Target Sign Research Articles

3-Dimensional Demonstration of Fetal Anal Canal and Sphincter

To identify the fetal anal canal and sphincter using 3-dimensional (3 D) ultrasound. 3 D volumes of the fetal pelvis were acquired prospectively in 52 fetuses between 10 and 39 gestational weeks. A standard method for evaluating the fetal anal canal and sphincter was developed. Measurements of mucosal and muscular circumferences and the length of the anal canal were taken. The anal canal was demonstrated in 46 out of 50 patients (92 %). The sonographic characteristics of the anal canal in the axial plane appear like a "target sign" with an echogenic mucosa in the center, the hypoechoic internal sphincter muscle surrounding it and an outer echogenic circle reflecting the external sphincter. Measurements of mucosal and internal sphincter circumferences and the length of the anal canal demonstrated linear growth during pregnancy (p < 0.01). One case of anal atresia was demonstrated. The fetal anal canal can be visualized when a systematic analysis is performed using a 3 D volume dataset.

Right Lower-Quadrant Pain—More Than One Diagnosis

When a patient presents with right-lower-quadrant pain in the emergency room, the diagnosis of appendicitis must always be considered, but the differential diagnosis for this symptom includes many other etiologies. We describe a case of an 8-year-old girl with von Willebrand disease who presented with right-lower-quadrant pain and was found to have an appendiceal wall hematoma. During her evaluation, an ultrasound of the abdomen was performed, and the results were initially interpreted as an intussusception. Although ultrasound is a highly reliable way to diagnose appendicitis and intussusception, the case illustrates that the thickened abdominal wall that occurs in a mural hematoma can appear like the "target sign" that is usually associated with intussusception, and in certain clinical scenarios, alternative forms of imaging may be of value.

Ischemic Colitis: A Case Study Highlighting A Unique Association

Purpose: A 27-year-old male with no significant medical history presented with a two-day history of lower abdominal pain and hematochezia. Abdominal pain was characterized as cramping and located in the bilateral lower quadrants. Pain was associated with a large, bloody bowel movement and patient denied any other associated symptoms. On physical exam, patient was tachycardic and abdomen was tender diffusely with voluntary guarding. Lab work was significant only for a leukocytosis of 13. CT A/P w/ contrast illustrated diffuse bowel wall thickening from the mid- transverse colon to the distal sigmoid colon and possibly involving the rectum. The descending colon was well circumscribed and demonstrated loss of haustration with concordant target sign. Pericolonic fat stranding was seen in the region of the splenic flexure and proximal descending colon. Colonoscopy revealed discontinuous areas of polypoid, cobblestoned, nonbleeding serpintine ulcerated mucosa in the transverse colon. An area of mucosa in the terminal ileum was nodular. Based on the radiologic and colonoscopy findings, a presumptive diagnosis of IBD was made while we awaited biopsy results. Colonoscopic biopsies were significant for necrosis of superficial mucosal layer with relative sparing of the deeper portion. The lamina propria in the involved areas appeared hyalinized with hemorrhage - findings all characteristic of ischemic colitis. History taking had also revealed a 5 month history of taking Adderall and urine toxicology also confirmed amphetamine usage. Ischemic colitis is a common cause of lower gastrointestinal bleeding leading to approximately 10% to 19% of hospital admissions. Most patients with colon ischemia are older with atherosclerotic disease or diabetes mellitus. Several conditions, as well as a wide variety of medications, are known to predispose to colonic ischemia. Many of these medications are under-recognized. Adderall is a prescription stimulant which has gained popularity for labeled or unlabeled use among the younger population. We report a case of ischemic colitis in a young patient linked to the use of Adderall. Adderall consists of a mixture of dextroamphetamine and amphetamine salts and is a prescription drug for attention deficit/hyperactivity disorder (ADHD) and narcolepsy. The association of ischemic colitis with dextroamphetamine has only been documented in the literature in one published case report from 1991. This case illustrates the potential for severe vascular ischemia with use of prescription stimulants such as Adderall. It also highlights the value of a complete history in young patients presenting with colitis.

CT findings of small bowel strangulation: the importance of contrast enhancement

The purpose of this study is to illustrate computed tomography (CT) findings suggestive of small bowel strangulation. We have performed the precontrast and postcontrast CT with single and multidetector CT scanners and evaluated the bowel wall changes and mesentery changes and correlated them with the operative findings. The direct CT findings suggestive of small bowel strangulation included high-density bowel wall on precontrast scans; lack of, or diminished contrast enhancement of the involved bowel wall; localized mesenteric fluid accumulation (mesenteric congestion); and localized pneumatosis. The indirect CT signs included C- or U-shaped loops with mesenteric vessels converging toward the obstruction site, ascites, target sign, two adjacent collapsed round loops, and whirl sign. We particularly emphasize the importance of contrast enhancement of bowel mucosa for early diagnosis to differentiate strangulation from a mechanical obstruction without bowel ischemia, and also the importance to differentiate proximal secondary gas-filled dilated small bowel loops from distal primary involved fluid-filled small bowel loops because these two types of small bowel loops are present in the single peritoneal cavity. As early recognition of small bowel strangulation may help improve the patient outcome because the involved bowel loops can be preserved without resection, it is essential to become familiar with the CT signs suggested small bowel obstruction strangulation.

Solitary oropharyngeal neurofibroma: MR appearance with pathologic correlation and review of the literature

Although neurofibroma is a common soft tissue tumor of the head and neck, neurofibroma of the oropharynx is extremely rare. Here, we report a case of neurofibroma of the palatine tonsil. Magnetic resonance imaging was useful in demonstrating the location of the tumor as well as its well-defined appearance. The present case showed a target sign; the tumor exhibited peripheral hyperintensity and central hypointensity on T2-weighted images, reflecting its characteristic zonal anatomy.

Small intrahepatic mass-forming cholangiocarcinoma: target sign on diffusion-weighted imaging for differentiation from hepatocellular carcinoma

To determine the differential MRI features of small mass-forming intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC). Sixty-four patients with pathologically proven small ICCs (n = 32) and HCCs (n = 32) (≤ 3.0 cm in diameter) who had undergone preoperative gadoxetic acid-enhanced MRI and DWI were enrolled in this study. Images were analyzed for the shape of the lesions, the presence of biliary dilatation, hyperenhancement (>50 % of the tumor volume) or rim enhancement on the arterial phase, capsular enhancement, and the presence of target appearance (a central enhancement with hypointense rim) on the hepatobiliary phase and on DWI (a central hypointense area with a peripheral hyperintense rim). Statistical significance of these findings was determined by the χ(2) or Fisher's exact test. Multivariate analysis was performed to identify independent imaging findings that allow differentiation of the two diseases. Univariate analysis revealed that the following significant parameters favor ICC over HCC: lobulating shape, rim enhancement on arterial phase, target appearance on the hepatobiliary phase, and DWI (P < 0.05). Multivariate logistic regression analysis revealed that only target appearance on the DWI was a significant and independent variable predictive of ICC, as 24 ICCs (75.0 %) and one HCC (3.1 %) showed this feature (P = 0.0003). A target appearance on the DWI was the most reliable imaging feature for distinguishing small mass-forming ICC from small HCC.

Paradoxical uptake of Gd-EOB-DTPA on the hepatobiliary phase in the evaluation of hepatic metastasis from breast cancer: is the “target sign” a common finding?

PurposeThe purpose was to describe magnetic resonance imaging (MRI) findings of breast cancer liver metastasis using gadoxetic acid (Gd-EOB-DTPA) with an emphasis on the added value of the hepatobiliary phase (HBP). Material and methodsNine patients with 13 liver metastases were included in the study after the medical records of 29 breast cancer patients who underwent Gd-EOB-DTPA-enhanced MRI between February 2008 and June 2010 were reviewed. The diagnoses of liver metastasis were established by percutaneous liver biopsy or surgery and on the basis of image findings. Two radiologists retrospectively evaluated signal intensity (SI) and sizes of metastases and patterns of enhancement in an HBP. The SI ratio was calculated as the SI of the central hyperintense portion in “target” lesions divided by the SI of nearby normal liver parenchyma on the HBP. We also measured apparent diffusion coefficient (ADC) values from Diffusion Weighted Image (DWI). ResultsLiver metastases were all hypointense [n=13/13 (100%)] on T1-weighted imaging (WI), and many lesions had a “target” appearance with a central high SI and a peripheral low SI rim (47%) on T2WI. Dynamic study showed rim enhancement on the arterial phase (85%) and a “target” appearance, consisting of a central enhancing portion with peripheral washout or hypointense rim, on the HBP (62%). The mean SI ratio was 0.7. The mean ADC value of “target” appearing metastases was 1.25 (×10−3 mm2/s; range 1.3–1.6) compared with a mean value of 0.8 (×10−3 mm2/s; range 0.8–1.4) in homogeneous defect on the HBP. There was statistically significant difference (P<.05). ConclusionBreast cancer liver metastases commonly demonstrated as a peripheral ring enhancement on arterial dominant phase and a target sign with a central round enhancing portion and a peripheral hypointense rim on the HBP.

Gastrointestinal stromal tumor: a very rare cause of jejunoileal intussusception in a 6-year-old girl

A 6-year-old girl was admitted to the emergency department with abdominal pain and bilious vomiting of 3 days in duration. Abdominal ultrasound examination showed an 8-cm-long intussuscepted intestinal segment with a target sign. There was a 26 × 28 × 23 mm nonperistaltic anechoic cystic mass suggestive of a duplication cyst. At laparotomy, the ileocecal region was normal with many enlarged lymph nodes from which biopsies were taken. There was a 20-cm-long intussuscepted segment at the proximal ileum close to the jejunum. After manual reduction, a 2-cm-long edematous segment resembling a duplication cyst served as the lead point. The segment was excised, and a primary bowel anastomosis was performed. She was discharged on the fifth postoperative day. The histopathologic examination revealed that the excised segment contained a gastrointestinal stromal tumor measuring 2.5 cm, with a mitotic rate of 2 to 3 mitoses per 50 high-power fields (low-risk group) showing an infiltrative growth pattern. On immunohistochemistry assay, some of the tumor cells were CD117 and CD34 positive, whereas all of them were smooth muscle actin and S-100 positive but CD10 negative. Staining index with Ki-67 was 5%. Surgical margins were free of tumor. The lymph nodes showed reactive hyperplasia. She was referred to the pediatric oncology department for further evaluation. Gastrointestinal stromal tumors are common in adults and may lead to intussusception. To the best of our knowledge, this is the first childhood case of gastrointestinal stromal tumor causing jejunoileal intussusception in the literature.

Retroperitoneal schwannomas in the anterior pararenal space: dynamic enhanced multi-slice CT and MR findings

To evaluate the imaging features of schwannomas in the anterior pararenal space (APS), especially focusing on dynamic enhanced multi-slice CT (MSCT) and MR findings. Eight patients with pathologically proved retroperitoneal schwannomas in the APS underwent dynamic enhanced multi-slice CT (MSCT), while three of these patients also had a contrast-enhanced MR examination. The imaging findings were retrospectively reviewed. All eight cases exhibited forward displacement of the pancreas, and three cases showed lateral displacement and compression of the inferior vena cava. The tumors had round or oval shape with a maximal axial diameter of 4.0-12.3 cm (average, 6.7 cm). All eight tumors were solitary and well circumscribed. Of the eight retroperitoneal schwannomas in the APS, six exhibited a capsule with thickness of 1.0-2.0 mm, one showed punctate calcification, two displayed cystic degeneration, and three revealed a "target sign" on CT and MR. The tumors were hypo-dense on unenhanced CT images, hyper-intense on T2W images, and homogeneously hypo-intense on T1W images. All eight tumors exhibited gradual enhancement on dynamic enhanced CT or MR images. One case showed delayed enhancement. Heterogeneous enhancement was the dominant pattern occurring in seven out of eight tumors. The imaging findings of schwannoma in the APS correspond with its pathological composition. Schwannoma should be included in the differential diagnosis of tumors in the APS.

Mo1399 Endoscopic Recognition of the Target Sign - Impact on Clinically Significant Perforation During Endoscopic Mucosal Resection of Large Colonic Lesions: A Multi-Centre, Prospective Cohort Study

Mo1399 Endoscopic Recognition of the Target Sign - Impact on Clinically Significant Perforation During Endoscopic Mucosal Resection of Large Colonic Lesions: A Multi-Centre, Prospective Cohort Study

Intussusception

RADIOLOGY FINDINGS An abdominal ultrasound reveals a characteristic target sign in the transverse plane (concentric rings formed by multiple layers of bowel wall) in the right lower quadrant compatible with an ileocolic intussusception (Fig. 1). The patient subsequently underwent single-contrast water-soluble reduction enema, which revealed an intraluminal filling defect (M) in the proximal ascending colon (Fig. 2A) compatible with an intussusceptum, which was successfully reduced by the contrast column to the level of the cecum, allowing reflux of contrast into the small bowel. However, a masslike filling defect (asterisk) persisted along the medial aspect of the cecum (Fig. 2B). A targeted ultrasound performed after the reduction enema confirmed successful reduction of the intussusception, with fluid seen traversing a thickened, edematous ileocecal valve (arrows; Fig. 3), which accounts for persistence of a

Teaching Neuro Images : MRI “target sign” and neurofibromatosis type 1

A 9-year-old girl presented with a firm occipital swelling. She had multiple cafe-au-lait lesions without other clinical features or family history of neurofibromatosis type 1 (NF1). MRI showed subcutaneous soft tissue mass in the left occipito-temporal region …

Endoscopic full-thickness resection of a lateral spreading rectal tumor after unplanned injection of dilute hyaluronic acid into the subserosal layer (with video)

A 74-year-old woman underwent colonoscopy for investigation of a liver tumor. A lateral spreading tumor of the non-granular type (LST-NG), 25mm in diameter, was detected at the rectosigmoid junction. As magnifying image-enhanced colonoscopy suggested a tubulovillous adenoma, endoscopic mucosal resection (EMR) was chosen for removal of the LST-NG. The lesion was effectively and evenly lifted after injection of 0.4% hyaluronic acid diluted with glycerol in the ratio of 1:1. A small amount of indigo-carmine dye was also added for coloration of the plane of resection. The lesion was completely removed en bloc. Although a blue-colored layer was identified in the resection defect, a small amount of a whitish layer was detected above the blue layer. The muscle layer was clearly located on the underside of the resected polyp. A total of 14 endoclips were used to close the defect completely. The patient was successfully treated conservatively without surgery. Histology of the resected specimen showed that it contained a tubulovillous adenoma with the submucosal layer and both layers of the muscularis propria. The surgical margin was free of neoplastic change horizontally and vertically. To the best of our knowledge, this is the first case report of full-thickness resection associated with EMR after unplanned injection of dilute hyaluronic acid into the subserosal layer rather than the intended submucosal layer. We describe how to promptly recognize this complication during colonoscopy, in order to achieve immediate closure of the defect, with the identification of a "mirror target sign" on the colonic wall.

Magnetic resonance colonography in rats with TNBS-induced colitis: A feasibility and validation study

Magnetic resonance colonography (MRC) has been recently developed to assess bowel inflammation in inflammatory bowel disease (IBD) patients. Evaluating animal models of inflammation with MRC may be important in new drug-screening processes. The aim of this study was to assess the feasibility of MRC in colitic rats and confront it with model characteristics. Colitis was induced by rectal injection of trinitrobenzene-sulfonic acid (TNBS) in 13 rats while six rats received the vehicle. MRC was performed at day 2. Colon inflammation and production of inflammatory mediators were evaluated. Image quality was assessed by wall and motion artifacts. MRC criteria were bowel wall thickness, wall signal intensity on T2-weighted (T2w) and T1w images, the appearance of a target sign pattern, and irregular patterns of mucosal surface. MRC quality was good or excellent in 16/21 examinations with no difference between groups. Colitis rats were significantly different from controls in terms of wall thickness (P = 0.004), the appearance of a target sign pattern (P = 0.02), irregular patterns of mucosal surface (P = 0.01), and hyperintensity on T1w images (P = 0.03). All MRC criteria except maximal bowel wall thickness were associated with colon weight:length ratio and inflammatory biomarkers (all P < 0.05). Minimal bowel wall thickness and wall signal intensity on T2w images were associated with histological score (P < 0.05). MRC is feasible and reliable in rats with TNBS-induced colitis. MRC criteria including colon wall thickness, wall signal intensity on T2w images, hyperintensity in T1w sequence, and the appearance of a target sign pattern may be potential targets for new IBD drugs.

Multiple FNH-Like Lesions in a Patient with Chronic Budd-Chiari Syndrome: Gd-EOB-Enhanced MRI and BR1 CEUS Findings

A-26-year old female patient with chronic Budd-Chiari syndrome due to different underlying blood disorders applied for a two-year followup of the liver with Gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic-acid-(Gd-EOB-DTPA-) enhanced MRI. The liver function tests were raised. Besides showing a progressive hepatosplenomegaly and a cirrhotic liver alteration, the MRI revealed multiple new nodular lesions in all liver segments. These lesions showed typical patterns in the precontrast images, while there was an arterial and a persistent portal venous enhancement. In the hepatobiliary liver-specific late phase, a central “washout” and a persistent rim enhancement were observed (target sign). The additionally performed contrast-enhanced ultrasonography showed a strong zentrifugal arterial enhancement of the lesions followed by an isoechoic enhancement in the portal venous and delayed liver phase. Histologically these lesions turned out as focal nodular hyperplasias (FNH) or FNH-like lesions, also known as large regenerative nodules (LRNs). Differentiation between regenerative nodules like LRN and hepatocellular carcinoma (HCC) in cirrhotic livers is crucial, and the target sign in the hepatobiliary phase of Gd-EOB-DTPA as well as the centrifugal arterial enhancement followed by an isoenhancement during a CEUS might be useful for establishing the correct diagnosis of such hypervascular lesions with proliferated and likely aberrant bile ducts.

Imaging findings of neurogenic tumours in the head and neck region

The aim of this study was to describe the CT, MRI and ultrasonography findings of five cases of neurogenic tumours in the head and neck region. Five neurogenic tumours were analysed with respect to their CT value, the presence of cystic change, target sign, lobulation, connection to the nerve and vascularity. The contrast-enhanced CT (ECT) of the schwannomas demonstrated either a mass with low enhancement (two out of three cases), which reflected the predominant Antoni B components, or a mass with cystic changes, which was an Antoni A-based schwannoma displaying cystic changes (one out of three cases). On MRI, all tumours showed homogeneous and isointense signals for muscle on T₁ weighted images (T₁ WIs). T₂ weighted images (T₂ WIs) and gadolinium (Gd)-enhanced T₁ WIs demonstrated target sign in both schwannomas. Ultrasound examination showed a well-defined, ovoid or round hypoechoic mass. The direct connection to the nerve was demonstrated in two of the five cases. Lobulation was observed in only one of the five cases and cystic changes were observed in one of the five cases. In all of the cases, no vascularity was seen in power Doppler images (PDIs) obtained percutaneously. Low-enhanced areas on ECTs can be specific for schwannomas, which suggests the predominance of Antoni B components. The target sign on T₂ WIs and Gd-enhanced T₁ WIs can be specific, which can be used to differentiate the two different components (Antoni A and Antoni B). The direct connection to the nerve can be a specific finding for neurogenic tumours; however, at present the sensitivity is 40%.

Neurofibromatosis Type 1 Presenting with Plexiform Neurofibromas in Two Patients: MRI Features

Neurofibromatosis type 1 (NF1), also known as peripheral neurofibromatosis or von Recklinghausen's disease, is one of the most common genetic disorders. It is inherited in an autosomal dominant pattern. Multiple cutaneous neurofibromas are hallmark lesions of NF1. Localized and plexiform neurofibromas of the paraspinal and sacral region are the most common abdominal neoplasms in NF1. Herein, we report two patients with a known history of NF1 presenting with multiple, extensive localized and plexiform neurofibromas. We describe the important distinguishing features of these tumors as seen on magnetic resonance imaging (MRI), including very bright signal intensity and target sign on T2 weighted images.

Intussusception Status-Post Roux-En-Y Gastric Bypass

A 38-year-old female presented with acute onset epigastric abdominal pain and vomiting. Surgical history included gastric bypass surgery 8 years prior and cesarean delivery. The patient was in severe distress, afebrile, had significant epigastric tenderness with guarding, normal bowel sounds, and no distention or masses. Results for white blood cell count, serum chemistry panel, anion gap, urinalysis, liver function tests, lipase test, and plain radiographs were all normal; computed tomography (CT) of the abdomen/pelvis showed intussusception at the jejunojejunal anastomosis (Figure). The patient underwent resection of the affected bowel segment and had an uneventful recovery. Roux-en-Y gastric bypass (RYGB) is the most common surgical treatment of morbid obesity in the United States.1–5 The frequency of small-bowel obstruction after laparoscopic RYGB is between 0.2% to 4.5% and can occur months to years after the procedure.1,5 Small-bowel obstruction in these patients is usually caused by adhesions, internal hernias, and rarely, intussusception.1–5 Intussusception must be considered because ischemia and necrosis of the affected bowel segment can occur.5 Clinical presentation can be acute or subacute (recurrent vague abdominal pain) and is variable (most patients do not appear ill). The most common presentation is vague abdominal pain, nausea, and vomiting.4 Severity of pain is usually out of proportion to physical examination. Lack of obstruction symptoms does not rule out intussusception. Findings on plain radiographs are often negative.1,5 CT of the abdomen and pelvis (oral and intravenous contrast) is the diagnostic test of choice, with an accuracy of 80%. Pathognomonic findings include a “target sign” (Figure).5 Patients with a history of gastric bypass surgery, persistent abdominal pain, and a negative CT finding still require surgical evaluation and possibly surgical exploration.1,5 Blind nasogastric tube placement can lead to perforation at the gastrojejunostomy.1 Treatment is surgical intervention, usually with resection of the affected bowel segment and reconstruction of a new jejunojejunostomy distally.1 Recurrences can occur after surgical repair.1

Endoscopic and radiographic features of gastrointestinal involvement in vasculitis

Vasculitis is an inflammation of vessel walls, followed by alteration of the blood flow and damage to the dependent organ. Vasculitis can cause local or diffuse pathologic changes in the gastrointestinal (GI) tract. The variety of GI lesions includes ulcer, submucosal edema, hemorrhage, paralytic ileus, mesenteric ischemia, bowel obstruction, and life-threatening perforation.The endoscopic and radiographic features of GI involvement in vasculitisare reviewed with the emphasis on small-vessel vasculitis by presenting our typical cases, including Churg-Strauss syndrome, Henoch-Schönlein purpura, systemic lupus erythematosus, and Behçet's disease. Important endoscopic features are ischemic enterocolitis and ulcer. Characteristic computed tomographic findings include bowel wall thickening with the target sign and engorgement of mesenteric vessels with comb sign. Knowledge of endoscopic and radiographic GI manifestations can help make an early diagnosis and establish treatment strategy.

Methodological and theoretical issues in the adaptation of sign language tests: An example from the adaptation of a test to German Sign Language

Despite the current need for reliable and valid test instruments in different countries in order to monitor the sign language acquisition of deaf children, very few tests are commercially available that offer strong evidence for their psychometric properties. This mirrors the current state of affairs for many sign languages, where very little research is available. No previous empirical study has focused explicitly on the linguistic, methodological, and theoretical issues involved in the process of adapting a test from a source sign language to a target sign language. Problems during the adaptation process can arise from linguistic differences between the source and the target language and differences in the source and the target cultures. Both are important aspects that need to be considered in the adaptation of a sign language test from a source to a target language. This study proposes a model for sign language test adaptation, based on the adaptation of the British Sign Language Receptive Skills Test to German Sign Language. The model includes different methodological steps, with a particular focus on construct validation.