The accessory spleen: prevalence and imaging findings in 1,735 consecutive patients examined by multidetector computed tomography

OBJECTIVE

To analyze the prevalence and CT findings of accessory spleens in the normal population.

MATERIAL AND METHODS

CT-examinations of 1735 consecutive patients, all examined by triple phase 16-row multidetector computed tomography (MDCT) of the abdomen, were retrospectively analyzed with special emphasis on the presence, location and imaging aspects of accessory spleens.

RESULTS

199 patients showed an accessory spleen (11%). Size of accessory spleens ranged from 3 to 20 mm (mean 10 mm). In 60% the accessory spleen was located at the level of the splenic hilum and in 33% at the level of the lower pole. In 46% the accessory spleen was located medially and in 43% ventrally. 19 patients presented with two (1.1%) and seven patients with three accessory spleens (0.4%), respectively. One patient showed splenosis and one patient showed an enlarged accessory spleen (5 cm) secondary to a splenic apoplexy (i.e. hemorrhagic infarction) of the accessory spleen, caused by torsion.

CONCLUSION

Accessory spleens may be identified by MDCT in about 11% of patients. Familiarity with normal imaging findings and knowledge on differential diagnoses, possible pathologies and potential pitfalls helps to differentiate from other findings in the upper abdomen.

[CT - diagnosis and differential diagnosis of inflammatory acute intestinal conditions]

Multidetector-row CT has shown over the past years that it is able to provide reliable diagnoses in various acute intestinal conditions. The presented article provides an overview of primary and secondary inflammatory acute intestinal pathologies and their differential diagnoses.

[CT - diagnosis and differential diagnosis of non-inflammatory acute intestinal conditions]

Multidetector-row CT has shown over the past years that it is able to provide reliable diagnoses in various acute intestinal conditions. The presented article provides an overview of non-inflammatory acute intestinal pathologies, ranging from obstruction to ischemia.

Juxtapapillary duodenal diverticula: MDCT findings in 1010 patients and proposal for a new classification

The aim of this study is to analyze the MDCT findings of juxtapapillary duodenal diverticula (JPDD) and to propose a new radiological classification. CT-examinations of 1010 consecutive patients, all examined by 16-row MDCT of the abdomen over a time period of 20 months were retrospectively analyzed. All study patients were examined by triple phase CT (native, arterial and portal venous CT scan) of the abdomen and all recieved positive oral contrast prior to the examination. Thirty-three patients showed a juxtapapillary duodenal diverticulum, which could be seen on all CT scans, but jusually was depicted most clearly on the thin collimated arterial phase CT images. Size of diverticula range from 4 mm to 4.5 cm (mean 1.7 cm). In 17 cases the diverticulum was located ventrally to the vaterian sphincter complex, extending less or more into the pancreas at the site where the dorsal and the ventral anlage of the pancreas have fused (type I). 12 diverticula were located dorsally to the sphincter complex (type II). Three patients presented with a bilobated juxtapapillary diverticulum extending to both sides, ventrally and dorsally (type III) and one patient showed a little diverticulum ventrally to the minor papilla (type IV).Three patients presented with food impaction in the diverticulum but only one of these patients with a large IPDD showed a Lemmel-syndrome, whereas the other three patients with non-calculous extrahepatic cholostasis showed larger diverticula without food impaction. MDCT allows to identify four different types of juxtapapillary duodenal diverticula and using the proposed classification may be helpful for a more exact, anatomy based radiological description of this CT finding.

[Cross sectional imaging findings in ectopic pancreatitis]

Two patients with ectopic pancreas, associated with pancreas divisum are presented. In one of these patients MDCT examination showed an island of pancreatic parenchyma, isolated from the pancreatic head and located within the anterior wall of the duodenal bulb, where ectopic pancreas could be confirmed by endoscopy. The other patient suffered from acute pancreatitis according to the clinical and laboratory findings. However, MDCT showed a normal pancreas. Here the only abnormality on CT was found in an area of inflamed and infiltrated fatty tissue ventrally to the descending duodenum and the pancreatic head, which was clearly separated from pancreatic head. While these CT findings alone were non-specific, MRT allowed to identify an island of ectopic pancreas within this area of inflammation. Additionally both patient showed pancreas divisum. These two cases nicely demonstrate, that ectopic pancreas may be recognized by MDCT. However, familiarity with the embryology of the pancreas and knowledge about a probable association of pancreas divisum and ectopic pancreas may be helpful for the correct interpretation of imaging findings. Furthermore, in cases of ectopic pancreatitis CT may show only nonspecific extrapancreatic soft tissue inflammation and MRT may become necessary to identify the enclosed island of ectopic pancreatic tissue.

[Medullary osteoidosteoma of the os pisiforme]

A case of a medullary osteoidosteoma of the pisiforme bone is presented that appeared as a light bulb on MR-Angiography while causing diffuse hypointensity of the pisiforme bone and of the surrounding soft tissue on T1- and diffuse hyperintensity of these regions on T2-w and T1- w postcontrast images. Although not surprising according to the typical appearance of osteoidostomas on triple phase scintigraphy, the light bulb sign of osteoidosteomas on MRA has not yet been reported and familiarity with this findings may be of value in order to avoid their confusion with vascular lesions such as aneurysms or pseudoaneurysms during MR-angiography.

[Sonography of the thyroid]

According to its superficial anatomical location the thyroid gland is easily accessible by sonography. Ultrasound is a reliable examination to detect various pathologies of the thyroid gland and it should always be combined with a sonography of the surrounding soft tissues and vessels. Sonography allows an exact documentation of the size, volume and parenchymal echostructure of the thyroid gland as well as detection of various diffuse and focal abnormalities of the gland itself and of the surrounding structures. The presented article gives an overview of the sonographic diagnoses and differential diagnoses of various diffuse and focal pathologies of the thyroid gland as well as some recommendations regarding their possible further diagnostic approach.

Asymptomatic nonspecific serum hyperamylasemia and hyperlipasemia: spectrum of MRCP findings and clinical implications

We assessed the magnetic resonance cholangiopancreatographic (MRCP) findings in patients with asymptomatic, mild elevations of serum amylase and lipase levels to determine whether there might be a pathoanatomic cause for these laboratory abnormalities. MRCP was performed in 633 consecutive patients. Of these, 54 (8.5%) images were obtained in patients with asymptomatic serum hyperamylasemia and hyperlipasemia. MRCP was performed on a 1.0-T MR system; breath-hold gradient-recall, half-Fourier acquisition, and rapid acquisition with relaxation enhancement sequences were obtained. Findings were verified by follow-up, biopsy, or surgery. One-sided, large-sample z tests were used to compare the incidence of abnormalities between the study and control groups (579 patients). The pancreas appeared abnormal on MRCP in 31 patients (57%), including the pancreas divisum in 10 patients (18.5%). Other findings included morphologic changes compatible with chronic pancreatitis in nine patients (16.6%) and a healed pancreatic laceration, juxtapapillary duodenal diverticulum, papillary sclerosis, intraductal pancreatic lithiasis, and hemochromatosis in one patient each (1.9%). Small cystic lesions (< 1 cm) within the pancreas were seen in 15 patients (27.8%). In eight patients, these were associated with other abnormalities (pancreas divisum in three patients, chronic pancreatitis in four, and pancreatic laceration in one). No malignancy was diagnosed. The incidences of normal examination (p = 0.01), pancreas divisum (p < 0.005), and a small cystic lesion (p = 0.01) as solitary findings in this subgroup of patients were significantly higher when compared with the remainder of the studied population. Investigation of asymptomatic patients with nonspecific hyperamylasemia and hyperlipasemia by means of MRCP yielded pancreatic findings in more than 50% of these patients. Pancreas divisum was found more often than expected in the general population.

Usual and unusual causes of extrahepatic cholestasis: assessment with magnetic resonance cholangiography and fast MRI

Cholestasis may result from hepatocellular (intrahepatic) disease or biliary tract (extrahepatic) abnormalities. Etiologies causing extrahepatic cholestasis are extremely diverse and invasive procedures, such as endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC), were previously required to establish the diagnosis. Due to refinements of magnetic resonance imaging (MRI) techniques, the patient with extrahepatic cholestasis currently can be evaluated noninvasively, and the information revealed frequently exceeds the findings obtained by ERCP and PTC. In this essay, we illustrate the classic MR cholangiographic (MRC) and MRI features of a variety of disorders causing extrahepatic cholestasis, including non-neoplastic disorders of the biliary tract (congenital abnormalities, infectious processes, iatrogenic disorders, and postsurgical complications) and neoplastic conditions (e.g., tumors of the pancreas, biliary tree, liver, ampulla, and regional lymph nodes). In most cases, familiarity with the key MRC features in addition to information obtained via cross-sectional MR images provide sufficient information for adequate lesion characterization.

[A 63-old patient with right-sided hypogastric pain at 6 months after appendectomy]

Anhand einer Fallbeschreibung werden die Differentialdiagnosen bei rechtsseitigem Unterbauchschmerz mit den entsprechenden weiterführenden Abklärungen besprochen. Schwerpunktmässig wird im Kommentar anhand des beschriebenen Falles auf die Bildgebung von Dünndarmprozessen und im speziellen auf das diffuse, grosszellige B-Zell-Lymphom (Schwerpunkt Therapie, Prognose) eingegangen.

Unenhanced helical computed tomography vs intravenous urography in patients with acute flank pain: accuracy and economic impact in a randomized prospective trial

Unenhanced helical computed tomography (UHCT) has evolved into a well-accepted alternative to intravenous urography (IVU) in patients with acute flank pain and suspected ureterolithiasis. The purpose of our randomized prospective study was to analyse the diagnostic accuracy of UHCT vs IVU in the normal clinical setting with special interest on economic impact, applied radiation dose and time savings in patient management. A total of 122 consecutive patients with acute flank pain suggestive of urolithiasis were randomized for UHCT ( n=59) or IVU ( n=63). Patient management (time, contrast media), costs and radiation dose were analysed. The films were independently interpreted by four radiologists, unaware of previous findings, clinical history and clinical outcome. Alternative diagnoses if present were assessed. Direct costs of UHCT and IVU are nearly identical (310/309 Euro). Indirect costs are much lower for UHCT because it saves examination time and when performed immediately initial abdominal plain film (KUB) and sonography are not necessary. Time delay between access to the emergency room and start of the imaging procedure was 32 h 7 min for UHCT and 36 h 55 min for IVU. The UHCT took an average in-room time of 23 min vs 1 h 21 min for IVU. Mild to moderate adverse reactions for contrast material were seen in 3 (5%) patients. The UHCT was safe, as no contrast material was needed. The mean applied radiation dose was 3.3 mSv for IVU and 6.5 mSv for UHCT. Alternative diagnoses were identified in 4 (7%) UHCT patients and 3 (5%) IVU patients. Sensitivity and specificity of UHCT and IVU was 94.1 and 94.2%, and 85.2 and 90.4%, respectively. In patients with suspected renal colic KUB and US may be the least expensive and most easily accessable modalities; however, if needed and available, UHCT can be considered a better alternative than IVU because it has a higher diagnostic accuracy and a better economic impact since it is more effective, faster, less expensive and less risky than IVU. In addition, it also has the capability of detecting various additional renal and extrarenal pathologies.

Unusual cross-sectional imaging findings in hepatic peliosis

Hepatic peliosis is a rare entity that represents focal, multifocal, segmental, or diffuse dilatation of liver sinusoids. Hepatic peliosis is often associated with chronic wasting diseases but also has been reported in association with anabolic, contraceptive, or other hormonal treatment, and even in context with HIV-related bacterial infections. Hepatic peliosis is usually clinically unapparent and mostly found only during autopsy, but occasionally it may lead to diagnostic problems if detected radiologically since the imaging findings in hepatic peliosis are quite variable according to the variety of its possible histologic features as well as the possibility of additional hemorrhage. We present a case of hepatic peliosis associated with bronchial carcinoma that showed moderate centripetal enhancement during the portal-venous phase on CT, pronounced venous pooling on contrast enhanced T1-weighted images acquired during the hepatic-venous phase, and bright signal on T2-weighted images, thus mimicking in some way a capillary hemangioma. We also discuss some not yet described CT and MR features of this rare entity which should be included into the differential diagnosis of atypical liver lesions in patients with the above-mentioned conditions.

[Is multidetector computerized tomography currently the primary diagnostic method of choice in diagnostic imaging of acute intestinal ischemia?]

Die frühzeitige diagnostische Erfassung einer akuten Darmischämie ist für die betroffenen Patienten der wohl wichtigste, von ärztlicher Seite her beeinflussbare prognostische Faktor. Aus diesem Grunde bedarf es einer Abklärungsmethode, welche nicht nur in der Lage ist, hinsichtlich der breiten Differentialdiagnose eines akuten Abdomens, sondern auch speziell bei der akuten Darmischämie zuverlässige diagnostische Hinweise zu liefern und welche als wenig invasives Verfahren ohne die mit der Katheterangiographie oft verbundene Hemmschwelle früh und rechtzeitig eingesetzt werden kann. Die Multidetektor-Computertomographie (MDCT) hat im Laufe der letzten Jahre bewiesen, dass sie diese Bedingungen erfüllt, und gleichzeitig eine exakte Beurteilung von mesenterialen Gefässen wie auch Darm- und Umgebungsstrukturen erlaubt. Die der Katheter-Angiographie vergleichbare Sensitivität der Multidetektor-Computertomographie hinsichtlich der Erfassung der akuten Darmischämie unterstreicht des weiteren, dass die Multidetektor-Computertomographie heutzutage auch bei Abklärung der akuten Darmischämie als die initiale bildgebende Abklärunsgmethode der Wahl angesehen und eingesetzt werden sollte.

Colonic involvement in non-necrotizing acute pancreatitis: correlation of CT findings with the clinical course of affected patients

The purpose of this study was to describe CT findings of colonic involvement in acute non-necrotizing pancreatitis and to analyze the correlation between colonic wall thickening at CT and the clinical course of these patients. The CT examinations of 19 consecutive patients with acute non-necrotizing pancreatitis who were not treated with antibiotics initially were analyzed retrospectively. The severity of acute pancreatitis was categorized according to the CT severity index (CTSI) and the presence of colonic wall thickening at the initial CT was compared with the clinical course of all patients. Seven of 11 patients with a CTSI of 4 showed a colonic wall thickening, whereas the remaining patients with a CTSI of 4 (n=4), CTSI of 3 (n=5), and CTSI of 2 (n=3) showed no colonic abnormalities at CT. Patients with colonic wall thickening presented more often with fever, showed higher levels of infectious parameters, needed more often antibiotic therapy, and had more requests for additional CT examinations and CT-guided fluid aspirations as well as a longer duration of hospital stay as compared with patients without colonic wall involvement, even if the latter presented with the same CTSI initially. It is well known that translocation of the colonic flora may significantly influence the clinical course of patients with acute pancreatitis, and our results indicate that patients with acute pancreatitis who present with colonic wall thickening at CT have an increased risk for a complicated clinical course regarding systemic infection.

[Imaging diagnosis of inflammatory bowel disease]

The term "chronic inflammatory bowel disease" represents a spectrum of diseases out of which ulcerous colitis and Crohn's disease are the far most common. Large bowel enemas have lost their relevance compared to colonoscopy over the past years and small bowel enteroclysis has also been widely replaced by CT- and especially MR-enteroclysis meanwhile. The diagnostic value of computed tomography and MR-tomography in chronic inflammatory bowel disease is based on the excellent visualization and documentation of extent and severity of bowel wall inflammation, estimation of inflammatory activity of the disease and of detection of potential extraintestinal complications and/or additional diagnoses by these two methods. Nevertheless, conventional radiological techniques as well as sonography may still be valuable under certain conditions. Furthermore, nowadays imaging of chronic inflammatory bowel diseases includes also White Blood Cell scintigraphy as well as Positrone Emission Tomography which provide informations about extent and especially activity of the disease. The presented article provides an overview of the possibilities and limitations of the available imaging modalities in inflammatory bowel diseases and helps the reader to decide under what conditions which one of the available examinations should be regarded as the most appropriate and promising one.

Three-dimensional dynamic MR-hysterosalpingography; a new, low invasive, radiation-free and less painful radiological approach to female infertility

BACKGROUND

The purpose of this study was to propose a new method for imaging the uterine cavity and Fallopian tube patency by three-dimensional dynamic magnetic resonance hysterosalpingography (3D dMR-HSG) and to analyse if, by using a higher viscosity contrast solution, direct visualization of the Fallopian tubes may be achieved by this new technique.

METHODS

10 consecutive infertile women underwent 3D dMR-HSG and conventional HSG as gold standard. 3D dMR-HSG consisted of injection of 20 ml of a gadolinium-polyvidone solution into the uterine cavity while acquiring five consecutive three-dimensional (3D) T1-weighted MR-sequences.

RESULTS

In three patients the catheter became dislodged during 3D dMR-HSG. However, in one of these patients the examination was still partially diagnostic. Imaging findings of 3D dMR-HSG showed good correlation with conventional hysterosalpingography and allowed 3D imaging of the uterine cavity and of Fallopian tube patency in 8/10 patients and direct visualization of the Fallopian tubes in 5/7 patients.

CONCLUSION

3D dMR-HSG represents a new and promising imaging approach to female infertility causing less pain and avoiding exposure of the ovaries to ionizing radiation. By using a higher viscosity MR-contrast agent it allows not only visualization of uterine cavity and Fallopian tube patency but also direct visualization of Fallopian tubes.

Flush symptoms caused by a mesenteric carcinoid without liver metastases

Flushing is a known symptom in intestinal carcinoid tumors which usually occurs only in the presence of liver metastases. A 62-year-old women presented with abdominal pain, nausea and flush symptoms. US, CT, octreotide scintigraphy and biopsy revealed a primary mesenteric carcinoid with retroperitoneal lymph node metastases and a solitary leftsided supraclavicular lymph node metastasis proving lymphatic spread over the thoracic duct, but liver metastases were excluded. This is a report on a mesenteric carcinoid which lead to flush symptoms despite absence of liver metastases, since retroperitoneal lymph node metastases enabled a direct hormone release into the systemic circulation.

Hepatic veno-occlusive disease: MRI findings

We present magnetic resonance imaging findings in a patient with proven hepatic veno-occlusive disease (VOD) caused by the use of "poppers," a recreational drug used during anal intercourse. Although this report emphasizes the differential magnetic resonance imaging features between VOD and Budd-Chiari syndrome, our case is unique because the VOD was induced by unrelated substances.

[Value of radiological imaging after laparoscopic gastric banding]

Over the past years "laparoscopic gastric banding" has evolved to one of the leading surgical techniques for the treatment of patients with morbid obesity. Mainly two systems are used worldwide; the "LAP BAND" (ASGB--Adjustable Silicone Gastric Banding) and the "Swedish Band" (SAGB--Swedish Adjustable Gastric Banding) which may both be implanted laparoscopically around the proximal stomach at a suprabursal position, about 2 cm distally to the cardia, with the intention to create a small pouch and, therefore, to provide an earlier satiation. Both systems show only minor differences regarding their consistency and their opacity as well as regarding the volume of the system. However, the working mechanisms and the principal techniques of surgical implantation, luminal adjustment and management of postoperative weight loss as well as the way how to perform radiological controls in these patients are quite similar in both systems. Although these patients might be managed postoperatively by the clinicians alone, it has become well accepted over the past years that radiological controls are not only important for an exact luminal adjustment but crucial for the management of an ideal postoperative weight loss and for the detection of various postoperative complications. This article describes the radiographic appearances of both systems, instructs how to perform postoperative radiological controls in these patients and provides an overview of the known postoperative complications together with some recommendations regarding their therapeutic approach.

CT findings in eosinophilic enterocolitis with predominantly serosal and muscular bowel wall infiltration

A 44-year-old female presented with tenderness of her abdomen, vomiting, intestinal obstruction, hypoalbuminemia and blood eosinophilia. Gastroscopy was normal and colonoscopic biopsies showed only non-specific inflammation of the colonic mucosa and submucosa. CT revealed large amounts of ascites and bilateral pleural effusions but eosinophil counts in the ascites were normal. At CT the jejunum was dilated and showed marked prominence of the valvulae whereas the ileum and the colon presented with a diffuse and hypoattenuating bowel wall thickening. The bowel wall thickening was most pronounced in the colon which especially showed also an impressive thickening and hyperenhancement mainly of its outer bowel wall layers. Parasitic infection could be excluded as well as a specific allergic response. In context with the known blood eosinophilia the diagnosis of an eosinophilic enterocolitis was suspected already by CT but finally only surgical full thickness biopsies could confirm the rare diagnosis of an eosinophilic enterocolitis with predominantly serosal and muscular bowel wall infiltration.

Swallowing abnormalities in multiple sclerosis: correlation between videofluoroscopy and subjective symptoms

The purpose of this study was to evaluate if subjective symptoms indicating an impaired deglutition correlate with videofluoroscopic findings in patients with multiple sclerosis (MS). Videofluoroscopic examinations of 18 MS patients were analyzed by a radiologist and a logopedist and compared with the symptoms of these patients. Four patients complained about permanent dysphagia. Six patients reported mild and intermittent difficulties in swallowing, but were asymptomatic at the time of videofluoroscopy. Eight patients had no symptoms regarding their deglutition. All patients ( n=4) who complained of permanent dysphagia showed aspiration. All patients ( n=6) with mild and intermittent difficulties in swallowing showed undercoating of the epiglottis and/or laryngeal penetration. Of those 8 patients without any swallowing symptoms, only 2 had a normal videofluoroscopy. Swallowing abnormalities seem to be much more frequent in patients with MS than generally believed and they may easily be missed clinically as long as the patients do not aspirate.

Pseudotumor of the pancreatic head associated with idiopathic retroperitoneal fibrosis

A 68-year-old male presented with abdominal pain and obstructive jaundice. CT revealed a large mass in the pancreatic head that was initially interpreted as pancreatic carcinoma. Needle biopsy revealed only fibrous tissue with signs of chronic inflammation. Together with typical findings of an idiopathic retroperitoneal fibrosis, the final diagnosis of multifocal idiopathic fibrosclerosis with focal pseudotumorous pancreatic head fibrosis could be made.

Three-dimensional dynamic MR hysterosalpingography: a preliminary report

The aim of this study was to evaluate the feasibility of three-dimensional dynamic MR hysterosalpingography (3D MR HSG) for visualization of the cavum uteri and demonstration of bilateral fallopian tube patency as an alternative to conventional hysterosalpingography. Five infertile female patients underwent 3D dynamic MR HSG prior to conventional hysterosalpingography. The MR protocol consisted of axial T1-weighted spin-echo (SE), axial/coronal T2-weighted fast SE (FSE), and 3D MR angiography sequences before, during, and after injection of a diluted gadolinium solution into the cavum uteri via a balloon catheter. Positioning of the catheter was feasible in all patients. In one patient the catheter slipped out during MRI and in one patient the catheter was placed far in the cavum uteri. In three patients catheter position was optimal at the level of the cervical canal. Evaluation of pelvic anatomy, myometrium, and ovaries was possible in all patients on the basis of T1-weighted SE and T2-weighted FSE. Three-dimensional visualization of the dilated cavum uteri was possible in four patients. In these four patients 3D MR HSG also proved bilateral fallopian tube patency which was confirmed in each patient by conventional hysterosalpingography. Three-dimensional MR HSG is feasible and further research should be done to determine if this technique can evolve into an alternative technique to conventional hysterosalpingography with the advantages of no radiation and additional visualization of the uterus wall and ovaries.

Acute appendicitis in a young adult with midgut malrotation: a case report

Midgut malrotation is defined as a developmental anomaly that may cause atypical clinical symptoms in relatively common intestinal disorders due to altered anatomy. A 27-year-old woman presented with acute left-sided abdominal pain. Underlying type Ia malrotation prevented the correct clinical diagnosis of perforated, ulcerated appendicitis. Cross-sectional imaging demonstrated all the typical signs of this type of malrotation, i.e., right-sided duodenojejunal junction, left positioned cecum and ascending colon, inverted position of the superior mesenteric vessels, and hypoplasia of the uncinate process of pancreas, and surgical treatment was initiated.

Pneumatosis intestinalis and portomesenteric venous gas in intestinal ischemia: correlation of CT findings with severity of ischemia and clinical outcome

OBJECTIVE

The purpose of this study was to analyze the correlation between pneumatosis or portomesenteric venous gas, or both, the severity of mural involvement, and the clinical outcome in patients with small- or large-bowel ischemia.

MATERIALS AND METHODS

CT scans of 23 consecutive patients presenting with pneumatosis or portomesenteric venous gas caused by bowel ischemia were reviewed. The presence and extent of both CT findings were compared with the clinical outcome in all patients and with the severity and extent of ischemic bowel wall damage as determined by surgery (15 patients), autopsy (three patients), or follow-up (five patients).

RESULTS

Seven patients showed isolated pneumatosis, and 16 patients showed portomesenteric venous gas with or without pneumatosis (11 and five patients, respectively). Pneumatosis and portomesenteric venous gas were associated with transmural bowel infarction in 14 (78%) of 18 patients and 13 (81%) of 16 patients, respectively. Nine patients (56%) with portomesenteric venous gas died. Of seven patients with infarction limited to one bowel segment (jejunum, ileum, or colon), only one patient (14%) died, whereas of the 10 patients with infarction of two or three bowel segments, eight patients (80%) died.

CONCLUSION

CT findings of pneumatosis intestinalis and portomesenteric venous gas due to bowel ischemia do not generally allow prediction of transmural bowel infarction, because they may be observed in patients with only partial ischemic bowel wall damage. The clinical outcome of patients with bowel ischemia with these CT findings seems to depend mainly on the severity and extent of their underlying disease.

Hepatic imaging with multidetector CT

Combining the advantages of a multirow detector array with a fast gantry rotation time, multidetector computed tomographic (CT) scanners can acquire sections at a faster rate than was previously possible. As a result, multidetector CT permits scanning during multiple specific phases of intravenous contrast enhancement and the acquisition of very thin sections over a large area, allowing the creation of multiplanar reconstructions with high z-axis resolution. The authors present an imaging strategy for the diagnosis and staging of hepatic pathologic conditions that emphasizes the role of multidetector CT. Users must master several scanning parameters to obtain the best image quality. For hepatic CT, it is practical to use relatively narrow collimation, increasing the pitch as needed to cover the entire liver. The choice of reconstruction interval is dependent on the problem for which the study is being performed. Water is recommended as an oral contrast agent for non-axial reconstructions, since high-attenuation oral contrast agents might degrade them. Appropriate scanning delays for hepatic CT are dependent on the contrast-agent injection strategy used. A triple-pass technique, highlighting the arterial, parenchymal, and portal venous phases of enhancement, is recommended.

Anterior versus posterior slippage: two different types of eccentric pouch dilatation in patients with adjustable laparoscopic gastric banding

PURPOSE

To describe two different types of band dislocation that may occur in morbidly obese patients following adjustable laparoscopic gastric banding (ALGB) with the LAP-BAND.

MATERIALS AND METHODS

170 morbidly obese patients were treated with an LAP-BAND at our institution. In the first 20 patients the band was positioned transbursally, which means that the lesser sac is penetrated during laparoscopic band implantation. In the following 150 patients the operation technique was changed to suprabursal band positioning where the lesser sac is not penetrated. Plain radiographs and single contrast studies of all patients who developed band instability in the follow-up were analyzed retrospectively and compared to the clinical and intraoperative findings and to the operation technique used.

RESULTS

Over a time period of 3.5 years 'posterior slippage' occurred in all 20 patients with transbursal band placement, but it never occurred after suprabursal band placement. Never- theless 4 patients with suprabursal band placement presented with an eccentric pouch dilatation, secondary to 'anterior slippage' after the seromuscular stitches had burst on the anterior and superior surface of the band. All these patients presented with food intolerance and all of them had to be reoperated. The radiographic findings were pathognomonic for each type of band dislocation.

CONCLUSION

Band dislocation is a known major complication that may occur following ALGB and it may present in two different forms. While 'posterior slippage' can be avoided if the band is placed suprabursally, 'anterior slippage' may still occur. It is important to be familiar with both types of band dislocation since they require early detection and surgical band replacement or band refixation.

Pseudo-achalasia following laparoscopically placed adjustable gastric banding

BACKGROUND

The complication of pseudo-achalasia may occur after laparoscopic adjustable gastric banding (LAGB) in patients with normal band position and normal stomal width. We hypothesized that this complication occurs especially in patients with preexisting insufficiency of the lower esophageal sphincter (LES), who show poor compliance secondary to lacking the sensation of satiety and who therefore also have insufficient weight loss at follow-up.

METHODS

Early and late postoperative barium meal studies of 120 LAGB patients were retrospectively analyzed to identify patients who developed esophageal widening and dysmotility despite normal band position and normal stomal width. Results were compared with preoperative endoscopies, clinical findings, each patient's compliance with dietary instructions and postoperative weight loss.

RESULTS

9/120 patients developed pouch dilatation, esophageal widening and esophageal dysmotility as a late complication, despite normal band position and normal stomal width. All these patients had shown preexisting insufficiency of their LES endoscopically. They all showed bad compliance with dietary instruction, and they all abused their distal esophagus as an additional pouch. 7 of these patients presented with insufficient weight loss at follow-up, whereas of 3 other patients with pre-existing LES insufficiency who had shown good compliance, only 1 showed insufficient weight loss. Insufficient weight loss after 1 year was significantly more common in patients with pre-existing LES insufficiency (8/12 patients, 67%) than in patients with a competent LES (26/108 patients, 24%).

CONCLUSION

Patients with pre-existing LES insufficiency appear to be at risk for pouch dilatation and esophageal decompensation despite normal band position and normal stomal width. These patients are prone to show lack of satiety and poor compliance with dietary instruction, use of their lower esophagus as additional space for food, and tend to have insufficient weight loss. Preoperative manometry should be used to identify such patients, where the indication for gastric banding should be discussed very critically.

Spontaneous volume changes in gastric banding devices: complications of a semipermeable membrane

The goal of this study was to prove that adjustable laparoscopic gastric banding (LAP-BAND) is semipermeable and that luminal adjustment with saline leads to spontaneous fluid loss, luminal widening, and effect loss which makes repeated readjustments necessary. In 64 patients stoma adjustment was performed with saline according to the guidelines of the manufacturer (group 1). In 32 patients hyperosmolar contrast material was used for stoma readjustments with the intention to detect a system leakage after spontaneous fluid loss and spontaneous luminal widening was observed (group 2). After spontaneous luminal narrowing had occurred in group 2, all patients from group 2 and all additional patients (n = 148) underwent stoma (re-) adjustment with iso-osmolar contrast material (group 3). Spontaneous fluid changes which led to spontaneous changes of the luminal width were then analyzed for the different filling substances in each group. Fifty-two patients from group 1 presented with effect loss because a spontaneous luminal widening had occurred secondary to a fluid loss of 0.1-0.2 ml/month. All 32 patients from group 2 presented with increasing obstruction and food intolerance because a spontaneous luminal narrowing had occurred secondary to a spontaneous fluid gain of 0.1-0.3 ml/month. In our patients from group 3, where stoma adjustment was performed with iso-osmolar contrast material, no spontaneous fluid changes were observed and luminal width/degree of obstruction did not change. The LAP-BAND is semipermeable. Stoma adjustment should not be performed with saline in order to avoid spontaneous luminal widening and the need for repeated readjustments. Stoma adjustments with hyperosmolar contrast material are clearly contraindicated since osmotic fluid gain leads to increasing obstruction. Stoma adjustments should be performed using iso-osmolar filling media which provide a stable luminal obstruction.

Imaging findings in idiopathic pelvic fibrosis

Two patients presented with ureteric obstruction, and voiding symptoms and constipation, respectively, and were examined by means of intravenous urography and computed tomography. One patient was additionally examined by means of MR tomography. After CT (performed in both patients) and MRT (performed in one patient) had shown a diffuse, contrast-enhancing, infiltrating process in the small pelvis with infiltration of adjacent organs and vessels, surgical biopsy proved the diagnosis of idiopathic pelvic fibrosis. Extension of retroperitoneal fibrosis below the pelvic rim is very rare. Clinical symptoms of pelvic fibrosis are variable and imaging findings may lead to a broad list of differential diagnoses. We present two patients with idiopathic pelvic fibrosis and discuss radiological findings and differential diagnoses of this rare disease.

Omental infarction associated with right-sided heart failure

A 31-year-old man with a known congenital heart disease presented with cardial decompensation and an acute abdomen with tenderness in the right inferior abdominal quadrant. Because infectious parameters were slightly elevated, acute appendicitis was suspected. A CT scan showed an isolated focal infiltration of the omentum, superficial to the ascending colon, small amounts of ascites, and dilated hepatic and mesenteric veins. Laparoscopic resection and histopathologic examination confirmed hemorrhagic omental infarction due to thromboses of several small omental veins. This is a report on the pathogenesis, differential diagnoses, and CT findings of omental infarction.

Nonocclusive ischemic colitis in a 12-year-old girl: value of unenhanced spiral computed tomography

A 12-year-old girl was hit by a car and arrived in the emergency room in hemorrhagic shock. Contrast-enhanced computed tomography of the abdomen showed traumatic rupture of the liver and large amounts of intraperitoneal hemorrhage. Unenhanced computed tomography showed a hyperdense thickening of the wall of the descending colon. This finding was consistent with a nonocclusive ischemic colitis, which was confirmed some days later by endoscopy, at a time when the patient had already developed Gram-negative bacteremia. We discuss the pathogenesis of nonocclusive ischemic colitis, computed tomography findings, and the value of unenhanced computed tomography.

Spiral CT in an acute spontaneous aorto-caval fistula

A patient with a known infrarenal atherosclerotic aneurysm measuring 8 cm presented with sudden dyspnoe, lower back pain and enormous venous congestion of the lower extremities. Spiral CT rendered precise diagnosis and localisation of a large and acute spontaneous aorto-caval fistula and made early surgical intervention possible. Abdominal aorto-caval fistulas are rare complications and can occur after surgery, trauma or spontaneously in an atherosclerotic or inflammatory aneurysm. Spiral CT enables a rapid and precise diagnosis facilitating the planning of the therapeutic approach to this complication.

Adjustable laparoscopic gastric banding in patients with morbid obesity: radiographic management, results, and postoperative complications

PURPOSE

To determine the role of radiographic assessment in patients who underwent an adjustable laparoscopic gastric banding (ALGB) for the treatment of morbid obesity, and to evaluate the frequency and type of postoperative complications.

MATERIALS AND METHODS

From September 1995 to March 1998, 98 consecutive patients (18 men, 80 women; mean age, 39 years; age range, 22-62 years) with morbid obesity (mean body weight, 132 kg; mean body mass index, 47.1 kg/m(2)) underwent ALGB. In all patients, fluoroscopy was performed postoperatively to confirm band position and to exclude perforation and at 6-8 weeks later to measure and adjust the stoma between the pouch and stomach for optimal weight loss. All patients underwent another examination 12 months postoperatively, whereas patients with unsatisfactory weight loss or patients suspected of having complications were examined earlier and on several occasions.

RESULTS

Port puncture was feasible in all cases, and stomal adjustments could easily be repeated. Absolute (ie, total) weight loss after 1 year ranged from 8.8% to 39.2% (mean, 18.3%). Twenty patients showed unsatisfactory weight loss. No early complications occurred. Late complications occurred in 34 patients and included pouch dilatation (concentric or eccentric with posterior slippage), eccentric band herniation, band penetration, disconnection, axial pouch herniation, and port-site infection.

CONCLUSION

ALGB is an effective method in the treatment of morbid obesity. Radiographic assessments are crucial in the management of weight loss and detection of postoperative complications.

Pelvic and lower extremity veins: contrast-enhanced three-dimensional MR venography with a dedicated vascular coil-initial experience

PURPOSE

To assess the performance of three-dimensional (3D) magnetic resonance (MR) venography of the pelvis and lower extremities in patients without acute deep venous thrombosis by using a lower extremity vascular coil and pedal injection of paramagnetic contrast material.

MATERIALS AND METHODS

Conventional and MR venography were performed in 35 legs in 25 patients referred for evaluation of varicosities (n = 8) and postthrombotic changes (n = 7) and assessment of the great saphenous veins prior to bypass surgery (n = 10). Injection of 120 mL of diluted (1:15) gadopentetate dimeglumine into a pedal vein was performed manually at a rate of 1 mL/sec, and 3D gradient-recalled echo data sets of the upper and lower veins were collected. Conventional and MR venographic images were analyzed separately in a blinded fashion.

RESULTS

MR image quality was comparable to that of conventional venograms. Varicose changes of the great and small saphenous veins (sensitivity, 94% [44 of 47]; specificity, 96% [89 of 93]) were assessed as reliably as their status before bypass surgery (sensitivity, 98% [53 of 54]; specificity, 92% [47 of 51]). Postthrombotic changes were diagnosed with a sensitivity of 100% [13 of 13] and a specificity of 98% [88 of 90].

CONCLUSION

Direct 3D MR venography comprehensively displays the lower extremity venous system and permits assessment of postthrombotic and varicose changes and the bypass suitability of the saphenous vein.

FDG PET-negative liver metastases of a malignant melanoma and FDG PET-positive hurthle cell tumor of the thyroid

A Hurthle cell tumor (oncocytoma) of the thyroid presented as a hypermetabolic focus in a fluorodeoxyglucose positron emission tomography (FDG PET) study which was performed as staging procedure in a patient with malignant melanoma. This finding led to the initial diagnosis of a metastasis. In contrast, multiple liver metastases, seen on MRI and sonography, did not show any increased FDG uptake. Cytology results of one liver mass confirmed a melanoma metastasis, and of the neck mass, a Hurthle cell tumor. The Hurthle cell tumor was, based on clinical evidence, thought to be benign. This is the first description of a FDG PET-positive benign Hurthle cell tumor, with FDG PET-negative liver metastases of a malignant melanoma, in the same patient.