Li-Fraumeni Syndrome: Imaging Features and Guidelines.

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant familial cancer syndrome caused by germline mutations of the tumor protein p53 gene (TP53), which encodes the p53 transcription factor, also known as the "guardian of the genome." The most common types of cancer found in families with LFS include sarcomas, leukemia, breast malignancies, brain tumors, and adrenocortical cancers. Osteosarcoma and rhabdomyosarcoma are the most common sarcomas. Patients with LFS are at increased risk of developing early-onset gastric and colon cancers. They are also at increased risk for several other cancers involving the thyroid, lungs, ovaries, and skin. The lifetime risk of cancer in individuals with LFS is greater than 70% in males and greater than 90% in females. Some patients with LFS develop multiple primary cancers during their lifetime, and guidelines have been established for screening these patients. Whole-body MRI is the preferred modality for annual screening of these patients. The management guidelines for patients with LFS vary, as these individuals are more susceptible to developing radiation-induced cancers-for example, women with LFS and breast cancer are treated with total mastectomy instead of lumpectomy with radiation to the breast. The authors review the role of imaging, imaging guidelines, and imaging features of tumors in the setting of LFS. ©RSNA, 2024 Supplemental material is available for this article.

The Role of Imaging for Gastrointestinal Bleeding: Consensus Recommendations From the American College of Gastroenterology and Society of Abdominal Radiology.

Gastrointestinal (GI) bleeding is the most common GI diagnosis leading to hospitalization within the United States. Prompt diagnosis and treatment of GI bleeding is critical to improving patient outcomes and reducing high healthcare utilization and costs. Radiologic techniques including computed tomography angiography, catheter angiography, computed tomography enterography, magnetic resonance enterography, nuclear medicine red blood cell scan, and technetium-99m pertechnetate scintigraphy (Meckel scan) are frequently used to evaluate patients with GI bleeding and are complementary to GI endoscopy. However, multiple management guidelines exist which differ in the recommended utilization of these radiologic examinations. This variability can lead to confusion as to how these tests should be used in the evaluation of GI bleeding. In this document, a panel of experts from the American College of Gastroenterology and Society of Abdominal Radiology provide a review of the radiologic examinations used to evaluate for GI bleeding including nomenclature, technique, performance, advantages, and limitations. A comparison of advantages and limitations relative to endoscopic examinations is also included. Finally, consensus statements and recommendations on technical parameters and utilization of radiologic techniques for GI bleeding are provided.

Deciphering ovarian torsion: insights from CT imaging analysis.

PURPOSE: In the milieu of emergency medicine, pelvic and lower abdominal pain present recurrently, with ovarian torsion posing a formidable diagnostic quandary amid multifarious etiologies. Given the burgeoning reliance on CT in acute care settings, it invariably assumes primacy as the principal imaging modality. This study endeavors to elucidate the CT imaging manifestations encountered by surgically confirmed ovarian torsion patients and utilizing CT to differentiate necrosis. METHODS: A retrospective analysis (January, 2015- April, 2019) utilizing hospital archives was conducted on patients diagnosed with ovarian torsion, post-surgery. Inclusion criteria encompassed patients who underwent CT examinations within one week of diagnosis. A large array of CT findings encompassing midline orientation, uterine deviation, intraovarian hematoma/mass, and multiple others were systematically documented. RESULTS: 90 patients were diagnosed with ovarian torsion- 53 (59%) had CT within one week of diagnosis, 41(77%) underwent a CT with IV contrast and 12 (23%) without IV contrast. Mean age was 43 years (range 19-77 years), with near equal distribution of involvement of each ovary. Mean maximum ovarian diameter was 11.7 ± 6.3 cm (4.2-34.8 cm). Most common imaging features include the presence of thickened pedicle (43/53, 81%), midline ovary (41/53, 77%), presence of thickened fallopian tube (31/49, 63%), and ipsilateral uterine deviation (33/53, 62%). Based on contemporaneous imaging report, torsion was diagnosed in 25/ 53 studies giving a sensitivity of 47%. CONCLUSION: Enlarged ovarian dimensions (> 3.0 cm), thickened vascular pedicle or fallopian tube, midline ovarian disposition with ipsilateral uterine deviation, and the presence of a whirlpool sign emerged as predominant CT imaging features in surgically confirmed ovarian torsion cases, serving as pivotal diagnostic aides for radiologists. Concomitant pelvic free fluid and intraovarian hematoma signify necrotic changes, indicative of ischemic severity and disease progression.

Dual-Energy CT Evaluation of Gastrointestinal Bleeding.

Gastrointestinal (GI) bleeding is a potentially life-threatening condition accounting for more than 300 000 annual hospitalizations. Multidetector abdominopelvic CT angiography is commonly used in the evaluation of patients with GI bleeding. Given that many patients with severe overt GI bleeding are unlikely to tolerate bowel preparation, and inpatient colonoscopy is frequently limited by suboptimal preparation obscuring mucosal visibility, CT angiography is recommended as a first-line diagnostic test in patients with severe hematochezia to localize a source of bleeding. Assessment of these patients with conventional single-energy CT systems typically requires the performance of a noncontrast series followed by imaging during multiple postcontrast phases. Dual-energy CT (DECT) offers several potential advantages for performing these examinations. DECT may eliminate the need for a noncontrast acquisition by allowing the creation of virtual noncontrast (VNC) images from contrast-enhanced data, affording significant radiation dose reduction while maintaining diagnostic accuracy. VNC images can help radiologists to differentiate active bleeding, hyperattenuating enteric contents, hematomas, and enhancing masses. Additional postprocessing techniques such as low-kiloelectron voltage virtual monoenergetic images, iodine maps, and iodine overlay images can increase the conspicuity of contrast material extravasation and improve the visibility of subtle causes of GI bleeding, thereby increasing diagnostic confidence and assisting with problem solving. GI bleeding can also be diagnosed with routine single-phase DECT scans by constructing VNC images and iodine maps. Radiologists should also be aware of the potential pitfalls and limitations of DECT. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Imaging features of toxicities associated with immune checkpoint inhibitors.

The past decade has witnessed a change in landscape of cancer management with the advent of precision oncology. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment and have played an important role in improving patient survival. While the patients are living longer, treatment with ICIs are sometimes associated with adverse effects, some of which could be fatal. Radiologists can play a crucial role by early identification of some of these adverse effects during restaging scans. Our paper focuses on the imaging features of commonly occurring ICI toxicities based on organ system.

Mesenchymal neoplasms of the urinary bladder: a comprehensive review with focus on cross-sectional imaging findings.

Mesenchymal neoplasms of the urinary bladder are exceedingly rare and display remarkable diversity. These tumors demonstrate distinct pathological features as well as variable biological behavior and cross-sectional imaging findings. The rarity of tumors, nonspecific symptoms and seemingly normal cystoscopic findings (particularly with small and exophytic tumors) frequently lead to misdiagnosis or missed diagnosis. While some tumors display characteristic cross-sectional imaging findings that may suggest a diagnosis, imaging findings are mostly nonspecific. Histopathological examination is required for accurate diagnosis, management and prognostication. The purpose of this article is to review the cross-sectional imaging findings of a diverse spectrum of mesenchymal tumors of the urinary bladder.

Anastomosing hemangioma: a current update on clinical, pathological and imaging features.

Anastomosing hemangioma (AH) is a rare, benign vascular neoplasm with distinctive histopathology and characteristic tumor distribution. AHs show marked proclivity to involve the kidneys, gonads and the retroperitoneal soft tissues; kidney is the most common target site often in the context of end stage renal disease. Recent studies have identified activating mutations of GNA genes that drive the molecular pathogenesis of AHs. AH appears as a solitary, well-circumscribed, hypervascular tumor that charters a benign course with an excellent prognosis. The purpose of this article is to provide a current update on clinical, pathological and imaging features of anastomotic hemangioma.

Impact of measurement method on interobserver variability of apparent diffusion coefficient of lesions in prostate MRI.

PURPOSE: To compare the inter-observer variability of apparent diffusion coefficient (ADC) values of prostate lesions measured by 2D-region of interest (ROI) with and without specific measurement instruction. METHODS: Forty lesions in 40 patients who underwent prostate MR followed by targeted prostate biopsy were evaluated. A multi-reader study (10 readers) was performed to assess the agreement of ADC values between 2D-ROI without specific instruction and 2D-ROI with specific instruction to place a 9-pixel size 2D-ROI covering the lowest ADC area. The computer script generated multiple overlapping 9-pixel 2D-ROIs within a 3D-ROI encompassing the entire lesion placed by a single reader. The lowest mean ADC values from each 2D-small-ROI were used as reference values. Inter-observer agreement was assessed using the Bland-Altman plot. Intraclass correlation coefficient (ICC) was assessed between ADC values measured by 10 readers and the computer-calculated reference values. RESULTS: Ten lesions were benign, 6 were Gleason score 6 prostate carcinoma (PCa), and 24 were clinically significant PCa. The mean±SD ADC reference value by 9-pixel-ROI was 733 ± 186 (10-6 mm2/s). The 95% limits of agreement of ADC values among readers were better with specific instruction (±112) than those without (±205). ICC between reader-measured ADC values and computer-calculated reference values ranged from 0.736-0.949 with specific instruction and 0.349-0.919 without specific instruction. CONCLUSION: Interobserver agreement of ADC values can be improved by indicating a measurement method (use of a specific ROI size covering the lowest ADC area).

Utility of an automatic adaptive iterative metal artifact reduction AiMAR algorithm in improving CT imaging of patients with hip prostheses evaluated for suspected bladder malignancy.

PURPOSE: To compare the utility of a novel metal artifact reduction algorithm to standard imaging in improving visualization of key structures, diagnostic confidence, and patient-level confidence in malignancy in patients with suspected bladder cancer. METHODS: Patients with hip implants undergoing CT urography for suspected bladder malignancy were enrolled. Images were reconstructed using 3 methods: (1) Filtered Back Projection (FBP), (2) Iterative Metal Artifact Reduction (iMAR), and (3) Adaptive Iterative Metal Artifact Reduction (AiMAR) strength 4. In multiple reading sessions, three radiologists graded visualization of critical anatomic structures and artifact severity (6-point scales, lower scores desirable), and diagnostic confidence in blinded fashion. They also graded patient-level confidence in malignancy based on imaging findings in each patient. RESULTS: Thirty-two patients (8 females) with a mean age of 74.5 ± 8.5 years were included. The median (range) visualization scores for FBP, iMAR, and AiMAR were 3.6 (1.1-4.9), 1.6 (0.3-2.8), and 1.6 (0.3-2.6), respectively. Both iMAR and AiMAR had anatomic visualization and artifact scores better than FBP (P < 0.001 for both) and similar to each other (P > 0.05). Structures with the most improvement in visualization score with the use of metal artifact reduction algorithms included the obturator internus muscle, internal and external iliac nodal chains, and vagina. iMAR and AiMAR improved diagnostic confidence (P < 0.001) and patient-level confidence in malignancy (P ≤ 0.24). CONCLUSION: For patients with hip prostheses and suspected bladder malignancy, the use of iMAR or AiMAR was shown to significantly reduce metal artifacts, thus improving diagnostic confidence and patient-level confidence in malignancy.

Current update on status of saline infusion sonohysterosalpingography.

The purpose of this article is to elucidate the current role of saline infusion sonohysterosalpingography (SIS) in evaluation of various uterine pathologies. SIS improves visualization of the endometrium and pathologies related to endometrial cavity, as well as it can simultaneously assess tubal patency. SIS provides high-resolution images, and three-dimensional (3D) reformatted images provide excellent orientation for radiologists as well as the clinicians about the underlying pathologies. This article will discuss imaging technique, indications, pearls, and pitfalls in imaging, diverse disease pathologies, and ultimately compare performance of SIS among other different imaging modalities. SIS as an adjunct imaging modality results in a greater diagnostic yield for diverse uterine pathologies.

Impact of dual-energy 50-keV virtual monoenergetic images on radiologist confidence in detection of key imaging findings of small hepatocellular carcinomas using multiphase liver CT.

BACKGROUND: Dual-energy virtual monoenergetic images can increase iodine signal, potentially increasing the conspicuity of hepatic masses. PURPOSE: To determine if dual-energy 50-keV virtual monoenergetic images improve visualization of key imaging findings or diagnostic confidence for small (≤2 cm) hepatocellular carcinomas (HCC) at multiphase, contrast-enhanced liver computed tomography (CT). MATERIAL AND METHODS: Patients with chronic liver disease underwent multiphase dual-energy CT imaging for HCC, with late arterial and delayed phase dual-energy 50-keV images reconstructed. Two non-reader subspecialized gastrointestinal (GI) radiologists established the reference standard, determining the location and diagnosis of all hepatic lesions using predetermined criteria. Three GI radiologists interpreted mixed kV CT images without or with dual-energy 50-keV images. Radiologists identified potential HCCs and rated their confidence (0-100 scales) in imaging findings of arterial enhancement, enhancing capsule, tumor washout, and LI-RADS 5 (2018) category. RESULTS: In total, 45 patients (14 women; mean age = 59.5 ± 10.9 years) with chronic liver disease were included. Of them, 19 patients had 25 HCCs ≤2 cm (mean size = 1.5 ± 0.4 cm). There were 17 LI-RADS 3 and 4 lesions and 19 benign lesions. Reader confidence in imaging findings of arterial enhancement, enhancing capsule, and non-peripheral washout significantly increased with dual-energy images (P ≤ 0.022). Overall confidence in HCC diagnosis increased significantly with dual-energy 50-keV images (52.4 vs. 68.8; P = 0.001). Dual-energy images demonstrated a slight but significant decrease in overall image quality. CONCLUSION: Radiologist confidence in key imaging features of small HCCs and confidence in imaging diagnosis increases with use of dual-energy 50-keV images at multiphase, contrast-enhanced liver CT.

Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms.

Gastrointestinal (GI) bleeding is a common potentially life-threatening medical condition frequently requiring multidisciplinary collaboration to reach the proper diagnosis and guide management. GI bleeding can be overt (eg, visible hemorrhage such as hematemesis, hematochezia, or melena) or occult (eg, positive fecal occult blood test or iron deficiency anemia). Upper GI bleeding, which originates proximal to the ligament of Treitz, is more common than lower GI bleeding, which arises distal to the ligament of Treitz. Small bowel bleeding accounts for 5-10% of GI bleeding cases commonly manifesting as obscure GI bleeding, where the source remains unknown after complete GI tract endoscopic and imaging evaluation. CT can aid in identifying the location and cause of bleeding and is an important complementary tool to endoscopy, nuclear medicine, and angiography in evaluating patients with GI bleeding. For radiologists, interpreting CT scans in patients with GI bleeding can be challenging owing to the large number of images and the diverse potential causes of bleeding. The purpose of this pictorial review by the Society of Abdominal Radiology GI Bleeding Disease-Focused Panel is to provide a practical resource for radiologists interpreting GI bleeding CT studies that reviews the proper GI bleeding terminology, the most common causes of GI bleeding, key patient history and risk factors, the optimal CT imaging technique, and guidelines for case interpretation and illustrates many common causes of GI bleeding. A CT reporting template is included to help generate radiology reports that can add value to patient care. An invited commentary by Al Hawary is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Challenges in Diagnosis and Management of Hemobilia.

Hemobilia, or hemorrhage within the biliary system, is an uncommon form of upper gastrointestinal (GI) bleeding that presents unique diagnostic and therapeutic challenges. Most cases are the result of iatrogenic trauma, although accidental trauma and a variety of inflammatory, infectious, and neoplastic processes have also been implicated. Timely diagnosis can often be difficult, as the classic triad of upper GI hemorrhage, biliary colic, and jaundice is present in a minority of cases, and there may be considerable delay in the onset of bleeding after the initial injury. Therefore, the radiologist must maintain a high index of suspicion for this condition and be attuned to its imaging characteristics across a variety of modalities. CT is the first-line diagnostic modality in evaluation of hemobilia, while catheter angiography and endoscopy play vital and complementary roles in both diagnosis and treatment. The authors review the clinical manifestations and multimodality imaging features of hemobilia, describe the wide variety of underlying causes, and highlight key management considerations.©RSNA, 2021.

Baseline MR Staging of Rectal Cancer: A Practical Approach.

As therapeutic options to treat rectal cancers have advanced over the last several decades, MRI has become the standard of care for baseline local tumor and nodal staging of rectal cancers. An understanding of the technique, anatomy, tumor appearance, and elements of staging on MRI is essential to provide prognostic information and to guide neoadjuvant chemoradiation and surgical treatment. We provide a framework for imaging the rectum on MRI followed by a practical case-based approach to interpretation of pre-treatment MRI of the rectum in evaluation of rectal cancers, with examples and illustrations of the range of local tumor (T) stage and nodal (N) disease involvement. This approach can be paired with standardized reporting templates to support clear, accurate and clinically relevant imaging assessment of rectal cancers.

Imaging of Renal Cancer.

Renal masses are common incidental findings on cross-sectional imaging. Accurate characterization of renal masses is essential to guide management. Renal mass CT protocol comprises of a good quality noncontrast, corticomedullary and nephrographic phases, with each phase providing complementary information for diagnosis. Attenuation measurements in different phases are central to the 'golden-rules' in renal mass imaging in the characterization of renal masses. Newer modalities like dual energy CT scan obviate need for repeat imaging by generation of iodine-overlay image and also help in eliminating artifactual pseudoenhancement which can be problematic, especially in small endophytic cysts. Contrast- enhanced ultrasound (CEUS) is extremely sensitive in identification of enhancing components in indeterminate masses, especially in the setting of renal failure as the microbubbles are not excreted via the renal route. The Bosniak classification for renal cystic masses has been revised in 2019 to standardize terminology and further improve upon the original version. The current version includes CT and MRI, although CEUS is yet to be included. Image- guided biopsy of renal mass helps confirm the diagnosis and also gives information regarding the subtype and grading and is useful in avoiding overtreatment of benign entities, and in active surveillance. Multiparametric MRI can potentially help avoid needle biopsy in a subset of patients by accurate characterization through a previously validated algorithm.

Autoimmune pancreatitis: an update.

OBJECTIVE: Since the time of inception of autoimmune pancreatitis (AIP), our knowledge of autoimmune pancreatitis has expanded significantly. The aim of this review is to provide an update on clinical manifestations, diagnosis, imaging features, and treatment of AIP. BACKGROUND AND CLINICAL SIGNIFICANCE: Type 1 AIP is the pancreatic manifestation of IgG4-related systemic disease, which can be diagnosed using a combination of clinical, histopathological, pancreatic imaging findings in conjunction with manifestation in other organs, as well of responsiveness to steroid treatment. It is vital to differentiate AIP from pancreatic cancer since both can mimic each other clinically and radiologically. Type 2 AIP is a rare but distinct subtype of AIP which occurs mostly in the younger patient. CONCLUSION: AIP is steroid-responsive chronic pancreatitis with distinct manifestations on imaging.

Reducing radiation dose for multi-phase contrast-enhanced dual energy renal CT: pilot study evaluating prior iterative reconstruction.

PURPOSE: Prior iterative reconstruction (PIR) uses spatial information from one phase of enhancement to reduce image noise in other phases. We sought to determine if PIR could reduce radiation dose while preserving observer performance and CT number at multi-phase dual energy (DE) renal CT. METHODS: CT projection data from multi-phase DE renal CT examinations were collected. Images corresponding to 40% radiation dose were reconstructed using validated noise insertion and PIR. Three genitourinary radiologists examined routine and 40% dose PIR images. Probability of malignancy was assessed [from 0 to 100] with malignancy assumed at probability ≥ 75. Observer performance was compared on a per patient and per lesion level. CT number accuracy was measured. RESULTS: Twenty-three patients had 49 renal lesions (11 solid renal neoplasms). CT number was nearly identical between techniques (mean CT number difference: unenhanced 2 ± 2 HU; enhanced 4 ± 4 HU). AUC for malignancy was similar between multi-phase routine dose DE and lower dose PIR images [per patient: 0.950 vs. 0.916 (p = 0.356); per lesion: 0.931 vs. 0.884 (p = 0.304)]. Per patient sensitivity was also similar (78% routine dose vs. 82% lower dose [p ≥ 0.99]), as was specificity (91% routine dose vs. 93% lower dose PIR [p > 0.99]), with similar findings on a per lesion level. Subjective image quality was also similar (p = 0.34). CONCLUSIONS: Prior iterative reconstruction is a new reconstruction method for multi-phase CT examinations that promises to facilitate radiation dose reduction by over 50% for multi-phase DE renal CT exams without compromising CT number or observer performance.

Neuroleptic Malignant Syndrome with Minimal Dose of Amisulpride.

Amisulpride is an atypical antipsychotic drug, it helps in alleviation of symptoms of psychotic illnesses. Extrapyramidal features have been reported after taking amisulpride. Neuroleptic malignant syndrome (NMS) with amisulpride is rare, and have been reported earlier. In all the earlier reported cases patient received more than 150 mg of amisulpride. To the best of our knowledge we are reporting a case of NMS with very minimal dose of Amisulpride (50 mg) taken for very short period.

MDCT imaging of the stomach: advances and applications.

The stomach may be involved by a myriad of pathologies ranging from benign aetiologies like inflammation to malignant aetiologies like carcinoma or lymphoma. Multidetector CT (MDCT) of the stomach is the first-line imaging for patients with suspected gastric pathologies. Conventionally, CT imaging had the advantage of simultaneous detection of the mural and extramural disease extent, but advances in MDCT have allowed mucosal assessment by virtual endoscopy (VE). Also, better three-dimensional (3D) post-processing techniques have enabled more robust and accurate pre-operative planning in patients undergoing gastrectomy and even predict the response to surgery for patients undergoing laparoscopic sleeve gastrectomy for weight loss. The ability of CT to obtain stomach volume (for bariatric surgery patients) and 3D VE images depends on various patient and protocol factors that are important for a radiologist to understand. We review the appropriate CT imaging protocol in the patients with suspected gastric pathologies and highlight the imaging pearls of various gastric pathologies on CT and VE.

Symptomatic Coronary Cameral Fistula.

Coronary cameral fistula is a rare entity and is characterized by an abnormal communication between coronary artery and a cardiac chamber. It is usually congenital and asymptomatic in majority of patients. If symptomatic the patients usually present in childhood. We present a case of 45-year-old male who presented with anginal chest pain and dyspnea on exertion for last 1 year. His exercise treadmill test was positive for ischemic changes and ECG-gated contrast enhanced CT was done for further evaluation. CT showed a large right coronary artery to right atrium fistula. It also ruled out any coronary atherosclerosis as reason for chest pain and ischemic symptoms on exercise treadmill test. The fistula was successfully closed by surgery and there was resolution of chest pain and dyspnea.