Lorenzo E. Derchi

Spiral CT of the abdomen after distention of small bowel loops with transparent enema in patients with Crohn's disease

AbstractBackground: To evaluate the capability of a computed tomographic (CT) technique that combines distention of the small bowel loops with a transparent enema with contrast-enhanced spiral CT of the abdomen in patients with Crohns disease. Methods: We evaluated the abdomen with spiral CT after distention of the small bowel loops with a transparent enema of methylcellulose in 40 patients consecutively referred for radiologic evaluation of Crohns disease of the small bowel. Fluid was infused through a nasojejunal catheter with a peristaltic pump. Ultrasonography was used to prevent bowel overdistention and detect arrival of methylcellulose to the cecum. Contrast-enhanced spiral CT of the abdomen was then performed, and the degree of contrast enhancement and the thickness of the walls of the involved loops were evaluated. A series of 10 patients with retrograde distention of the last ileal loop from large bowel water enema was used as a control. The results of the CT were compared with those of conventional radiographic small bowel studies. Results: The normal small bowel wall was 1.9–2.5 mm thick (mean = 2.1 mm); density values of the normal enhanced wall varied between 25 and 60 HU (mean = 32 HU) and presented a homogeneous structure. Bowel segments involved by the disease were 4–12.5 mm thick (mean = 9.2 mm), had density values of 75–150 HU (mean = 105 HU), and showed a multilayered appearance. Compared with conventional radiography, CT detected longer lesions or additional segments involved by the disease process in 14 cases, 11 additional fistulas, two abscesses, and mesenteric changes in 21 cases. Conclusions: The small bowel CT enema technique provides good results in the study of patients with Crohns disease and can be used to evaluate patients with advanced lesions.

Sonographic evaluation of tears of the gastrocnemius medial head ("tennis leg")

Rupture of the medial head of the gastrocnemius muscle, or tennis leg, is a common lesion affecting middle‐aged persons. An imaging examination may be needed to rule out other diseases and assess the severity of the tear. We reviewed the sonographic images of 65 patients with clinically suspected tennis leg. Fifty‐one partial and 14 complete tears were diagnosed. Twenty‐five patients had follow‐up examinations (15 days to 24 months; mean, 45 days). The torn muscle fibers, hematoma, and the reparative process were appreciated by ultrasonography. Ultrasonography may be a useful noninvasive, low‐cost modality for diagnosis and follow‐up of tennis leg.

US and MR imaging of peripheral nerves in leprosy

Abstract Objective. To analyze peripheral nerves with ultrasonography (US) and magnetic resonance imaging (MR) in leprosy and assess the role of imaging in leprosy patients. Design and patients. Fifty-eight nerves with abnormal clinical features or electromyograms were examined in 23 leprosy patients by means of gray-scale US, Doppler US and MR imaging. Image analysis included: measurement of nerve cross-sectional area; assessment of nerve structure and MR signal intensities; identification of nerve compression within osteofibrous tunnels; detection of endoneural color flow signals and Gd-DTPA enhancement. Correlations were made with clinical findings and a control group of 20 subjects. Fourteen nerves in active reversal reaction were followed up after therapy. Results. Leprosy nerves were classified into three groups based on imaging appearance: group I consisted of 17 normal-appearing nerves; group II, of 30 enlarged nerves with fascicular abnormalities; group III, of 11 nerves with absent fascicular structure. Group II nerves were from patients subjected to reversal reactions; 75% of patients with group III nerves had a history of erythema nodosum leprosum. Nerve compression in osteofibrous tunnels was identified in 33% of group II and 18% of group III nerves. Doppler US and MR imaging were 74% and 92% sensitive in identifying active reactions, based on detection of endoneural color flow signals, long T2 and Gd enhancement. In 64% of cases, follow-up studies showed decreased color flow and Gd uptake after steroids and decompressive surgery. Conclusions. US and MR imaging are able to detect nerves abnormalities in leprosy. Active reversal reactions are indicated by endoneural color flow signals as well as by an increased T2 signal and Gd enhancement. These signs would suggest rapid progression of nerve damage and a poor prognosis unless antireactional treatment is started.

Power Doppler sonography: clinical applications

OBJECTIVE Color Doppler imaging (CD) has had a great impact on ultrasonography (US). This technique depicts local flow by encoding an estimate of the mean Doppler frequency shift at a particular position in color. However, the choice of the mean frequency shift as the parameter for representing flow in color Doppler is somewhat arbitrary. Power Doppler ultrasound is a technique that encodes the power in the Doppler signal in color. This parameter is fundamentally different from the mean frequency shift. The frequency is determined by the velocity of the red blood cells, while the power depends on the amount of blood present. Providing an image of a different property of blood flow, power Doppler has shown several key advantages over colour Doppler, including higher sensitivity to flow, better edge definition and depiction of continuity of flow. In this paper we review the results of power Doppler clinical studies. MATERIALS AND METHODS All relevant information available in the literature on the potential clinical applications of this technique was revised to give a detailed survey. RESULTS The increased flow sensitivity and better vascular detailing of power Doppler have been used to detect flow presence and characteristics in vessels that are poorly imaged with conventional color Doppler. The improved depiction of tissue vasculature has shown potential advantages, especially in some areas, such as the cortex of native kidneys and renal allografts, the prepuberal testis, the infant hip and the bowel wall, in which color Doppler is not sensitive enough to detect clinically important, slow and poor flow in small vessels. In inflammatory conditions, power Doppler was valuable in depicting increased flow in vessels that are dilated because of inflammatory response. In this field, advantages have been reported in acute cholecystitis and in inflammatory states of musculoskeletal tissues. The higher sensitivity to slow flow and the improved detailing of the course of tortuous and irregular vessels made power Doppler a promising technique to image intratumoral vessels and, thereby, to ameliorate the accuracy of color Doppler in predicting the likelihood of benign versus malignant nature of nodules. Specific flow patterns, missed at color Doppler studies, have been indicated with power Doppler in some tumors of the liver and breast. In different settings, power Doppler also permitted to monitor serial blood flow changes after therapy and to display them as color intensity, allowing the observer to distinguish flow changes. CONCLUSION Although the actual role of power Doppler in changing patient management has not been assessed yet, this technique can depict flow which was previously undetectable, and thus permits an easier and more confident diagnosis in body regions where the ultrasound signal is weak because blood vessels are small.

Ultrasonic diagnosis of Osgood-Schlatter and Sinding-Larsen-Johansson diseases of the knee

High resolution ultrasonography of the knee was performed on 82 young patients with clinically suspected Osgood-Schlatter disease and on 30 normal subjects; in 45 pathological cases (55%) comparative X-ray films were taken. The ultrasound pictures were equally or more effective than X-ray images in 45/45 cases; their value was particularly marked for soft tissue study. The typical sonographic changes of the ossification center, of the cartilage, and of the surrounding soft tissues are described and classified, both for Osgood-Schlatter and for Sinding-Larsen-Johansson diseases. These signs are based mainly upon cartilage swelling and edema, fragmentation of the ossification center, thickening of the patellar tendon, and bursitis of the infra-patellar bursa. Ultrasonography is proposed as a simple and reliable method for the diagnosis of knee joint osteochondrosis. The ultrasound picture is also suitable for periodical follow-up the course of the disease.

Mammographic density estimation: Comparison among BI-RADS categories, a semi-automated software and a fully automated one

Although breast density is considered a strong predictor of breast cancer risk, its quantitative assessment is difficult. The aim of this study is to demonstrate that breast density assessment with a fully automated software is feasible and correlates with the semi-automated evaluation and the quantitative BI-RADS standards. A data set of 160 mammograms was evaluated by three blinded radiologists. Intra-observer (reader 1: k=0.71; reader 2: k=0.76; reader 3: k=0.62) and inter-observer (reader 1 vs reader 2: k=0.72; reader 2 vs reader 3: k=0.80; reader 3 vs reader 1: k=0.72) variability for the semi-automated software were good on a four-grade scale (D1/D2/D3/D4) and correlated with BI-RADS evaluation made by other two blinded radiologists (r=0.65, p<0.01). Inter-observer (reader 1 vs reader 2: k=0.85; reader 2 vs reader 3: k=0.91; reader 3 vs reader 1: k=0.85) variability for the semi-automated software was very good on a two-grade scale (D1-D2/D3-D4). The use of the fully automated software eliminated intra- and inter-observer differences, correlated with BI-RADS categories (r=0.62, p<0.01) and can replace the semi-automated one (Bland-Altman statistics). Our study demonstrates that automated estimation of breast density is feasible and eliminates subjectivity. Furthermore both the semi-automated and the fully automated density estimation are more accurate than BI-RADS quantitative evaluation and could also be used in the daily clinical practice.

Sonographic evaluation of digital annular pulley tears

Abstract  Objective. To evaluate the sonographic (US) appearance of digital annular pulley (DAP) tears in high-level rock climbers. Design and patients. We performed a retrospective analysis of the US examinations of 16 high-level rock climbers with clinical signs of DAP lesions. MRI and surgical evaluation were performed in five and three patients respectively. The normal US and MRI appearances of DAP were evaluated in 40 and three normal fingers respectively. Results. Nine of 16 patients presented a DAP tear. In eight subjects (seven with complete tears involving the fourth finger and one the fifth finger), US diagnosis was based on the indirect sign of volar bowstringing of the flexor tendons. Injured pulleys were not appreciated by US. Tears concerned the A2 and A3 in six patients and the A3 and A4 in two patients. A2 pulley thickening and hypoechogenicity compatible with a partial tear was demonstrated in one patient. MRI and surgical data correlated well with the US findings. Four patients had tenosynovitis of the flexor tendons but no evidence of pulley disruption. US examinations of three patients were normal. In the healthy subjects US demonstrated DAP in 16 of 40 digits. Conclusion. US can diagnose DAP tears and correlates with the MRI and surgical data. Because of its low cost and non-invasiveness we suggest US as the first imaging modality in the evaluation of injuries of the digital pulley.

Power Doppler sonography: General principles, clinical applications, and future prospects

Abstract. Power Doppler sonography (PD) is a technique that displays the strength of the Doppler signal, rather than the flow velocity and directional information. Its increased flow sensitivity and better vascular delineation have been used to document the presence and characteristics of flow in vessels that are poorly imaged with conventional color Doppler (CD), to identify areas of ischemia, to demonstrate inflammatory hyperemia or increased and irregular flow in tumors, as well as to assess serial vascular changes related to interval therapy. The present review reports the general principles of PD, portrays the results of clinical studies available in the literature, and suggests future trends of development.

Acute Segmental Testicular Infarction at Contrast-Enhanced Ultrasound: Early Features and Changes During Follow-Up

OBJECTIVE The purpose of this retrospective study was to assess whether contrast-enhanced ultrasound is useful for characterization of acute segmental testicular infarction. MATERIALS AND METHODS Twenty men with acute scrotal pain and suspected segmental testicular infarction underwent contrast-enhanced ultrasound. Three patients underwent orchiectomy. For the other patients, the final diagnosis was based on the absence of tumor markers and a change in the size or shape of the tumor during follow-up. Forty-nine color Doppler ultrasound studies (16 within 24 hours of the onset of pain; 14, 2-17 days after pain onset; 19 after 1 month or more), and 38 contrast-enhanced ultrasound studies (13 within 24 hours after pain onset; nine, 2-17 days; 16 after 1 month or more) were performed. RESULTS Fourteen of 16 lesions examined within 24 hours were oval, and two were wedge shaped. Eight lesions were isoechoic to the testis, six were hypoechoic, and two had mixed echogenicity. Twelve lesions were avascular and four were hypovascular at color Doppler examination. Contrast-enhanced ultrasound showed avascular parenchymal lobules in all cases and without perilesional rim enhancement in 12 of 13 studies. Two to 17 days after the symptoms appeared, contrast-enhanced ultrasound showed avascular lobules in all cases and perilesional rim enhancement in eight examinations. After 1 month or more, contrast-enhanced ultrasound depicted intralesional vascular spots in 12 of 14 infarcts. Perilesional enhancement was absent. CONCLUSION Recognition of lobular morphologic characteristics and the presence of perilesional rim enhancement at contrast-enhanced ultrasound can increase confidence in the diagnosis of segmental testicular infarction compared with reliance on gray-scale and color Doppler findings. Changes in lesion features during follow-up confirm the differential diagnosis from other testicular lesions and allow conservative management.

Role of contrast enhanced ultrasound in acute scrotal diseases

ObjectiveTo evaluate the efficacy of contrast-enhanced ultrasound (CEUS) in patients with acute scrotal pain not defined at ultrasound (US) with colour Doppler .MethodsCEUS was carried out in 50 patients with acute scrotal pain or scrotal trauma showing testicular lesion of undefined nature at US. The accuracy of US and CEUS findings versus definitive diagnosis (surgery or follow-up) was calculated.ResultsTwenty-three patients had a final diagnosis of testicular tumour, three abscess, eight focal infarction, seven trauma, three testicular torsion, one haematoma. Five patients were negative. Thirty-five patients were operated (23 testicular tumours, six trauma, three testicular torsion, one abscess, one focal infarction, and one haematoma) and 15 underwent medical treatment or were discharged. US provided a definitive diagnosis in 34/50 as compared to the 48/50 patients diagnosed at CEUS. Sensitivity and specificity were 76% and 45% for US and 96% and 100% for CEUS respectively.ConclusionsCEUS was more accurate in the final diagnosis compared to US, potentially reducing the need for further imaging. In particular CEUS can be proposed in emergency in cases where US diagnosis remains inconclusive, namely in infarction, and trauma, when testicular torsion cannot be ruled out, and in identifying testicular mass.