Imaging findings after liver resection by using radiofrequency parenchymal coagulation devices: initial experiences

PURPOSE

To retrospectively evaluate the imaging features and potential pitfalls in interpreting the findings at the site of surgery in patients undergoing hepatic resection by using the InLine and TissueLink radiofrequency devices for parenchymal coagulation prior to transection.

MATERIALS AND METHODS

This HIPAA-compliant study was approved by the Institutional Review Board with waiver of informed consent. Twenty-six patients (14 men, 12 women; mean age, 56 years), in whom intraoperative Inline and TissueLink devices were used for resection of hepatocellular carcinoma or metastatic liver disease or other liver tumors, were identified. Information such as tumor characteristics, diagnostic studies, surgical therapy, and surveillance methods were reviewed. All computed tomographic (CT) and positron emission tomographic (PET) scans and the single magnetic resonance and ultrasonographic images of the abdomen were retrospectively reviewed by a radiologist and compared with the initial interpreting physician's report.

RESULTS

Of 35 CT scans, 33 revealed a hypodense line of demarcation (mean thickness, 13.2 mm) between the surgical resection clips and the normal liver parenchyma. This demarcation was interpreted as "could not exclude site recurrence" in three cases and "recurrence or probable recurrence" in five cases. In two CT scans, the hypodense demarcation was not present. In all seven PET scans, the uniform hypermetabolic activity associated with the demarcation was labeled as a recurrence. At follow-up CT (median, 12.5 months), marginal recurrence was not detected in 25 patients, though in one case there was a recurrence in close proximity to the surgical site.

CONCLUSION

The use of InLine and TissueLink devices during hepatectomy is associated with a linear hypodense demarcation at the surgical margin that also demonstrates a symmetrical rimlike hypermetabolic activity seen on PET scans.

Potential pitfalls and methods of improving in utero diagnosis of transposition of the great arteries, including the baby bird's beak image

OBJECTIVE

The goal of this study was to analyze our recent experience with fetuses with transposition of the great arteries (TGA) to identify potential pitfalls and possible methods to better detect conotruncal anomalies such as TGA.

METHODS

We analyzed all nonreferral obstetric ultrasound examinations in which we performed basic, targeted, or formal fetal echocardiography with a newborn diagnosis of TGA.

RESULTS

Nine neonates had TGA. Five of these cases were diagnosed prenatally, and 4 of these had complex congenital heart abnormalities. In these 4 cases, there were abnormalities in the cardiac axis (n = 3), abnormal valves or ventricular size (n = 2), and ventricular septal defects (n = 3) that were detected on the 4-chamber view of the heart. In all cases that were not detected prenatally, both prospective and retrospective reviews of the 4-chamber heart appeared normal. The prospective analyses of the outflow tracts were all interpreted as normal, whereas the retrospective review showed subtle abnormalities such as the "baby bird's beak" image. In review of these cases, there was failure to show the "crisscross" relationship of the outflow tracts. In 1 case, 5 short axis views of the heart, retrospectively showed the artery originating from the left ventricle and bifurcated, representing the pulmonary artery.

CONCLUSIONS

Transposition of the great arteries may be associated with complex cardiac disease that could be detected on the 4-chamber view of the heart. When the 4-chamber view is normal, it is important to identify the crisscross relationship of the outflow tracts. If this is not done, it is important to document that the pulmonary artery bifurcates and originates from the right ventricle. Five short axis views of the heart may be helpful to detect conotruncal abnormalities.

Testicular microlithiasis: our experience of 10 years

OBJECTIVE

Testicular microlithiasis (TM) is characterized on sonography by multiple microprecipitates in the testes. The correlation between TM and testicular malignancies is variable. The purpose of this study was to review our 10-year experience regarding the prevalence of TM and its association with testicular malignancies.

METHODS

This was a retrospective study in which 3254 testicular sonographic examinations over a 10-year period identified 137 patients with TM. Testicular microlithiasis was divided into 2 groups: classic TM (CTM; >or= 5 calcifications per image) and limited TM (<5 calcifications/image). A control population without TM was also randomly selected during the same period. Associations with testicular cancers and other findings were then noted and compared between the TM and control groups.

RESULTS

One hundred thirty-seven (4.6%) of the 2957 individual patients with scrotal sonographic examinations had TM; 8 (5.8%) of the 137 patients with TM had testicular cancer, whereas 1 (0.73%) of the 137 patients without TM had primary testicular cancer (P = .04). There were 9 testicular neoplasms in 8 patients, all of whom had CTM. Thirty patients with TM and no malignancy were followed for an average of 19 months (range, 1-90 months; SD, 19.7 months); none had tumor development.

CONCLUSIONS

We found a strong association between TM and testicular malignancy. We think that the most prudent use of resources for early detection of malignancy would be to have all patients with CTM perform testicular self-examinations, and follow-up sonography should be limited to a subgroup of patients with CTM and other associated risk factors.

A phase II trial of image-guided radiofrequency ablation of small invasive breast carcinomas: use of saline-cooled tip electrode

BACKGROUND

Local ablative therapy of breast cancer represents the next frontier in the evolution of minimally-invasive breast conservation therapy. We performed this Phase II trial to determine the efficacy and safety of Radiofrequency (RF) ablation of small invasive breast carcinomas.

METHODS

Seventeen patients with biopsy-proven invasive breast cancer, < or = 1.5 cm in diameter were enrolled in this trial. Under ultrasound guidance, the tumor and a 5 mm margin of surrounding breast tissue were ablated with saline-cooled RF electrode followed by surgical resection. Pathologic and immunohistochemical stains were performed to assess tumor viability. We examined whether loss of ER, PR receptor and pancytokeratin expression following RF ablation would correlate with non-viability.

RESULTS

Fifteen patients completed the treatment. The mean tumor size was 1.28 cm. The mean ablation time was 21 minutes using a mean power of 35.5 watts. During ablation, the tumors became progressively echogenic that corresponded with the region of severe electrocautery injury at pathological examination. Of the 15 treated patients, NADPH viability staining was available for 14 patients and in 13 (92.8%), there was no evidence of viable malignant cells. ER, PR expression and pancytokeratin immunohistochemistry analysis were unreliable surrogates for determining non-viability. Following RF ablation, 2 patients developed skin puckering.

CONCLUSIONS

RF ablation is a promising minimally invasive treatment of small breast carcinomas, as it can achieve effective cell killing with a low complication rate. Further research is necessary to optimize this image-guided technique and evaluate its future role as the sole local therapy.

The Utility of Sonography for the Triage of Blunt Abdominal Trauma Patients to Exploratory Laparotomy

OBJECTIVE

The purpose of this study was to assess the utility of focused abdominal sonography for trauma (FAST) in the triage of hypotensive and normotensive blunt abdominal trauma patients to exploratory laparotomy.

MATERIALS AND METHODS

Data entered in a trauma registry database were retrospectively reviewed and were correlated with medical records, radiology reports, and surgical laparotomy reports. In the setting of blunt abdominal trauma, hypotensive patients were compared with normotensive patients who underwent FAST.

RESULTS

During the 6-year study period, 4,029 patients with blunt abdominal trauma underwent sonography, 122 of whom were hypotensive on arrival and underwent FAST. Of 87 hypotensive patients with positive findings on FAST, 69 (79%) were taken directly to exploratory laparotomy without the need for CT. In predicting the need for therapeutic laparotomy in hypotensive patients, the sensitivity of FAST was 85%, specificity was 60%, and accuracy was 77%. Of the 3,907 normotensive patients, 3,584 had negative FAST findings, whereas 323 had positive FAST findings. In normotensive patients, the sensitivity of FAST was 85%, specificity was 96%, and accuracy was 96%. In the combined patient population (all hypotensive and normotensive patients), 4,029 patients with blunt abdominal trauma underwent sonography: 3,619 had negative and 410 had positive FAST findings. In all patients regardless of blood pressure, the sensitivity of FAST was 85%, specificity was 96%, and accuracy was 95%.

CONCLUSION

Hypotensive patients screened in the emergency department with positive FAST findings may be triaged directly to therapeutic laparotomy, depending on the results of the sonography examination, without the need for CT.

Appearance of Solid Organ Injury with Contrast-Enhanced Sonography in Blunt Abdominal Trauma: Preliminary Experience

OBJECTIVE

The purpose of this study was to compare the detection rate of injury and characterize imaging findings of contrast-enhanced sonography and non-contrast-enhanced sonography in the setting of confirmed solid organ injury.

SUBJECTS AND METHODS

This prospective study involved identifying hepatic, splenic, and renal injuries on contrast-enhanced CT. After injury identification, both non-contrast-enhanced sonography and contrast-enhanced sonography were performed to identify the possible injury and to analyze the appearance of the injury. The sonographic appearance of hepatic, splenic, and renal injuries was then analyzed, and the conspicuity of the injuries was graded on a scale from 0 (nonvisualization) to 3 (high visualization).

RESULTS

Non-contrast-enhanced sonography revealed 11 (50%) of 22 injuries, whereas contrast-enhanced sonography depicted 20 (91%) of 22 injuries. The average grade for conspicuity of injuries was increased from 0.67 to 2.33 for spleen injuries and from 1.0 to 2.2 for liver injuries comparing non-contrast-enhanced with contrast-enhanced sonography, respectively, on a scale from 0, being nonvisualization, to 3, being high visualization. The splenic injuries appeared hypoechoic with occasional areas of normal enhancing splenic tissue within the laceration with contrast-enhanced sonography. Different patterns were observed in liver injuries including a central hypoechoic region. In some liver injuries there was a surrounding hyperechoic region.

CONCLUSION

Contrast-enhanced sonography greatly enhances visualization of liver and spleen injuries compared with non-contrast-enhanced sonography. Solid organ injuries usually appeared hypoechoic on contrast-enhanced sonography, but often a hyperechoic region surrounding the injury also was identified with liver injuries.

Combined head and abdominal computed tomography for blunt trauma: which patients with minor head trauma benefit most?

The widespread availability of computed tomography (CT) in the diagnosis and management of blunt trauma has created the possibility of overuse without clear indications. Some clinicians believe that patients with head injury, intoxication, and/or distracting injury have an unreliable abdominal examination and should undergo combined head and abdomen CT. The objective of this study was to evaluate which patients with minor head trauma benefit most from combined head and abdomen CT. Consecutive blunt trauma patients, with a Glasgow coma scale (GCS) of 14 or 15, who underwent concomitant head and abdomen CT upon admission to a level I trauma center over a 2-year period were retrospectively reviewed. Patient demographics, mechanism of injury, physical exam, hospital course, and radiological and laboratory findings were recorded. Patients were divided into four subgroups based upon the presence or absence of intracranial and/or intraabdominal injury detected by CT. Among the 1,478 blunt head trauma patients, only 18 (1%) patients had both head and abdominal injuries detected by combined CT. One-hundred twelve (8%) patients had only head injuries, and 131 (9%) had only intraabdominal injuries detected. Patients with a GCS of 14 were more likely to have isolated head injury [odds ratio (OR) 3.1, P=0.001], while those with loss of consciousness were more likely to have combined head and intraabdominal injury (OR 6.8, P=0.03) or isolated head injury (OR 1.7, P=0.02). Abdominal tenderness was associated with increased risk of isolated intraabdominal injury (OR 1.8, P=0.0015). Hematuria was associated with increased risk of combined head and intraabdominal injury (OR 8.3, P=0.0004) or isolated intraabdominal injury (OR 7.9, P=0.0001). Patients with loss of consciousness and/or GCS of 14 frequently undergo head CT. The addition of an abdomen CT scan in this patient population should be based on objective clinical criteria such as presence of abdominal tenderness and/or hematuria.

Efficacy of Transhepatic Radiofrequency Ablation of Renal Cell Carcinoma

OBJECTIVE

The purpose of this report is to describe an alternative, using a transhepatic route, to CT guidance of radiofrequency ablation of renal masses.

CONCLUSION

In four supine patients, radiofrequency ablation of a right renal mass was performed under sonographic guidance. The radiofrequency ablation needle was placed transhepatically into the mass. Color sonography was useful in guiding needle placement and avoiding intervening vessels in the liver and kidney. This technique may be used in selected patients as an alternative to CT guidance of radiofrequency ablation.

Pelvic free fluid: clinical importance for reproductive age women with blunt abdominal trauma

OBJECTIVE

To evaluate the importance of isolated pelvic free fluid (FF) detected by ultrasound examination in pregnant patients and in non-pregnant reproductive age women with blunt abdominal trauma (BAT).

METHODS

Reproductive age women aged 10-50 years who presented with BAT and underwent focused abdominal sonography for trauma (FAST) from January 1995 to June 2002 at a Level 1 trauma center were included. Patients were assigned to four groups according to the location of FF detected by ultrasound (Group 1, no FF; Group 2, FF in pelvis; Group 3, FF in abdomen; Group 4, FF in abdomen and pelvis). Ultrasound findings were compared with intra-abdominal and pelvic injuries detected by computed tomography and/or laparotomy. Pair-wise comparison was performed using a Fisher's exact test.

RESULTS

Ultrasound detection of FF in the abdomen alone or FF in the abdomen and pelvis was significantly associated with intra-abdominal injury (IAI) compared to those without FF (P < 0.001) for both pregnant and non-pregnant reproductive age women. FF isolated to the pelvis was also associated with a higher injury rate compared to no FF in pregnant women (30% vs. 3%, P = 0.005) and in non-pregnant reproductive age women (39.5% vs. 3.7%, P < 0.001).

CONCLUSIONS

In reproductive age women with BAT, ultrasound detection of FF in the abdomen alone, in both the abdomen and pelvis, or isolated to the pelvis is associated with a higher IAI rate. Therefore, isolated FF in the pelvis should not necessarily be considered physiological in pregnant and non-pregnant patients with BAT.

Do All Patients With Left Costal Margin Injuries Require Radiographic Evaluation for Intraabdominal Injury?

STUDY OBJECTIVE

We determine whether all patients with pain or tenderness to the left lower ribs after blunt traumatic injury require abdominal computed tomography (CT) scanning for the detection of splenic injury.

METHODS

This was a prospective, observational cohort of all blunt-trauma patients who had pain or tenderness to the left lower ribs and presented to the emergency department (ED) of a Level I trauma center. Patients were enrolled if they had a Glasgow Coma Scale (GCS) score greater than 13 and pain or tenderness to the left lower ribs (ribs 7 to 12). Patients with pain or tenderness to the left lower ribs were considered to have pleuritic pain if the pain increased with inspiration or cough. All hemodynamically stable patients underwent abdominal CT scanning for detection of intraabdominal injuries. Data forms collecting information on the medical history and physical examination of all patients were completed before radiographic imaging. Patients with left lower rib pain or tenderness were considered to have "isolated" left lower rib injury if they were without all of the following: ED or out-of-hospital systolic blood pressure less than 90 mm Hg, abdominal or flank tenderness, pelvic or femur fractures, and gross hematuria.

RESULTS

Eight hundred seventy-five patients had left lower rib pain or tenderness, 63 (7.2%; 95% confidence interval [CI] 5.6% to 9.1%) patients had splenic injuries, and 20 (2.3%; 95% CI 1.4% to 3.5%) patients had left renal injuries. Five hundred seventy-four patients had additional indications for abdominal imaging, leaving 301 patients with "isolated" left lower rib injury. Of the 301 patients, 9 (3.0%; 95% CI 1.4% to 5.6%) had splenic injuries. All 9 patients had a pleuritic component to their rib tenderness, and 3 (33%) patients underwent splenectomy.

CONCLUSION

A small but important percentage of patients with pain or tenderness to the left lower ribs has splenic injuries. All patients with splenic injury had pleuritic pain.

The fast is positive, now what? Derivation of a clinical decision rule to determine the need for therapeutic laparotomy in adults with blunt torso trauma and a positive trauma ultrasound

INTRODUCTION

The object of this study was to derive a clinical decision rule for therapeutic laparotomy among adult blunt trauma patients with a positive abdominal ultrasound for trauma (FAST) examination.

METHODS

We retrospectively reviewed the trauma registry and medical records of all critical trauma patients who underwent a FAST examination in the emergency department (ED) in a university Level I trauma center over a 3-year period. Blunt trauma patients aged >16 years who had a positive FAST examination (defined as the presence of intraperitoneal fluid) were eligible. We selected seven clinical and ultrasound variables available during ED resuscitation for analysis: age, presence of an episode of hypotension (systolic blood pressure <90 torr in the ED), presence of abdominal tenderness, chest injury, pelvic fracture, femur fracture, and FAST fluid location (right upper quadrant [RUQ] only; RUQ plus other location; other location only). The primary outcome variable was whether a laparotomy was performed and whether this laparotomy was needed to provide the definitive surgical intervention ("therapeutic laparotomy"). We analyzed the variables using binary recursive partitioning analysis to create a decision rule.

RESULTS

There were 2336 FAST examinations performed during the study period, resulting in 230 (9.8%) positive examinations in patients meeting inclusion criteria. There were 135 patients who had therapeutic laparotomies and 95 who did not need laparotomy. The groups were similar in baseline characteristics. In the recursive partitioning analysis, the first node in the decision tree was the presence of fluid in the RUQ. Of the 144 patients with RUQ fluid, 105 (73%, 95% confidence interval [CI] 64%-80%) required therapeutic laparotomy. Of the 86 patients without RUQ fluid, 30 (35%, 95% CI 25%-46%) nevertheless required therapeutic laparotomies, and the variables blood pressure, femur fracture, abdominal tenderness, and age further divided these patient into high- and low-risk groups. Of the 12 patients without RUQ fluid who had normal blood pressures, no femur fractures, no abdominal tenderness, and were aged 60 years and younger, none (95% CI 0%-22%) required therapeutic laparotomy. In conclusion, given a positive FAST examination, the presence of fluid in the RUQ is an important predictor of the need for therapeutic laparotomy.

CONCLUSION

In the absence of fluid in the RUQ, there are other clinical variables that may allow for the development of a clinical decision rule regarding the need for therapeutic laparotomy.

Endometrial and endocervical micro echogenic foci: sonographic appearance with clinical and histologic correlation

OBJECTIVE

The purpose of this research was to determine the clinical and histologic importance of small echogenic foci seen in the endometrium/endocervix on pelvic sonography.

METHODS

A retrospective study was performed on 62 women, aged 28 to 81 years, who had echogenic foci of the endometrium and endocervix. Patients' medical records were accessed to review pertinent obstetric and gynecologic information. Additionally, histopathologic slides from patients who underwent diagnostic procedures (endometrial biopsy or dilation and curettage) or hysterectomy were reviewed.

RESULTS

The clinical information for the 62 women included the following: mean age, 49 years; history of exogenous hormonal use, 84%; prior abortion (therapeutic or spontaneous), 57%; prior dilation and curettage, 56%; prior cesarean delivery, 28%; and sexually transmitted disease, 36%. The initial finding of echogenic foci was followed by ultrasound examinations in 18 patients for a mean interval of 16 months. Of the 18 patients, the foci remained unchanged in 13 women and disappeared or became less prominent in the other 5. Histopathologic results were available in 28 women, and microcalcifications were found in 15 of them. The etiology most common was microcalcification but also included crystals, debris from laminaria, and ossified tissues. Clinical follow-up in 62 patients showed that this condition was mostly benign (endometrioid carcinoma developed in 1 patient).

CONCLUSIONS

Histopathologic studies showed microcalcifications, which are the most common cause of echogenic foci. The foci were stable with time and seemed to be an incidental finding associated mostly with benign conditions. The etiologic factors for echogenic foci may be numerous.

Ultrasound probe pressure as a source of error in prostate localization for external beam radiotherapy

PURPOSE

A pelvic phantom was constructed to evaluate the effect of ultrasound probe pressure during performance of bipolar acquisition technique (BAT) for prostate localization for radiotherapy.

METHODS AND MATERIALS

A pelvic phantom of a gelatin mold with a water-filled balloon representing the bladder and rectum and a central encapsulated clay sphere representing the prostate was constructed. This phantom was then scanned using planning computed tomography (CT). The geometric information of the phantom was outlined in two planes. The phantom was then scanned using the BAT system with mild and moderate ultrasound probe pressure. Differences in prostate depth between the CT and BAT systems were displayed.

RESULTS

A difference of 1 cm between the phantom surface and the prostate could be produced with moderate ultrasound probe pressure. The differences were similar between the CT- and BAT-generated contours and were dependent on the ultrasound probe pressure.

CONCLUSION

Care must be taken not to cause any alteration in prostate localization with increasing ultrasound probe pressure when using BAT localization. Increased probe pressure may introduce errors in prostate localization and under dose the target.

Blunt Abdominal Injury in the Pregnant Patient: Detection with US

PURPOSE

To determine the accuracy of ultrasonography (US) for the detection of blunt intraabdominal injury in pregnant patients and to compare differences between pregnant and nonpregnant patients of childbearing age.

MATERIALS AND METHODS

A retrospective review of results of all consecutive emergency blunt trauma US examinations performed at a level I trauma center from January 1995 to June 2002 was conducted. Data on demographics, free fluid location, and patient outcome were collected. Injuries were determined on the basis of results of computed tomography and/or laparotomy. The Student t test was used to detect differences between continuous variables, and chi(2) analysis was used to evaluate differences between proportions.

RESULTS

A total of 2319 US examinations for blunt trauma were performed in girls and women between the ages of 10 and 50 years. There were 328 pregnant patients, 23 of whom had intraabdominal injury. The mean age of the pregnant patients was 24.7 years +/- 6.1 (standard deviation) (age range, 14-42 years). In pregnant patients, the sensitivity of US was 61% (14 of 23 patients), the specificity was 94.4% (288 of 305 patients), and the accuracy was 92.1% (302 of 328 patients). Pregnant patients were significantly more likely to have sustained injuries from assault (odds ratio: 2.6, P < .001). The most common pattern of free fluid accumulation detected at US in pregnant patients was that of fluid in the left and right upper quadrants and pelvis (n = 4, 29%); the second most common pattern was one of isolated pelvic fluid (n = 3, 21%).

CONCLUSION

For detection of intraabdominal injury, US was less sensitive in pregnant patients than in nonpregnant patients but was highly specific in both subgroups. The sensitivity of US was highest in pregnant patients during the first trimester.

The history of interventional ultrasound

Ultrasound has been used to guide interventional procedures for more than 30 years. Initial applications included biopsy techniques and simple aspiration of fluid collections. However, with improved sonographic imaging and the use of different ultrasonic probes as well as development of less invasive therapies, there has been an increase in the use of ultrasound to guide interventional procedures. Interventional ultrasound has become routine in most medical specialties. Because of the remarkable success of interventional procedures guided by sonography, combined with an outstanding safety record, there is no doubt that there will be a future increase in the number and types of interventional procedures performed under sonographic guidance.

Normal organ volume assessment from abdominal CT

We determined the normal distribution of abdominal organ volumes measured from abdominal computed tomographic (CT) images. A total of 149 adult abdominal CT studies were selected, and 711 organs (388 from males, 323 from females) were outlined by hand on each CT image by using a computer. More than 18000 organ outlines were traced. The organs studied included left and right kidneys, left and right adrenals, spleen, pancreas, and liver, and the first lumbar vertebrae was also evaluated. Using the known pixel size and section thickness, organ volumes were computed. Organ volumes were corrected for height and weight for each sex. The normal and cumulative normal distributions for each organ studied were computed, demonstrating the range of organ volumes for each sex that exist in the normal adult population. Organ volumes ranged from a mean of 4.4 mL (female left adrenal) to 1710 mL (male liver). Mean organ volumes were 64.4, 156.5, 179.8, and 1411 mL for the female pancreas, kidneys, spleen, and liver, respectively. Corresponding male volumes were 87.4, 193.1, 238.4, and 1710 mL, respectively. Tabular data are provided that indicate the relative size for each organ volume in terms of the cumulative probability distribution. Normative data are provided to allow physicians to estimate where in the normal range a particular organ volume lays. Organ volumes may be useful as quantitative indices of pathologic conditions.

Emergency ultrasound in trauma patients

US will be used more frequently in the future for the evaluation of traumatized patients. Previously,the main focus of the sonographic examination was for the detection of free fluid. Unstable patients with free fluid often can be triaged to the operation room without further imaging tests. In patients who are more stable or in whom US results are negative, CT is required. Based on recent studies, sonography has a sensitivity rate of approximately 40% in direct detection of solid organ injuries. In the future, however, with the use of contrast-enhanced agents, sonography may more reliably detect solid organ injuries. Within the chest, US has been shown to be helpful in detecting pleural effusions and may be useful in detecting pericardial effusions. US has been shown to be sensitive in detecting pneumothoraces in traumatized patients.

Sonographic patterns of intraperitoneal hemorrhage associated with blunt splenic injury

OBJECTIVE

To determine the correlation between sonographic detection of free fluid in the left upper quadrant and blunt splenic injury.

METHODS

A retrospective review was conducted of all consecutive emergency blunt trauma sonograms obtained at a level I trauma center from January 1995 to January 2001. Data were collected on demographics, free fluid location, and patient outcome. Injuries were determined from computed tomography, diagnostic peritoneal lavage, laparotomy, or a combination thereof.

RESULTS

A total of 4320 blunt trauma sonograms were obtained, and 596 patients (14%) had intra-abdominal injuries. The mean age was 33.7 +/- 19.1 years (range, 1-95 years), with 294 (49%) male and 302 (51%) female. There was no statistical difference between age, sex, or mechanism for all subgroups. There were 409 true-positive, 187 false-negative, 88 false-positive, and 3636 true-negative findings. Sensitivity of sonography for detecting all intra-abdominal injuries was 68%, and specificity was 97.6%; sensitivity for detecting isolated splenic injuries was 73.8%. Locations of free fluid in patients with nonsplenic injuries were compared with those in patients with splenic injuries. Isolated left upper quadrant free fluid was significantly associated with splenic injury (odds ratio = 3.0; P = .002), followed by diffuse free fluid (odds ratio = 2.1; P = .005). A subanalysis of isolated splenic injuries also revealed a significant association with left upper quadrant free fluid (odds ratio = 3.1; P = .007) and diffuse free fluid (odds ratio = 2.7; P = .0007).

CONCLUSIONS

Free fluid in the left upper quadrant is significantly associated with splenic injury. This finding should triage patients more rapidly to computed tomography, angiography, embolization, and laparotomy.

Correlation of Ureteral Stone Measurements by CT and Plain Film Radiography: Utility of the KUB

BACKGROUND AND PURPOSE

The practice of utilizing helical CT to evaluate patients suspected of renal colic is increasing. Little is known about the accuracy of CT in estimating stone size or the utility of an accompanying plain abdominal radiograph (KUB film). The purpose of our study was to compare ureteral stone size estimation by helical CT and plain film and determine whether a KUB film provides additional information useful in patient management.

PATIENTS AND METHODS

Thirty consecutive patients (17 male, 13 female) having both a helical CT and a KUB study for evaluation of renal colic secondary to ureteral calculi comprised the study population. Calculus number, location, and dimensions were determined from these images. Stone dimensions were measured using electronic calipers on a picture archiving and communications system. Information found by KUB and CT was compared, and both sets of stone measurements were correlated with patient outcome.

RESULTS

The mean maximal stone transverse diameter and length were similar on CT and plain film: 5.8 mm v 5.8 mm and 9.5 mm v 8.9 mm, respectively (P = 0.57 and 0.29, respectively). The mean anteroposterior stone diameter on CT of 6.8 mm was statistically greater than the transverse diameter as measured by both CT and KUB, which were 5.8 mm and 5.8 mm (P = 0.0002 and 0.0007, respectively). Eleven patients spontaneously passed their stones, while 19 patients required intervention. Patient outcome, as predicted by transverse stone width, was similar for CT and KUB data.

CONCLUSIONS

The management of patients with ureteral calculi relies on estimated stone size and the stone's potential for spontaneous passage. Stone dimensions estimated by CT are similar to the size determined by plain film radiography. Although plain film radiography does not provide information on stone dimensions beyond that obtained with CT, it does reveal precise stone location and radiolucency, data helpful in following and treating patients.