Nishat Bharwani

Adrenocortical Carcinoma: The Range of Appearances on CT and MRI

OBJECTIVE Adrenocortical carcinoma (ACC) is a rare, aggressive tumor arising from the adrenal cortex that typically presents late with a large mass. The increased use of cross-sectional imaging for unrelated reasons has led to a greater number of ACCs being detected incidentally at an earlier stage. Recognition of the typical clinical, biochemical, and imaging findings is imperative for rapid diagnosis, prompt intervention, and early use of the appropriate therapy. CONCLUSION Cross-sectional imaging with CT and MRI is essential for determining the extent of local and distant tumor spread. Complete surgical resection is currently the only potentially curative treatment of ACC, and the information attained from CT and MRI is important to guide surgery and further patient management.

MRI appearances of uterine malignant mixed müllerian tumors.

OBJECTIVE Uterine malignant mixed müllerian tumors (MMMTs) are rare aggressive tumors with a high incidence of lymphatic, peritoneal, and pulmonary metastases. Preoperative differentiation from endometrial adenocarcinoma would be beneficial because their prognoses differ. MATERIALS AND METHODS We retrospectively reviewed MRI examinations of 51 histologically confirmed MMMTs. Tumor size, growth pattern, and imaging characteristics were recorded. Data were compared with MRI appearances of 73 endometrial adenocarcinomas. RESULTS On T1-weighted images, MMMTs were predominantly isointense to myometrium (76%) and endometrium (71%), with heterogeneous texture in 33% of cases and hyperintense foci in 27% of cases. On T2-weighted images, 92% of MMMTs were hyperintense to myometrium and either hypointense (55%) or isointense (41%) to endometrium. In 12% of cases, large heterogeneous MMMTs obliterated uterine architecture and were aggressive in appearance, whereas in 88% of cases, the appearances were indistinguishable from those of endometrial adenocarcinoma. Significantly more MMMTs than endometrial adenocarcinomas had cervical invasion (p = 0.008) and nodal enlargement (p = 0.00008). Dynamic contrast-enhanced images (available for 19 of 51 patients) obtained at less than 1 minute after administration of contrast agent showed MMMT enhancement to be hypointense (42%; 5/12 patients) or isointense (33%; 4/12 patients) to myometrium; between 1 and 4 minutes after administration of contrast agent, tumors were hypointense (58%; 7/12 patients); and at more than 4 minutes after administration of contrast agent (n = 18), MMMTs were isointense in 56% of cases. This finding is significantly different from that for endometrial adenocarcinoma, where enhancement is less than that of myometrium in 90% of cases (p = 4 × 10⁻⁸). CONCLUSION MMMTs do not have a pathognomonic MRI appearance. However, radiologic suspicion should increase in the presence of large heterogeneous infiltrative tumors or when tumoral enhancement equals or exceeds that of myometrium.

Centrally Infiltrating Renal Masses on CT: Differentiating Intrarenal Transitional Cell Carcinoma From Centrally Located Renal Cell Carcinoma

OBJECTIVE The objective of our study was to retrospectively determine the accuracy of CT for differentiating intrarenal transitional cell carcinoma (TCC) from centrally located renal cell carcinoma (RCC) and to define the most discriminating diagnostic CT features. MATERIALS AND METHODS CT studies of 98 pathologically proven central renal tumors (64 centrally located RCCs and 34 intrarenal TCCs) seen over 5 years at three university hospitals were reviewed by five specialty-trained radiologists who were blinded to the final diagnosis. Multiple CT features and global impression were graded on a 4-point score. The sensitivity and specificity of each feature and of global assessment were calculated and compared using receiver operating characteristic (ROC) analysis. Interobserver agreement (kappa values) was also calculated for each parameter. RESULTS All five readers recognized intrarenal TCCs with a high diagnostic accuracy (sensitivity, 90%; specificity, 90%; area under ROC curve [AUC], 0.80-0.95 for global assessment) with moderate-to-excellent interobserver agreement (κ = 0.72-1). Six CT features were most diagnostically specific for identifying intrarenal TCCs: tumor centered within the collecting system; focal filling defect in the pelvicalyceal system; preserved renal shape; absence of cystic or necrotic change; homogeneous tumor enhancement; and tumor extension toward the ureteropelvic junction (sensitivity, 68-82%; specificity, 79-89%; AUC, 0.75-0.84). There was moderate-to-good agreement among the readers over all these features (κ = 0.44-0.69). CONCLUSION Intrarenal TCC can be recognized with a high accuracy on CT; global impression showed the best diagnostic performance. A solid, homogeneously enhancing mass that is centered on the collecting system and extends toward the ureteropelvic junction combined with a focal pelvicalyceal filling defect and preserved renal outline is more likely to be an intrarenal TCC than a centrally located RCC.

FDG PET/CT Pitfalls in Gynecologic and Genitourinary Oncologic Imaging

The role of whole-body positron emission tomography (PET)/computed tomography (CT) with fluorodeoxyglucose ( FDG fluorodeoxyglucose ) is now established in the assessment of many gynecologic and genitourinary malignant tumors. FDG fluorodeoxyglucose PET/CT has been widely adopted for staging assessments in patients with suspected advanced disease, in cases of suspected disease recurrence, and for determining prognosis in a number of malignancies. A number of pitfalls are commonly encountered when reviewing FDG fluorodeoxyglucose PET/CT scans in gynecologic and genitourinary cases; these pitfalls can be classified into those that yield potential false-positive or false-negative results. Potential false positives include physiologic uptake of FDG fluorodeoxyglucose by the endometrium and ovaries in premenopausal patients, physiologic renal excretion of FDG fluorodeoxyglucose into the ureters and the urinary bladder, and increased FDG fluorodeoxyglucose activity in benign conditions such as uterine fibroids, pelvic inflammatory disease, and benign endometriotic cysts. Potential false negatives include low-level FDG fluorodeoxyglucose uptake by necrotic, mucinous, cystic, or low-grade tumors and the masking of serosal and peritoneal disease by adjacent physiologic bowel or bladder activity. In addition, there are inherent technical limitations-such as motion artifact (from respiratory motion and bowel peristalsis) and the limited spatial resolution of PET-that may limit the assessment of small-volume malignant disease. Knowledge of the key imaging features of physiologic and nonphysiologic FDG fluorodeoxyglucose uptake, in addition to understanding the principles of adequate patient preparation and PET scanning protocols, is important for accurate interpretation of gynecologic and genitourinary oncologic FDG fluorodeoxyglucose PET/CT studies. ©RSNA, 2017.

Post-Radiation Therapy Imaging Appearances in Cervical Carcinoma.

Locally advanced and node-positive cervical cancers are usually treated with external beam radiation therapy and intracavitary brachytherapy with concomitant chemotherapy. In patients with locally advanced cervical cancer, imaging plays a vital role in pretreatment planning, assessment of primary tumor response to treatment, follow-up, and evaluation of treatment-related complications. Radiation therapy planning is crucial to successful local and regional control of disease. Patient selection criteria for radiation therapy with concomitant chemotherapy are described, as is assessment of treatment response of the primary cervical tumor at magnetic resonance (MR) imaging. Image interpretation can be challenging because of radiation therapy-related changes in the pelvic organs. Expected changes in the bladder, bowel, and bone marrow after radiation therapy are described, and multimodality imaging findings at computed tomography, MR imaging, and fluorine 18 fluorodeoxyglucose positron emission tomography are illustrated. Complications after radiation therapy have declined over recent years because of targeted radiation therapy. These complications can be divided into acute and chronic effects, where acute toxic effects occur within weeks of treatment. Chronic complications include cervical stenosis, small bowel stricture, fistula formation, and insufficiency fractures. Imaging is an essential tool in the care of patients with cervical cancer treated with chemotherapy and radiation therapy. The reporting radiologist should be familiar with the expected imaging appearances of the pelvic organs after radiation therapy, as well as potential complications, to avoid pitfalls in image interpretation.

Cervical Cancer Staging: A Resident's Primer: Women's Imaging.

This presentation provides a pictorial correlation between the MR imaging appearances of cervical cancer and the FIGO (2009) staging system and highlights various pitfalls that may lead to misinterpretation. Furthermore, use of contrast-enhanced CT and FDG PET/CT for detection of distal spread of disease is demonstrated. The value of imaging in follow-up of recurrent disease is discussed.

Subfertility: What the Radiologist Needs to Know

The role of imaging in subfertility is well established but is changing. In addition to traditional fertility assessments, there is an emerging role for the radiologist. The role of imaging in fertility-restoring procedures in benign disease and congenital malformations is evolving, and there is a growing need for accurate identification of young candidates suitable for fertility-preserving surgery in the oncologic setting. To facilitate this developing role, knowledge of the key imaging modalities used and potential therapeutic applications is important for accurate diagnosis and interpretation by the radiologist. ©RSNA, 2017.

MRI reporting standard for chronic pelvic pain: consensus development

AIM To identify radiological parameters that should be reported on gynaecological MRI in order to create a standardized assessment pro forma for reporting CPP, which may be used in clinical practice. METHODS Chronic pelvic pain (CPP) in females is a common problem presenting a major challenge to healthcare providers. The complex multifactorial aetiology requires a multidisciplinary approach and often necessitates diagnostic laparoscopy for assessment. MRI is emerging as a potential non-invasive alternative for evaluation of CPP; however, standardization of reporting is required for it to be used in routine clinical practice. A two-generational Delphi survey with an expert panel of 28 radiologists specializing in gynaecological MRI from across the UK was used to refine a proposed reporting template for CPP. RESULTS 75% response rate for the first round and 79% for the second. Following the second round, agreement was reached on the structure of the pro forma and the way in which information was sought, with overall consistency of agreement between experts deemed as fair (intraclass correlation coefficient = 0.394). This was accepted as the final version by consensus. CONCLUSION The standardized pro forma developed in this study will form the basis for future prospective evaluation of MRI in CPP. This template could be modified for the assessment of other benign gynaecological conditions. ADVANCES IN KNOWLEDGE Female CPP is a significant problem presenting challenges for clinicians. MRI is often used for evaluation and standardization of techniques, and reporting is required. The pro forma developed in this study will form the basis for future prospective MRI evaluation.