Infarcts and ischemia in the abdomen: an imaging perspective with an emphasis on cross-sectional imaging findings

Infarcts and ischemia of abdominal organs may present with acute abdominal pain, and early diagnosis is crucial to prevent morbidity and mortality. Unfortunately, some of these patients present in poor clinical conditions to the emergency department, and imaging specialists are crucial for optimal outcomes. Although the radiological diagnosis of abdominal infarcts is often straightforward, it is vital to use the appropriate imaging modalities and correct imaging techniques for their detection. Additionally, some non-infarct-related abdominal pathologies may mimic infarcts, cause diagnostic confusion, and result in delayed diagnosis or misdiagnosis. In this article, we aimed to outline the general imaging approach, present cross-sectional imaging findings of infarcts and ischemia in several abdominal organs, including but not limited to, liver, spleen, kidneys, adrenals, omentum, and intestinal segments with relevant vascular anatomy, discuss possible differential diagnoses and emphasize important clinical/radiological clues that may assist radiologists in the diagnostic process.

Cross-sectional imaging findings of splenic infections: is differential diagnosis possible?

The spleen plays an important role in the immunological homeostasis of the body. Several neoplastic and non-neoplastic diseases may affect this organ, and imaging is of fundamental importance for diagnosis. Infectious diseases of the spleen can be encountered in daily radiology practice, and differential diagnosis may sometimes be challenging. Infectious involvement of the spleen can be primary or secondary to a different source outside the spleen. Despite the fact that different infectious diseases may cause similar imaging findings, we believe that differential diagnosis between different causes may also be possible in certain patients with imaging. Early diagnosis may potentially enhance patients’ treatment and outcome. In this review, we aimed to increase imaging specialists’ awareness of splenic infections by describing the multimodality imaging features of common and atypical infections of the spleen with their differential diagnoses.

Cross-sectional imaging features of unusual adrenal lesions: a radiopathological correlation

The detection rates of adrenal masses are increasing with the common and widespread use of cross-sectional imaging. Adrenal adenomas, myelolipomas, metastases, pheochromocytomas, and adrenocortical tumors are well-known and relatively common adrenal tumors. However, there are many less-known neoplastic and nonneoplastic adrenal diseases that might affect the adrenal glands in addition to these common lesions. These rare entities include, but are not limited to, hydatid cysts, congenital adrenal hyperplasia, Wolman disease, adrenal tuberculosis, primary adrenal lymphoma. This article aims to present imaging findings of these unusual lesions in accordance with their pathologic characteristics. We think that the simultaneous presentation of the pathological findings with the imaging features may facilitate the learning process and may potentially enhance the recognition of these entities.

Identifying the deceiver: the non-neoplastic mimickers of genital system neoplasms

Tumors of the genital system are common and imaging is of crucial importance for their detection and diagnosis. Several non-neoplastic diseases may mimic these tumors and differential diagnosis may be difficult in certain cases. Misdiagnosing non-neoplastic diseases as tumor may prompt unnecessary medical treatment or surgical interventions. In this article, we aimed to present the imaging characteristics of non-neoplastic diseases of the male and female genital systems that may mimic neoplastic processes. Increasing awareness of the imaging specialists to these entities may have a severe positive impact on the management of these patients.

Immunoglobulin G4-related systemic disease: mesenteric and peritoneal involvement with radiopathological correlation and differential diagnoses

Since its first introduction in 2003 by Kamisawa et al., IgG4-related disease has gained wide interest in the imaging community, and several manuscripts have been published regarding its imaging features. In addition to initial observations in the pancreaticobiliary system, it is now well known that the disease may involve every organ system in the body. There is not much information in the imaging literature about the involvement of mesentery, omentum, and peritoneum in this disease. This article aims to provide more information about the imaging findings of IgG4-related disease regarding these areas by making radiopathological correlations and discussing the possible differential diagnoses.

Can we differentiate neoplastic and non-neoplastic spontaneous adrenal bleeding? Imaging findings with radiopathologic correlation

Spontaneous adrenal bleeding is a rare clinical event with non-specific clinical features. Life-threatening bleeding in the adrenal glands may be promptly diagnosed with imaging. Computed tomography (CT) is generally the first imaging modality to be used in these patients. However, in the acute phase of bleeding, it may be difficult to detect the underlying mass from the large hematoma. In these patients, additional imaging studies such as magnetic resonance imaging or positron emission tomography/CT may be utilized to rule out a neoplastic mass as the source of bleeding. In patients where an underlying neoplastic mass could not be identified at the time of initial diagnosis, follow-up imaging may be helpful after the acute phase subsides.

The role of interventional radiology in the treatment of patients with pancreatic cancer

Interventional radiology (IR) provides minimally invasive therapeutic and palliative options for the treatment of pancreatic cancer depending on the stage of the disease. IR plays a critical, and also a very effective role, in both pre- and post-operative care of the patients with early stage resectable disease and also in palliative treatment of the patients with locally advanced or metastatic disease. In this article, we aimed to present the capability and the limitations of IR procedures including: local treatment options of primary and metastatic pancreatic cancer, palliation of biliary and intestinal obstructions, minimally invasive treatment of post-operative complications, and pain management.

Role of imaging in visceral vascular emergencies

Differential diagnosis in non-traumatic acute abdomen is broad and unrelated diseases may simulate each other from a clinical perspective. Despite the fact that they are not as common, acute abdominal pain due to diseases related to visceral vessels may be life-threating if not detected and treated promptly. Thrombosis, dissection, and aneurysm in the abdominal visceral arteries or thrombosis in visceral veins may cause acute abdominal pain. Imaging with appropriate protocoling plays a fundamental role in both early diagnosis and determination of the treatment approach in these cases where early treatment can be life-saving. Computed tomography (CT) appears to be the most effective modality for the diagnosis as it provides high detail images in a very short time. Patient cooperation is also a less concern as compared to magnetic resonance imaging (MRI). As the imaging findings may sometimes be really subtle, diagnosis may be difficult especially to inexperienced imagers. Correct protocoling is also very critical to detect arterial abnormalities as visceral arterial abnormalities may not be detectable in portal phase only abdominal CT scans. In this article, we aimed to increase awareness among imaging specialists to these not very common causes of acute abdomen.

Imaging findings of infectious and inflammatory diseases of the urinary system mimicking neoplastic diseases

Neoplastic diseases affecting the urinary organs are common, and diagnosis by imaging is usually straightforward. However, infectious/inflammatory processes also commonly affect these organs and can be mistaken for a neoplasm. Familiarity with these potential mimickers and awareness of their imaging presentations are key for correct diagnosis. We present the imaging findings of non-neoplastic infectious/inflammatory diseases that can mimic a neoplastic process.

Tumor in the veins: an abdominal perspective with an emphasis on CT and MR imaging

Endovenous tumor thrombus in abdomen should be accurately diagnosed as it is a significant finding that may change medical and surgical treatment approaches. As some underlying reasons for endovenous tumor thrombi are relatively rare and imaging findings may be quite subtle, they can be easily overlooked which may have important clinical consequences. In this paper, we described the various imaging aspects of endovenous tumor thrombi originating from various tumor types in different venous structures of the abdomen.

Non-neoplastic hepatopancreatobiliary lesions simulating malignancy: can we differentiate?

Despite the success of cross-sectional imaging in evaluating hepatopancreatobiliary system malignancies, several non-malignant disease processes may closely mimic malignancy. Differentiating these benign diseases from malignancy may be difficult, or even impossible, even in the hands of experienced imagers. In this manuscript, we present benign mimics involving the hepatopancreatobiliary system and try to increase awareness of these potential pitfalls.

Primary lymphomas of the intraabdominal solid organs and the gastrointestinal tract: spectrum of imaging findings with histopathological confirmation

Unlike nodal lymphoma, primary lymphomas of the intraabdominal organs are uncommon neoplasms whose diagnosis may be challenging in certain clinical circumstances. Despite this difficulty for imaging diagnosis, there are several imaging features on ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography that may suggest the correct diagnosis. The scope of this review is to describe and illustrate the imaging features of primary lymphoma of intraabdominal organs providing clues to the diagnosis, together with their pathological correlations.

Imaging in secondary tumors of the ovary

Metastatic involvement of the ovaries is not rare. The most common tumor types metastasizing to the ovaries, from non-gynecological organs, are breast, colorectal, gastric, and appendix tumors. Lymphogenous, hematogenous, and transcoelomic pathways have all been proposed among potential pathways. Early diagnosis and treatment have an important potential to improve the patient outcome. Krukenberg tumors typically appear as complex semisolid masses with varying amounts of solid and cystic components. Ovarian metastases from the colon primaries are predominantly cystic in nature. Secondary lymphomatous involvement of ovary is mostly bilateral and solid with heterogeneous signal intensity on MRI. Metastatic breast cancer to the ovaries is typically bilateral and tends to be of small size. Among all the other imaging characteristics, bilateral involvement of secondary tumors of the ovary appears to be most potentially helpful finding in differentiating from primary ones.

Secondary Tumors of the Urinary System: An Imaging Conundrum

Imaging features of metastases to the urinary system may closely mimic primary urinary tract tumors, and differential diagnosis by imaging alone may be problematic or even impossible in some cases. The main purpose of this article was to familiarize radiologists with imaging findings of metastasis to the urinary system on cross-sectional imaging, with an emphasis on abdominal and pelvic computed tomography and magnetic resonance imaging. In addition, we review the clinical importance and implications of metastases to the urinary tract and provide information on diagnostic work-ups.

Computed Tomography-Based Diagnosis of Gastric Vein Invasion in Patients with Gastric Cancer

Objective

The objective of this study was to demonstrate computed tomography (CT)-based diagnosis of venous invasion in patients with gastric cancer and its prognostic value.

Materials and Methods

Medical records and CT examinations of 530 patients with gastric cancer diagnosed after biopsy from February 2003 to December 2015 were included in this retrospective study. An imaging-based diagnosis of venous invasion was established when one of the following criteria were satisfied: 1) tumoral enhancement in the lumen of the vein, 2) tumor protruding through the course of a vein, and 3) distention of the vein due to extension of the gastric tumor. CT-based diagnosis of gastric vein invasion was established in 11/530 patients.

Results

Histopathological examination revealed poorly differentiated gastric adenocarcinoma (n=10) and neuroendocrine carcinoma (n=1). The median survival of the patients after the initial CT was 153.5 (range: 6-1275) days. Tumor invasion was observed at the aberrant left gastric vein (n=2), right gastroepiploic and superior mesenteric vein (n=2), gastric vein (n=4), and short gastric vein (n=3). Two of the three patients with short gastric vein invasion died 6 and 7 days after the initial CT, respectively.

Conclusion

All draining veins of the stomach can be invaded by gastric cancer; CT can enable diagnosis that may be important for prognosis and surgical planning. The presence of short gastric vein invasion detected by CT may be associated with poor prognosis.

Role of multimodality imaging in the diagnosis of lymphoproliferative malignancies and hematologic disorders of the kidneys

Lymphoproliferative and hematologic disorders of the kidney may present with focal or diffuse renal parenchymal involvement in clinical practice. Radiologic findings of lymphoproliferative and hematologic disorders of the kidney may mimick primary neoplastic and inflammatory disorders of the kidney. All cross-sectional imaging modalities including ultrasonography, computed tomography, and magnetic resonance imaging may be used in the diagnosis of these diseases. Percutaneous biopsy may be used in problematic cases for definitive diagnosis.

Diverticulitis: a comprehensive review with usual and unusual complications

Abstract

Diverticulitis is characterized by inflammation of the outpouchings of the bowel wall. Imaging findings of diverticulitis include edematous thickening of the bowel wall with inflammatory changes within the adjacent mesenteric fat. Uncomplicated diverticulitis can be treated conservatively; however, complicated diverticulitis may not be responsive to medical treatment and life-threatening conditions may occur. In this review, we aimed to illustrate the ultrasonography (US) and computed tomography (CT) features of diverticulitis and its complications including perforation, phlegmon, abscess, ascending septic thrombophlebitis (phylephlebitis), bleeding, intestinal obstruction, and fistula.

Teaching Points

• Complications of diverticulitis may be highly variable.

• It may be difficult to diagnose diverticulitis as underlying cause of severe complications.

• MDCT is essential for the primary diagnosis of the acute diverticulitis and its complications.

Magnetic Resonance Imaging of Liver Metastasis

Liver magnetic resonance imaging (MRI) is becoming the gold standard in liver metastasis detection and treatment response assessment. The most sensitive magnetic resonance sequences are diffusion-weighted images and hepatobiliary phase images after Gd-EOB-DTPA. Peripheral ring enhancement, diffusion restriction, and hypointensity on hepatobiliary phase images are hallmarks of liver metastases. In patients with normal ultrasonography, computed tomography (CT), and positron emission tomography (PET)-CT findings and high clinical suspicion of metastasis, MRI should be performed for diagnosis of unseen metastasis. In melanoma, colon cancer, and neuroendocrine tumor metastases, MRI allows confident diagnosis of treatment-related changes in liver and enables differential diagnosis from primary liver tumors. Focal nodular hyperplasia-like nodules in patients who received platinum-based chemotherapy, hypersteatosis, and focal fat can mimic metastasis. In cancer patients with fatty liver, MRI should be preferred to CT. Although the first-line imaging for metastases is CT, MRI can be used as a problem-solving method. MRI may be used as the first-line method in patients who would undergo curative surgery or metastatectomy. Current limitation of MRI is low sensitivity for metastasis smaller than 3mm. MRI fingerprinting, glucoCEST MRI, and PET-MRI may allow simpler and more sensitive diagnosis of liver metastasis.

Imaging findings of renal toxicity in patients on chronic lithium therapy

Lithium salts are the mainstay of treatment of bipolar disorder. However, the therapeutic index of lithium is narrow, and severe side effects may be seen. Nephrotoxicity is the most important side effect, which may progress to chronic renal failure. In this pictorial essay, we present ultrasonography, computed tomography, and magnetic resonance imaging findings of renal toxicity secondary to chronic lithium use. We believe that imaging could be extremely helpful for the evaluation of renal toxicity and may even detect preclinical stages of renal parenchymal injury. A combination of different imaging modalities may help clarify findings detected on one modality.

Abundant macroscopic fat in intra-abdominal lymph nodes involved in the course of a patient with chronic lymphocytic leukaemia: presentation of imaging findings with biopsy correlation

The presence of a small amount of macroscopic fat is not unusual in the hilar region of normal lymph nodes. However, abundant replacement of the lymph node with fat is highly unusual and may appear as metastatic lymph node disease in the course of fat-predominant liposarcomas or in the case of coeliac disease complicated by cavitating lymph node syndrome. In this case report, a patient with chronic lymphocytic leukaemia/small lymphocytic lymphoma who demonstrated an increasing abundance of macroscopic fat in the diseased lymph nodes is presented. To the best of our knowledge, the imaging findings of abundant fat in lymph nodes in the course of lymphoma have not been reported before. The presence of macroscopic fat may be seen in the presence of actively involved lymph nodes in the presence of chronic lymphocytic leukaemia.

Case report. Peripancreatic intranodal haemangioma mimicking pancreatic neuroendocrine tumour: imaging and pathological findings

Haemangiomas are common benign tumours that are generally detected within the skin, mucosal surfaces and soft tissues. However, intranodal haemangiomas are extremely rare and are among the benign primary vascular abnormalities of the lymph nodes that include lymphangioma, haemangioendothelioma, angiomyomatous hamartoma and haemangiomas. In this case report, we present the imaging and pathological findings of an intranodal haemangioma in the pancreatic head simulating a pancreatic neuroendocrine tumour. To the best of our knowledge, this is the first report of an intranodal haemangioma in this location.