Medications as causes of intraluminal hyperdensities: what radiologists need to know

In computed tomography (CT) angiogram or some dedicated CT studies of the abdomen, the use of positive enteric contrast should be avoided as its presence could decrease the sensitivity of the test. There are, however, cases of CT scans with unexpected hyperdense intraluminal contents detected due to the use of certain oral or rectal medications. Reports on medications as causes of intraluminal hyperdensities are sparse in the English literature. We have studied several commonly used medications and revealed that many drugs appear hyperdense in CT scans. The presence of unexpected intraluminal hyperdensities can potentially cause erroneous interpretation of images and in some cases decrease the sensitivity of the test. The hyperdense bowel contents may be mistaken as acute hemorrhage in CT angiogram for detection of GI bleeding. Active GI bleeding, presented as intraluminal extravasation of contrast material, can also be obscured. Certain intra-abdominal pathologies could be masked, for example, in plain CT scan for detection of urinary tract stones or in contrast CT study for suspected bowel ischaemia. It is important for radiologists and clinicians to be aware of this situation in order to prevent misinterpretation of images and to select the most appropriate imaging modality when such unexpected intraluminal hyperdensities are encountered.     

CT enteroclysis in the diagnosis of obscure gastrointestinal bleeding: initial results

AIM: To evaluate the usefulness of computed tomography (CT) enteroclysis in patients with obscure gastrointestinal (GI) bleeding. MATERIALS AND METHODS: In a prospective study, CT enteroclysis was performed in 21 patients (median age 50 years; range 13-71 years) with obscure GI bleeding in which the source of the bleeding could not be detected despite the patient having undergone both upper GI endoscopic and colonoscopic examinations. The entire abdomen and pelvis was examined in the arterial and venous phases using multisection CT after distending the small intestine with 2l of 0.5% methylcellulose as a neutral enteral contrast medium and the administration of 150ml intravenous contrast medium. RESULTS: Adequate distension of the small intestine was achieved in 20 of the 21 (95.2%) patients. Potential causes of GI bleeding were identified in 10 of the 21 (47.6%) patients using CT enteroclysis. The cause of the bleeding could be detected nine of 14 (64.3%) patients with overt, obscure GI bleeding. However, for patients with occult, obscure GI bleeding, the cause of the bleeding was identified in only one of the seven (14.3%) patients. The lesions identified by CT enteroclysis included small bowel tumours (n=2), small bowel intussusceptions (n=2), intestinal tuberculosis (n=2), and vascular lesions (n=3). All vascular lesions were seen equally well in both the arterial and venous phases. CONCLUSIONS: The success rate in detection of the cause of bleeding using CT enteroclysis was 47.6% in patients with obscure GI bleeding. The diagnostic yield was higher in patients with overt, obscure GI bleeding than in those with occult obscure GI bleeding.     

An initial experience: using helical CT imaging to detect obscure gastrointestinal bleeding

Obscure gastrointestinal (GI) bleeding is a common but frustrating disease for clinicians because of its elusive nature despite extensive work-up. We evaluate the role of helical computed tomography (CT) imaging using rapid infusion of intravenous contrast and water as oral contrast in the work-up of patients who are actively bleeding. Helical CT may be a useful noninvasive, alternative study to consider when routine work-up fails to determine the cause of active GI bleeding. Our preliminary study shows that helical CT was able to identify a wide variety of causes of obscure GI bleeding.     

Abdominal wall hematomata and colonic tumor detected on labeled red blood cell scintigraphy: case report

Gastrointestinal (GI) bleeding is not uncommon and responsible for considerable morbidity and mortality. Radionuclide red blood cell scintigraphy (RBCS) is a well established imaging modality for identifying patients with ongoing active GI bleeding. However, false positive RBCS are known to occur. The authors report the findings of a RBCS in an elderly female, who developed GI bleeding following the commencement of anticoagulant therapy. Although active GI bleeding was not identified, two abdominal wall hematomata and a cecal adenocarcinoma were detected. Distinguishing features of these lesions are described.     

Acute massive gastrointestinal bleeding: detection and localization with arterial phase multi-detector row helical CT

PURPOSE: To prospectively evaluate accuracy of arterial phase multi-detector row helical computed tomography (CT) for detection and localization of acute massive gastrointestinal (GI) bleeding, with angiography as reference standard. MATERIALS AND METHODS: Institutional review board approved this study; written informed consent was obtained from each patient or patient's family after procedures, including radiation dose, were explained. Twenty-six consecutive patients (17 men, nine women; age range, 18-89 years) had acute massive GI bleeding (defined as requirement of transfusion of at least 4 units of blood during 24 hours in the hospital or as hypotension with systolic blood pressure <90 mm Hg) and underwent arterial phase multi-detector row CT before angiography. Scans were obtained during arterial phase to identify extravasation of contrast material with attenuation greater than 90 HU within bowel lumen; this finding was considered diagnostic for active GI bleeding. Presence of contrast medium extravasation in each anatomic location was recorded. Sensitivity, specificity, positive and negative predictive values, and accuracy of multi-detector row CT for detection of acute GI bleeding were assessed. Accuracy for localization of acute GI bleeding was assessed by comparing locations of active bleeding at both multi-detector row CT and angiography in each patient who had active bleeding. RESULTS: Arterial phase multi-detector row CT depicted extravasation of contrast material in 21 of 26 patients. Overall location-based sensitivity, specificity, accuracy, and positive and negative predictive values of multi-detector row CT for detection of GI bleeding were 90.9% (20 of 22), 99% (107 of 108), 97.6% (127 of 130), 95% (20 of 21), and 98% (107 of 109), respectively. Overall patient-based accuracy of multi-detector row CT for detection of acute GI bleeding was 88.5% (23 of 26). The location of contrast material extravasation on multi-detector row CT scans corresponded exactly to that of active bleeding on angiograms in all patients with contrast medium extravasation at both multi-detector row CT and angiography. CONCLUSION: Arterial phase multi-detector row CT is accurate for detection and localization of bleeding sites in patients with acute massive GI bleeding.     

Diagnostic Performance of CT Angiography in Patients Visiting Emergency Department with Overt Gastrointestinal Bleeding

Objective

To investigate the diagnostic performance of computed tomography angiography (CTA) in identifying the cause of bleeding and to determine the clinical features associated with a positive test result of CTA in patients visiting emergency department with overt gastrointestinal (GI) bleeding.

Materials and Methods

We included 111 consecutive patients (61 men and 50 women; mean age: 63.4 years; range: 28-89 years) who visited emergency department with overt GI bleeding. They underwent CTA as a first-line diagnostic modality from July through December 2010. Two radiologists retrospectively reviewed the CTA images and determined the presence of any definite or potential bleeding focus by consensus. An independent assessor determined the cause of bleeding based on other diagnostic studies and/or clinical follow-up. The diagnostic performance of CTA and clinical characteristics associated with positive CTA results were analyzed.

Results

To identify a definite or potential bleeding focus, the diagnostic yield of CTA was 61.3% (68 of 111). The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value were 84.8% (67 of 79), 96.9% (31 of 32), 98.5% (67 of 68), and 72.1% (31 of 43), respectively. Positive CTA results were associated with the presence of massive bleeding (p = 0.001, odds ratio: 11.506).

Conclusion

Computed tomography angiography as a first-line diagnostic modality in patients presenting with overt GI bleeding showed a fairly high accuracy. It could identify definite or potential bleeding focus with a moderate diagnostic yield and a high PPV. CTA is particularly useful in patients with massive bleeding.     

Multi-detector CT: review of its use in acute GI haemorrhage

The advent of multi-section computed tomography (CT) technology allows the non-invasive assessment of the arterial tree. Using current software, it is now possible to produce high-quality, angiographic-like images that can be used to plan and guide therapeutic procedures. One such clinical situation is the assessment of patients with acute gastrointestinal (GI) haemorrhage. Multi-section CT has a number of advantages over conventional angiography in this situation. The simplicity and non-invasive nature of the technique compared with conventional angiography make CT angiography possible in situations where conventional angiography is not available. Movement artefact from respiration and peristalsis is a common problem in the interpretation of conventional angiography; this is essentially abolished with rapid acquisition times and the use of multi-planar images to remove overlying bowel loops. Cross-sectional imaging with the ability for multi-planar reconstruction allows the accurate anatomical localization of the bleeding site, as well as an assessment of the underlying pathology: this can be used to plan therapy (embolization or surgery). The aim of this paper is to review the current use of CT in the investigation of patients with GI haemorrhage, illustrated with images from our Institution. For patients in whom GI endoscopy has failed to establish a diagnosis, we propose multi-section CT angiography as the initial imaging investigation in acute GI haemorrhage.     

Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT

The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT.     

CT findings of walled-off pancreatic necrosis (WOPN): differentiation from pseudocyst and prediction of outcome after endoscopic therapy

Computed tomography (CT) findings that may differentiate walled-off pancreatic necrosis (WOPN) from pancreatic pseudocyst were investigated. CT examinations performed before endoscopic therapy of pancreatic fluid collection (PFC) in 73 patients (45 WOPN, 28 pseudocysts) were evaluated retrospectively by two radiologists. PFC was evaluated for size, extension to paracolic space, characteristics of wall and internal structure. The pancreas was evaluated for deformity or discontinuity, and pancreatic duct dilation. CT findings that were associated with WOPN or pseudocyst were identified. CT score (number of CT findings associated with WOPN minus number of findings associated with pseudocyst) was calculated for each PFC. PFC was categorized as WOPN or pseudocyst using a CT score threshold. Larger size, extension to paracolic space, irregular wall definition, presence of fat attenuation debris in PFC, pancreatic deformity or discontinuity (P < 0.05–0.0001) were findings associated with WOPN. Presence of pancreatic duct dilation was associated with pseudocyst. Using a CT score of 2 or higher as a threshold, CT differentiated WOPN from pseudocyst with an accuracy of 79.5–83.6%. Thus, CT can differentiate WOPN from pseudocysts.     

Transjugular Endovascular Recanalization of Splenic Vein in Patients with Regional Portal Hypertension Complicated by Gastrointestinal Bleeding

Purpose

Regional portal hypertension (RPH) is an uncommon clinical syndrome resulting from splenic vein stenosis/occlusion, which may cause gastrointestinal (GI) bleeding from the esophagogastric varices. The present study evaluated the safety and efficacy of transjugular endovascular recanalization of splenic vein in patients with GI bleeding secondary to RPH.

Methods

From December 2008 to May 2011, 11 patients who were diagnosed with RPH complicated by GI bleeding and had undergone transjugular endovascular recanalization of splenic vein were reviewed retrospectively. Contrast-enhanced computed tomography revealed splenic vein stenosis in six cases and splenic vein occlusion in five. Etiology of RPH was chronic pancreatitis (n = 7), acute pancreatitis with pancreatic pseudocyst (n = 2), pancreatic injury (n = 1), and isolated pancreatic tuberculosis (n = 1).

Results

Technical success was achieved in 8 of 11 patients via the transjugular approach, including six patients with splenic vein stenosis and two patients with splenic vein occlusion. Two patients underwent splenic vein venoplasty only, whereas four patients underwent bare stents deployment and two covered stents. Splenic vein pressure gradient (SPG) was reduced from 21.5 ± 7.3 to 2.9 ± 1.4 mmHg after the procedure (P < 0.01). For the remaining three patients who had technical failures, splenic artery embolization and subsequent splenectomy was performed. During a median follow-up time of 17.5 (range, 3–34) months, no recurrence of GI bleeding was observed.

Conclusions

Transjugular endovascular recanalization of splenic vein is a safe and effective therapeutic option in patients with RPH complicated by GI bleeding and is not associated with an increased risk of procedure-related complications.     

Acute pancreatitis and its complications. Computed tomography and sonography

Acute pancreatitis is a clinical diagnosis. In most patients with uncomplicated acute pancreatitis, there is no need for radiologic confirmation or work-up. However, in some patients, the diagnosis may be in doubt, or associated abnormalities or complications of acute pancreatitis may be suspected by the patient's protracted course or severity of disease. In these patients, radiology can be extremely helpful. CT is the best single radiologic imaging modality to evaluate these patients. With modern scanners, there are no failures, and CT provides a complete view of the pancreas and peripancreatic tissues, despite overlying bowel gas or other anatomic features that may limit the sonographic evaluation. Sonography may be helpful in evaluating possible biliary complications of acute pancreatitis, in evaluating thin patients with a good sonic window to the pancreas, or in evaluating patients who have a clearly defined complication such as a large pseudocyst. Sonography is also helpful for serial studies following the size of the fluid collection. The complications of pancreatitis include fluid collections and pseudocysts, which may become infected or develop bleeding within them, vascular complications including occlusion of the splenic vein with secondary development of varices, pancreatic ascites, and pancreatic abscess. While these complications can be evaluated by various radiologic methods, they are most effectively evaluated by CT. However, for some cases in which the cause of a cystic mass is in doubt or for cases of suspected pancreatic abscess, radiologic studies may be unable to provide a definitive diagnosis. In these cases, percutaneous needle aspiration will assist in the diagnosis.     

Acute gastrointestinal bleeding: the potential role of 64 MDCT and 3D imaging in the diagnosis

Advancements in both CT scanner technology and three-dimensional (3D) imaging software have now made it feasible to image patients with acute GI bleeding in an effort to identify the bleeding source. This pictorial essay will explore the potential role of utilizing 64 MDCT and 3D imaging in patients presenting with acute gastrointestinal bleeding. A discussion of current technology, appropriate CT protocols, and interpretation strategies will be included.     

Splenic complications in inflammatory pancreatic diseases]

Pancreatitis in combination with splenic and vascular complications is dangerous and potentially lethal. The most common complications are intestinal or intraperitoneal hemorrhage resulting directly from either vascular changes, such as erosion of the splenic artery, formation of a pseudoaneurysm, hemorrhage into a pseudocyst, or rupture of a pseudocyst with perforation into the colon, or complications in the spleen, such as anemic or hemorrhagic infarction, abscess or rupture. CT is the method of choice for the diagnosis of splenic complications of pancreatitis. Angiography is indicated in every severe hemorrhage in the presence of pancreatitis, to demonstrate vascular changes and to localize the source of hemorrhage. In addition, acute arterial bleeding can be successfully treated with catheter embolization.     

What is the role of plain radiography in patients with foreign bodies in the gastrointestinal tract?

Foreign bodies (FBs) in the gastrointestinal (GI) tract can show a wide range of clinical manifestations ranging from spontaneous evacuation to severe complication. Plain radiography is a straightforward and important initial imaging modality in cases of FB ingestion or insertion and is also helpful for follow-up purposes. Careful evaluations of the plain radiographs can determine the presence and nature of FBs, and help predict their precise locations and facilitate risk assessment. In this review, a wide variety of FBs in the GI tract are illustrated, and the role of plain radiography in patient management is discussed.     

Computed tomography versus magnetic resonance imaging in high-dose-rate prostate brachytherapy planning: The impact on patient-reported health-related quality of life

PurposeHigh-dose-rate (HDR) prostate brachytherapy uses volumetric imaging for treatment planning. Our institution transitioned from computed tomography (CT)-based planning to MRI-based planning with the hypothesis that improved visualization could reduce treatment-related toxicity. This study aimed to compare the patient-reported health-related quality of life (hrQOL) and physician-graded toxicity outcomes of CT-based and MRI-based HDR prostate brachytherapy.MethodsFrom 2016 to 2019, 122 patients with low- or intermediate-risk prostate cancer were treated with HDR brachytherapy as monotherapy. Patients underwent CT only or CT and MRI imaging for treatment planning and were grouped per treatment planning imaging modality. Patient-reported hrQOL in the genitourinary (GU), gastrointestinal (GI), and sexual domains was assessed using International Prostate Symptom Score and Expanded Prostate Cancer Index Composite Short Form-26 questionnaires. Baseline characteristics, changes in hrQOL scores, and physician-graded toxicities were compared between groups.ResultsThe median follow-up was 18 months. Patient-reported GU, GI, and sexual scores worsened after treatment but returned toward baseline over time. The CT cohort had a lower baseline mean International Prostate Symptom Score (5.8 vs. 7.8, p = 0.03). The other patient-reported GU and GI scores did not differ between groups. Overall, sexual scores were similar between the CT and MRI cohorts (p = 0.08) but favored the MRI cohort at later follow-up with a smaller decrease in Expanded Prostate Cancer Index Composite Short Form-26 sexual score from baseline at 18 months (4.9 vs. 19.8, p = 0.05). Maximum physician-graded GU, GI, and sexual toxicity rates of grade ≥2 were 68%, 3%, and 53%, respectively, with no difference between the cohorts (p = 0.31).ConclusionOur study shows that CT- and MRI-based HDR brachytherapy results in similar rates of GU and GI toxicity. MRI-based planning may result in improved erectile function recovery compared with CT-based planning.     

十二指肠肿瘤的影像学诊断和评价

目的：评价CT和钡剂造影（GI）诊断和鉴别诊断十二指肠肿瘤的价值。方法：42例十二指肠肿瘤（腺癌28例,平滑肌肉瘤6例,恶性淋巴瘤1例,腺瘤2例,平滑肌瘤3例,脂肪瘤2例）的临床特征,CT和GI表现对照病理所见进行分析。对各影像学方法（CT、GI、CT＋GI）在显示病变,定形（明确病变的确切部位、大小、形态）和定性诊断与鉴别诊断中的作用,以0－3分记分法进行评价。结果：十二指肠肿瘤的主要临床表现为肠腔占位（23．81％）、肠道出血（11．90％）和黄疸（38．10％）三大类。它与病变部位关系密切,而与病变的良恶性及其大小并不一致。25例兼做CT和GI者中,CT敏感性最高,100％可发现病变。1例球后段癌阻塞道GI无法诊断,敏感性为97．62％。但GI特异性（3分）为60．0％,CT仅52．0％,CT＋GI则可达92．0％。结论：CT和GI诊断与鉴别诊断十二指肠肿瘤各有利弊,综合二种技术,可提高诊断正确性。     

CT scanning and ultrasound in the evaluation of pancreatic pseudocysts: a preliminary comparison

A retrospective review of 12 surgically proved cases of pancreatic pseudocyst was performed. CT correctly demonstrated 6/8 uncomplicated pseudocysts and 4/4 infected pseudocysts. Ultrasound identified 7/8 uncomplicated and 2/4 infected pseudocysts. Errors by one modality are due to limitations not shared by the other method. This suggests a basis for the complementary use of CT scanning and ultrasound in the evaluation of suspected pancreatic pseudocysts.     

Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT

This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleeding.     

Percutaneous drainage of mediastinal pseudocysts

Percutaneous catheter drainage of a mediastinal pseudocyst was performed in two patients. Access was gained through computed tomography (CT)-guided puncture of the abdominal portion of the pseudocyst in one patient, and a transhepatic-subxiphoid approach was used in the other. Guide wires and catheters were advanced into the mediastinal pseudocysts under CT control. Drainage was technically successful in both patients, with no procedure-related complications. Percutaneous drainage is an alternative to the surgical treatment of symptomatic and nonresolving mediastinal pseudocysts, provided that a safe access route can be found.     

Imaging evaluation of post pancreatic surgery

The role of several imaging techniques in patients submitted to pancreatic surgery with special emphasis to single-slice helical computed tomography (CT) and multidetector-row CT (MDCT) was reviewed. Several surgical options may be performed such as Whipple procedure, distal pancreatectomy, central pancreatectomy, and total pancreatectomy. Ultrasound examination may be used to detect peritoneal fluid in the early post-operative period as well as lesion recurrence in long-term follow-up. Radiological gastrointestinal studies has a major role in evaluation of intestinal functionality. In spite of the advent of other imaging modalities, CT is the most effective after pancreatic surgery. On post-operative CT, the most common findings were small fluid peritoneal or pancreatic collections, stranding of the mesenteric fat with perivascular cuffing, reactive adenopathy and pneumobilia. In addition, CT may demonstrate early (leakage of anastomosis, pancreatico-jejunal fistula, haemorrage, acute pancreatitis of the remnant pancreas, peritonitis), and late (chronic fistula, abscess, aneurysms, anastomotic bilio-digestive stenosis, perianastomotic ulcers, biloma, and intra-abdominal bleeding) surgical complications. In the follow-up evaluation, CT may show tumor recurrence, liver and lymph nodes metastasis. Magnetic resonance may be used as alternative imaging modality to CT, when renal insufficiency or contrast sensitivity prevents the use of iodinated i.v. contrast material or when the biliary tree study is primarily requested. The knowledge of the type of surgical procedures, the proper identification of the anastomoses as well as the normal post-operative imaging appearances are essential for an accurate detection of the complications and recurrent disease.