Allen J. Cohen

CT cystography in the evaluation of bladder trauma.

At our trauma center we have replaced plain film cystography with CT cystography to evaluate trauma patients with hematuria sent for emergent CT of the abdomen and pelvis. Ten cases of ruptured bladders evaluated by CT are tabulated, and characteristic images are presented.

Dynamic CT in superior mesenteric artery syndrome.

In superior mesenteric artery (SMA) syndrome the third portion of the duodenum is entrapped by the aorta and the SMA. We used dynamic CT to study five patients with SMA syndrome due to cachexia, cast syndrome, scleroderma, trauma, and periaortic adenopathy. This method provides diagnostic insight into the etiology and possible therapeutic options in the care of these patients.

Prevalence of hiatal hernia in the morbidly obese

BACKGROUND Morbidly obese patients commonly have gastroesophageal reflux (GERD) and associated hiatal hernias. As such, some surgeons routinely perform a concomitant hiatal hernia repair during bariatric surgery. However, the intraoperative inspection for a hiatal hernia based on laparoscopic visualization can be misleading. The aim of this study was to assess the prevalence of hiatal hernias in morbidly obese patients based on preoperative upper gastrointestinal (GI) contrast study. METHODS Data on 181 patients who underwent routine upper GI contrast study as part of a preoperative workup for bariatric surgery were reviewed. The upper GI studies were examined for the presence of hiatal hernias and GERD. Hiatal hernias were categorized by size as small (≤2 cm), moderate (2-5 cm), or large (>5 cm). GERD was based on radiologic evidence and categorized as mild, moderate, or severe. RESULTS The mean age of the cohort was 44 years, with a mean body mass index of 43 kg/m(2). Of the 181 patients overall, based on the upper GI contrast study, the prevalence of hiatal hernia was 37.0% and of GERD was 39.8%; the prevalence of moderate or large hiatal hernia was 4.4%, and the prevalence of moderate or severe GERD was 13.3%. CONCLUSIONS Based on upper GI contrast study, we identified the presence of a hiatal hernia in nearly 40% of morbidly obese patients. The results from this study suggest that surgeons should evaluate the morbidly obese patient for the presence of hiatal hernias and perform concomitant repair at the time of the bariatric procedure, particularly in patients undergoing gastric banding and sleeve gastrectomy, while less so in the gastric bypass patient.

Low-dose and Standard Computed Tomography Scans Yield Equivalent Stone Measurements

OBJECTIVE To ascertain the reliability of low-dose computed tomography (CT) compared with standard CT in the determination of stone size, density, and skin-to-stone distance (SSD). MATERIALS AND METHODS A total of 10 patients seen in the emergency room within a mean of 23 days (range 0-51) underwent both conventional CT and low-dose CT for the same stone. The radiation dose reduction was calculated according to the patients body mass index. The CT scans were performed with 2-mm section cuts, and 3-dimensional reconstruction was performed to obtain the coronal views. The stone size was measured (ie, height, width, and length), and the Hounsfield units were calculated. In addition, the SSD was calculated for the nonmoving renal stones. RESULTS No difference was found in stone size between the 2 dosage levels, as measured by the height, width, length, and volume of the stone (P = .9, P = .7, P = .8, and P = .8 respectively). In addition, no difference in Hounsfield units was appreciated between the 2 scan types (P = .6). Finally, no significant difference was found in the SSD (P = .5). Between the 2 scans, the average effective dose reduction was 73%, from 23 to 6 mSv (P = .002). CONCLUSION No significant difference was found in the measurement of stone size, Hounsfield units, or SSD between the low-dose and conventional-dose CT scans. However, the low-dose CT scans resulted in a marked reduction in the radiation dose to the patient.

CT Signs of Duodenal Perforation Secondary to Blunt Abdominal Trauma

Two cases of duodenal perforation secondary to blunt abdominal trauma demonstrate CT findings of focal bowel wall thickening, interruption of progress of bowel contrast medium, and extraluminal gas and fluid.

Pyomyositis: Early detection utilizing multiple imaging modalities

Pyomyositis represents 3% to 4% of surgical admissions in East Africa, however, there were no reported cases in the United States prior to 1971. Since, there have been numerous reports of this entity. Four recent cases are presented utilizing multiple imaging modalities including magnetic resonance. MR was very sensitive to early soft tissue inflammatory processes and demonstrated these focal abscesses with superior anatomic localization. MR is advocated in the initial evaluation of a focal process. In a systemic, nonfocal process, nuclear medicine WBC or Gallium Scans to localize areas for further MR scanning is recommended.

CT evaluation of placental abruption in pregnant trauma patients

The purpose of the study was to assess the possibility of placental injury detection on computed tomography (CT) in pregnant trauma patients. The images and dictated reports of 44 CT scans of pregnant women who presented to the University of California Irvine Medical Center (UCIMC) from 2003 to 2008 for traumatic abdominal conditions were reviewed for placental abruption. Performances of original dictated reports, an untrained reviewer, and a trained reviewer (who was trained on 22 non-traumatic scans) were compared. Of the 66 pregnant women who received abdominal CT scans, 44 sustained abdominal trauma. Seven suffered placental abruptions, all of which were identified on CT. Sensitivity and specificity were 100% and 79.5%, respectively, for the untrained reviewer, 100% and 82.1% for the trained reviewer, and 42.9% and 89.7% for the original dictated reports. Placental abruptions are often overlooked on CT scan. Sensitivity may be improved by systematic evaluation of the placenta and specificity by training on normal placental morphology.

Optimizing the patient positioning for PICC line tip determination

Central venous catheters (CVCs) are used for both emergent and long-term vascular access for the infusion of numerous therapeutic agents such as chemotherapy, parenteral nutrition, antibiotics, and analgesics, as well as for temporary hemodialysis or hemoperfusion [1]. Current standard of care dictates that CVC insertion should be followed by an immediate chest radiograph to confirm appropriate position [2]. Radiographic confirmation of central venous line placement is important because it is not possible to determine CVC tip position clinically. Although many catheter tips can be localized on the standard frontal radiograph, there are occasions when a second radiograph is necessary to localize the position of the CVC tip accurately [3]. We hypothesized that a right posterior obligue chest radiograph would more consistently enable the catheter tip to be seen as it reduces the superimposition of mediastinal structures. One hundred chest radiographs taken in an anteroposterior (AP) projection and 100 chest radiographs taken in a right posterior oblique (RPO) projection after a peripherally inserted central catheter (PICC) line placement at UCI Medical Center from June 2000 to November 2002 were read by two radiologists. Forty-one percent of AP readings were discrepant and 4% had the annotation “difficult to identify the position of the tip” although the identification of tip position was similar. Fifty-five percent of AP readings were in agreement with no note of any difficulty. Eighteen percent of RPO readings were discrepant and 2% had the annotation “difficult to identify the position of the tip” although the identification of tip position was similar. Eighty percent of RPO readings were in agreement with no note of any difficulty.

The role of oral contrast administration immediately prior to the computed tomographic evaluation of the blunt trauma victim

BACKGROUND It is unclear whether the administration of oral contrast followed by immediate computerised tomographic (CT) scanning presents a significant risk of aspiration and whether it is useful in the diagnosis of hollow viscus injury. OBJECTIVE Determine the number of intestinal perforations diagnosed by oral contrast enhanced CT scans for blunt trauma and identify those who developed aspiration pneumonitis causally related to oral contrast administration. METHODS We analysed a database of consecutive blunt trauma admissions over a 2-year period. The majority received oral contrast immediately prior to CT scanning. We determined the number of intestinal perforations identified by abdominal CT confirmed at laparatomy and the number of cases of aspiration pneumonia. RESULTS Nine (1%) of the 1173 CT scans identified enteric perforations. Oral contrast enhanced CT scans demonstrated pneumoperitoneum (3), extraluminal contrast extravasation (2), and the presence of free fluid with small bowel wall thickening (8). In this same cohort, eight (0.7%) cases of aspiration pneumonia were diagnosed within 48 h of admission in patients with a mean GCS of 4.25; only one (0.1%) was temporally related to oral contrast administration. In a prospective study, none of the 65 consecutive patients who received oral contrast had witnessed aspiration. CONCLUSIONS Oral contrast administration given immediately prior to CT scanning does not increase the risk of clinically significant aspiration and assists in the detection of enteric perforation.

Cardiac pheochromocytoma: resection after diagnosis by 111-indium octreotide scan.

Cardiac pheochromocytoma is an exceedingly rare and unusual clinical entity. Only 37 previous surgically treated adult patients were found in review of the surgical literature. We report the case of a 13-year-old boy who had a cardiac pheochromocytoma that was localized by the 111-indium diethylenetriamine pentaacetic acid octreotide scintigraphy scan and confirmed by magnetic resonance imaging after computed tomographic and B1-iodine-metaiodobenzylguanidine scans had failed. At operation, a 6-cm pheochromocytoma of the left atrium was found and successfully resected with reconstruction of the left atrium using autologous pericardium.