Imaging review of spontaneous renal hemorrhage.

Spontaneous renal hemorrhage (SRH) is a diagnostic challenge and a significant cause of morbidity, and sometimes mortality. Early identification is essential to institute lifesaving and reno-protective interventions. In this review, we classify spontaneous renal hemorrhage by location, presentation and etiology. We also discuss the diagnostic approach to renal hemorrhage and optimum imaging modalities to arrive at the diagnosis. Finally, we review strategies to avoid missing a diagnosis of SRH and discuss the pitfalls of imaging in the presence of renal hemorrhage.

Computer Tomography Angiography of Peripheral Vascular Injuries.

Peripheral vascular injuries are a rare finding in the setting of trauma but an important source of morbidity and mortality when present. Fast and accurate diagnosis followed by rapid repair of vascular injuries are important for achieving the best clinical outcomes. The advancements in computer tomography (CT) and decades of experience in vascular imaging have allowed radiologists to become important contributors for the diagnosis and characterization of peripheral vascular injury. We review the epidemiology of peripheral vascular injuries, indications for imaging, ways to optimize CT technique, imaging findings, and common challenges for accurate diagnosis of such injuries.

Diagnostic performance of triple-contrast versus single-contrast multi-detector computed tomography for the evaluation of penetrating bowel injury.

PURPOSE: Selecting groups of low-risk penetrating trauma patients to forego laparotomy can be challenging. The presence of bowel injury may prevent non-operative management. Optimal CT technique to detect bowel injury related to penetrating injury is controversial. Our goal is to compare the diagnostic performance of triple-contrast (oral, rectal, and IV) against IV contrast-only CT, for the detection of bowel injury from penetrating abdominopelvic trauma, using surgical diagnosis as the reference standard. METHODS: Nine hundred ninety-seven patients who underwent CT for penetrating torso trauma at a single institution between 2009 and 2016 in our HIPPA-compliant and institutional review board-approved retrospective cohort study. A total of 143 patients, including 15 females and 123 males underwent a pre-operative CT, followed by exploratory laparotomy. Of these, 56 patients received triple-contrast CT. CT examinations were independently reviewed by two radiologists, blinded to surgical outcome and clinical presentation. Results were stratified by contrast type and injury mechanism and were compared based upon diagnostic performance indicators of sensitivity, specificity, negative predictive value, and positive predictive value. Area under the receiving operating characteristics curves were analyzed for determination of diagnostic accuracy. RESULTS: Bowel injury was present in 45 out of 143 patients (10 on triple-contrast group and 35 on IV contrast-only group). Specificity and accuracy were higher with triple-contrast CT (98% specific, 97-99% accurate) compared to IV contrast-only CT (66% specific, 78-79% accurate). Sensitivity was highest with IV contrast-only CT (91% sensitive) compared with triple-contrast CT (75% sensitive), although this difference was not statistically significant. Triple-contrast technique increased diagnostic accuracy for both radiologists regardless of mechanism of injury. CONCLUSION: In our retrospective single-institution cohort study, triple-contrast MDCT had greater accuracy, specificity, and positive predictive values when compared to IV contrast-only CT in evaluating for bowel injury from penetrating wounds.

Evaluation of penetrating abdominal and pelvic trauma.

Penetrating abdominal trauma comprises a wide variety of injuries that will manifest themselves at imaging depending on the distinct mechanism of injury. The use of computed tomography (CT) for hemodynamically stable victims of penetrating torso trauma continues to increase in clinical practice allowing more patients to undergo initial selective non-surgical management. High diagnostic accuracy in this setting helps patients avoid unnecessary surgical intervention and ultimately reduce morbidity, mortality and associated medical costs. This review will present the evidence and the controversies surrounding the imaging of patients with penetrating abdominopelvic injuries. Available protocols, current MDCT technique controversies, organ-specific injuries, and key MDCT findings requiring intervention in patients with penetrating abdominal and pelvic trauma are presented. In the hemodynamically stable patient, the radiologist will play a key role in the triage of these patients to operative or nonoperative management.

Imaging evaluation of diaphragmatic injuries: Improving interpretation accuracy.

Diaphragmatic Injuries (DIs) remain a challenging diagnosis with potential catastrophic delayed complications. A high degree of suspicion in every case of severe blunt thoracoabdominal trauma or penetrating thoracoabdominal injury is essential. This review will present the evidence and controversies on this topic providing a practical tutorial for radiologists hoping to improve their interpretive accuracy for both blunt and penetrating DIs. The imaging signs of diaphragmatic injuries will be explained with emphasis on multidetector CT. Diagnostic pitfalls, available protocols and other issues will be presented.

Perineural spread in head and neck malignancies: clinical significance and evaluation with 18F-FDG PET/CT.

Certain tumors of the head and neck use peripheral nerves as a direct conduit for tumor growth away from the primary site by a process known as perineural spread. Perineural spread is associated with decreased survival and a higher risk of local recurrence and metastasis. Radiologists play an important role in the assessment and management of head and neck cancer, and positron emission tomography/computed tomography (PET/CT) with 2-[fluorine 18]fluoro-2-deoxy-d-glucose (FDG) is part of the work-up and follow-up of many affected patients. Awareness of abnormal FDG uptake patterns within the head and neck is fundamental for diagnosing perineural spread. The cranial nerves most commonly affected by perineural spread are the trigeminal and facial nerves. Risk of perineural spread increases with a midface location of the tumor, male gender, increasing tumor size, recurrence after treatment, and poor histologic differentiation. Focal or linear increased FDG uptake along the V2 division of the trigeminal nerve or along the medial surface of the mandible, or asymmetric activity in the masticator space, foramen ovale, or Meckel cave should raise suspicion for perineural spread. If FDG PET/CT findings suggest perineural spread, the radiologist should look at available results of other imaging studies, especially magnetic resonance imaging, to confirm the diagnosis. Knowledge of common FDG PET/CT patterns of neoplastic involvement along the cranial nerves and potential diagnostic pitfalls is of the utmost importance for adequate staging and treatment planning.

Radiopharmaceuticals: when and how to use them to treat metastatic bone pain.

Bone pain due to skeletal metastases constitutes the most common type of cancer-related pain. The management of bone pain remains challenging and is not standardized. In patients with multifocal osteoblastic metastases, systemic radiopharmaceuticals should be the preferred adjunctive therapy for pain palliation. The lack of general knowledge about radiopharmaceuticals, their clinical utility and safety profiles, constitutes the major cause for their underutilization. Our goal is to review the indications, selection criteria, efficacy, and toxicities of two approved radiopharmaceuticals for bone pain palliation: strontium-89 and samarium-153. Finally, a brief review of the data on combination therapy with bisphosphonates or chemotherapy is included.

Utility of positron emission tomography scans in mantle cell lymphoma.

Positron emission tomography (PET) scans are widely used in patients with lymphoma but little is known about their utility in mantle cell lymphoma (MCL). MCL patients were included from two prospective trials and one observational study at our institution. A total of 276 PET scans were performed among 52 patients. After a median follow-up of 37.5 months, the 3-year event-free survival (EFS) and overall survival (OS) were 73% (95% confidence interval [CI]: 61-85%) and 92% (95% CI 85-100%), respectively. There were 34 pretreatment PET scans, 26 interim, 28 end-of-treatment, 162 surveillance, and 26 scans at relapse or beyond. Pretreatment PETs were positive in 94%. A negative interim or end-of-therapy PET scan was not significantly associated with better EFS or OS, but no deaths were observed in patients who had a negative interim or end-of-therapy PET. Surveillance PET scans had a high false positive rate (35%) and low positive predictive value (8%). PET scans contributed to an earlier diagnosis of relapse in only two out of the 18 patients (11%) who relapsed. PET scans did not meaningfully contribute to staging or surveillance of MCL patients in this study. There was a trend toward improved survival in patients who had a negative end-of-therapy PET scan.

F-18 FDG PET positive hilar and mediastinal lymphadenopathy mimicking metastatic disease in a melanoma patient treated with interferon-alpha-2b.

A 49-year-old man with a history of recurrent melanoma in the parotid was treated with parotidectomy, external beam radiation, and high-dose interferon-alpha-2b. Combined F-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) performed for restaging demonstrated multiple bilateral hilar and mediastinal hypermetabolic foci corresponding to hilar and mediastinal lymphadenopathy. Cytologic specimens obtained by bronchoscopy were negative for malignancy, revealing reactive lymph nodes. Subsequent FDG PET/CT showed regression of the findings. Awareness of possible interferon-associated reaction in melanoma patients who undergo FDG PET is important to avoid pitfalls in the interpretation.

Systemic metabolic radiopharmaceutical therapy in the treatment of metastatic bone pain.

Bone pain due to skeletal metastases constitutes the most common type of chronic pain among patients with cancer. It significantly decreases the patient's quality of life and is associated with comorbidities, such as hypercalcemia, pathologic fractures and spinal cord compression. Approximately 65% of patients with prostate or breast cancer and 35% of those with advanced lung, thyroid, and kidney cancers will have symptomatic skeletal metastases. The management of bone pain is extremely difficult and involves a multidisciplinary approach, which usually includes analgesics, hormone therapies, bisphosphonates, external beam radiation, and systemic radiopharmaceuticals. In patients with extensive osseous metastases, systemic radiopharmaceuticals should be the preferred adjunctive therapy for pain palliation. In this article, we review the current approved radiopharmaceutical armamentarium for bone pain palliation, focusing on indications, patient selection, efficacy, and different biochemical characteristics and toxicity of strontium-89 chloride, samarium-153 lexidronam, and rhenium-186 etidronate. A brief discussion on the available data on rhenium-188 is presented focusing on its major advantages and disadvantages. We also perform a concise appraisal of the other available treatment options, including pharmacologic and hormonal treatment modalities, external beam radiation, and bisphosphonates. Finally, the available data on combination therapy of radiopharmaceuticals with bisphosphonates or chemotherapy are discussed.

FDG PET/CT of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease.

The term extranodal disease refers to lymphomatous infiltration of anatomic sites other than the lymph nodes. Almost any organ can be affected by lymphoma, with the most common extranodal sites of involvement being the stomach, spleen, Waldeyer ring, central nervous system, lung, bone, and skin. The prevalence of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease has increased in the past decade. The imaging characteristics of extranodal involvement can be subtle or absent at conventional computed tomography (CT). Imaging of tumor metabolism with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) has facilitated the identification of affected extranodal sites, even when CT has demonstrated no lesions. More recently, hybrid PET/CT has become the standard imaging modality for initial staging, follow-up, and treatment response assessment in patients with lymphoma and has proved superior to CT in these settings. Certain PET/CT patterns are suggestive of extranodal disease and can help differentiate tumor from normal physiologic FDG activity, particularly in the mucosal tissues, bone marrow, and organs of the gastrointestinal tract. Familiarity with the different extranodal manifestations in various locations is critical for correct image interpretation. In addition, a knowledge of the differences in FDG avidity among the histologic subtypes of lymphoma, appropriate timing of scanning after therapeutic interventions, and use of techniques to prevent brown fat uptake are essential for providing the oncologist with accurate information.