Diagnosing appendicitis with CT and ultrasound using prospective patient stratification by body mass index

Purpose: To determine the accuracy of CT and ultrasonography (US) in diagnosing appendicitis in adults stratified to either modality on the basis of body mass index (BMI), a measure of body habitus. Methods: Seventy-two adults with suspected appendicitis and demonstrating atypical clinical features were prospectively stratified to either appendiceal CT or US based on BMI. Patients with BMI < 30 underwent US and with BMI ≥ 30 underwent CT. Outcomes were determined by surgery, the medical record, and clinical follow-up after 3 months. Results: Of the 72 patients enrolled, 30 (24 women and 6 men) underwent CT and 42 (35 women and 7 men) underwent US. The average BMI was 34 ± 4 among patients who had CT and 24 ± 3 among patients who had US. Of the patients who had CT scans, 4 had positive scans for appendicitis and all of these were proven at surgery to have appendicitis. The remaining 26 patients had negative CT scans for appendicitis. Twenty-two of these were subsequently proven either by surgery or clinical follow-up not to have appendicitis, while 4 were lost to follow-up. This corresponds to a sensitivity, specificity, positive predictive value, and negative predictive value of 100 %. Twelve ultrasound examinations were positive for appendicitis. Nine of these patients had appendicitis proven at surgery, 1 had a perforated Meckel's diverticulum, and 2 did not have appendicitis after clinical follow-up. Twenty-seven patients had negative ultrasound exams for appendicitis. However, 6 of these had appendicitis proven at surgery, 17 did not have appendicitis, and 4 were lost to follow-up. Three patients had ultrasound exams that were equivocal for appendicitis; of these, 1 had appendicitis and 2 did not. For US, this corresponds to a sensitivity of 60 %, specificity of 85 %, PPV of 75 %, and NPV of 74 %. Conclusion: This study suggests that CT is an accurate method of evaluating adults with suspected appendicitis who have BMI ≥ 30. Stratifying patients with BMI < 30 to US did not reproduce the results already reported in the literature.     

MRI vs. ultrasound for suspected appendicitis during pregnancy

PURPOSE: To compare the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ultrasound (US) and MRI in evaluation of pregnant patients with a clinical suspicion of appendicitis. MATERIALS AND METHODS: A total of 33 pregnant patients with suspected appendicitis underwent US and MRI. The original imaging reports generated at the time of presentation were used for data analysis. Pathology reports were used for disease confirmation in patients who underwent appendectomy. When surgery was not performed, a medical record review was performed. The sensitivity, specificity, PPV, and NPV were calculated for US and MRI in the diagnosis of appendicitis. RESULTS: Five of the 33 patients had pathologically-proven appendicitis. Four of the five patients with appendicitis were correctly diagnosed at MRI while one was interpreted as indeterminate (appendix not seen). At US, one was correctly diagnosed, one was incorrectly diagnosed as normal, and three were interpreted as indeterminate (appendix not seen). In 13 patients, a normal appendix was diagnosed at MRI, none of whom had appendicitis. In three patients, a normal appendix was diagnosed at US, one of whom had appendicitis. When the appendix was visualized at MRI, the sensitivity, specificity, PPV, and NPV for the diagnosis of appendicitis was 100% for all parameters. When the appendix was visualized at US, the sensitivity, specificity, PPV, and NPV for the diagnosis of appendicitis was 50%, 100%, 100%, and 66%, respectively. CONCLUSION: Based on a relatively small number of true-positives, our data suggests that MRI is very useful for the diagnosis and exclusion of appendicitis in pregnant women.     

Radiologic evaluation of acute appendicitis in the busy community hospital

Purpose: To evaluate the accuracy of limited computed tomography (CT) in the hands of the average radiologist in a busy community hospital assessing a patient for acute appendicitis. Materials and methods: Ninety-six consecutive patients were examined with CT and the results, independently reported, were correlated with histopathologic findings and clinical follow-up. Results: Forty-three patients had acute appendicitis, 53 patients did not; sensitivity was 89 %, specificity 91 %, accuracy 90 %, positive predictive value 91 %, and negative predictive value 90 %. Nonvisualization of the appendix did not necessarily preclude an accurate assessment for acute appendicitis. Conclusion: Limited CT of the pelvis using rectal contrast only is a useful radiographic test for evaluating acute appendicitis, with practical application for the average radiologist in a busy community hospital.     

CT evaluation of appendicitis and diverticulitis. Part I: Appendicitis

CT has become the primary imaging modality for evaluation of possible appendicitis. About 20 % of patients taken to surgery for appendicitis without CT have had a normal appendix removed. CT has demonstrated overall accuracy of between 93 % and 98 %. Alternative diagnoses are seen in 34–80 % of patients without appendicitis but who were suspected of having appendicitis. For evaluation of appendicitis different techniques have been successful, including the use of no contrast, use of oral and intravenous contrast, and use of rectally administered contrast. Scanning of the entire abdomen and pelvis and scanning of an area limited to the right lower quadrant are also options. Ultrasonography has been shown to have a role in pediatric patients. If ultrasonography is positive, CT is not necessary. If ultrasonography is negative, CT should follow.     

Helical computed tomography diagnosis of gastrointestinal perforation in the elderly patient

Purpose: To determine the value of helical CT in a consecutive series of elderly patients referred with clinically suspected gastrointestinal perforation. Methods: Our series comprised 34 consecutive elderly patients (mean age: 68 years) presenting with acute abdominal symptoms potentially suggestive of gastrointestinal perforation. All the patients were prospectively subjected to abdominal computed tomography (CT). On helical CT, the presence of free air was considered diagnostic of gastrointestinal perforation. Other findings such as intraperitoneal free fluid, thickening of bowel wall, streaky density within the mesentery, “dirty fat” sign, and focal collection of extraluminal fecal matter (“dirty mass”) were considered indirect findings of perforation. Results: At surgery, the following sites of perforation were found: duodenum (38.2 %), stomach (29.4 %), ileum (8.8 %), sigmoid colon (8.8 %), rectum (5.8 %), and jejunum, appendix, and transverse colon (2.9 % of cases each). CT demonstrated the presence of free air in 94.1 % of cases; intraperitoneal free fluid was present in 76.4 % of patients and thickening of bowel wall in 50 %. Streaky density within the mesentery was found in one patient. Conclusion: CT is a reliable diagnostic method by which to assess gastrointestinal perforation, because it provides excellent contrast resolution to depict the presence of even small amounts of free air in the abdomen. This is particularly helpful where elderly patients are concerned.     

MR imaging evaluation of acute appendicitis in pregnancy

PURPOSE: To retrospectively assess the diagnostic performance of magnetic resonance (MR) imaging in pregnant patients suspected of having acute appendicitis. MATERIALS AND METHODS: The study was approved by the committee on clinical investigations and was HIPAA compliant. The informed consent requirement was waived. MR images were obtained in 51 consecutive pregnant patients (mean age, 28.3 years) who were clinically suspected of having acute appendicitis. In this protocol for pregnant patients, MR imaging is performed when findings at ultrasonography (US) are inconclusive or additional information is needed. Four patients had appendicitis, which was confirmed at surgery in three patients and at follow-up computed tomography in one patient. Initial interpretations were used for patient care and to calculate diagnostic accuracy. The appendix was considered normal at MR imaging if its diameter was less than or equal to 6 mm or if it was filled with air, oral contrast material, or both. An enlarged fluid-filled appendix (>7 mm in diameter) was considered an abnormal finding. An appendix with a diameter of 6-7 mm was considered an inconclusive finding; in those cases, the presence of periappendiceal inflammation was used for the final diagnosis. Three radiologists retrospectively assessed the visualization of the appendix by using a 5-point scale. Statistical analysis was performed by using the median and Fisher exact tests and the Spearman correlation coefficient. RESULTS: MR images were positive for appendicitis in four patients and inconclusive in three. In the three patients with inconclusive results, the appendix was not seen in two patients and was borderline enlarged (7 mm in diameter) in the third. The overall sensitivity, specificity, prevalence-adjusted positive and negative predictive values, and accuracy for MR imaging was 100%, 93.6%, 1.4%, 100%, and 94.0%, respectively. CONCLUSION: MR imaging is an excellent modality for use in excluding acute appendicitis in pregnant women who present with acute abdominal pain and in whom a normal appendix is not visualized at US.     

Safety of colon contrast material in (helical) CT examination of patients with suspected diverticulitis

Purpose: Today patients with suspected diverticulitis are commonly imaged with a CT scan utilizing a variety of methods of contrast medium administration. Although CT with rectally administered colon contrast has demonstrated a high diagnostic accuracy, concerns have been raised over its safety in patients with diverticulitis. The following retrospective investigation was undertaken to answer this concern. Materials and methods: Between January, 1997, and July, 1999, 308 patients with suspected diverticulitis were examined in the Emergency Radiology Division of the Massachusetts General Hospital by means of a helical CT scan performed with rectally administered colon contrast material. The patients' CT findings were correlated with their clinical courses and/or surgical findings. Results: Of the 308 CT scans, 115 (37.3 %) were positive for diverticulitis. Of 193 patients without diverticulitis, 91 (47.1 % of patients without diverticulitis) had alternative diagnoses made by CT, such as small bowel obstruction, epiploic appendagitis, and urinary tract calculi. No complications due to colon contrast material were noted. Even in cases where there was free extraluminal air, no extravasated contrast material was seen. Rectally administered colon contrast was well tolerated by patients and provided excellent large bowel opacification. This method saved imaging time in an emergency setting, as there was no need to wait for oral contrast to reach the colon. Conclusion: Out of 308 CT scans, there were no complications from the use of rectally administered colon contrast material. No case of traumatic bowel perforation secondary to colon contrast material was observed. Rectally administered colon contrast material is safe in the CT examination of patients with suspected diverticulitis.     

A prospective comparative study of non-contrast helical computed tomography and intravenous urogram for the assessment of renal colic

Objective: To compare noncontrast helical computed tomography (NCHCT) and intravenous urography (IVU) for diagnosis of urinary calculi in evaluation of renal colic. Materials and methods: A 4-month prospective paired study compared NCHCT and IVU in patients being evaluated for renal colic. Each patient was studied with NCHCT followed by an IVU. An IVU was regarded as positive if any of the following were identified: delayed filling, hydronephrosis, hydroureter, ureteral calculus, or extravasation of contrast. A NCHCT was regarded as positive if any of the following were identified: hydronephrosis, hydroureter, ureteral calculus, or perinephric or ureteral inflammatory change. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) were reported using the clinical outcome as the gold standard, by either observation of passage or retrieval of calculus. Bladder distention was noted on NCHCT relative to the level of the acetabulum. The charts were also reviewed retrospectively for the results of urinalysis. Results: One hundred sixty-eight patients had both examinations interpreted. Nineteen positive NCHCT and IVU studies were eliminated due to lack of observation or retrieval of calculus, leaving 149 studies for interpretation. NCHCT had Se 0.98, Sp 0.95, PPV 0.98, and NPV 0.95. IVU had Se 0.83, Sp 0.95, PPV 0.97, and NPV 0.67. In 13/168 (8 %) cases, and in 9/37 (24 %) negative cases, NCHCT offered an alternative diagnosis. Ureterovesical junction (UVJ) calculus was identified on 84 NCHCT scans, with near-even distribution between well, partially, and poorly distended bladder. No UVJ calculus was identified on IVU that was not present on NCHCT. Absence of hematuria was found in 26 % of patients with proven urolithiasis. Conclusion: NCHCT is superior to IVU for the evaluation of renal colic. NCHCT identifies significant pathology in 24 % of cases negative for ureteral obstruction/calculus. Bladder distention does not play an important role in detection of UVJ calculus. Hematuria is not universally present in patients with painful urolithiasis.     

Sonography in acute appendicitis: diagnostic utility and influence upon management and outcome

A study is made of the diagnostic utility of echography in clinically suspected appendicitis, and its influence upon patient management and outcome. A total of 374 consecutive patients with possible appendicitis were prospectively evaluated by ultrasound. Two groups were established: group A (high clinical probability, ≥ 0.70) and group B (moderate clinical probability, 0.20–0.60). In group-A patients (n = 105, 28 %), prevalence of appendicitis = 0.90) underwent surgery regardless of the echographic findings. In group B (n = 269, 72 %), prevalence of appendicitis = 0.28) surgery was performed in the event of positive echography, whereas negative echographic findings did not definitively discard appendicitis. The diagnostic utility of echography was evaluated by applying the Pauker-Kasirer threshold approach to clinical decision making. The influence of ultrasound upon outcome was in turn evaluated by contrasting the total appendectomized patients (190 of 374) with a series of 181 individuals subjected to appendectomy prior to the introduction of echography. The probability of appendicitis in the presence of positive echography was 0.95 in group A (sensitivity = 0.92) and 0.89 in group B (sensitivity = 0.91). The probability of appendicitis in the event of negative ultrasound was 0.58 in group A (specificity = 0.55) and 0.03 in group B (specificity = 0.95) . In 46 % of cases the echographic findings led to a change in therapeutic regimen. In addition, the incidence of negative appendectomies was significantly reduced (19.3 vs 11.6 % with echography; p = 0.03), as was the delay in establishing a diagnosis (under 6 h in 68.5 vs 84.2 % with echography; p = 0.002) and the number of medical acts required (three in 71.3 vs 84.1 % with echography; p = 0.001). There was no significant reduction in the incidence of perforated appendicitis (17.1 vs 17.9 % with echography), in the number of postoperative complications (13.8 vs 7.6 % with echography), or in the days of hospital stay (4.44 vs 4.80 with echography). Echography proved useful in group B, and was generally of little utility in group A. The technique had a positive influence on treatment, with management reorientation in a considerable number of patients, and on outcome, since ultrasound contributed to establishing an earlier diagnosis, with a reduction of unnecessary appendectomies. Received: 4 October 1999, Revised: 11 February 2000, Accepted: 17 May 2000     

Optimisation of the MR protocol in pregnant women with suspected acute appendicitis

Purpose

To investigate the optimal magnetic resonance (MR) imaging protocol in pregnant women suspected of having acute appendicitis.

Materials and methods

One hundred and forty-six pregnant women with suspected appendicitis were included. MR images were reviewed by two radiologists in three separate sessions. In session 1, only axial single-shot turbo spin echo (SSH-TSE) T2-weighted images (WI) were included with other routine sequences. In sessions 2 and 3, coronal and sagittal T2WI were sequentially added. The visibility of the appendix and diagnostic confidence of appendicitis were evaluated in each session using a 5-point grading scale. If diseases other than appendicitis were suspected, specific diagnosis with a 5-point confidence scale was recorded. Diagnostic performance for appendicitis and other diseases were evaluated.

Results

Twenty-five patients (17.1%) were diagnosed with appendicitis. Among the patients with normal appendix, 28 were diagnosed with other disease. Diagnostic performance including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve values for diagnosing appendicitis and other diseases showed no significant difference among sets for both reviewers (p>0.05).

Conclusion

Diagnostic performance of MR in pregnant patients with suspected appendicitis can be preserved with omission of sagittal or both coronal and sagittal SSH-T2WI.

Key points

? Diagnostic performance of appendicitis is preserved with omission of sagittal/coronal T2WIs.? Diagnosis of other disease may be sufficient with axial T2WIs only.? Careful serial omission of sagittal and coronal T2WIs can be considered.

     

Comparison of ultrasonography with computed tomography in the diagnosis of nasal bone fractures

Objectives

The aim of this study is to compare ultrasonography with CT in the diagnosis of nasal bone fractures.

Methods

40 patients (9 female and 31 male) with mid-facial fractures, which were suspected nasal bone fractures, were included. All of the patients had mid-facial CT images. Ultrasonography with a 7.5 MHz transducer (Aloka 3500, Tokyo, Japan) was used to evaluate the nasal bone fractures. All of the sonograms were compared with CT findings for sensitivity, specificity and predictive values. A χ² test was applied to the data to assess statistical significance.

Results

CT diagnosed nasal bone fractures in 24 of the 40 patients (9 unilateral fractures and 15 bilateral fractures) while ultrasonography diagnosed the fractured bones in 23 patients (9 unilateral fractures and 14 bilateral fractures). Ultrasonography missed one fractured bone in a bilateral fractured case and a unilateral fracture was also missed (two false-negative results). The sensitivity and specificity of ultrasonography in assessing nasal bone fracture in comparison with CT were 94.9% and 100%, respectively. The positive predictive value (PPV) and the negative predictive value (NPV) of ultrasonographic evaluation of the nasal bone fractures were 100% and 95.3%, respectively. The χ² test did not show any significant difference between CT and ultrasonography in diagnosis of nasal bone fractures (P = 0.819).

Conclusion

Ultrasonography can be used as a first line of diagnostic imaging for evaluating nasal bone fractures, especially in children and pregnant women.     

The value of contrast-enhanced helical CT scan with rectal contrast enema in the diagnosis of acute appendicitis

BACKGROUND: The aim of this retrospective study is to assess the accuracy of single slice helical CT scan with intravenous, and rectal contrast (CTRC) in the diagnosis of acute appendicitis (AA) in patients with suspected AA, with particular analysis of the diagnostic signs. PARTICIPANTS AND METHODS: Abdomino-pelvic helical CTRC was performed on 75 consecutive patients with suspicion of AA. Radiologic diagnosis was compared with surgical/pathologic results and clinical follow-up. In addition, the CTRC examinations were retrospectively reviewed independently by two experienced radiologists using predefined diagnostic criteria. The sensitivity, specificity, and frequency of each diagnostic sign were calculated. The interobserver agreement and the statistical significance of the frequency for each diagnostic criterion were assessed using the Kappa and Fisher tests, respectively. RESULTS: The accuracy of helical CTRC in the diagnosis of AA was 94.7%, sensitivity 100%, specificity 90%, PPV 89.7%, and the NPV 100%. Wall enhancement and nonopacification of the appendix recorded the highest sensitivity and specificity (97% and 100%, 94% and 95%, respectively). Appendiceal thickness greater than 6 mm was present in 100% of true-positive cases. However, 26.5% of true-negative cases had also an appendiceal diameter exceeding 6 mm, a value used as a cut-off for normal appendiceal diameter. The highest interobserver agreement was recorded for appendiceal wall enhancement and for nonopacification of the appendix (K=0.97 and 0.88, respectively). CONCLUSIONS: CTRC is an accurate and relatively fast technique for investigation of patients with suspected AA. A negative CTRC can exclude completely the diagnosis of AA. Nonopacification of the appendix and appendiceal wall enhancement are highly sensitive, specific, and reproducible, signs representing major criteria for the diagnosis of AA.     

MDCT for suspected appendicitis in the elderly: diagnostic performance and patient outcome

Elderly adults are at increased risk for complications related to both delayed diagnosis of appendicitis and to unnecessary appendectomy. We assessed the diagnostic performance of computed tomography (CT) in a consecutive elderly cohort with clinically suspected appendicitis. CT findings and clinical outcomes were analyzed for 262 consecutive adult patients age 65 and older (mean 75.6 ± 7.5 years; range 65–94; M/F 111:151) referred for clinically suspected appendicitis at a single medical center between January 2000 and December 2009. The overall prevalence of proven acute appendicitis in this elderly cohort with clinically suspected appendicitis was 16.8% (44/262). CT sensitivity, specificity, PPV, and NPV for acute appendicitis were 100% (44/44), 99.1% (216/218), 95.7% (44/46), and 100.0% (216/216), respectively. The negative appendectomy rate was 2.3% (1/43). The perforation rate was 40.9% (18/44). There were no false-negative and two false-positive CT interpretations. All patients with appendicitis suspected on CT were hospitalized (44/44), with an average stay of 5.7 ± 3.2 days, and 93.5% (43/46) underwent appendectomy. Overall surgical complication rate was 34.9% (15/43). Compared with younger adults over the same period, elderly patients had higher rates of perforation and surgical complications, and longer hospital stays (p < 0.003). CT is highly accurate for the evaluation of clinically suspected appendicitis in elderly patients. Prompt diagnosis is important given the higher rates perforation and surgical complications relative to younger adults.     

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. Received: 14 July 1999; Revised: 12 October 1999; Accepted: 4 November 1999     

The role of 256-slice CT in differentiation between non-perforated and perforated appendicitis

Objective

The objective of the present study was to analyze the efficacy of 256-slice CT in differentiation between the perforated and non-perforated appendicitis.

Can MR Measurement of Renal Artery Flow and Renal Volume Predict the Outcome of Percutaneous Transluminal Renal Angioplasty?

Purpose: Predicting therapeutic benefit from percutaneous transluminal renal angioplasty (PTRA) in patients with renal artery stenosis (RAS) remains difficult. This study investigates whether magnetic resonance (MR)-based renal artery flow measurements relative to renal parenchymal volume can predict clinical outcome following PTRA. Methods: The data on 23 patients (13 men, 10 women; age range 47–82 years, mean age 64 years) were analyzed. The indication for treatment was hypertension (n = 18) or renal insufficiency (n = 5). Thirty-four cases of RAS were identified: bilateral disease was manifest in 11 and unilateral disease in 12 patients. The MR imaging protocol included a breath-hold, cardiac-gated cine phase-contrast sequence for renal flow measurement and a fast multiplanar spoiled gradient-echo sequence for renal volume measurement. MR measurements were performed on the day prior to and the day following PTRA. Clinical success was defined as (a) a reduction in diastolic blood pressure > 15% or (b) a reduction in serum creatinine > 20%. Kidneys were categorized as normal volume or low volume. A renal flow index (RFI) was calculated by dividing the renal flow (ml/min) by the renal volume (cm³). Results: Clinical success was observed in 11 patients. Twelve patients did not benefit from angioplasty. Normal kidney volume was seen in 10 of 11 responders and in 8 of 12 nonresponders, resulting in a sensitivity of 91%, specificity of 33%, a positive predictive value (PPV) of 56% and a negative predictive value (NPV) of 80%. A RFI below a threshold of 1.5 ml/min/cm³ predicted successful outcome with 100% sensitivity, 33% specificity, 58% PPV, and 100% NPV. The combination of normal renal volume and a RFI below 1.5 ml/min/cm³ identified PTRA responders with a sensitivity of 91%, a specificity of 67%, a PPV of 71%, and a NPV of 89%. PTRA resulted in a greater increase in renal flow in responders compared with nonresponders (p < 0.001). Conclusion: A combination of cine phase-contrast MR renal flow and parenchymal volume measurements enables identification of patients benefiting from PTRA with a high sensitivity and NPV, but only moderate specificity and PPV.     

Routine abdominal ultrasonography and computed tomography in multiple trauma patients: relevance to therapy in 105 patients

Purpose: To examine treatment decisions in multiple trauma patients and determine how often these decisions are based on abdominal ultrasonography (US) findings, and how frequently these decisions are altered by subsequent computed tomographic (CT) imaging. Methods: From August 1996 to July 1997 we prospectively performed abdominal US followed by abdominal CT in all hemodynamically stable multiple trauma victims who did not need immediate surgery. We recorded the results from both modalities, as well as the treatment decisions based on these results. We also noted how frequently therapy based on US results was altered by the subsequent CT findings. Results: Treatment decisions were influenced by either US or CT in 27 of 105 patients (25.7 %). US was interpreted as normal in 76 patients (72.4 %), including 5 (6.6 %) who were subsequently found to have therapeutically significant findings on CT. US was interpreted as abnormal in 29 (27.6 %) patients, 12 of whom (41.4 %) had their management altered by subsequent CT results. Conclusions: Abdominal CT findings prompt changes in therapy in only a small number of stable multiple trauma patients who exhibit normal abdominal US. On the other hand, CT may have an impact on acute therapy in a large number of patients who exhibit abnormal US. Our results demonstrate that a diagnostic approach in hemodynamically stable patients is possible with US serving as a decision maker to determine whether further CT imaging is needed.     

Overview of emergency radiological management of the pregnant patient, especially the traumatized pregnant patient

Both traumatic and nontraumatic acute emergencies are seen in hospitals in women of childbearing age. The effects of radiation are theoretically most deleterious from 10 days after conception until roughly the end of the first trimester. However, there should be no hesitation about performing appropriate emergency imaging studies at any time during pregnancy. If time permits, the presence and age of the fetus should be determined through physical examination, appropriate laboratory studies, and the obtaining of adequate medical historical information. Imaging studies can be roughly classified into two main categories, those with minimal radiation effect and those that may expose the fetus to significant potential ionizing energy. The radiologist must be responsible for the determination of the most appropriate studies needed and in what sequence. Traumatized pregnant patients especially require maternal and fetal monitoring prior to arrival at the hospital and throughout the hospital stay. Fetal demise is a significant risk in case of both minor and major trauma. Maternal survival is the most significant factor in fetal well-being, with a fetal death approaching 80 % in cases of maternal shock and almost 100 % where there is partial or complete abruptio placentae. Properly performed imaging of the pregnant female, where the uterus is not likely to be exposed to ionizing radiation, should be cause little concern. Depending on the clinical presentation, appropriate first images might include a cervical spine, a portable chest film, an abdominal film, and a lateral decubitus view to check for suspected bowel perforation. This should be rapidly followed by fetal and then maternal ultrasonography. Overall, CT may be the best single abdominal study for severe abdominal problems where multiple organ damage is suspected. MRI for neurological disease and carefully monitored of selective vascular embolization for life-threatening abdominal bleeding are other important legitimate imaging studies.     

Cervical spine injury: accuracy of helical CT used as a screening technique

Objective: The study objective was to determine the sensitivity and specificity of a helical CT technique to screen for cervical spine injury in a high-risk trauma population. Materials and methods: The helical CT reports for a consecutive series of 601 high-risk adult blunt trauma victims were reviewed. Findings were confirmed using an independent reference standard, which consisted of additional cervical spine imaging (CT, MRI, or radiography), operative findings, autopsy results or clinical outcome. Results: Sensitivity and specificity of helical CT for injury were 77/81 (95 %; 95 % confidence limits: 90–100 %) and 484/520 (93 %; 95 % confidence limits 91–95 %) respectively. Four false negative cases were comprised of three missed ligamentous injuries and one missed fracture. False positive cases (n = 36) were mostly attributed to possible facet fracture (n = 6), possible ligamentous injury (n = 8) or technically inadequate scan (n = 6).The overall accuracy of the helical CT protocol for cervical spine injury in this population was 561/601 (93 %; 95 % confidence limits 91–95 %). Conclusion: Helical CT has high accuracy for cervical spine injury. We believe that helical CT should be the preferred imaging strategy in high-risk blunt trauma patients.     

Conventional and hydrocolonic US of the appendix with CT correlation performed by on-call radiology residents

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the feasibility and accuracy of emergent hydrocolonic ultrasonography (US) performed by on-call residents in patients suspected of having appendicitis. MATERIALS AND METHODS: Thirty-one patients with a clinically equivocal diagnosis of appendicitis were prospectively evaluated with conventional US, hydrocolonic US, and appendiceal computed tomography (CT). Midlevel radiology residents performed the US examinations while they were on call. Sensitivity, specificity, and accuracy for diagnosing appendicitis were calculated for conventional and hydrocolonic US by using clinical outcome as the standard. Results of US and CT of the appendix were also correlated. Residents recorded their diagnostic confidence for conventional and hydrocolonic US. All patients were able to hold the rectally administered contrast material until completion of both hydrocolonic US and appendiceal CT. RESULTS: The sensitivity for detecting appendicitis with conventional US, hydrocolonic US, and appendiceal CT was 50%, 75%, and 100%, respectively. Specificity was 96%, 93%, and 93%, respectively. Identification of the normal and abnormal appendix improved from 13% (four of 31 patients) with conventional US to 35% (11 of 31 patients) with hydrocolonic US. The radiology residents' diagnostic confidence increased from 0.74 with conventional US to 0.83 with hydrocolonic US. CONCLUSION: Hydrocolonic US is a feasible addition to conventional US examination for patients suspected of having appendicitis. It improves sensitivity, increases radiology residents' confidence, and is well tolerated by patients.