Main Imaging Features of Crohn's Disease: Agreement between MR-Enterography and CT-Enterography.

BACKGROUND: Only a few studies have compared the accuracy of magnetic resonance enterography (MRE) and computed tomography enterography (CTE) in the diagnosis of Crohn's disease and its complications. OBJECTIVES: To compare the sensitivity of MRE and CTE analysis in their ability to detect, sign-by-sign, 10 classical imaging signs of Crohn's disease. METHODS: The study group comprised 42 biopsy-proven Crohn's disease patients who underwent both CTE and MRE within an average period of 6 weeks. Agreement between the two modalities in detecting the 10 most significant radiological signs of CD was evaluated using the Kappa index. The sensitivity of MRE and CTE was calculated using a standard of reference composed of all the findings seen by CTE and/or MRE. We analyzed MRE and CTE sensitivity separately in two groups, according to the time interval between the examinations. RESULTS: Agreement between CTE and MRE was more than 70% in 8 of the 10 signs: mural thickening, phlegmon, stenosis, skip lesions, mucosal stratification, fistula, abscess, and creeping fat. The Kappa level of agreement values for CTE versus MRE varied between substantial for phlegmon and skip lesions; moderate for fistula, creeping fat, abscess and mural thickening; and fair for stenosis and dilatation. CTE detected more findings than MRE, except for creeping fat and fistula. There was no significant difference in the sensitivity of CTE and MRE in the two groups defined by the time interval (time < 1.5 and time > 1.5 months) except for detection of dilatation. CONCLUSIONS: Almost all imaging signs of Crohn's disease were detected equally well by both modalities regardless of the time interval between examinations. We therefore consider MRE to be reliable for imaging and follow-up in patients with Crohn's disease who may need recurrent imaging.

Concomitant findings and clinical significance of a fluid crescent between the iliacus muscle and iliac bone on MRI.

BACKGROUND: Some routine magnetic resonance imaging (MRI) examinations show a thin line of fluid signal intensity along the iliac crest ("fluid crescent") between the iliacus muscle and the iliac bone. This fluid crescent has not been described before. PURPOSE: To evaluate the clinical context and significance of the fluid crescent. MATERIAL AND METHODS: MRI examinations of the abdomen and pelvis performed over 1 year were retrospectively reviewed twice for the presence of a fluid crescent. The relationship between the presence of a fluid crescent and associated abnormal findings, including ascites, iliopsoas compartment, and bone and soft tissue pathologies, was evaluated. RESULTS: Forty-one out of 254 MRI studies (male:female ratio, 136:118; mean age, 42 years) demonstrated a fluid crescent (16%). Thirty-eight of them had associated MRI pathologies: edema of the hip muscles = 24, ascites = 11, iliac bone = 21, and iliopsoas compartment = 7. Correlations between the presence of a fluid crescent and pathological findings were highly significant (P < 0.0001), except for the presence of fluid in the hip joint. CONCLUSION: A fluid crescent is an abnormal MRI finding strongly associated with iliopsoas compartment pathology, ascites, hip muscle edema, and pelvic bone abnormalities. The nature of this fluid crescent is yet to be determined.

Spontaneous suburothelial hemorrhage in coagulopathic patients: CT diagnosis.

OBJECTIVE: The objective of our study was to identify and describe the spectrum of CT findings in patients with coagulopathy-induced suburothelial hemorrhage involving the renal collecting system. CONCLUSION: CT findings of suburothelial hemorrhage are often subtle and are best appreciated on unenhanced CT scans because of the high density of the hemorrhage. After contrast injection, uniformly thickened soft tissue enveloping the collecting system is suggestive of this condition. Clinical information regarding the presence of coagulopathy is essential for the radiologist to entertain this relatively rare diagnosis.

Magnetic resonance enterography: 4 years experience in a tertiary medical center.

BACKGROUND: Assessment of small intestinal disease remains a challenge for both clinicians and radiologists. Modern magnetic resonance enterography (MRE) is a nonradiation modality that can demonstrate both intestinal wall pathologies and extraluminal lesions. OBJECTIVES: To analyze the results of 213 MRE scans performed since 2005. METHODS: Consecutive MRE scans performed in our academic medical center between December 2005 and November 2009 were reviewed for patients' demographic data, indications for the examination, and main imaging findings. The imaging signs recorded were mural changes, intraluminal filling defects as well as mesenteric and extraintestinal inflammatory findings. RESULTS: During the study period 213 MRE scans were performed; 70% of them for proven or suspected Crohn's disease (CD) of the small bowel. Another indication was small bowel neoplasm (6% of the scans). Bowel wall thickening and enhancement were seen in 60% and 53% of MRE scans, respectively. Mesenteric involvement was found in 52% of the patients. Incidental extraintestinal findings were detected in 17% of the scans. In 22% of the scans there was no pathological finding. CONCLUSIONS: In our 4-year clinical experience with MRE this non-invasive and non-radiating modality proved to be a reliable technique for the evaluation and long-term follow-up of small bowel pathologies. The most common clinical indication was the evaluation of Crohn's disease. With physicians' increased awareness, the use of MRE in the evaluation of other small bowel pathologies such as neoplasm and celiac disease will increase. curate assessment of small intestinal disease remains c a challenge for both clinicians and radiologists. Until a decade ago, the modality most used to examine the small bowel in its entirety was barium-based techniques, such as neoplasm and celiac disease will increase.

Checkmark: a sign for the detection of iliopsoas pathology on MRI of the hip.

BACKGROUND: The iliopsoas compartment can be involved in many different disease processes with a wide variety of symptoms that may simulate avascular necrosis (AVN) of the femoral head. The psoas muscle merges with the iliacus to form a checkmark ( radical) shape in the coronal MRI plane, with normal muscle intensities, on both sides of the spine. PURPOSE: To evaluate whether abnormality of this checkmark shape (obliteration or abnormal intensity), the checkmark sign, can be used as a simple indicator of iliopsoas pathologies on MR examinations performed for suspected AVN of the hip. MATERIAL AND METHODS: A total of 75 hip MRI examinations performed during 2007 for suspected AVN (male:female ratio, 44:31; average age, 41 years) were retrospectively assessed. The iliopsoas compartment was assessed on the coronal T1 and T2 fat saturated sequences for the presence of the checkmark sign by a consensus of two readers. RESULTS: Twenty-six patients had signs of AVN and 49 patients had either other hip findings or normal hips. A normal checkmark shape was observed in all but two examinations. Obliteration of the checkmark shape, a positive checkmark sign, in those two was due to psoas compartment pathology (infection and hematoma of the iliopsoas compartment). CONCLUSION: A positive checkmark sign (abnormal shape or intensity) can serve as a clue for unsuspected iliopsoas pathology when evaluating MRI of the hip in patients with suspected AVN.

Contrast-enhanced CT colonography with 64-slice MDCT compared to endoscopic colonoscopy in the follow-up of patients after colorectal cancer resection.

BACKGROUND: Seventy percent of newly diagnosed colorectal cancer cases are potential candidates for curative surgery, but after resection, in 30%, the tumor will recur. Postoperative follow-up includes endoscopic colonoscopy (EC) and computed tomography (CT). There have been only a few publications on the use of contrast-enhanced CT colonography (CECTC) in the follow-up of these patients. METHODS: Twenty-nine consecutive patients after resection of colorectal cancer underwent CECTC and EC on the same day. CECTC studies were reviewed for identification of strictures, recurrence, polyps and metastases. RESULTS: The anastomosis was identified in 96% of patients on CECTC and in 82% on endoscopic colonoscopy. One stricture was identified by both techniques. One extraluminal recurrence was depicted only on CECTC. Sensitivity in detecting polyps was per polyp 93% and per patient 100%. CONCLUSION: CECTC performed on a 64-slice multidetector CT is reliable in imaging the postoperative colon for the follow-up of patients after resection of colorectal cancer.

Multislice CT compared to small bowel follow-through in the evaluation of patients with Crohn disease.

BACKGROUND: Patients with Crohn disease (CD) often undergo both multislice computed tomography (MSCT) and small bowel follow-through (SBFT) for evaluation of their disease. We compared the findings on computed tomography (CT) and SBFT in patients with CD to determine whether MSCT can be the modality of choice in the evaluation of these patients. METHODS: We reviewed the CT and SBFT studies of 41 patients with CD. The findings were evaluated by three experienced abdominal imagers. RESULTS: There was no statistical difference in the detection of mural involvement of the small bowel. The CT showed additional involvement of the colon, mesenteric involvement, and extraenteric complications. CONCLUSION: Multislice CT is a reliable modality in demonstrating enteric as well as extraenteric pathological findings in patients with CD. We suggest that MSCT can replace SBFT in the evaluation of patients with CD.

Abdominal CT findings in nontraumatic colorectal perforation.

Colorectal perforation is an emergent medical condition in which the diagnosis and the etiology are often established on CT, the common imaging modality used for evaluating the acute abdomen. The cardinal, direct CT features suggesting perforation are extraluminal air and enteric contrast, added by secondary signs of bowel pathology, such as focal bowel wall thickening and bowel wall defect. This pictorial review will illustrate the CT findings of colorectal perforation caused by various clinical entities.

Gas in the kidney: CT findings.

Gas in the renal parenchyma is a rare finding seen best with computed tomography (CT). It can be encountered in a wide range of clinical conditions, some of them life-threatening like emphysematous pyelonephritis, whereas in others, it may represent a postoperative or procedure outcome. The latter are not usually a clinical emergency (for example, after nephrostomy insertion or in a urinary intestinal connection). Due to the increasing use of abdominal CT examinations, radiologists, especially in emergency setting, should be aware of this rare finding and be familiar with its differential diagnosis.

Cardiovascular calcifications after radiation therapy for Hodgkin lymphoma: computed tomography detection and clinical correlation.

OBJECTIVE: To study cardiovascular calcifications, detected by computed tomography, in patients following mediastinal radiation for Hodgkin lymphoma, and correlate them with clinical findings. MATERIALS AND METHODS: Fifteen patients,

Computed tomographic features of afferent loop syndrome: pictorial essay.

ALS, a rare condition, is often difficult to diagnose clinically but has a characteristic CT appearance as a U-shaped, fluid-filled tubular structure crossing the midline between the abdominal aorta and the superior mesenteric artery. Radiologists should be familiar with this rare entity, as awareness of its pathognomonic CT features will aid in establishing the correct diagnosis as well as in offering a tentative etiology as a guide for treatment.

[Outcome of a residency program in radiology for immigrants and other physicians by Maccabi Healthcare Services].

BACKGROUND: Maccabi Healthcare Services has more than 20 Diagnostic Imaging Clinics in Israel, and many radiologists are needed to perform and interpret the imaging studies. There was a shortage of radiologists willing to work full-time in these clinics. In the late 1980s and early 1990s a large number of immigrants arrived in Israel, some of them radiologists, who were looking for a position at Maccabi. However, their training was inadequate for the needs of modern radiology. Therefore, a program in radiology was initiated to support a number of these physicians to complete additional training in radiology, a process that would facilitate their employment as radiologists for Maccabi Healthcare Services. OBJECTIVES: To support several years of residency in radiology for immigrants and other physicians who would, on completion of their residency, work as radiologists for Maccabi Healthcare Services. METHODS: A total of 21 physicians entered the program, 16 women and 5 men, including 11 physicians from the former Soviet Union. They started their training in various academic hospitals during the years 1991-1997. A questionnaire regarding the program was completed by the residents and the chairmen of the relevant departments were interviewed. RESULTS: All physicians except one, who left the country for medical reasons, have as of now successfully completed their residency, and are employed as radiologists in Maccabi. One candidate received a grant for one year of residency abroad, and has been employed by Maccabi since completing her residency. CONCLUSION: The program can be termed a success, as all the parties concerned--residents, Maccabi Healthcare Services and the participating hospitals, profited from the arrangement.

CT findings of intussusception in adults.

Intussusception is rare in adults, in contrast to its frequent occurrence in infants. The clinical presentation is variable, consisting mainly of abdominal pain that may be chronic, intermittent, or acute. The classic triad of nausea and vomiting, bloody diarrhea, and an abdominal mass typically present in children with intussusception does not usually appear in adults. This diagnosis is, therefore, rarely included in the differential diagnosis of adult patients with vague abdominal complaints. However, with increasing use of CT scanning in the evaluation of patients with abdominal pain, the diagnosis of intussusception can be readily suggested by the radiologist because of its virtually pathognomonic appearance on CT.

Mesenteric lymphadenopathy in children examined by US for chronic and/or recurrent abdominal pain.

BACKGROUND: Children with recurrent abdominal pain often undergo US to confirm or exclude organic disease. OBJECTIVE: To assess the prevalence of mesenteric lymphadenopathy on US in these children. MATERIALS AND METHODS: We prospectively studied 189 children with recurrent abdominal pain with US of the abdomen, using graded compression. The results were compared with 73 children in a control group. The children in both groups were divided into three age groups. The size, number, morphology and location of mesenteric lymph nodes were noted, as well as additional findings. Pediatricians followed the patients from 3 months to 1 year, and a repeat US study was done in 30 children. RESULTS: Mesenteric lymphadenopathy was present in 116 of 189 children (61.4%), with the greatest prevalence in boys in the younger age groups. The location of the nodes was mainly in the right lower quadrant. In the control group, 7 of 73 children had mesenteric lymphadenopathy, a significantly lower prevalence than in the study group ( P<0.001). Additional findings, apart from lymphadenopathy, were present in 27 (14.2%) of the 189 children in the study group, and in 5 (6.8%) of the 73 children in the control group. CONCLUSION: Mesenteric lymphadenopathy is a common, and often the only abnormal, finding on US in children with recurrent abdominal pain.

Vascular lesions of the renal sinus.

The renal sinus contains within it the collecting system of the kidney as well as lymphatics, nerves, and renovascular structures. This area may be affected by a large variety of pathological conditions arising from the various tissues in this site. Vascular lesions of the renal sinus are uncommon and may present clinically with acute symptoms and on imaging as a mass lesion. Awareness of the different vascular lesions affecting this area is essential for establishing the correct diagnosis and for appropriate treatment. The role of computed tomography is emphasized because it is the most commonly used modality to evaluate acute abdominal conditions as well as suspected renal masses, and the diagnosis can usually be made without the need for additional imaging modalities.

Perirectal urinoma from ureteral injury incurred during spinal surgery mimicking rectal perforation on computed tomography scan.

STUDY DESIGN: A case of a perirectal urinoma from a ureteral injury incurred during spinal surgery is reported. OBJECTIVES: To report ureteral injury as a rare complication of spinal surgery with misleading CT findings, and to emphasize the necessity of delayed scans in the diagnosis. SUMMARY OF BACKGROUND DATA: A ureteral injury is a rare complication of spinal surgery. In such a case, extravasated urine collects in the retroperitoneum and pelvis. This fluid opacifies after intravenous contrast, and delayed scans are necessary in the diagnosis. As clinical findings are usually nonspecific, CT is essential for the correct diagnosis. METHODS: A 55-year-old woman underwent discectomy and insertion of a disc prosthesis through an anterior left retroperitoneal approach. Fever and abdominal pain developed after 3 days. Computed tomography scan was performed to evaluate the patient's symptoms. RESULTS: Computed tomography with repeated delayed scans showed an opacifying fluid collection surrounding the rectum, remote from the site of surgery, yet compatible with a urinoma. Antegrade pyelography demonstrated an injury of the left ureter with extravasating urine, dissecting caudally. After a temporary nephrostomy, the patient recovered. CONCLUSIONS: Although ureteral injury after abdominal surgery is not so uncommon, it is very rarely incurred during spinal surgery. Because symptoms are usually nonspecific, the radiologist should be aware of this possible complication, and should perform CT with intravenous contrast material and with delayed scans because a rapid-sequence helical CT may not yet show opacification of the fluid present in the abdomen. This is the hallmark of the diagnosis.

Unexpected subdiaphragmatic findings on CT of the chest in septic patients after cardiac surgery.

AIM: to draw the attention to upper abdominal abnormalities, which may be revealed incidentally in patients referred for a chest computed tomography (CT) after cardiac surgery. MATERIALS AND METHODS: We reviewed prospectively and retrospectively the CT results of all patients referred for a chest CT, with suspected sternal infection or for other reasons, after cardiac surgery, to assess possible upper abdominal disease as visualized on lower cuts of the chest CT with abdominal windows. RESULTS: Out of a total of 205 patients in the study 39 (19%) had unexpected abdominal abnormalities. The organs involved in decreasing order of frequency were the spleen (n = 18), gallbladder (n = 15), pancreas (n = 9), kidneys (n = 6) and bowel (n = 3). Many patients had involvement of more than one organ. The lesions were mainly ischaemic and/or infectious in origin. These findings led to interventional procedures in 13 (33%) of the patients with a good outcome. CONCLUSIONS: We found a relatively high prevalence of abdominal abnormalities on CT of the chest in patients referred with suspected thoracic problems after cardiac surgery. Major findings on CT led to changes in the management of these patients. We recommend therefore viewing lung bases with abdominal windows as well as adding sections through the upper abdomen in patients who are referred for a chest CT after cardiac surgery with suspected thoracic problems.

Are referring clinicians aware of patients at risk from intravenous injection of iodinated contrast media?

AIM: The purpose of our study was to assess the level of awareness of referring clinicians to populations at risk for complications of intravascular administration of iodinated contrast media. SUBJECTS AND METHODS: Two hundred and three physicians from three university hospitals completed an anonymous questionnaire regarding risk factors and contraindications to the intravenous administration of iodinated contrast media. The questionnaire included medical conditions with increased risk for anaphylactoid reaction (asthma, hay fever and food allergy) as well as chemotoxic (ischaemic heart disease, phaeochromocytoma and myasthenia gravis) adverse reactions, some with dependence on renal function (metformin treatment, diabetes mellitus and multiple myeloma). Two additional multiple-choice questions addressed pre-medication protocols and risk of nephrotoxicity in diabetic patients. RESULTS: Asthma, food allergy and hay fever were recognized as risk factors by 81.3%, 77.8% and 61.6% of respondents respectively, while ischaemic heart disease, phaeochromocytoma and myasthenia gravis were defined as such only by 9.8%, 30.0% and 28.6% respectively. Metformin treatment, diabetes mellitus and multiple myeloma, in the presence of normal renal function, were considered as risk factors by 46.3%, 38.9% and 58.1% of respondents respectively. One of the generally accepted pre-medication protocols was selected by 89.8%. The risk of nephrotoxicity in a diabetic patient was correctly assessed by 63.5% of respondents. CONCLUSION: We found a relatively high awareness among referring clinicians of a potential anaphylactoid reaction and nephrotoxicity due to iodinated contrast media. However, additional chemotoxic adverse reactions are less well known. Future efforts to improve communication between clinicians and radiologists should be focused in this direction.

Calcification in lymphoma occurring before therapy: CT features and clinical correlation.

OBJECTIVE: Calcification in lymphoma occurring before therapy is rare. We assessed the prevalence, CT features, and clinical significance of calcification in nodes and masses in patients with lymphoma occurring before therapy. SUBJECTS AND METHODS: CT of the chest, abdomen, and pelvis of 956 newly diagnosed patients with lymphoma was evaluated prospectively for calcifications in enlarged lymph nodes and lymphoma masses. Findings were correlated with histologic type of disease, tissue parameters, and clinical course. Calcifications were further evaluated on follow-up CT. RESULTS: Of 956 patients with lymphoma (704 with non-Hodgkin's lymphoma and 252 with Hodgkin's lymphoma), eight patients (0.84%) showed calcifications in involved sites, seven of whom had non-Hodgkin's lymphoma and one of whom had Hodgkin's lymphoma. Calcifications were present in lymph nodes and masses in the mediastinum in five patients, in the retroperitoneum in two patients, and in the adrenal in one patient. All eight patients had the aggressive type of lymphoma. Four patients later relapsed, one of whom died. A fifth patient died after only minimal response to treatment. CONCLUSION: Calcification in patients with lymphoma occurring before therapy is rare as opposed to that in lymphoma after therapy. It occurred in our patients more often in the mediastinum, in patients with non-Hodgkin's lymphoma rather than in patients with Hodgkin's lymphoma, and only in patients with the aggressive type of disease.