GADOLINIUM-ENHANCED MR IMAGING OF LIVER CAPSULE AND PERITONEUM

Peritoneal Carcinosis: What the Radiologist Needs to Know

Peritoneal carcinosis is a condition characterized by the spread of cancer cells to the peritoneum, which is the thin membrane that lines the abdominal cavity. It is a serious condition that can result from many different types of cancer, including ovarian, colon, stomach, pancreatic, and appendix cancer. The diagnosis and quantification of lesions in peritoneal carcinosis are critical in the management of patients with the condition, and imaging plays a central role in this process. Radiologists play a vital role in the multidisciplinary management of patients with peritoneal carcinosis. They need to have a thorough understanding of the pathophysiology of the condition, the underlying neoplasms, and the typical imaging findings. In addition, they need to be aware of the differential diagnoses and the advantages and disadvantages of the various imaging methods available. Imaging plays a central role in the diagnosis and quantification of lesions, and radiologists play a critical role in this process. Ultrasound, computed tomography, magnetic resonance, and PET/CT scans are used to diagnose peritoneal carcinosis. Each imaging procedure has advantages and disadvantages, and particular imaging techniques are recommended based on patient conditions. Our aim is to provide knowledge to radiologists regarding appropriate techniques, imaging findings, differential diagnoses, and treatment options. With the advent of AI in oncology, the future of precision medicine appears promising, and the interconnection between structured reporting and AI is likely to improve diagnostic accuracy and treatment outcomes for patients with peritoneal carcinosis.

Imaging in metastatic breast cancer, CT, PET/CT, MRI, WB-DWI, CCA: review and new perspectives

BACKGROUND

Breast cancer is the most frequent cancer in women and remains the second leading cause of death in Western countries. It represents a heterogeneous group of diseases with diverse tumoral behaviour, treatment responsiveness and prognosis. While major progress in diagnosis and treatment has resulted in a decline in breast cancer-related mortality, some patients will relapse and prognosis in this cohort of patients remains poor. Treatment is determined according to tumor subtype; primarily hormone receptor status and HER2 expression. Menopausal status and site of disease relapse are also important considerations in treatment protocols.

MAIN BODY

Staging and repeated evaluation of patients with metastatic breast cancer are central to the accurate assessment of disease extent at diagnosis and during treatment; guiding ongoing clinical management. Advances have been made in the diagnostic and therapeutic fields, particularly with new targeted therapies. In parallel, oncological imaging has evolved exponentially with the development of functional and anatomical imaging techniques. Consistent, reproducible and validated methods of assessing response to therapy is critical in effectively managing patients with metastatic breast cancer.

CONCLUSION

Major progress has been made in oncological imaging over the last few decades. Accurate disease assessment at diagnosis and during treatment is important in the management of metastatic breast cancer. CT (and BS if appropriate) is generally widely available, relatively cheap and sufficient in many cases. However, several additional imaging modalities are emerging and can be used as adjuncts, particularly in pregnancy or other diagnostically challenging cases. Nevertheless, no single imaging technique is without limitation. The authors have evaluated the vast array of imaging techniques - individual, combined parametric and multimodal - that are available or that are emerging in the management of metastatic breast cancer. This includes WB DW-MRI, CCA, novel PET breast cancer-epitope specific radiotracers and radiogenomics.

Magnetic resonance imaging of pelvic metastases in male patients

Magnetic resonance (MR) imaging offers a noninvasive tool for diagnosis of primary and metastatic pelvic tumors. The diagnosis of a pelvic metastatic lesion implies an adverse prognosis and dictates the management strategies. Knowledge of normal MR imaging anatomy of the pelvis and the signal characteristics of normal and abnormal structures is essential for accurate interpretation of pelvic MR imaging. This article reviews imaging manifestations of nodal, visceral, and musculoskeletal metastatic lesions of the pelvis along with current and evolving MR imaging techniques.

MR imaging of the peritoneal spread of malignancy

MR imaging provides a highly sensitive and accurate means to depict tumor involving the peritoneum and bowel serosa. The ability of MR imaging to depict subtle peritoneal metastases plays a critical role in diagnosing and monitoring the oncologic patient with known or suspected peritoneal spread of malignancy. In this review I will describe the mechanisms of peritoneal tumor spread, and MR techniques and protocols for peritoneal imaging. A detailed description of the MR appearance of peritoneal tumor at different anatomic sites will be provided followed by a discussion of clinical applications for MR imaging of peritoneal malignancy.

Desmoplastic small round cell tumor in childhood: the St. Jude Children's Research Hospital experience

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare, primarily intra-abdominal tumor that has a poor outcome with current therapies.

PROCEDURE

We retrospectively reviewed patient characteristics, presenting symptoms, tumor pathology, treatment, and outcome of 11 pediatric patients with DSRCT at our institution.

RESULTS

The cohort included 1 female and 10 male patients. Median age at diagnosis was 14 years (range 5-21 years). In eight (73%) patients, the primary tumor was abdominal or pelvic, and in one patient each, it was submental, mediastinal, and paratesticular. Nine (82%) patients had metastatic disease. All tumors showed polyphenotypic differentiation by immunohistochemistry. The EWS-WT1 transcript was detected in six of seven tumors tested. One tumor showed rhabdomyoblastic differentiation after therapy. All patients received chemotherapy; eight underwent surgical resection, seven received primary site radiation, and four received myeloablative chemotherapy with stem-cell support. Three (27%) patients are alive 23 months, 8 years, and 10 years from diagnosis. Two died of treatment-related toxicity, six died of disease. None of the patients in whom surgery and initial chemotherapy failed to induce complete remission survived.

CONCLUSIONS

DSRCT is an aggressive malignancy that does not respond well to contemporary treatments, and patients who do not enter complete remission after initial chemotherapy and surgery appear to have a particularly dismal outcome. Patients with localized extra-abdominal disease have a better prognosis, most likely due to increased feasibility of resection. Better understanding of molecular and genetic mechanisms of tumorigenesis and treatment-related changes may contribute to development of more effective therapy for DSRCT.

Abdominal MRI advances in the detection of liver tumours and characterisation

With recent technical advances in hardware, software, and intravenous contrast agents, MRI has evolved into a clinically useful procedure to detect and characterise liver tumours. The combination of MRI systems with larger gradients, improved surface coils, and parallel imaging techniques have produced substantial improvements in MRI quality and speed of image acquisition. Images that previously needed several minutes to acquire can now be obtained in several seconds. The notably faster imaging capabilities of new MRI scanners are ideally suited for dynamic contrast-enhanced liver imaging in which early arterial-phase imaging is best for detecting hepatocellular carcinomas and hypervascular liver metastases. The inherent excellent soft-tissue contrast of MRI can be further improved by non-specific extracellular contrast agents and by liver-specific contrast agents. These contrast agents are now routinely used for liver imaging and improve the sensitivity and specificity of hepatobiliary MRI.

MRI evaluation of bulky tumor masses in the mesentery and bladder involvement in peritoneal carcinomatosis

AIM

Peritonectomy procedures with intraperitoneal chemohyperthermia are an effective but costly treatment for peritoneal carcinomatosis (PC). Consequently a proper selection of patients is necessary. We evaluated the benefit of MRI prior to surgery, in the detection of two of the main surgery contraindications: bulky mesenteric tumors and bladder implants.

METHODS

Three experts retrospectively reviewed abdominal and pelvic MRI from 19 cases of surgically proved PC (ovary: 7; colorectal: 7; gastric: 2; pseudomyxoma peritonei: 2; appendix: 1).

RESULTS

Mesenteric tumors were always identified as hypersignal masses on axial and coronal fat suppression gadolinium-enhanced T1 images (n=3). Three out of five bladder implants were detected. The two cases of bladder implants that were not detected on MRI were missed because the bladder was not filled. The best sequence for the detection of bladder involvement was axial T2-weighted images with bladder filling.

CONCLUSIONS

Evaluating the preoperative resectability of PC is crucial for patient management. MRI seems to reliably detect bulky mesenteric tumors and bladder implants on condition the bladder is filled and appropriate sequences are used.

MRI of the peritoneum: spectrum of abnormalities

OBJECTIVE

Our objective was to detail peritoneal anatomy, techniques for optimizing peritoneal MRI, and the MRI characteristics of several disease processes that frequently involve the peritoneum.

CONCLUSION

Homogeneous fat suppression and dynamic contrast-enhanced imaging, including delayed imaging, are critical technical factors for successful lesion detection and characterization on peritoneal MRI.

Magnetic Resonance Imaging of the Pancreas: The Future Is Now

MR imaging has made significant advances in recent years, with an increasingly important role in the detection, characterization, and staging of pancreatic diseases. MRI is appealing as a noninvasive imaging modality as it can evaluate the pancreas, the vasculature, and the pancreaticobiliary ducts in a single examination. Advantages of MRI include its excellent soft tissue contrast resolution and anatomic detail and absence of ionizing radiation. This article reviews the utility of MRI and its use not only as a problem-solving tool but its potential use as a primary examination (similar to CT) in a wide variety of pancreatic diseases.

Preoperative assessment of focal liver lesions: multidetector computed tomography challenges magnetic resonance imaging

PURPOSE

To investigate prospectively multidetector computed tomography (CT) (MDCT) and magnetic resonance (MR) imaging (MRI) in the preoperative assessment of focal liver lesions.

MATERIAL AND METHODS

Multiphasic MDCT and conventional gadolinium-enhanced MRI were performed on 31 consecutive patients prior to hepatic surgery. All images were blindly analyzed as consensus reading. Lesion counts and their relation to vascular structures and possible extrahepatic disease were determined. The data from the MDCT and MRI were compared with the results obtained by intraoperative ultrasound (IOUS) and palpation. Histopathologic verification was available.

RESULTS

At surgery, IOUS and palpation revealed 45 solid liver lesions. From these, preoperative MDCT detected 43 (96%) and MRI 35 (78%) deposits. MDCT performed statistically better than MRI in lesion detection (P=0.008). Assessment of lesion vascular proximity was correctly determined by MDCT in 98% of patients and by MRI in 87%. Statistical difference was found (P=0.002). IOUS and palpation changed the preoperative surgical plan as a result of extrahepatic disease in 8/31 (26%) cases. In MDCT as well in MRI extrahepatic involvement was suspected in two cases.

CONCLUSION

MDCT was superior to MRI and nearly equal to IOUS in liver lesion detection and in the determination of lesion vascular proximity. However, both techniques fail to reliably detect extrahepatic disease.

Abdominal pain and preeclampsia: sonographic findings in the maternal liver

OBJECTIVE

To describe sonographic findings in livers of pregnant women with severe preeclampsia and abdominal pain.

METHODS

Over a 12-month period, we performed serial sonographic examinations on 32 pregnant women with severe preeclampsia and acute right upper quadrant and epigastric pain. On each sonogram we observed the liver size and texture, "periportal halo" sign, gallbladder wall, Glisson capsule thickness, painful compression of the liver and gallbladder, and ascites. The pancreas, spleen, kidneys, and uterus were also studied. Sonography was repeated after delivery.

RESULTS

Initial sonograms showed liver abnormalities in 28 patients. Abnormalities consisted of liver hypertrophy (n = 24), hyperechoic thickening of the periportal area (periportal halo sign; n = 23), striated thickening of the gallbladder wall (n = 27), hyperechoic thickening of the Glisson capsule (n = 11), liver areas of increased echogenicity (n = 11), subcapsular hematoma (n = 1), and subcapsular calcification (n = 1). Probe compression of the liver enhanced abdominal pain (n = 13), whereas the gallbladder was painless in all cases. No gallbladder stones were detected. Ascites (n = 16) and pleural effusion (n = 11) were also present. In no case did we detect abnormalities of the pancreas, kidneys, or spleen. All patients eventually had hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome according to the American College of Obstetricians and Gynecologists classification. In 7 cases, HELLP syndrome developed postpartum. Three patients also had eclampsia. Follow-up sonograms highlighted quick regression of abnormalities after delivery.

CONCLUSIONS

The livers of women with severe preeclampsia who had HELLP syndrome showed sonographic abnormalities before biological abnormalities. Serial sonographic examinations could therefore contribute to the obstetric care of these women. Preeclampsia and HELLP syndrome should be routinely checked for in all pregnant women with acute abdominal pain.