopsy.

Splenic imaging with ultrasmall superparamagnetic iron oxide ferumoxtran-10 (AMI-7227): preliminary observations.

PURPOSE: Ferumoxtran-10 (ultrasmall superparamagnetic iron oxide; Combidex, AMI-7227) is a long-circulating MR contrast agent with reticuloendothelial uptake known to enhance tissue T1 and T2 relaxation rates. The purpose of this study was to assess the effect of ferumoxtran-10-enhanced MRI in evaluating focal splenic lesions. METHOD: Eighteen patients underwent MR evaluation of the spleen. Two of these patients with exophytic normal splenic tissue (splenules) and 13 of these patients with 24 focal splenic lesions (7 cysts, 2 hemangiomas, 7 metastases, 1 infarct, 7 lymphoma) were assessed by T1-weighted gradient echo and T2-weighted fast SE MRI following intravenous administration of ferumoxtran-10 (1.1 mg of Fe/kg). Qualitative analysis involving improved lesion detection and/or characterization, additional information from postcontrast images affecting staging, and patient management was performed. Quantitative measurements of lesion-to-spleen contrast-to-noise ratio were also performed. RESULTS: Additional information was provided by ferumoxtran-10-enhanced images in 15 of 18 patients. In 8 of 15 (53%) patients, improved lesion detection (i.e., number of lesions) was obtained on contrast-enhanced images. Improved lesion visualization (i.e., conspicuity) was noted in 11 of 15 (73%) of patients. In 10 of 15 (67%) patients, postcontrast imaging provided additional information leading to lesion characterization. Staging of disease and patient management were affected in 5 of 15 (33%) and 6 of 15 (40%) patients, respectively. CONCLUSION: Ferumoxtran-10 is a promising contrast agent for the evaluation of focal splenic lesions.

MRI contrast agents for evaluating focal hepatic lesions.

Contrast-enhanced magnetic resonance imaging (MRI) has become an important tool in the detection and characterization of focal hepatic lesions especially when other investigations such as ultrasound (US) and computed tomography (CT) are inconclusive. The purpose of this pictorial review is to briefly summarize the properties of various MRI contrast agents used in hepatic imaging and to highlight their role in evaluation of focal hepatic lesions.

MR imaging of the liver with Gd-BOPTA: quantitative analysis of T1-weighted images at two different doses.

This study evaluates the efficacy of gadobentate-dimeglumine (Gd-BOPTA) for enhancement of liver signal-to-noise ratio (SNR) and lesion-liver contrast-to-noise ratio (CNR) on T1-weighted spin-echo (SE) and gradient-recalled-echo (GRE) images at two different doses. Fifty patients with known or suspected liver lesions were examined at 1.5 T. T1-weighted SE (TR/TE 300/12 msec) and GRE images (TR/TE80/4.2 msec/flip angle 80 degrees) were obtained before and at 40-80 minutes and 90-120 minutes after administration of 0.05 or 0.1 mmol/kg Gd-BOPTA. Quantitative measurements of tissue signal intensity were performed at each dose. Liver showed significant enhancement after Gd-BOPTA on T1-weighted SE and GRE images (0.05 mmol: P < 0.05; 0.1 mmol: P < 0.001). The dose of 0.1 mmol/kg provided higher liver SNR than 0.05 mmol/kg. Mean liver SNR was higher on GRE than SE images (P < 0.0001). Lesion-liver CNR significantly increased on GRE images after 0.1 mmol (P < 0.05). There was a trend toward superiority of 0.1 mmol over 0.05 mmol/kg. GRE images were superior to SE images for pre- and post Gd-BOPTA lesion-liver CNR (P < 0.05). Our study suggests that Gd-BOPTA provides prolonged enhancement of liver SNR and CNR, that a dose of 0.1 mmol/Kg appears to be superior than 0.05 mmol/Kg, and that GRE techniques should be used in preference over SE techniques.

MR lymphangiography using ultrasmall superparamagnetic iron oxide in patients with primary abdominal and pelvic malignancies: radiographic-pathologic correlation.

OBJECTIVE: The purpose of this study was to administer ultrasmall superparamagnetic iron oxide (USPIO) and compare changes in signal intensity of lymph nodes in patients with primary abdominal and pelvic malignancies. Also, we correlated radiographic with pathologic findings. SUBJECTS AND METHODS: Nineteen patients with proven primary abdominal or pelvic cancer (prostatic [n = 10]; colonic [n = 5]; endometrial [n = 1]; Merkel cell tumor [n = 1]; lymphoma [n = 1]; seminoma [n = 1]) were enrolled as part of our phase II and phase III clinical trials. In these patients, 49 lymph nodes (mean size, 1.4 cm) revealed on CT or MR imaging were evaluated on T1-weighted spin-echo, T2-weighted fast spin-echo, and T2*-weighted gradient-echo MR imaging at 1.5 T 24-36 hr after IV administration of USPIO. Quantitative analyses used measurements of unenhanced and enhanced region-of-interest values in lymph nodes. Qualitative assessment used subjective evaluation and classification of changes in signal intensity. All patients underwent lymph node biopsy or surgical dissection followed by histopathologic correlation. RESULTS: Of the 49 lymph nodes that were evaluated, 20 were benign and 29 were malignant. A decrease in nodal signal intensity on enhanced T2-weighted and T2*-weighted gradient-echo images was seen in 20 benign lymph nodes and two malignant lymph nodes. No appreciable signal change was noted in 27 of the 29 malignant lymph nodes. The mean signal intensity on fast spin-echo T2-weighted images for benign lymph nodes changed from 186.48 (unenhanced) to 73.66 (enhanced). Conversely, mean signal intensity for malignant lymph nodes was relatively unchanged from 191.17 (unenhanced) to 183.18 (enhanced). CONCLUSION: USPIO appears to be a useful MR contrast agent for characterizing benign and malignant lymph nodes based on the enhancement criteria evaluated in our study.

Imaging guided biopsy of renal masses: indications, accuracy and impact on clinical management.

PURPOSE: We evaluated the indications, accuracy and impact of image guided biopsy of focal renal masses. MATERIALS AND METHODS: We retrospectively reviewed 79 image guided renal biopsies in 73 patients. Indications, imaging, and histological and clinical features were analyzed. We assumed that nephrectomy, partial nephrectomy or surgical biopsy of suspicious masses would be done when no percutaneous biopsy had been performed. A change in management was defined as surgical to nonsurgical. RESULTS: Clinical management was altered due to results in 32 of the 79 biopsies (41%) in cases managed nonoperatively, including positive and negative biopsies in those followed clinically and with imaging. Of 79 biopsies 49 (62%) were diagnosed positive for malignancy, including 15 (31%) that were not and 34 (69%) that were renal cell carcinoma. The histological diagnosis was negative on 25 biopsies (32%) and positive or negative on 74 (94%). All 5 of the 79 false-negative biopsies (6%) were due to insufficient tissue and involved highly suspicious imaging findings that required further evaluation, such as repeat biopsy or surgery. Renal cell carcinoma was identified in 4 of the 5 cases. In 12 of the 24 patients (50%) with a pre-biopsy history of nonrenal cancer biopsies were diagnostic of nonrenal cancer. No patient had major complications and in 4 small hematomas were treated with observation only. CONCLUSIONS: Image guided renal mass biopsy is safe, reliable and accurate, and it changes clinical management in many cases by avoiding nephrectomy or other surgical options. Radiologists should promote imaging guided biopsy as a potentially useful option for managing suspicious or indeterminate renal masses.