Administration Of Oral Contrast Material Research Articles

54-Year-Old Woman With Altered Mental Status and Abdominal Pain

54-Year-Old Woman With Altered Mental Status and Abdominal Pain

Half of Anastomotic Leaks After Esophagectomy Are Undetected on Initial Postoperative Esophagram

BackgroundThe sensitivity of fluoroscopic esophagography with oral administration of contrast material to exclude anastomotic leak after esophagectomy is not well documented, and the consequences of missing a leak in this setting have not been previously described. MethodsWe performed a retrospective cohort study of a prospectively maintained institutional database of patients undergoing esophagectomy with esophagogastric anastomosis from 2008 to 2020. Relevant details of leaks, management, and outcomes were obtained from the database and formal chart review. Statistical analysis was performed to compare patients with and without leaks and those with false-negative vs positive esophagrams. ResultsThere were 384 patients who underwent esophagectomy with gastric reconstruction; the majority were Ivor-Lewis (82%), and 51% were wholly or partially minimally invasive. By use of a broad definition of leak, 55 patients (16.7%) developed an anastomotic leak. Of the 55 patients, 27 (49%) who ultimately were found to have a leak initially had a normal esophagram result (performed on average on postoperative day 6). Those with a normal initial esophagram result were more likely to have an uncontained leak (81% vs 29%; P < .01), to require unplanned readmission (70% vs 39%; P = .02), and to undergo reoperation (44% vs 11%; P < .01). ConclusionsEarly postoperative esophagrams intended to evaluate anastomotic integrity have a low sensitivity of 51%, and leaks missed on the initial esophagram have greater clinical consequences than those identified on the initial esophagram. These findings suggest that a high index of suspicion must be maintained even after a normal esophagram result and call into question the common practice of using this test to triage patients for diet advancement.

Imaging of postoperative complications following Ivor-Lewis esophagectomy

Postoperative imaging plays a key role in the identification of complications after Ivor-Lewis esophagectomy (ILE). Careful analysis of imaging examinations can help identify the cause of the presenting symptoms and the mechanism of the complication. The complex surgical procedure used in ILE results in anatomical changes that make imaging interpretation challenging for many radiologists. The purpose of this review was to make radiologists more familiar with the imaging findings of normal anatomical changes and those of complications following ILE to enable accurate evaluation of patients with an altered postoperative course. Anastomotic leak, gastric conduit necrosis and pleuropulmonary complications are the most serious complications after ILE. Computed tomography used in conjunction with oral administration of contrast material is the preferred diagnostic tool, although it conveys limited sensitivity for the diagnosis of anastomotic fistula. In combination with early endoscopic assessment, it can also help early recognition of complications and appropriate therapeutic management.

SU‐F‐I‐29: Investigating the Impact of the Amount of Contrast Material Used in Abdominal CT Examinations Regarding the Diagnosis of Appendicolith

Purpose:The purpose of this study is to report the case of a young adult in which the incomplete oral administration of contrast material led to diagnosis of an appendicolith, which cause acute appendicitis.Methods:A male 34 years old underwent CT examination due to acute abdominal pain in the upper abdomen. An ultrasound examination of the upper abdomen and kidneys, an x‐ray examination of the abdomen and a CT scan of the entire abdomen and pelvis after both oral and IV administration of contrast material were performed. In the ultrasound examination, both kidneys gallbladder and spleen appeared normal and the x‐ray examination did not show any pathological findings. As part of the CT examination, the patient received oral contrast material less than 500 ml due to lack of cooperation by the patient as a result of his abdominal pain.Results:The CT abdomen revealed a severely inflamed appendix that was significantly dilated at 1.1 cm. Moreover, it demonstrated a 1.4 cm appendicolith. The portion of the oral contrast material that was injected to the patient covered the upper abdomen and as a result an appendicolith could be revealed in the lower abdomen. If the patient had received the 1,000ml of contrast material, the whole abdomen would have been covered with the contrast in danger to lose the appendicolith, which caused the inflammation.Conclusion:Based on the findings of this study, in suspicion of acute appendicitis nephrolithiasis and ureterolithiasis, we propose to start the CT protocol with a CT scan without oral contrast material and then proceed with oral and IV contrast not only to succeed gastric intestinal differentiation but also to avoid covering the lower abdomen and obscure any small stones that may exist.

Routine Use of Positive Oral Contrast Material Is Not Required for Oncology Patients Undergoing Follow-up Multidetector CT

The purpose of this retrospective medical audit was to evaluate the effect of discontinuing routine administration of oral contrast material to oncology patients undergoing follow-up multidetector computed tomography (CT) on reader evaluation of study adequacy. Analysis of 100 patients' experience of CT shows that positive oral contrast material was their least pleasant experience (P < .0001). Abandoning the routine use of positive oral contrast material for follow-up scans in general oncology patients undergoing multidetector CT, with section reconstruction thickness of 2.5 mm, was audited for 447 patents and included 5-13-month follow-up. The patient satisfaction study and clinical audit were performed according to local institutional audit guidelines. Since this was a clinical audit project, ethical approval was not required under UK National Health Service research governance arrangements. No patient needed to be recalled, no related diagnostic error has been reported, and follow-up CT, available in 285 of 447 cases (64%), revealed no error on the audited scan. We conclude that the routine use of positive oral contrast material is unnecessary for follow-up multidetector CT for general oncology indications.

F-18]Fluorodeoxyglucose Positron Emission Tomography and Positron Emission Tomography

We retrospectively assessed the diagnostic utility of dedicated positron emission tomography (PET) and hybrid PET-computed tomography (CT) scans with [F-18]fluorodeoxyglucose (FDG) in the imaging evaluation of patients with known or suspected recurrent and metastatic cholangiocarcinoma. The study group included 24 patients (13 males and 11 females; age range, 34-75 years) with known or suspected recurrent and metastatic cholangiocarcinoma. We performed 8 dedicated PET scans (Siemens 953/A, Knoxville, Tenn) in 8 patients and 24 hybrid PET-CT scans (Siemens Biograph, Knoxville, Tenn) in 16 patients. Four patients underwent both pretreatment and posttreatment scans. Nonenhanced CT transmission scans were obtained for attenuation correction after administration of oral contrast material. PET images were obtained 60 minutes after the intravenous administration of 15 mCi (555 MBq) FDG. Prior treatments included surgery alone in 12 patients, surgery and chemotherapy in 6 patients, and surgery and combined chemoradiation therapy in 6 patients. Diagnostic validation was conducted through clinical and radiologic follow-up (2 months to 8 years). PET and CT were concordant in 18 patients. PET-CT correctly localized a hypermetabolic metastatic lesion in the anterior subdiaphragmatic fat instead of within the liver and was falsely negative in intrahepatic infiltrating type cholangiocarcinoma. PET was discordant with CT in 6 patients. PET was negative in an enlarged right cardiophrenic lymph node on CT, which remained stable for 1 year. In 1 patient, PET-CT scan showed hypermetabolic peritoneal disease in the right paracolic gutter without definite corresponding structural abnormalities, which was subsequently confirmed on a follow-up PET-CT scan performed 6 months after the initial study, at which time peritoneal nodular thickening was evident on concurrent CT. PET-CT documented the progression of locally recurrent and metastatic disease in another patient based on interval appearance of several new hypermetabolic lesions and significant increase in the standardized uptake values of the known lesions despite little interval change in the size and morphologic character of lesions on concurrent CT. It was also helpful in excluding metabolically active disease in patients with contrast enhancement at either surgical margin of hepatic resection site or focally within hepatic parenchyma and in an osseous lesion. Overall, based on the clinically relevant patient basis for detection of recurrent and metastatic cholangiocarcinoma, the sensitivity and specificity of PET (alone and combined with CT) were 94% and 100% and, for CT alone, were 82% and 43%, respectively. FDG PET and PET-CT are useful in the imaging evaluation of patients with cholangiocarcinoma (except for infiltrating type) for detection of recurrent and metastatic disease and for assessment of treatment response. In particular, the combined structural and metabolic information of PET-CT enhances the diagnostic confidence in lesion characterization.

Functional MRI in the evaluation of oesophageal motility: feasibility, MRI patterns of normality, and preliminary experience in subjects with motility disorders

The aim of this study was to introduce functional magnetic resonance imaging (fMRI) with T1-weighted turbo fast low-angle shot (FLASH) sequences in the evaluation of oesophageal motility and morphology, to formulate MRI patterns of normality in healthy subjects and to demonstrate the feasibility of the method by obtaining a preliminary experience in the study of subjects affected by oesophageal motility disorders. Thirty healthy volunteers and seven patients with radiological and manometric diagnoses of oesophageal motility disorders underwent fMRI with dynamic T1- weighted turbo-FLASH (TFL) sequences during the administration of oral contrast material. Evaluation of oesophageal function and morphology proved possible in all subjects, as well as the formulation of normality patterns. In patients with motility disorders, fMRI correctly visualised the typical alterations in agreement with radiological and manometric findings. Functional MRI sequences acquired during the administration of oral contrast material can evaluate oesophageal transit, providing information on motility and morphology; furthermore, this modality can properly visualise the typical functional and morphological alterations of motility disorders.

Is administration of enteric contrast material safe before abdominal CT in children who require sedation? Experience with chloral hydrate and pentobarbital.

It has been common practice to administer enteric contrast material in preparation for abdominal CT in children who require sedation to be examined. At some institutions, the practice of administering an anesthetic or enteric contrast material before sedation is being challenged because it violates the "nothing by mouth" status that is otherwise strictly enforced before sedation. Our purpose was to review our safety record in administering enteric contrast material for CT before sedation. Radiology reports, medical records, and department incident reports were reviewed for the past 5 years from all patients who required sedation for abdominal CT. Patient age and sex, type of sedation, and complications (defined as vomiting with aspiration) related to enteric contrast material before the sedation were recorded. For routine oral contrast material, diluted Hypaque (meglumine diatrizoate) was administered in an age-based amount 1-2 hr before scanning. For sedation, depending on the patient's age, either oral chloral hydrate (70-100 mg/kg) or IV pentobarbital (3 mg/kg with repeated doses of up to 7 mg/kg) was used. Three hundred sixty-seven patients who received oral contrast material before sedation for abdominal CT were identified (200 boys, 167 girls; age range, 1 month-19 years; mean age, 2.9 years). Chloral hydrate was used in 30 patients and IV pentobarbital in 337 patients. No complications related to the administration of oral contrast material before sedation were identified. The practice of administering oral contrast material in children before sedation for abdominal CT appears to be safe when using the sedation drugs and protocols in place at our institution. Further study of the safety of this practice should be undertaken.

Blunt Duodenal Rupture

19-year-old, nonrestrained male driver was admitted to the hospital after a high-speed rollover motor vehicle collision. At admission, he was awake and alert with stable vital signs and complained of diffuse abdominal pain. Most of his pain was localized over an abrasion on the right upper quadrant. Focused abdominal sonography for trauma showed a small amount of fluid in Morison’s pouch and in the right paracolic gutter. Because of the free intraperitoneal fluid and suspicion of intraabdominal injury, IV contrast‐ enhanced helical CT of the abdomen without oral contrast material was performed, which showed duodenal rupture and liver laceration (Fig. 1). At laparotomy, a laceration involving more than 50% of the duodenal circumference was found along the lateral border of the duodenum at the junction of the descending (zone 2) and horizontal (zone 3) segments. The liver laceration was not actively bleeding. The duodenal laceration was closed. Duodenal rupture occurs in 2‐20% of patients with blunt abdominal injury and often occurs after blows to the upper abdomen or abdominal compression from high-riding seat belts. Forty percent of patients with duodenal injuries have other concomitant surgically important intraabdominal injuries, such as hepatic (38%) or pancreatic (28%) injuries [1]. In patients with blunt abdominal injury without physical findings that suggest the need for emergent laparotomy, focused abdominal sonography provides an alternative to diagnostic peritoneal lavage. Focused abdominal sonography is faster and less invasive than diagnostic peritoneal lavage and can occasionally reveal injuries in the retroperitoneum [2]. Focused abdominal sonography that reveals free fluid suggests hemoperitoneum or bowel injury, which requires abdominal CT or laparotomy. We believe there is little need for immediate diagnostic peritoneal lavage after abdominal sonography that reveals abnormal findings. Although somewhat controversial, IV contrast‐enhanced abdominal CT without oral contrast medium facilitates patient scheduling by diminishing patient transit time and dependence on patient cooperation and will not obscure important findings such as bowel hemorrhage or appendicolith [3]. Deferring the administration of oral contrast material has not been convincingly shown to decrease overall diagnostic sensitivity for surgically important injuries to intraabdominal contents or the retroperitoneum [4]. CT findings of free intraabdominal fluid without solid-organ injury should prompt diagnostic peritoneal lavage or laparotomy to exclude hollow viscus injuries. Diagnostic peritoneal lavage or focused abdominal sonography may fail to reveal slightly abnormal findings; therefore, a high degree of clinical suspicion of further injury is required to prompt CT or laparotomy before the onset of sepsis [5, 6]. This case illustrates how the sonographic finding of free intraperitoneal fluid prompted further examination with CT, which revealed retroperitoneal and peritoneal injuries. In patients with duodenal trauma, there is an increased incidence of pancreatic injuries requiring complex repairs, which are associated with increased morbidity and mortality. Early diagnosis allows greater opportunity for definitive repair at the initial surgery and lowers the risks of sepsis, coagulopathy, and pancreatic necrosis.

Value of negative oral contrast media in MR cholangiopancreatography (MRCP)

Evaluation of the use of a negative oral contrast material in MR cholangiopancreatography (MRCP). We performed MRCP in single-shot technique (TSE, TR = 2800 ms, TE = 1100 ms, ETL = 64) in 38 patients before and 20-30 min after oral administration of 300-600 ml of a negative oral contrast material. The visualization ducts and details important for the diagnosis was evaluated in a blinded manner. Ductal diameters were measured. Both sets of images were evaluated qualitatively. The ductal diameters did not change after administration of oral contrast material. In 1/3 of all cases the ductal structures were superimposed by a high signal intensity of fluid in the gastrointestinal tract, especially in the tail of the pancreas. After administration of oral contrast material only in 3 patients could a complete visualization of the ducts not be achieved. In 5 cases, details relevant for the diagnostic decision could be seen only on post-contrast images. The anatomic orientation was not compromised by the absence of signal in the gastrointestinal tract. Negative oral contrast material should be given before performing a MRCP to provide non-superimposed visualization of the bile and pancreatic ducts. There is no negative influence of the oral contrast material on the diameter of the ducts.

Tube thoracostomy complicates unrecognized diaphragmatic rupture.

A case of traumatic diaphragmatic rupture is reported in which herniated stomach mimicked a tension pneumothorax. Tube thoracostomy by trocar caused insertion of the pleural drain into the intrathoracic stomach. CT scan of the thorax after oral administration of contrast material revealed the correct diagnosis. After removal of the drain and retraction of the stomach into the abdomen the gastric perforation and diaphragmatic defect could be closed by suture. The further course of the patient was uneventful. This case report underlines the importance of differential diagnosis of symptoms in a case with a history of blunt chest trauma and shows the risks of unnecessary use of a trocar.

Aspiration after administration of oral contrast material in children undergoing abdominal CT for trauma.

The practice of routinely administering oral contrast material to children undergoing abdominal CT for blunt trauma is controversial, primarily because of the increased risk of aspiration. The purpose of this study was to determine how often aspiration occurs in this population of children. We retrospectively studied 50 children who underwent abdominal CT scans after blunt trauma. All children received diluted 3% water-soluble oral contrast material. The medical record of each child was reviewed for evidence of aspiration pneumonia as many as 48 hr after the CT. In each patient, sections of the CT scan through the lung bases were examined for opacities. When lung opacities were identified, they were classified as atelectasis, confusion, laceration, or nonspecific. We made attenuation measurements of lung opacities larger than 1 cm, and each measurement was compared with the attenuation measurement of contrast material in that patient's stomach. Student's two-tailed t test was used to compare the two measurements. Four patients were febrile after the CT scan, but in none was aspiration pneumonia suspected to be the cause. The remaining 46 patients did not have any clinical evidence of aspiration. Twelve of the 50 patients had pulmonary opacities revealed by CT that were sufficiently large that attenuation measurements could be obtained. The opacity in one of these patients was classified as nonspecific, and the attenuation was as high as that of contrast material in the stomach. No clinically symptomatic episodes of aspiration pneumonia were found in 50 pediatric patients with blunt trauma who were given oral contrast material for abdominal CT. Although one of the children had CT findings that suggested clinically silent aspiration of oral contrast material, no evidence was found that administration of oral contrast material was harmful.

A new technique of administration of oral contrast material for abdominal CT: the drip ingestion method.

A dequate distention ofthe gastrointestinal tract with oral contrast materials is essential to achieve the highest quality images in abdominal Cl’ examination [1, 2]. We designed a technique that we have called the drip ingestion method of administration of oral contrast material for abdominal CT. We investigated the usefulness ofthis technique in maximizing the distention of the gastrointesfinal tract in abdominal CT examination.

Diagnostic pitfalls in abdominal CT.

Many factors result in suboptimal performance of abdominal computed tomography (CT) or inaccurate interpretation of the images. Improper technique, observers' errors, and lack of clinical information are major contributors to misdiagnoses. Because of inadequate oral administration of contrast material, normal structures (eg, bowel) may remain unopacified and simulate tumors. Repeat scanning with additional contrast material and sodium bicarbonate, at selected levels, and perhaps with changes in patient position often reveals the true nature of pseudotumors in the gastrointestinal tract. Dynamic CT of the liver, performed during contrast material injection, yields the best results. Occasionally, reconstruction of axial images in coronal or sagittal planes helps delineate normal sectional anatomic variations of the diaphragm and liver and avoid misdiagnosis of pseudomasses. Volume averaging can cause problems when the section thicknesses are larger than the lesions (eg, small hepatic cysts) or structures are very close (eg, kidney and spleen); repeat CT with thinner sections is needed to obtain accurate attenuation values or delineate normal anatomic relationships. The gallbladder, spleen, and pancreas can change position due to prior surgery and raise suspicion of a mass unless clinical history is known. Familiarity with these and other pitfalls described herein should lead to accurate interpretation of CT scans.

Cholecystography in infants.

Roentgen visualization of the gallbladders of infants has been consistently unsatisfactory and has been of little value in diagnosis of lesions of the biliary tract. Satisfactory cholecystograms have been commonly obtained in patients older than three years when the adult dose of either tetraiodophenolphthalein or iodoalphionic acid (Priodax) has been used.1As a rule, films have been taken about 14 hours after the oral administration of contrast material. In 1945 Hrdlicka, Watkins, and Robb2reported that they had obtained satisfactory gallbladder shadows in two infants 9 and 10 months of age and in three of four infants 12 to 18 months of age. Iodoalphionic acid was used in doses two or three times the usual adult requirement per kilogram of body weight. In infants from one to seven months, no satisfactory gallbladder shadows appeared. Films were made 12 to 18 hours after the oral administration of the contrast