Film Subtraction Research Articles

S2774 An Unusual Case of Duodenal Obstruction from an Unsuspected Intramural Hematoma

INTRODUCTION: Intramural duodenal hematoma (IDH) is an unusual presentation after blunt abdominal trauma. IDH rarely leads to gastric outlet obstruction (GOO), acute pancreatitis, obstructive cholestasis, and gastrointestinal hemorrhage. We report first case of delayed presentation of large IDH associated with acute pancreatitis and GOO four months after abdominal trauma. CASE DESCRIPTION/METHODS: A 53-year-old man with history of diabetes mellitus, alcohol use disorder presented with upper abdominal pain, nausea and vomiting of 2 days duration. Reports fall on to the edge of bathtub and hitting his abdomen 4 months ago. Abdominal exam revealed a non-tender palpable mass in the epigastrium. Labs were significant for elevated AST-214, ALT-63, ALP- 218, lipase-419, and CA 19-9 -377.8. A CT scan of Abdomen showed a large duodenal intramural mass without enhancement and upstream GOO, which is new compared to prior CT scan done a year ago for other reasons. An MRI of the abdomen showed a large heterogeneous duodenal filling defect, with no internal enhancement likely representing a hematoma (Figure 1). Patient underwent EGD and Endoscopic ultrasound(EUS) that showed a submucosal duodenal mass occupying the entire lumen of the duodenum (Figure 2). FNA showed many inflammatory and necrotic cells and was non-diagnostic. Patient had persistent obstruction despite one week of conservative therapy with Nasogastric decompression and TPN (Figure 3). He underwent surgical hematoma evacuation with a feeding jejunostomy tube placement and was discharged on post-operative day 7 after tolerating oral feeds, normalization of lipase and LFTs. DISCUSSION: Most cases of IDH are secondary to blunt abdominal trauma. Spontaneous IDH occurs in patients with bleeding disorders, anticoagulation therapy, vascular collagen diseases, or after invasive endoscopic procedures. IDH is more frequent among children. Due to its anatomic location and high submucosal vascularity distal duodenum is the most common site involved. Symptomatic patients present with GOO symptoms. Compression of the ampulla or pancreatobiliary ducts can cause acute pancreatitis and obstructive jaundice. Cross sectional imaging aids in diagnosis and to evaluate for complications such as perforation or retroperitoneal hemorrhage. EGD and EUS are helpful when imaging is inconclusive. Most patients improve with conservative management by 1 week. Surgical, image guided or endoscopic drainage is needed in patients who fail conservative management or develop complications.Figure 1.: A: CT scan of abdomen showing large heterogeneous filling defect ( arrow) extending from 1st to 3rd portion of duodenum, measuring at least 13 cm × 5.6 cm resulting in upstream gastric outlet obstruction, as evidenced by distended stomach and contrast not passing in to small bowel. B: MRI of abdomen- Post contrast subtraction films showing large heterogenous filling defect (arrow) with no internal enhancement, likely representing a hematoma.Figure 2.: A: ESD showing large 4-5 cm smooth, subepithelial duodenal mass involving the bulb and the duodenal sweep occupying 99% of the lumen of the duodenum. B: -Linear EUS imaging showing a 37.2 mm × 60.5 mm subepithelial lesion in the duodenal bulb. Due to local inflammation and the large size of the lesion, the layers of the duodenum could not be well defined.Figure 3.: Upper Gastrointestinal series showing filling defect in the lateral aspect of the duodenum with a narrow trail of contrast coursing in the residual medial lumen at 1 week of conservative therapy.

Angiographic film subtraction using a laser digitizer and computer processing.

Digital subtraction angiography has been accepted as an invaluable clinical tool over the past decade; however, film-screen-based angiography is still performed routinely when high-resolution or large field-of-view angiograms are needed. A technique is presented whereby two films from an angiographic sequence are digitized using a high-resolution laser digitizer, and the digitized images are aligned, subtracted, and displayed using the computer. To accommodate for some types of patient motion, an image warping algorithm is presented and discussed in detail. The warping algorithm is piecewise linear, using triangular regions for warping, resulting in a global nonlinear transform across triangle elements. An algorithm describing optimal triangle selection also is discussed. The results show that subtraction images of excellent quality can be produced by the proposed technique, and suggest that, in some settings, digitized subtraction films may be preferred over conventional film subtraction.

Use of personal computers and digitized film angiograms to produce subtraction angiograms.

Digitization of film angiograms for subtraction purposes alleviates many of the problems associated with conventional film subtraction techniques. In this method, conventional film angiograms are digitized with a laser digitizer. An unenhanced image is subtracted from a contrast material-enhanced image with image processing software and a personal computer. Image registration and the contrast of the subtraction mask image are adjusted as necessary to obtain complete subtractions. Subtraction images produced with this method are superior to subtraction images produced with conventional film subtraction techniques; all areas and densities of a digitized subtraction image exhibit nearly perfect subtraction. Digitized film angiograms and image processing software provide a useful alternative to traditional techniques for producing subtraction angiograms. Digital film subtraction provides more control over image registration, eliminates the need for an intermediate subtraction mask image, and allows the user to control the contrast, window width, and window level of the final image.

165. CR サブトラクションを用いた照射野の照合(治療-照射野照合・治療システム)

165. CR サブトラクションを用いた照射野の照合(治療-照射野照合・治療システム)

Arthrography of painful hips following arthroplasty: digital versus plain film subtraction

Digital and manual subtraction images obtained during the arthrographic evaluation of 78 painful hip prostheses were reviewed retrospectively. Revision arthroplasty was performed in 53 of these cases, and the arthrographic and surgical findings were correlated. The digital and manual subtraction images were evaluated without knowledge of the surgical results using established criteria for component loosening. Digital subtraction arthrography of the femoral component demonstrated a 96% sensitivity and 100% specificity for the diagnosis of component loosening. Sensitivity and specificity for acetabular component loosening were 83% and 80%, respectively. Plain film subtraction of the femoral component demonstrated a 79% sensitivity and 100% specificity; the sensitivity and specificity for the acetabular component were 75% and 80%, respectively. The difference between detection of femoral component loosening on digital as opposed to manual subtraction images was statistically significant (P less than 0.05). This study demonstrate that digital subtraction improves the evaluation of femoral component loosening in painful hip prostheses.

Blurred-Mask Density Compression for Improved Reproduction of Radiographs

A film-based, blurred-mask subtraction technique can be used to reduce the apparent density range of medical radiographs so that a wider range of actual densities can be captured with video digitizers or reproduced on photographic paper for publication. The density compression and the edge enhancement resulting from this process is examined. A good balance between compression and enhancement for small structures was obtained with a 6-mm gap between the subtraction film and the original when producing the mask. As an example, a photographic print of a compressed chest film showed significant condensation of image information within the restricted reflection density scale of the print paper; detail was well demonstrated in the mediastinal, retrocardiac, and subdiaphragmatic regions that was not shown in the noncompressed print.

Stereoscopic display of MR angiograms

Recent developments in magnetic resonance (MR) allow high resolution imaging of flowing blood. To overcome the tomographic nature of conventional MR acquisitions, projection angiograms can be produced. These angiograms are similar in their display of blood vessels to plain film or digital subtraction angiograms. However, the three-dimensional information inherent in them is partly lost when single projections are viewed. We describe a method of three-dimensional display consisting of stereo pairs of the MR angiograms. With these an examiner experienced in stereo viewing can recover depth perception.

91. サブトラクションフィルムの迅速現像処理について(フィルム処理)

反転露光域を決めることによって, サブトラクションフィルムの最適露光時間が得られた.SRX-1001 60秒処理で従来とほぼ同等の画像が得られ, 検査時間内での処理が可能になった.しかし, 露光時間が長くサブトラクター光源等の検討を要する.今後迅速処理用フィルムの開発が望まれる.最後に, 本研究に御協力して下さったコニカ株式会社に深く感謝致します.

Lymphatic opacification in the prosthetic hip

A retrospective analysis of 52 patients with hip pain following total hip replacement was made. Each of them was evaluated by plain radiographs, technetium 99m pyrophosphate scans, arthrography with plain film subtraction technique, and culture of joint fluid. In 30 cases there was evidence of prosthetic loosening, and in 21 of these lymphatic opacification during arthrography was seen. In 15 cases with lymphatic opacification the diagnosis of prosthetic loosening was subsequently confirmed by prosthetic revision. In none of the 22 cases in which no evidence of prosthetic loosening was seen was there lymphatic opacification. It is concluded that lymphatic opacification during arthrography for pain following total hip prosthesis is a valuable ancillary sign of loosening.

91. サブトラクションフィルムの迅速現像処理について

91. サブトラクションフィルムの迅速現像処理について

Angiographic Findings of Vertebral Dissecting Aneurysm

The authors report two cases of vertebral dissecting aneurysm. The first case, a 49-year-old female, developed severe headache and computed tomography scan showed subarachnoid hemorrhage (SAH), but 4-vessel cerebral angiography failed to show an aneurysm. The second angiograms obtained 2 weeks later showed possible aneurysmal dilatation on the right vertebral artery. The third angiograms, 2.5 months after SAH, disclosed a right vertebral fusiform aneurysm on the arterial phase and it was diagnosed as a dissecting aneurysm since the contrast medium remained until the very late venous phase. The previous angiograms were reviewed using the subtraction technique, which revealed retention of the contrast medium. The second case, a 42-year-old female, suffered from SAH. Left vertebral angiography revealed a fusiform aneurysmal tapered narrowing just distal to the aneurysm, which was a typical "pearl and string sign." The subtraction film of the venous phase also showed retention of the contrast medium in the aneurysmal portion. These findings accurately diagnosed dissecting aneurysm of the vertebral artery. Since the classical true diagnostic "double lumen sign" was rarely observed in the angiograms, it was not easy to diagnose dissecting aneurysm of the vertebral artery. The authors emphasize the angiographic findings of retention of the contrast medium in the venous phase as a "true diagnostic sign" for correct diagnosis of dissecting aneurysm.

The use of subtraction arthrography in total hip arthroplasties.

The results of plain film radiography and subtraction arthrography in 24 patients prior to revision surgery for a loosened total hip arthroplasty (T.H.A.) were compared with operative findings. Loosening of both the acetabular and the femoral components was evaluated. In plain film radiography the overall accuracy for evidence of loosening in 22 acetabular and 23 femoral components was 58%. The overall accuracy with arthrography was 93%. Three results were false-negatives; arthrography showing no evidence of loosening, while the arthroplasty was found to be loose on surgical evaluation. The results of this study are compared with findings reported in the literature. Arthrography was performed by a lateral puncture technique. There were no complications. The use of the puncture technique has not been described previously. The extent of contrast leakage into the interfaces is described and discussed.

Computer-processed subtraction arthrography.

We describe a film subtraction method using computer processing. The computer processed subtraction arthrograms in 16 cases were compared with conventional photographic subtraction. Although the computer reduced image resolution, it presented significant advantages over photographic film subtraction, including faster access to subtraction, optimal superimposition of mask and postinjection films by the radiologists, reduction of artifacts, and time saved.

Primary central nervous system lymphoma.

A retrospective analysis of 21 cases of primary central nervous system (CNS) lymphoma is reported. All patients presented with a solitary mass in the supratentorial region. None had previously received immunosuppressive therapy. Neuroradiological studies included technetium-99m-pertechnetate brain scanning in eight cases, cerebral arteriography in all 21 cases, and computerized tomography (CT) in 14 cases. The characteristic features were increased uptake in brain scans, mass effect in arteriograms, and marked contrast enhancement on CT scans. Abnormal tumor vessels were occasionally seen on arteriography, and subtraction films were usually required to appreciate tumor stain. All patients underwent craniotomy, and histological studies of the tumors showed a diffuse type of lymphoma in all cases. Immunoglobulin testing was performed in 19 cases and a monoclonal spike was verified in 10, suggesting a B cell origin. All patients were followed until their death except one who was still alive 12 months from onset of symptoms. Therapy included subtotal resection in all 21 cases, whole-brain irradiation in six cases, chemotherapy in two cases, and a combination of whole-brain irradiation and chemotherapy in nine cases. Three different forms of chemotherapy were used. The results suggest that chemotherapy is an important addition to subtotal resection and whole-brain irradiation in the treatment of primary CNS lymphoma.

Digital processing of film radiographs

Initial clinical experience with a system for the digitization, processing, and display of film radiographs is described. Film is digitized using a high-intensity laser scanner; the recorded image data may then be subjected to a wide variety of processing options, with display of processed images on television monitors. The possibilities of clinical applications to processing and display of chest radiographs and film mammograms are described. A comparison of conventional analog subtraction and digitized film subtraction angiography indicated equivalent diagnostic capability, with the advantage of flexible, interactive image processing with the digital technique. A specially designed, energy-selective cassette permits dual-energy imaging from two films effectively exposed to different x-ray energy spectra. Dual-energy imaging may be capable of the characterization of body materials, including lung nodules, and useful for eliminating obscuring radiographic shadows overlying regions of interest.

Enhancement of radiographs used for publication

A technique in which a subtraction film mask is used to enhance radiographic detail and provide a balanced density appropriate for purposes of publication is described and examples are illustrated.

Subtraction radiology demonstrates crestal bone loss in experimentally induced marginal periodontitis

The potential diagnostic usefulness of subtraction radiology in dentistry was evaluated by means of an experimental model of marginal periodontitis in cynomolgus monkeys. Beam-guiding, field-limiting, intraoral radiographic instruments were modified to allow construction of appliances which yielded repeatable superimposable radiographic images during the course of a 16-week study. Marginal periodontitis was induced in monkeys by means of circumferential silk sutures tied around mandibular second molar and second premolar cementoenamel junctions, and serial radiographs were taken at weekly intervals for 16 weeks. Control subtraction masks were made from pretreatment radiographs, and bone loss was evaluated by means of elapsed-time films to give the subtraction prints. The subtraction films clearly showed increasing bone loss with time and were produced easily with size 0 dental films. This technique appears to have considerable potential usefulness in the evaluation of bone-density changes in experimental models of dental diseases as well as in the clinical setting.

Intravenous Arteriography Using Digital Subtraction Techniques

The application of digital computers to electronic x-ray imaging devices has rejuvenated interest in the field of intravenous arteriography. By utilizing computer image subtraction techniques, digital roentgenographic systems based on fluoroscopy or computed tomography (scanned projection radiography) provide significantly improved vascular imaging compared with conventional film subtraction methods. Digital subtraction angiography schemes isolate contrast media in the vessel by detecting differences in images obtained before and after the injection of contrast medium or changes in the relative attenuation of contrast media at different x-ray energies. Present applications include carotid and peripheral arteriography, thoracic and abdominal aortography, pulmonary arteriography, and ventriculography. Future applications may include intracerebral and coronary arteriography. These systems should provide low-risk outpatient screening arteriography.

Small vascular malformation of choroid plexus in lateral ventricle. Diagnostic problems of the lesion (author's transl)

The authors presented four cases of small vascular malformation (SVM) of choroid plexus in the lateral ventricle and reviewed the 21 cases reported since 1950. Although 85% of the reported cases occurred in the first four decades of life, two of the authors' series were over 40 years old. The initial symptom was a subarachnoid hemorrhage in 85% of the reported cases and all cases in the authors' series. Focal neurological deficits were present in 33% of the reported cases and two of the authors' series. Diagnosis of the lesion was made antemortem in 16 of the reported 21 cases and all of the authors' series. Eight of the 16 cases were diagnosed by angiography, two by CT scan, five at the time of operative exploration for intracerebral hematoma or mass lesion in the lateral ventricle and one after plexectomy for hydrocephalus. Among the 15 reported cases with cerebral angiography, the feeding artery, nidus and draining vein were visualized in only seven cases. Case 1 and Case 2 of the authors' series showed similar angiographic findings. Histologically these SVMs were all arteriovenous malformations (AVM). However, only one of the six reported cases of SVM classified as either cavernous, or venous angioma or teleangiectasis revealed a small vascular area of radiopaque material. In Case 3 of venous angioma, serial angiography showed a very small, spotted vascular lesion in the early arterial phase, and revealed a nearly homogeneous area of contrast material of small size in the venous phase. In Case 4 of cavernous angioma, both a small vascular lesion and early venous filling were demonstrated by serial angiography. CT scans revealed abnormal vascular lesions in two out of four reported cases of choroid plexus SVM in the lateral ventricle. It was possible to detect the precise anatomical location of the SVM, such as whether a lesion was confined to the choroid plexus or involved deep nuclei. CT scans were also valuable as shown in Case 4 for the identification of cavernous or venous angioma which sometimes did not show apparent angiographic findings. CT scans safely showed either the extent of the hematoma or the degree of hydrocephalus accompanying the SVM. In conclusion, the authors emphasize that in cases of subarachnoid hemorrhage with neither aneurysms nor macroangioma, the possibility of the presence of choroid plexus SVM in the lateral ventricle must be considered. A combination of serial and magnification angiography, the film subtraction technique and CT scanning is very useful and necessary in identifing this type of lesion.

Dual energy film subtraction technique for detecting calcification in solitary pulmonary nodules.

A simple film subtraction technique has been devised that isolates calcium image contrast and mutes tissue image contrast. Two exposures are required. The first is made on XL film using a 65 kVp beam filtered with 2 mm aluminum. The second is made on OG (high contrast) film using a 130 kVp beam filtered with 2 mm copper and 2 mm aluminum. The effective energies of these two beams are approximately 45 keV and 83 keV, respectively. A subtraction image is made, using the low energy image for the mask. With this technique it is possible to detect concentrations of 125 mg/cm3 of diffuse calcification in a chest nodule 1 cm in diameter. If the presence of diffuse calcification is found to be an indicator of benignancy in solitary pulmonary nodules, this technique may have diagnostic value for the detection of such calcification. Computerized tomographic findings are discussed and related to this technique.