Robert A. Novelline

Introduction of appendiceal CT: impact on negative appendectomy and appendiceal perforation rates.

UNLABELLED OBJECTIVE To evaluate the impact of appendiceal computed tomography (CT) availability on negative appendectomy and appendiceal perforation rates. SUMMARY BACKGROUND DATA Appendiceal CT is 98% accurate. However, its impact on negative appendectomy and appendiceal perforation rates has not been reported. METHODS The authors reviewed the medical records of 493 consecutive patients who underwent appendectomy between 1992 and 1995, 209 consecutive patients who underwent appendectomy in 1997 (59% of whom had appendiceal CT), and 206 patients who underwent appendiceal CT in 1997 without subsequent appendectomy. RESULTS Before appendiceal CT, 98/493 patients (20%) taken to surgery had a normal appendix. After CT availability, 15/209 patients (7%) taken to surgery had a normal appendix; 7 patients did not have CT, 5 patients had surgery despite a negative CT, and 3 patients had a false-positive CT. Negative appendectomy rates were lowered overall (20% to 7%), in men (11% to 5%), in women (35% to 11%), in boys (10% to 5%), and in girls (18% to 12%). Appendiceal perforation rates dropped from 22% to 14% after CT availability. CT excluded appendicitis in 206 patients in 1997 who avoided appendectomy and identified alternative diagnoses in 105 of these patients (51%). CONCLUSION The availability of appendiceal CT coincided with a drop in the negative appendectomy rate from 20% to 7% in all patients, and to only 3% in patients with a positive CT. Perforation rates decreased from 22% to 14%. Appendiceal CT can be advocated in nearly all female and many male patients.

Sensitivity and specificity of the individual CT signs of appendicitis : Experience with 200 helical appendiceal CT examinations

PURPOSE Our goal was to determine the sensitivity, specificity, and diagnostic value of individual signs at helical appendiceal CT. METHOD Two hundred helical appendiceal CT scans (100 appendicitis and 100 normal appendix cases) were interpreted for individual signs of appendicitis. Scan findings were correlated with appendectomy or clinical follow-up results. RESULTS Individual CT signs identified and their sensitivity and specificity, respectively, included fat stranding (100%, 80%), enlarged (> 6 mm) unopacified appendix (93%, 100%), focal cecal apical thickening (69%, 100%), adenopathy (62%, 66%), appendolith(s) (44%, 100%), arrowhead sign (23%, 100%), paracolic gutter fluid (18%, 86%), abscess (11%, 100%), cecal bar (10%, 100%), extraluminal air (8%, 97%), phlegmon (7%, 99%), ileal (3%, 86%) or sigmoid (3%, 95%) wall thickening, and diffuse cecal wall thickening (0%, 91%). CONCLUSION Individual appendiceal CT signs of appendicitis vary in sensitivity, specificity, and thus diagnostic value. An enlarged appendix with periappendiceal fat stranding occurs in 93% of appendicitis CT cases. Less common but specific signs [cecal apical changes, appendolith(s) are usually present in the remaining appendicitis cases. Some signs seen with appendicitis (adenopathy, fat stranding, adjacent bowel wall thickening, fluid) can also be noted with alternative conditions, and in these cases normal appendix identification is the key to excluding appendicitis.

Fournier Gangrene: Role of Imaging

Fournier gangrene is a rapidly progressing necrotizing fasciitis involving the perineal, perianal, or genital regions and constitutes a true surgical emergency with a potentially high mortality rate. Although the diagnosis of Fournier gangrene is often made clinically, emergency computed tomography (CT) can lead to early diagnosis with accurate assessment of disease extent. CT not only helps evaluate the perineal structures that can become involved by Fournier gangrene, but also helps assess the retroperitoneum, to which the disease can spread. Findings at CT include asymmetric fascial thickening, subcutaneous emphysema, fluid collections, and abscess formation. Subcutaneous emphysema is the hallmark of Fournier gangrene but is not seen in all cases. Compared with radiography and ultrasonography, CT provides a higher specificity for the diagnosis of Fournier gangrene and superior evaluation of disease extent; however, diagnosis and evaluation can also be performed with these other modalities. The administration of broad-spectrum antibiotics and aggressive surgical débridement of the nonviable tissue are both essential for successful treatment. An awareness of the CT features of Fournier gangrene is imperative for prompt diagnosis and effective treatment planning.

Multidetector CT of Blunt Thoracic Trauma

Thoracic injuries are significant causes of morbidity and mortality in trauma patients. These injuries account for approximately 25% of trauma-related deaths in the United States, second only to head injuries. Radiologic imaging plays an important role in the diagnosis and management of blunt chest trauma. In addition to conventional radiography, multidetector computed tomography (CT) is increasingly being used, since it can quickly and accurately help diagnose a wide variety of injuries in trauma patients. Furthermore, multiplanar and volumetric reformatted CT images provide improved visualization of injuries, increased understanding of trauma-related diseases, and enhanced communication between the radiologist and the referring clinician.

Reformatted visceral protocol helical computed tomographic scanning allows conventional radiographs of the thoracic and lumbar spine to be eliminated in the evaluation of blunt trauma patients.

BACKGROUND Patients suffering high-energy injuries are at risk for occult thoracic and lumbar spine fractures, and the standard of care includes radiographic spine screening. Most such patients require computed tomographic (CT) scanning to screen for chest and/or abdominal visceral injury. Helical CT (HCT) scanning represents a major technologic change that allows data to be reformatted after the patient has left the radiology suite. We explored the possibility of using reformatted visceral protocol HCT scanning to replace radiographs of the thoracic and lumbar spine in the evaluation of seriously injured patients. METHODS A prospective evaluation of consecutive patients with thoracic and lumbar spine fractures admitted over a 12-month period to an urban Level I trauma center was completed. The ability of conventional radiography and reformatted HCT scanning to detect spine fractures was compared. RESULTS Of 1,915 trauma patients admitted, 78 (4.1%), with an average Injury Severity Score of 21.3 +/- 1.2, sustained one or more thoracic (n = 35 patients) or lumbar (n = 43 patients) spine fractures. The sensitivity of reformatted HCT scanning as a screening test for spine fractures was 97% for thoracic and 95% for lumbar spine fractures, compared with a sensitivity of 62% for thoracic and 86% for lumbar conventional radiographs. CONCLUSION Data obtained from HCT scanning performed to evaluate seriously injured multiple trauma patients for thoracic and abdominal visceral injury can be reformatted to screen for thoracic and lumbar spine fractures, providing accurate screening while eliminating the time, expense, and radiation exposure associated with conventional film radiography.

CT Cystography with Multiplanar Reformation for Suspected Bladder Rupture: Experience in 234 Cases

OBJECTIVE CT cystography has replaced conventional cystography in the evaluation of patients with suspected bladder rupture in most trauma centers. We performed this retrospective review to determine the accuracy of CT cystography and the role of multiplanar reformation in the diagnosis of bladder injury. MATERIALS AND METHODS The patient cohort was composed of trauma patients with clinically or CT-suspected bladder ruptures who were evaluated with CT cystography using two different MDCT scanners at our level 1 trauma center. The patients were identified through Folio, a radiology research tool software system. The CT cystography results were compared with the findings at surgery, clinical follow-up, or both. RESULTS Between January 1, 2000, and December 31, 2004, 234 patients were examined in our level 1 trauma center with CT cystography. From the total of 234 examinations, 216 (92.3%) were interpreted as negative and 18 examinations (7.7%) were interpreted as positive. On the 18 positive examinations, 11 were extraperitoneal bladder rupture, five were intraperitoneal bladder rupture, and two were combined intraperitoneal and extraperitoneal bladder rupture. Surgical bladder exploration and repair were performed in nine of the 18 cases. Seven (77.8%) of the nine cases had operative findings consistent with the CT cystogram findings. The overall sensitivity and specificity of CT cystography in diagnosing bladder rupture were each 100%. For extraperitoneal bladder rupture, the sensitivity and specificity were 92.8% and 100%, respectively. For intraperitoneal rupture, the sensitivity and specificity were 100% and 99%, respectively. CONCLUSION CT cystography is accurate for diagnosing bladder rupture. Sagittal and coronal multiplanar reformations may be helpful in identifying most sites of bladder rupture.

Helical CT of abdominal trauma.

CT has revolutionized the diagnostic work-up of trauma patients with suspected abdominal injuries. A wide range of intraperitoneal and retroperitoneal organ injuries can be quickly and accurately diagnosed with CT. Today, helical CT technology permits even faster examinations, with improved intravenous contrast opacification of parenchymal organs and vascular structures and reduced CT artifacts caused by patient motion, respiration, and arterial pulsation. Severely injured and potentially unstable patients, who might not have been able to tolerate the long CT examinations of the past, may be quickly evaluated today with helical CT. Accurate diagnosis requires high quality CT examinations that are performed with optimum CT protocols. This article reviews the currently recommended helical CT protocols for evaluating patients with suspected abdominal injuries, and the CT findings when injuries are present.

Inhibition of Angiotensin-Converting Enzyme for Diagnosis of Renal-Artery Stenosis

To determine its utility as an aid in diagnosis of renovascular hypertension, we administered nonapeptide converting-enzyme inhibitor (CEI) (which inhibits conversion of angiotensin I to angiotensin II) (0.25 mg per kilogram) to 14 unselected hypertensive patients undergoing bilateral renal-vein catheterization. In seven (Group I) predominantly unilateral disease was discovered by angiography (renal-artery stenosis in six and hydronephrosis in one); in the remaining seven (Group II) no rennal-artery abnormality was found. In Group I, mean (+/- S.E.) ratio of involved to uninvolved renal-vein plasma renin activity (PRA) increased from 2.94 +/- 0.91 before to 8.36 +/- 2.94 after CEI (P less than 0.01). In Group II, the ratio (of the initially higher to the lower side) was 1.99 +/- 0.49 before and 1.17 +/- 0.07 after CEI (P greater 0.02). Post-CEI PRA was predicted by pretreatment PRA. Mean blood pressure fell in both groups after CEI, and the decrement was predicted by pre-CEI PRA. These data suggest that CEI can be of use at the time of renal-vein catheterization, serving to increase diagnostic accuracy by increasing the difference in PRA between the two sides when there is unilateral disease.

Experience with a continuous, single-pass whole-body multidetector CT protocol for trauma: the three-minute multiple trauma CT scan

Purpose: To test the clinical feasibility and utility of a single-pass, whole-body multidetector CT (MDCT) protocol in the evaluation of the multiple trauma patient. Materials and methods: A whole-body, single-pass MDCT protocol was designed for optimal imaging quality and maximum flexibility for retrospective reconstruction and multiplanar reformation. Five consecutive trauma patients with moderate to severe mechanisms of injury were scanned on an MDCT scanner using the single-pass protocol. Times were recorded for the scan alone and for time spent in the CT bay. Times were compared with those for five random trauma patients scanned on a single-detector helical CT (SDHCT) scanner who were matched for body segments imaged and trauma severity. Results: Compared to SDHCT, MDCT scan times were shortened by a factor of 10 (3 min for MDCT vs 41 for SDHCT) and patient throughput times by a factor of 3 (23 min for MDCT vs 65 for SDHCT). Image quality was mildly compromised in MDCT by beam hardening due to arm position, but overall was comparable to segmental imaging. Conclusion: Whole-body MDCT is feasible and offers a marked time advantage over conventional segmental imaging in multiple trauma patients. Added flexibility through reformation of image data allows imaging evaluation as needed even after the patient has left the scanner bay.

The frequency and significance of thoracic injuries detected on abdominal CT scans of multiple trauma patients.

Of 174 multiple trauma patients undergoing abdominal CT examination for suspected abdominal trauma, 65 patients had 109 chest injuries detected by abdominal CT, chest film, or both examinations. Forty-one patients had 55 chest injuries at the base of the thorax which were not detected on the initial chest film. The most frequent chest injuries detected only by CT were pneumothroax, fracture (rib, thoracic spine, and sternum), lung contusion, aspiration pneumonia, hemothorax, and post-traumatic atelectasis. Seven patients whose chest injury initially was seen only at abdominal CT required treatment of the injury, suggesting that a variety of chest injuries which may vitally affect patients can be detected early in multiple trauma patients by abdominal CT, and that all abdominal trauma CT scans should be scrutinized for signs of a chest injury.