Isotropic CT examination of abdomen and pelvis diagnostic quality of reformat

RATIONALE AND OBJECTIVES

To evaluate the image quality of axial and coronal reformats obtained from isotropic resolution abdomino-pelvic computed tomography (CT) examinations.

MATERIALS AND METHODS

Thirty consecutive patients with intravenous contrast-enhanced abdomino-pelvic CT examinations (Brilliance 40, Philips Medical Systems, Cleveland, OH) were enrolled for the study. The raw data were reconstructed into two sets of source axial images: 0.9-mm slice widths with 0.45-mm reconstruction interval (isotropic resolution) and 4-mm slice widths with 3-mm reconstruction interval (anisotropic resolution: group A). Isotropic data set was reformatted into axial and coronal stacks (groups B and C, respectively) with 4-mm slice width and 3-mm interval. Three independent readers evaluated stacks A to C using a 3-point scale for resolution of hepatic vessels, edge sharpness of kidneys, respiratory motion artifact, reconstruction artifact, noise, and overall image quality.

RESULTS

There was no statistical difference among the groups A to C for vessel resolution, motion artifact, noise, and overall quality. The scores given to group C were significantly lower than those to groups A and B for reconstruction artifacts. There was no difference among groups A to C for overall impression of image quality. The interreader agreements were excellent for axial images (groups A and B) and moderate for coronal reformats.

CONCLUSION

Isotropic scanning of the abdomen and pelvis allows creation of reformats with similar image quality as similar thickness axial source images. These reformats are of sufficient quality to form the basis of clinical interpretation.

Pylephlebitis Associated with Acute Infected Choledocholithiasis

Pylephlebitis, also called septic thrombophlebitis of the portal vein, is a life-threatening complication of intra-abdominal infection. Although rare, it remains a less recognized entity with a high rate of mortality. We present a 66-year-old man with acute infected choledocholithiasis complicated with Bacteroides fragilis bacteremia. The contrast-enhanced computed tomography scan of the abdomen showed nearly total thrombotic occlusion of the left portal vein. The comprehensive studies for hypercoagulation disorders all yielded negative results. After endoscopic extraction of bile duct stones and broad-spectrum antibiotic therapy, the patient recuperated with complete recanalization of the occluded portal vein. To our knowledge, pylephlebitis associated with acute infected choledocholithiasis has never been reported. This report details the clinical features, radiographic findings, pathogenesis, and treatment of this distinctly unusual manifestation. Early identification of pylephlebitis and underlying intra-abdominal infection can be achieved by exquisite imaging studies with raised awareness in the clinical setting. Eradication of infectious foci and judicious administration of antimicrobials are essential to reduce the catastrophic morbidity and mortality of pylephlebitis.

Intraabdominal fetal echogenic masses: a practical guide to diagnosis and management

Intraabdominal calcifications and other echogenic masses are relatively common findings during fetal sonography. Many are associated with no additional risk for the fetus or neonate. They may arise from the liver, gallbladder, spleen, kidneys, adrenal glands, gastrointestinal tract, or peritoneal cavity. Detection of such lesions should prompt a detailed survey for additional findings and a review of the maternal history. In some cases, fetal karyotyping may be indicated. In most cases, the diagnosis, management, and outcome are determined according to a combination of specific ultrasound appearances and at least one additional maternal or fetal factor. In utero diagnosis can often be achieved with careful evaluation of the lesion echotexture, associated calcifications, additional findings, and evolution over time. In most cases, expectant management is sufficient, but some patients require transfer to a facility where early postnatal intervention is available. A systematic approach to the findings aids in differential diagnosis and management.

Direct Percutaneous Endoscopic Jejunostomy Placement in a Patient with Intracorporeal Left Ventricular Assist Device

We present a case involving a patient who required enteral feeding after implantation of an abdominally positioned left ventricular assist device. The position of the device occupied most of the abdomen, precluding percutaneous endoscopic gastrostomy tube placement. However, in the case presented, direct percutaneous endoscopic jejunostomy (DPEJ) tube placement was achieved without interfering with the intracorporeal device. To our knowledge, there are no previous reports in the literature of successful DPEJ placement in a patient with an abdominally positioned heart assist device. DPEJ should be considered as a long-term enteral feeding route when structural barriers prevent percutaneous gastric access.

Diffuse Abdominal Uptake Mimicking Peritonitis in Gallium Inflammatory Scan: An Unusual Feature of Acute Q Fever

The clinical features in patients with acute Q fever are variable. We present a patient with fever, abdominal distension, pericardial effusion, and diffuse gallium uptake in the abdominal cavity, mimicking peritonitis or peritoneum carcinomatosis. Serologic surveys revealed acute infection by Coxiella burnetii. The patient responded poorly to doxycycline and improved with oral levofloxacin. During the afebrile period, gallium inflammatory scan showed resolution of previous diffuse uptake in the abdomen, and cardiac echo resolution of pericardial effusion, which was suggestive of peritoneal inflammation related to acute C. burnetii infection. Therefore, clinicians in Taiwan should be alert to the possibility of acute Q fever in patients with fever of unknown cause, especially with clinical evidence of peritoneal and/or pericardial inflammation.

Immobilization effect of air-injected blanket (AIB) for abdomen fixation

A new device for reducing the amplitude of breathing motion by pressing a patient's abdomen using an air-injected blanket (AIB) for external beam radiation treatments has been designed and tested. The blanket has two layers sealed in all four sides similar to an empty pillow made of urethane. The blanket is spread over the patient's abdomen with both ends of the blanket fixed to the sides of the treatment couch or a baseboard. The inner side, or patient side, of the blanket is thinner and expands more than the outer side. When inflated, the blanket balloons and effectively puts an even pressure on the patient's abdomen. Fluoroscopic observation was performed to verify the usefulness of AIB for patients with lung, breast cancer, or abdominal cancers. Internal organ movement due to breathing was monitored and measured with and without AIB. With the help of AIB, the average range of diaphragm motion was reduced from 2.6 to 0.7 cm in the anterior-to-posterior direction and from 2.7 to 1.3 cm in the superior-to-inferior direction. The motion range in the right-to-left direction was negligible, for it was less than 0.5 cm. These initial testing demonstrated that AIB is useful for reducing patients' breathing motion in the thoracic and abdominal regions comfortably and consistently.

Megaesophagus was complicated with Billroth I gastroduodenostomy in a cat

A seven-year-old, female, domestic short hair cat was presented with a history of chronic anorexia. Radiographic examination revealed a large space-occupying calcified mass in the abdominal cavity. The mass was located in pylorus and did not extend into the duodenum and surrounding tissues. Billroth I gastroduodenostomy was conducted to remove the mass. Histopathological examination of the mass showed a lymphoma. Although Recovery following the operation was excellent, the patient showed intermittent vomiting unrelated to feeding. Radiographical examination revealed a megaesophagus, which was assumed to be a complication of the Billroth I procedure, since the condition was not observed before the procedure.

[Evaluation of Intra-abdominal fat distribution using X-ray CT data for detection of rectal cancer]

To develop a novel method of detecting rectal cancer, we assessed relationships between intra-abdominal fat distribution and rectal cancer in Japanese patients. Subjects comprised 38 patients with rectal cancer apparent on CT-colonography and 110 other cases. The intra-abdominal fat area was determined by calculating pixel distribution with attenuation values from -140 HU to -40 HU. The area of intra-abdominal fat was measured on axial images using an interslice gap of 10 mm. Profile curves of intra-abdominal fat were in the plane direction from diaphragm to anus. Of note is the fact that Ogura's peak, a secondary small peak around the rectal cancer, was apparent on the profile of intra-abdominal fat, with 73.7% of rectal cancers displaying Ogura's peak. In comparison, only 19.1% of other cases displayed Ogura's peak on this profile. The relationship between fat and rectal cancer is difficult to explain. However, making good use of these results showing intra-abdominal fat distribution, a computer-aided diagnosis (CAD) system for detecting rectal cancer according to the presence of Ogura's peak has potential as a method of mass screening. As only 148 cases were investigated in the present study, the accumulation of additional data is needed. More detailed studies with larger patient populations are warranted.

[Prophylaxis and treatment of intraabdominal purulent complications after performance of laparoscopic cholecystectomy using interventions with ultrasonographic control]

The results of treatment of 9103 patients, to whom laparoscopic cholecystectomy was performed, were adduced. In 6714 patients intraabdominal postoperative complications were absent, ultrasonographic investigation (USI) was not performed. Dynamical USI was done in 2389 patients, permitting to estimate timely the wound course severity in the gallbladder bed, to administer an adequate therapv, in 9 of them--to perform puncture of subhepatic formations under USI control. Intraabdominal infectious complications were revealed in 65 (0.71%) of patients.

Referred shoulder pain from ventriculoperitoneal shunts

The authors report on three pediatric patients with ventriculoperitoneal (VP) shunts who presented with chronic right shoulder pain. Imaging revealed that the distal peritoneal catheter was positioned between the right hemidiaphragm and liver. Following surgical repositioning of the distal tubing, all patients experienced resolution of their shoulder pain, which has not recurred. Although seemingly rare, referred shoulder pain from a VP shunt should be added to the list of complications seen with this method of cerebrospinal fluid diversion. The clinician who cares for patients with VP shunts may wish to evaluate cases of shoulder pain without obvious neural or musculoskeletal cause by performing imaging of the distal shunt tubing.

Pediatric applications of abdominal vascular Doppler imaging: Part I

Ultrasound is a remarkably powerful and versatile modality for pediatric imaging, without requiring exposure to radiation or sedatives. By providing information on blood flow, Doppler sonography can reveal details about normal physiology and disease processes not discernable from gray-scale anatomic images alone. However, in routine practice in many institutions Doppler remains underutilized, in part due to uncertainty of the meaning of changes in Doppler waveforms. In part I of this review, the basics of hemodynamics and how changes in blood flow affect the Doppler waveform are reviewed. Clinical applications in the investigation of hepatic disease are then discussed.

Pediatric applications of abdominal vascular Doppler: Part II

Ultrasound is a remarkably powerful and versatile modality for pediatric imaging, without requiring exposure to radiation or sedatives. By providing information on blood flow, Doppler sonography can reveal details about normal physiology and disease processes not discernable from gray-scale anatomic images alone. In part I, the basics of hemodynamics and effects on the Doppler waveform were discussed, along with clinical applications in hepatic disease. In part II, the application of Doppler in renal disease and in conditions affecting the deep abdominal vessels are discussed. The role of ultrasound contrast agents in pediatric Doppler imaging is briefly reviewed.

Ultrasound in emergency patients: better detection of free intraabdominal fluids by the use of tissue harmonic imaging

BACKGROUND

Ultrasound examination is one of the main investigative procedures in emergency patients who are hospitalized due to abdominal pain. Detectable free fluid collections are important hints to the definite, sometimes life-threatening diagnosis, but their detection in cases of only small amounts is difficult to perform by conventional sonography.

PATIENTS AND METHODS

We report about 25 cases of patients who suffered from acute abdominal pain and who were presented as emergency patients to our department of ultrasound. First, the examination was performed by conventional sonography (3.4 MHz). Only with the additional tissue harmonic imaging (THI, 2.3 MHz, pulse inversion) thin borders of free fluids around the liver or other abdominal organs (gallbladder, spleen, pancreas, bowel) could be detected leading to other important diagnostic or therapeutic steps. In this way, the diagnosis of pancreatitis, cholezystitis, peritonitis, peritoneal carcinosis, ascites (liver cirrhosis, serositis, postoperative status after laparotomy), bleeding or paralytic ileus could be elucidated.

CONCLUSION

THI sonography improves the detection of small amounts of free abdominal fluid collections. Therefore, this technique is helpful in the diagnostic procedure of emergency patients.

Radiologic aspects of abdominal hydatidosis in children

OBJECTIVE

To determine the location and radiological characteristics in children with abdominal hydatid disease (HD).

MATERIALS AND METHODS

Thirty-one children (average age: 7.2 years) with abdominal HD were studied. The number, location, diameter and internal architecture of the cysts were assessed with abdominal ultrasonography (US) and computed tomography (CT). Density measurements and enhancement patterns were determined on CT.

RESULTS

Twenty-one children had hepatic HD. The remaining 10 children had both hepatic and extrahepatic cysts. There were splenic cysts in five children, peritoneal cysts in two children and combined splenic and peritoneal cysts in three children. The most common site of the cysts was the liver (64%), followed by the spleen (20%) and the peritoneal cavity (16%). The seven intraabdominal cysts, which were not detected by US, were 20 mm or less in diameter.

CONCLUSION

CT may demonstrate additional small intrahepatic or unsuspected extrahepatic cysts. Although rare, splenic or peritoneal hydatidosis should be included in the differential diagnosis of a cystic splenic or peritoneal lesion. Familiarity with atypical locations of HD may be helpful in making a prompt, accurate diagnosis. We think that in particular patients, especially those who had diagnostic problem and who are under surgical planning, CT should be performed additionally.

Accurate volumetric measurements of anatomical cavities

OBJECTIVES

The volumetric assessment of anatomical cavities is of high relevance for various applications in medicine. Based on 3D scanning (i.e., CT) of these cavities, the volume can be determined by counting the volume elements of a segmentation of that cavity. Unfortunately, elements on the boundary of the segmentation require special treatment to obtain accurate volumetric measurements. In this paper, we propose a novel technique that in particular increases the accuracy of the volume estimation for the boundary elements of segmented anatomical objects.

METHODS

Based on a 3D segmentation of an anatomical cavity, we recursively subdivide boundary volume elements into a set of simple situations, where the volume can be estimated easily.

RESULTS

We performed volumetric measurements on seven datasets of phantom models made of plexiglass (see Fig. 1) scanned by a biplane angiography unit and assessed the quality of our method by comparing the measured volume by our novel method and by the fluid required to fill the phantom cavities.

CONCLUSIONS

Our method calculates a significantly more accurate volume of the segmented cavities than previous methods. Nevertheless, it is only slightly more computationally expensive.

[Prospects for ultrasonic diagnosis in peritoneal commissures of the abdominal organs]

In the nearest future the ultrasonic method of study will enable clinicians to diagnose quicker and more directly patients with peritoneal commissures of the abdominal cavity and will help to localize more directly the places of the greatest accumulation of commissures, confirm or discover various complications of peritoneal commissures. It will be especially important for the patients who have contraindications to X-ray examinations. It is certain that clinicians should be attracted by the precision of the ultrasonic method and by its non-traumatic nature and safety for a patient.

[Diagnosis of peritoneal adhesions of abdominal cavity organs]

The best results produced by objective methods in cases of scheduled examinations of patients with peritoneal commissures of the abdominal cavity organs are observed in a complex study being a combination of X-ray and radionuclide methods of study, ultrasonic method, MRI and laparoscopy.

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

In endemic areas with low prevalence and low intensity of infection, the diagnosis of hepatic pathology due to the Schistosoma mansoni infection is very difficult. In order to establish the hepatic morbidity, a double-blind study was achieved in Venezuelan endemic areas, with one group of patients with schistosomiasis and the other one of non-infected people, that were evaluated clinically and by abdominal ultrasound using the Cairo classification. Schistosomiasis diagnosis was established based on parasitologic and serological tests. The increase of the hepatic size at midclavicular and midsternal lines (in hepatometry) and the hard liver consistency were the clinical parameters able to differentiate infected persons from non infected ones, as well as the presence of left lobe hepatomegaly detected by abdominal ultrasound. The periportal thickening, especially the mild form, was frequent in all age groups in both infected and uninfected patients. There was not correlation between the intensity of infection and ultrasound under the current circumstances. Our data suggest that in Venezuela, a low endemic area of transmission of schistosomiasis, the hepatic morbidity is mild and uncommon. The Cairo classification seems to overestimate the prevalence of periportal pathology. The specificity of the method must be improved, especially for the recognition of precocious pathology. Other causes of hepatopathies must be investigated.

[Ultrasound investigation and mini-invasive ultrasound-assisted technologies in diagnosis and treatment of extra-organ separate fluid formations in abdominal cavity]

The authors discuss the use of ultrasound-assisted percutaneous puncture and drainage for diagnosis and treatment of extraorganic separate fluid formations in abdominal cavity (abscess, limited non-infected fluid formation, hematoma with clotted blood), determination of their sizes and obtaining material for laboratory study. 307 patients with various extraorganic separate fluid in formations in abdominal cavity were examined. Ultrasonic symptoms of abscess were described in 54 patients, of limited non-infected fluid formation--in 234, of hematoma with clotted blood in 19 patients. 146 patients were cured conservatively, 75 patients underwent US-assisted puncture, 76--US-assisted drainage. Mean time of drainage was 14 days (ranged from 10 to 20). There were neither complications nor lethal outcomes. Ultrasound examination and US-assisted mini-invasive surgery permit to detect precisely the nature of fluid formation, to perform timely and low-traumatic treatment.