A primer on rectal MRI in patients on watch-and-wait treatment for rectal cancer.

Total neoadjuvant treatment (TNT) for rectal cancer is becoming an accepted treatment paradigm and is changing the landscape of this disease, wherein up to 50% of patients who undergo TNT are able to avoid surgery. This places new demands on the radiologist in terms of interpreting degrees of response to treatment. This primer summarizes the Watch-and-Wait approach and the role of imaging, with illustrative "atlas-like" examples as an educational guide for radiologists.

Follow-up imaging of anal cancer after treatment.

Anal cancer treatment response assessment can be challenging with both magnetic resonance imaging (MRI) and clinical evaluation considered essential. MRI, in particular, has shown to be useful for the assessment of treatment response, the detection of recurrent disease in follow up and surveillance, and the evaluation of possible post-treatment complications as well as complications from the tumor itself. In this review, we focus on the role of imaging, mainly MRI, in anal cancer treatment response assessment.

Imaging of Anal Squamous Cell Carcinoma: Survey Results and Expert Opinion from the Rectal and Anal Cancer Disease-Focused Panel of the Society of Abdominal Radiology.

The role and method of image-based staging of anal cancer has evolved with the rapid development of newer imaging modalities and the need to address the rising incidence of this rare cancer. In 2014, the European Society of Medical Oncology mandated pelvic magnetic resonance imaging (MRI) for anal cancer and subsequently other societies such as the National Comprehensive Cancer Network followed suit with similar recommendations. Nevertheless, great variability exists from center to center and even within individual centers.

Restaging MRI of Rectal Adenocarcinoma after Neoadjuvant Chemoradiotherapy: Imaging Findings and Potential Pitfalls.

Rectal adenocarcinoma constitutes about one-third of all colorectal adenocarcinoma cases. Rectal MRI has become mandatory for evaluation of patients newly diagnosed with rectal cancer because it can help accurately stage the disease, impact the choice to give neoadjuvant therapy or proceed with up-front surgery, and even direct surgical dissection planes. Better understanding of neoadjuvant chemoradiotherapy effects on rectal tumors and recognition that up to 30% of patients can have a pathologic complete response have opened the door for the nonsurgical "watch-and-wait" management approach for rectal adenocarcinoma.

Nodal drainage pathways in primary rectal cancer: anatomy of regional and distant nodal spread.

Nodal involvement is a significant prognostic factor in rectal cancer and difficult to assess preoperatively. An understanding of the patterns of nodal spread from different regions of the rectum can assist in this process and is essential for the purposes of surgical planning. In this article we define patterns of spread to mesenteric and pelvic sidewall nodal subgroups and discuss the importance of accurate anatomic localization of nodes for the purposes of staging and surgical planning.

MR staging of anal cancer: what the radiologist needs to know.

Anal canal cancer is a rare disease and squamous cell carcinoma is the most common histologic subtype. Traditionally, anal cancer is imaged with CT and PET/CT for purposes of TNM staging. With the increased popularity of MRI for rectal cancer evaluation, MRI has become increasingly utilized for local staging of anal cancer.

Diagnosis and Diagnostic Imaging of Anal Canal Cancer.

Anal canal cancer is an uncommon malignancy but one that is often curable with optimal therapy. Owing to its unique location, histology, risk factors, and usual presentation, a careful diagnostic approach is warranted. This approach includes an excellent history and physical examination, including digital rectal examination, laboratory data, and comprehensive imaging.

Variation in positron emission tomography use after colon cancer resection.

Purpose: Colon cancer surveillance guidelines do not routinely include positron emission tomography (PET) imaging; however, its use after surgical resection has been increasing. We evaluated the secular patterns of PET use after surgical resection of colon cancer among elderly patients and identified factors associated with its increasing use.

Patients And Methods: We used the SEER-linked Medicare database (July 2001 through December 2009) to establish a retrospective cohort of patients age ≥ 66 years who had undergone surgical resection for colon cancer.

Local magnetic resonance imaging staging of rectal adenocarcinoma.

Successful multidisciplinary evaluation of potentially resectable rectal adenocarcinoma depends on high-resolution preoperative magnetic resonance imaging (MRI). Magnetic resonance imaging accurately identifies important risk factors of local recurrence and distant metastasis, thus facilitating enhanced preoperative prognostic stratification and treatment. When combined with appropriate neoadjuvant chemotherapy and total mesorectal excision, the treatment of rectal cancer has dramatically improved.

Intraoperative sonography during open partial nephrectomy for renal cell cancer: does it alter surgical management?

Objective: The purpose of this study is to evaluate whether intraoperative ultrasound (IOUS) during open partial nephrectomy alters the surgical management for renal cell cancer (RCC).

Materials And Methods: One hundred ninety-eight consecutive patients undergoing IOUS during open partial nephrectomy for RCC were selected for retrospective review of clinical and imaging data. Patient age and sex, the local extent of the primary lesion, and the presence of additional lesions were recorded.

Optimization of MR imaging for pretreatment evaluation of patients with endometrial and cervical cancer.

Endometrial and cervical cancer are the most common gynecologic malignancies in the world. Accurate staging of cervical and endometrial cancer is essential to determine the correct treatment approach. The current International Federation of Gynecology and Obstetrics (FIGO) staging system does not include modern imaging modalities.

MR imaging of ectopic pregnancy with an emphasis on unusual implantation sites.

Ectopic pregnancy (EP) is a life-threatening condition and remains the leading cause of death in the first trimester of pregnancy, although the mortality rate has significantly decreased over the past few decades because of earlier diagnoses and great improvements in treatment. EP is most commonly located in the ampullary portion of the fallopian tube and rarely in unusual sites such as the interstitium, cervix, cesarean scar, anomalous rudimentary horn of the uterus and peritoneal abdominal cavity. MRI may confirm or give additional information to ultrasonography, which is the most user-dependent imaging modality.

Pretreatment high-resolution rectal MRI and treatment response to neoadjuvant chemoradiation.

Background: Use of rectal MRI evaluation of patients with rectal cancer for primary tumor staging and for identification for poor prognostic features is increasing. MR imaging permits precise delineation of tumor anatomy and assessment of mesorectal tumor penetration and radial margin risk.

Objective: The aim of this study was to evaluate the ability of pretreatment rectal MRI to classify tumor response to neoadjuvant chemoradiation.

MR imaging for preoperative evaluation of primary rectal cancer: practical considerations.

High-resolution magnetic resonance (MR) imaging plays a pivotal role in the pretreatment assessment of primary rectal cancer. The success of this technique depends on obtaining good-quality high-resolution T2-weighted images of the primary tumor; the mesorectal fascia, peritoneal reflection, and other pelvic viscera; and superior rectal and pelvic sidewall lymph nodes. Although orthogonal axial high-resolution T2-weighted MR images are the cornerstone for the staging of primary rectal cancer, high-resolution sagittal and coronal images provide additional value, particularly in tumors that arise in a redundant tortuous rectum.

Quality initiatives: CT radiation dose reduction: how to implement change without sacrificing diagnostic quality.

The risks and benefits of using computed tomography (CT) as opposed to another imaging modality to accomplish a particular clinical goal should be weighed carefully. To accurately assess radiation risks and keep radiation doses as low as reasonably achievable, radiologists must be knowledgeable about the doses delivered during various types of CT studies performed at their institutions. The authors of this article propose a process improvement approach that includes the estimation of effective radiation dose levels, formulation of dose reduction goals, modification of acquisition protocols, assessment of effects on image quality, and implementation of changes necessary to ensure quality.

Magnetic resonance imaging of cystic adnexal lesions during pregnancy.

Management of cystic adnexal lesions diagnosed during pregnancy is a challenging issue for obstetricians. The range of treatment options changes from immediate surgery to close follow-up. This pictorial essay illustrates the magnetic resonance imaging findings of various cystic adnexal lesions in pregnant patients.

Gadolinium-based contrast exposure, nephrogenic systemic fibrosis, and gadolinium detection in tissue.

Objective: The objective of our study was to retrospectively review one institution's cases of nephrogenic systemic fibrosis (NSF), evaluate possible associated factors, determine the prevalence of NSF, and search for gadolinium in skin samples obtained from patients with NSF.

Materials And Methods: A retrospective review of our dermatopathology database from 1997 to 2007 was performed to search for patients with NSF. The records of patients with NSF were reviewed for factors suspected to be associated with NSF such as acidosis, low hemoglobin levels, low serum calcium levels, inflammatory conditions, serum antibodies, pharmaceutical erythropoietin, angiotensin-converting enzyme inhibitors, gadolinium-based contrast agents (GBCAs), renal failure, and dialysis.

MR imaging in the triage of pregnant patients with acute abdominal and pelvic pain.

Purpose: To retrospectively assess the performance of MR imaging in the evaluation and triage of pregnant patients presenting with acute abdominal or pelvic pain.

Method And Materials: MRI studies of pregnant patients who were referred for acute abdominal pain between 2001 and 2007 were included. MR images were retrospectively reviewed and compared with surgical and pathologic findings and clinical follow-up data.

Magnetic resonance imaging of the chest, abdomen, and pelvis in the evaluation of pregnant patients with neoplasms.

This article illustrates the magnetic resonance (MR) technique and MR imaging (MRI) findings of various neoplasms in chest, abdomen, and pelvis in pregnant patients. MRI can provide useful information about characterization and staging of maternal neoplasms without exposing the fetus to ionizing radiation and can be considered as a first-line cross sectional imaging method as an adjunct to ultrasonography.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia is an extremely rare pulmonary lesion, with only 39 cases reported in the literature. We report an additional case and review the literature. The patient is a 41-year-old man with a 5-year history of progressive dyspnea, cough, and wheezing.

Localization of appendix with MDCT and influence of findings on choice of appendectomy incision.

Objective: The purpose of this study was to show the relation between McBurney's point and the appendix in patients undergoing 3D MDCT and to investigate the effect of this information on a surgeon's choice of appendectomy incision.

Material And Methods: Among 142 adults undergoing consecutive MDCT studies, 100 patients (35 women, 65 men; mean age, 52.1 years) with an identifiable appendix on abdominopelvic MDCT examinations were selected for the study group.

Mimicks of pancreatic malignancy in patients with chronic pancreatitis: correlation of computed tomography imaging features with histopathologic findings.

Differentiation of chronic pancreatitis and pancreatic carcinoma can be a clinical and radiologic dilemma. Several patients with chronic pancreatitis can undergo unnecessary major abdominal surgery for benign lesions. This pictorial review illustrates the computed tomographic findings and histopathologic features of lesions mimicking pancreatic neoplasm in patients with chronic pancreatitis.