Acute splenic pathology on CT in patients with babesiosis.

PURPOSE: To better understand the occurrence of splenic disease as a potential manifestation of babesiosis by retrospectively estimating the frequency of acute splenic injury on abdominal and pelvic CT in a cohort of patients with active babesia infection. MATERIALS AND METHODS: In a search of our single institution, suburban teaching community hospital database, 57 patients were found to have positive babesia infection between the years 2021-2023. 29 of these patients underwent abdominal and pelvic CT (22 with and 7 without intravenous contrast), and 3 underwent abdominal ultrasound without any CT. The imaging was reviewed for the presence or absence of splenic abnormalities, and for follow-up imaging. Parasitemia levels at the time of imaging were also reviewed; parasitemia levels < 4% are associated with mild to moderate disease, whereas parasitemia levels > 4% are associated with severe disease. RESULTS: 21/32 (66%) patients who underwent any type of abdominal imaging (ultrasound, MRI, and CT) had splenomegaly. Of the 22 patients who had IV contrast-enhanced CT scans, 6 were found to have splenic infarction (27%). One of these 22 patients had multiple rounded non-peripheral hypoenhancing foci on both CT and MRI which did not meet criteria for infarction, in association with splenomegaly, and which resolved after treatment. 0/6 patients in the splenic infarction group had parasitemia levels greater than 4%, while 4 of the 16 patients (4/16) without infarction had parasitemia levels of greater than 4%. CONCLUSION: Our study showed that splenic disease in patients with babesiosis mostly took the form of splenomegaly, and in a substantial minority of patients as splenic infarction. There were no cases of splenic rupture and perisplenic hematoma in our case series, likely reflecting a limitation of the relatively small study size. Concordant with prior studies, we found no identifiable association between parasitemia levels and the presence of splenic infarction.

The Incidental Renal Mass- Update on Characterization and Management.

Renal masses are commonly encountered on cross-sectional imaging examinations performed for nonrenal indications. Although most can be dismissed as benign cysts, a subset will be either indeterminate or suspicious; in many cases, imaging cannot be used to reliably differentiate between benign and malignant masses. On-going research in defining characteristics of common renal masses on advanced imaging shows promise in offering solutions to this issue. A recent update of the Bosniak classification (used to categorize cystic renal masses) was proposed with the goals of decreasing imaging follow-up in likely benign cystic masses, and therefore avoiding unnecessary surgical resection of such masses.

Spectrum and Relevance of Incidental Bowel Findings on Computed Tomography.

A wide spectrum of incidental bowel findings can be seen on CT, including but not limited to, pneumatosis intestinalis, diverticular disease, non-obstructive bowel dilatation, transient small bowel intussusception, and submucosal fat. Radiologists should be aware that such findings are almost always benign and of little clinical significance in the absence of associated symptoms. Conversely, vigilance must be maintained when evaluating the bowel, because malignant neoplasms occasionally come to clinical attention as incidental imaging findings. When suspicious incidental bowel wall thickening is detected, the radiologist can alert the clinical team to the finding prior to the patient becoming symptomatic, potentially leading to definitive management at an early, more curable stage.

How to Read, Write, and Review the Imaging Literature.

Everyone at all levels in academic radiology is supposed to know how to read an original research article or a review article and to evaluate it critically, to participate in writing such manuscripts, and, as one becomes more senior, to participate in the peer review process, yet there is little formal teaching in our experience as to how to do these inter-related activities throughout radiology training. The purpose of this review article is therefore to provide our perspective - from the junior trainee to the senior radiology attending - as to how one should be reading, reviewing, and writing the imaging literature, and also providing guidance from other thought leaders in this area, and from the literature itself. We hope to inspire radiology trainees and radiologists at all levels, particularly those in academic careers, to more fully participate in peer review and in radiology publication.

Multimodality Imaging of the Pancreatic Neuroendocrine Tumors.

Pancreatic neuroendocrine tumors (PNETs) are uncommon pancreatic masses which arise from amine precursor and uptake decarboxylation cells. They are classified as functional or nonfunctional based on the associated clinical symptoms. Insulinomas and gastrinomas are the most common functional tumors. PNETs are also classified based on their biologic behavior as benign or malignant. While most PNETs are sporadic, a small percentage are associated with syndromes such as multiple endocrine neoplasia type 1, von Hippel-Lindau syndrome, and are usually multiple in those cases. On imaging, most PNETs are circumscribed and hypervascular masses; however, larger tumors are often heterogeneous. The presence of calcification, cystic degeneration, and necrosis increases the likelihood of malignancy and carries a poor prognosis. Metastases have similar imaging appearance to the primary lesion and are most commonly seen in the liver, locoregional lymph nodes, and bone. This article reviews the pathologic and radiologic features of pancreatic neuroendocrine tumors as well as imaging mimics and their distinguishing features.

CT Imaging of Emergent Renal Conditions.

The kidneys are paired intra-abdominal organs which provide essential functions and maintain homeostasis throughout the human body. Numerous disease processes affect the kidneys and cause acute renal dysfunction or other potentially catastrophic complications. These conditions can be broadly categorized into obstructive, infectious, hemorrhagic, traumatic, and vascular diseases. Imaging plays a vital role in the work-up and diagnosis of acute and emergent renal conditions. Evaluation of emergent renal conditions with a focus on CT imaging is discussed.

Nontraumatic large bowel perforation: spectrum of etiologies and CT findings.

Large bowel perforation is an abdominal emergency that results from a wide range of etiologies. Computed tomography is the most reliable modality in detecting the site of large bowel perforation. The diagnosis is made by identifying direct CT findings such as extraluminal gas or contrast and discontinuity along the bowel wall. Indirect CT findings can help support the diagnosis, and include bowel wall thickening, pericolic fat stranding, abnormal bowel wall enhancement, abscess, and a feculent collection adjacent to the bowel. Common etiologies that cause large bowel perforation are colon cancer, foreign body aspiration, stercoral colitis, diverticulitis, ischemia, inflammatory and infectious colitides, and various iatrogenic causes. Recognizing a large bowel perforation on CT can be difficult at times, and there are various entities that may be misinterpreted as a colonic perforation. The purpose of this article is to outline the MDCT technique used for evaluation of suspected colorectal perforation, discuss relevant imaging findings, review common etiologies, and point out potential pitfalls in making the diagnosis of large bowel perforation.

Clues to vascular disorders at non-contrast CT of the chest, abdomen, and pelvis.

Non-contrast chest CT scans are commonly performed while CT scans of the abdomen and pelvis are performed in a select subset of patients; those with limited renal function, an allergy to iodinated contrast, in the setting of suspected renal calculus, retroperitoneal hematoma, common duct calculus, abdominal aortic aneurysm with or without rupture, and in patients undergoing a PET-CT scan. In the absence of intravenous contrast, vascular structures may prove challenging to evaluate, yet their assessment is an important component of every non-contrast CT examination. We describe the key imaging features of both arterial and venous pathology, and review clues and common associated non-vascular findings, which can help the radiologist identify vascular disorders at non-contrast CT. Briefly, alternative imaging options are discussed.

Beyond appendicitis; radiologic review of unusual and rare pathology of the appendix.

Appendicitis is a very common cause of acute abdominal pathology, however, many other pathologic conditions of the appendix can be diagnosed utilizing CT. Examples of these conditions include primary appendiceal neoplasms, secondary inflammation of the appendix, stump appendicitis, endometriosis, appendicitis within a hernia, appendiceal diverticulosis and intussusception and intraluminal foreign bodies. The purpose of this article is to review appendiceal pathology outside of acute appendicitis, describe corresponding imaging findings on CT, and to illustrate various CT findings of appendiceal disease with representative cases.

Computed tomography of miscellaneous regional and diffuse small bowel disorders.

This article reviews the computed tomography (CT) findings of miscellaneous regional and diffuse small bowel disorders. CT technique and potential pitfalls are discussed. Several categories of regional and diffuse small bowel conditions are reviewed, with representative CT images. These disorders often have relatively nonspecific CT appearances, and correlation with the history, clinical, and laboratory findings in each specific case is critical. In selected conditions, the CT findings are highly specific. The imaging literature of some of the common as well as some of the less common entities is reviewed, and clues to narrowing the differential diagnosis are provided.

Endometriosis of abdominal and pelvic wall scars: multimodality imaging findings, pathologic correlation, and radiologic mimics.

Implantation of an endometriotic lesion within a pelvic or abdominal wall scar is an uncommon but well-described condition that may be the underlying cause of acute or chronic recurrent abdominal or pelvic pain, especially after cesarean section. Radiologists may not consider scar endometriosis when it is encountered at cross-sectional imaging. Cesarean section scars are the most common site of extraovarian or extrauterine endometriosis. The condition also has been identified in other uterine surgery-related scars and in the skin, subcutaneous tissues, and abdominal and pelvic wall musculature adjacent to these scars. The most plausible cause of scar endometriosis is implantation of endometrial stem cells at the surgical site at the time of uterine surgery. Patients with scar endometriosis may be asymptomatic or present with cyclical pain corresponding to the menstrual cycle. Cross-sectional imaging findings vary from the nonspecific to those suggestive of the diagnosis when combined with clinical history. In particular, the presence of blood products in an anterior abdominal wall mass at magnetic resonance (MR) imaging with no other explanation is strongly suggestive of scar endometriosis. Ultrasonography, computed tomography, and MR imaging may be used to depict an endometriotic lesion, exclude endometriosis, or provide evidence for an alternative diagnosis.

Imaging of abdominal pain in pregnancy.

This article reviews the evolving radiology and clinical literature on imaging of suspected common and relatively common maternal nonobstetric conditions of the abdomen and pelvis, including appendicitis, urolithiasis, and biliary disease, as well as on trauma to the maternal abdomen and pelvis and to the fetus. Recommendations for imaging these conditions, based on the literature to date and on the authors' experiences at two tertiary-care institutions with busy obstetric services, are proposed. The potential and theoretical fetal and maternal risks from such imaging are also reviewed.

CT enterography vs. capsule endoscopy.

Small bowel imaging has been revolutionized by CT enterography and capsule endoscopy. We present an overview of both imaging modalities, discuss advantages and disadvantages of each, and compare findings in Crohn's disease, occult gastrointestinal bleeding, and small bowel tumors. Both methods complement each other often providing information that the other one cannot.

Uncommon and unusual gastrointestinal causes of the acute abdomen: computed tomographic diagnosis.

There is a wide variety of uncommon and unusual gastrointestinal causes of acute abdominal and pelvic pain that may be prospectively diagnosed on computed tomography. We demonstrate 10 such diagnoses and briefly review the current computed tomography and clinical literature on intussusception occurring beyond early childhood, small bowel obstruction from internal hernia, cecal volvulus, intramural small bowel hemorrhage, Boerhaave's syndrome, gastrointestinal luminal foreign bodies, small bowel diverticulitis, hemoperitoneum secondary to abdominal tumor; gallstone ileus, and gallbladder torsion. Radiologists and clinicians need to be aware of these disorders, particularly with the widespread utilization of computed tomography (CT) in the management of patients with acute abdominal pain.

Spectrum of CT findings in rupture and impending rupture of abdominal aortic aneurysms.

Prompt diagnosis of rupture and impending rupture of abdominal aortic aneurysms is imperative. The computed tomographic (CT) findings of ruptured abdominal aortic aneurysms are often straightforward. Most ruptures are manifested as a retroperitoneal hematoma accompanied by an abdominal aortic aneurysm. Periaortic blood may extend into the perirenal space, the pararenal space, or both. Intraperitoneal extravasation may be an immediate or a delayed finding. Discontinuity of the aortic wall or a focal gap in otherwise continuous circumferential wall calcifications may point to the location of a rupture. There usually is a delay of several hours between the initial intramural hemorrhage and frank extravasation into the periaortic soft tissues. Contained or impending ruptures are more difficult to identify. A small amount of periaortic blood may be confused with the duodenum, perianeurysmal fibrosis, or adenopathy. Imaging features suggestive of instability or impending rupture include increased aneurysm size, a low thrombus-to-lumen ratio, and hemorrhage into a mural thrombus. A peripheral crescent-shaped area of hyperattenuation within an abdominal aortic aneurysm represents an acute intramural hemorrhage and is another CT sign of impending rupture. Draping of the posterior aspect of an aneurysmal aorta over the vertebrae is associated with a contained rupture.