Percutaneous microductectomy with a directional vacuum-assisted system guided by ultrasonography for the treatment of breast discharge: experience in 63 cases

Background: Vacuum-assisted devices are becoming a useful tool in the diagnosis and treatment of breast pathology. Recent publications show good results in percutaneous removal of benign lesions.

Purpose: To discuss our experience in percutaneous excision of ductal lesions with a vacuum-assisted, ultrasound-guided directional system.

Material and Methods: From January 2003 to July 2006, 63 patients with pathological nipple discharge and intraductal lesion identifiable on imaging were studied at two reference centers. Percutaneous excision with a vacuum-assisted device was offered as an alternative to surgery.

Results: A total of 71 lesions were diagnosed in 63 patients with a mean age of 52 years. All the patients presented nipple discharge. Mammography was normal in 65 cases (92%). Galactography showed an intraductal lesion in 67 cases (94%). Mean lesion size on ultrasonography was 7.4 mm (2-26 mm). Percutaneous excision was performed in 45 lesions (63%), while surgical excision was indicated in 26 lesions. The histopathological results in the 45 lesions biopsied demonstrated intraductal papilloma in 30 cases, dilated duct with papillomatous projections in 11, ductal ectasia with no papillary lesion in three, and a nonspecific benign result in one. Excision was considered complete in 41 lesions (91%). Clinical signs of discharge were resolved in 39 patients (95% of cases treated percutaneously). Mild complications occurred in four cases.

Conclusion: Percutaneous excision of ductal lesions with an ultrasound-guided, vacuum-assisted device is a safe procedure with high diagnostic and therapeutic value for the management of breast discharge.     

Computed tomography-guided pulmonary nodule localization before thoracoscopic resection

Purpose: To assess the success rate and complication rate of a CT-guided pulmonary nodule-marker system before thoracoscopic resection.

Material and Methods: In 24 patients (15 M, 9 F; age range, 18-71 years) a total of 25 pulmonary nodules (in 1 patient 2 lesions simultaneously) were marked with a special wire under CT-guidance and then thoracoscopically resected. We evaluated lesion size, lesion distance to the pleura, the time of intervention, complications, and thoracoscopic success rate.

Results: Mean lesion size was 7 mm (range 4-15 mm) and mean lesional distance to the pleura was 13 mm (range 2-31 mm). The pulmonary nodule-marker system was positioned successfully in all 25 pulmonary nodules within 5-11 min (mean 7.5 min). Minimal pneumothoraces were observed in five patients with no requirements of chest drains. In addition, no bleeding complications or hematothorax were observed. All 25 pulmonary nodules could be resected thoracoscopically. However, in one patient (4%), the guide-wire dislocated during thoracoscopy, but the lesion could be successfully resected during thoracoscopy.

Conclusion: The CT-guided placement of the pulmonary nodule-marker system used here offers a safe and accurate guide for the localization of small pulmonary nodules during thoracoscopic resection.     

Computed-tomography-guided punctures using a new guidance device

Purpose: To evaluate a new adjunctive guidance device, a puncture guide, constructed to simplify computed tomography (CT)-guided punctures and to make the procedure more accurate and safe.

Material and Methods: 17 patients referred for CT-guided punctures were included in the study. There were 10 thoracic and 7 abdominal or pelvic lesions with a mean maximum diameter of 29±18 mm. All punctures were performed using a laser guide combined with the new device. The needle guide created a streak artefact in the image, indicating the needle path.

Results: The puncture was successful at the first attempt in 15 of the 17 patients. The artefact was visible in all patients, and in the majority there was a distinct artefact reaching from the entry point to the lesion. The deviation between the angle of the streak artefact and the final angle of the needle was 1.1°.

Conclusion: The benefits of the puncture guide were the artefact pointing at the target, the needle support, and accuracy when performing CT-guided punctures.     

Magnetic resonance-guided biopsy of suspicious breast lesions with a handheld vacuum biopsy device

Purpose: To evaluate a handheld vacuum-assisted device system for magnetic resonance image (MRI)-guided breast lesion biopsy.

Material and Methods: In 32 patients, a total of 42 suspicious breast lesions (mean diameter 7.5 mm for mass lesions, 11.6 mm for non-masslike diffuse lesions) seen with MRI (no suspicious changes in breast ultrasound or mammography) were biopsied (27 lateral, 15 medial) using a 10G vacuum-assisted breast biopsy device under MR guidance. Histology of biopsy specimens was compared with final histology after surgery or follow-up in benign lesions.

Results: In all biopsies, technical success was achieved. Histology revealed 11 lesions with ductal carcinoma in situ (DCIS) or invasive cancer, three with intermediate lesions (LCIS) and 28 with benign breast lesions (adenosis, infected hematoma). In one patient with discordant results of MRI and histology, surgical excision revealed medullary cancer. In the follow-up (mean 18 months) of the histological benign lesions, no breast cancer development was observed. Besides minor complications (hematoma, n = 6), with no further therapeutic interventions, no complications occurred.

Conclusion: MRI-guided breast lesion biopsy using a handheld vacuum-assisted device is a safe and effective method for the work-up of suspicious lesions seen with breast MRI without changes in mammography or ultrasound. In the case of discordant histology of vacuum biopsy and breast MRI appearance, surgical excision is recommended.     

Needle tract seeding after vacuum-assisted breast biopsy

Background: A matter of substantial concern regarding all needle biopsy techniques is seeding along the biopsy needle tract.

Purpose: To assess cell seeding along the needle tract of vacuum-assisted breast biopsy (VABB).

Material and Methods: The study included 21 patients with ductal carcinoma in situ (DCIS) and 10 patients with invasive ductal carcinoma (IDC) diagnosed by VABB for nonpalpable mammographic lesions. VABB (11G, on a Fischer table) was performed, and the duration of the procedure was measured. After surgery, the whole needle tract was embedded in paraffin blocks, stained with hematoxylin-eosin, and examined by a pathologist.

Results: Cases with dissemination of cancer cells in the needle tract were not observed (one-sided 97.5% CI 0-10.0%). In 2/31 (6.5%) cases (95% CI 0.8-21.4%), benign epithelial cell displacement was observed, and the duration of VABB was significantly longer in these two cases (52.5±3.5 min vs. 42.0±4.4 min for cases without benign cell displacement; P = 0.018, Mann-Whitney-Wilcoxon test for independent samples).

Conclusion: No displacement of malignant cells within the 11G needle tract was documented. Benign cell displacement was associated with longer VABB duration. The phenomenon of tumor cell dissemination along the needle tract is of questionable clinical significance when the treatment guidelines are followed.     

The place of computed tomography as a guidance modality in percutaneous nephrostomy: analysis of a 10-year single-center experience

Background: Percutaneous nephrostomy (PCN) has been established as an effective technique for urinary decompression or diversion. This procedure may be performed with the guidance of fluoroscopy, ultrasonography, a combination of fluoroscopy and ultrasonography, computed tomography (CT), or magnetic resonance imaging.

Purpose: To retrospectively review experience with CT-guided PCN over a 10-year period in a single center.

Material and Methods: All CT-guided PCN procedures performed in adults at our institution between 1995 and 2005 were evaluated. In 882 patients, 1113 nephrostomy catheters were inserted. Interventional radiologists or radiology residents under direct attending supervision inserted all catheters. During the PCN procedure, bleeding, sepsis, and injuries to adjacent organs were regarded as major complications. Clinical events requiring nominal therapy with no sequelae were regarded as minor complications.

Results: PCN procedures were performed via 1-3 punctures in patients with grades 0-1 and 2 hydronephrosis, and via 1-2 punctures in patients with grade 3 hydronephrosis. They were carried out with a procedure time ranging from 9 to 26 min. All PCNs were considered as technically successful, and no major complications were observed. There were minor complications including transient macroscopic hematuria (28.6%, 19.9%, and 4.9% in patients with hydronephrosis grades 0-1, 2, and 3, respectively) and perirenal hematomas in a total of eight patients. No patient required additional intervention secondary to complications of the PCN procedure.

Conclusion: CT-guided PCN is an efficient and safe procedure with major and minor complication rates below the accepted thresholds. It can be used for the management of patients requiring nephrostomy insertion in inpatient settings, and might be a preferable procedure in patients with minimal or no dilatation of the renal pelvis.     

Is a flared stent effective for decreasing stent migration in canine prostatic urethra?

Background: Prostatic urethral stents are effective in relieving obstructions caused by benign prostatic hyperplasia (BPH). However, migration of these stents occurs frequently.

Purpose: To evaluate the efficacy of a flared stent for decreasing the migration rate in comparison with a straight stent in a canine prostatic urethral model.

Material and Methods: The flared stent (15 mm in diameter and 20 mm in length) was flared up to 19 mm at both ends to prevent migration. A straight stent with the same size was straight without flaring. Both stents were made of a nitinol wire filament and covered with an expanded polytetrafluoroethylene (ePTFE) membrane. The flared stent was inserted in the prostatic urethra of 10 dogs (group 1) and the straight stent in the prostatic urethra of 12 dogs (group 2). Follow-up retrograde urethrography (RUG) was performed 1, 4, and 8 weeks after stent placement. Fisher's exact test was used to compare the migration rate between the two groups. When stent migration occurred during the follow-up period, the same type of stent was inserted again.

Results: Three of 10 (30.0%) flared stents migrated into the urinary bladder between 1 week and 4 weeks after placement. Seven of 12 (58.3%) straight stents migrated into the urinary bladder 1 (n = 3), 4 (n = 1), and 8 (n = 3) weeks following placement. The flared stent group showed lower migration rate than the straight stent group, but the migration rate did not reach statistical significance (P = 0.231). After the second stent placement, one of three (33.3%) flared stents migrated again after 4 weeks and two of seven straight stents (28.6%) after 1 week.

Conclusion: Although the migration rate was not statistically significant, the flaring of the stent seemed to reduce the migration rate in comparison with straight stents in a canine prostatic urethral model. However, the migration rate of the flared stent was still high, and further developments are required to decrease migration rate.     

Magnetic resonance elastography of the human brain: a preliminary study

Purpose: To study the application of magnetic resonance elastography (MRE) in the human brain.

Material and Methods: An external force actuator was developed, which produced propagating shear waves in brain tissue. A modified phase-contrast gradient-echo sequence was developed. The propagating shear waves within the brain were directly imaged. The wave images were processed to obtain the elasticity image. Shear waves at 100 Hz, 150 Hz, and 200 Hz were applied.

Results: The propagating shear waves in the brain were visualized on wave images. The elasticity image revealed the difference in tissue elasticity between gray and white matter of the brain.

Conclusion: MRE could be an imaging technique for assessing the elasticity of brain tissue.     

Multidetector computed tomography and neuroendocrine pancreaticoduodenal tumors

Purpose: To investigate the accuracy of dedicated pancreatic multidetector computed tomography (MDCT) in the diagnosis of neuroendocrine pancreaticoduodenal tumors (NPTs).

Material and Methods: MDCT and other imaging studies in patients with suspected NPTs were identified. Thirty dedicated MDCT studies were done in 23 patients. Fourteen patients (16 operations) subsequently had surgery. Imaging reports were reviewed and findings compared with surgical findings and findings in other imaging studies.

Results: Patients with surgery: 19 NPTs (16 extrapancreatic gastrinomas and 3 pancreatic NPTs) were identified at surgery. MDCT identified 16 and somatostatin receptor scintigraphy (SRS) 11 out of 19 tumors. Endoscopic ultrasound detected 11 out of 14 NPTs. Patients without surgery: In 4 out of 9 patients, no NPTs were identified at MDCT.

Conclusion: Dedicated MDCT of the pancreas can identify many NPTs, including small duodenal and periduodenal tumors, and the detection rate is better than reported in the older literature on CT.     

Massive postpartum hemorrhage treated with transcatheter arterial embolization: technical aspects and long-term effects on fertility and menstrual cycle

Background: Transcatheter arterial embolization (TAE) is considered a safe, life-saving procedure in postpartum hemorrhage (PPH), but its long-term effect on menstruation and fertility is unclear.

Purpose: To investigate technical aspects and the evaluation of complications, focused on menstrual cycle and fertility, using TAE in patients with PPH.

Material and Methods: A retrospective study including 20 patients (seven with vaginal and 13 with cesarean delivery) with severe PPH treated with bilateral TAE of the uterine artery was carried out. All patients were asked to answer a questionnaire regarding their post-embolization history. In six patients, the radiation dose was measured.

Results: All 20 cases underwent bilateral TAE of the uterine artery. Gelfoam was used as the embolic agent. However, after cesarean delivery in six patients who had clear contrast medium extravasation and/or pseudoaneurysm-like lesion, metallic coils had to be used in order to achieve hemostasis. No major short- or long-term complications were registered. Normal menses resumed in all patients. Four patients had a total of five full-term and two preterm pregnancies, and all delivered healthy infants by cesarean section with no recurrence of PPH. The mean radiation dose to the ovaries was 586 mGy (range 204-729 mGy).

Conclusion: TAE in patients with PPH is safe and has no major short- or long-term side effects. A patient managed with TAE can expect return of normal menses and preservation of future fertility and successful pregnancies. PPH after cesarean section might need to be embolized with metallic coils in addition to Gelfoam in order to achieve secure hemostasis.     

Acceleration of primary liver tumor growth rate in embolized hepatic lobe after portal vein embolization

Background: Portal vein embolization (PVE) is now widely accepted as a useful preoperative procedure in selected patients undergoing extended hepatectomy. However, the effect of PVE on the growth of liver tumors has not been fully elucidated.

Purpose: To retrospectively evaluate the effects of PVE on the growth of liver tumors in the embolized lobes.

Material and Methods: Eight patients with a primary liver tumor, six hepatocellular carcinomas (HCC) and two cholangiocellular carcinomas (CCC), were studied. The growth rates of the tumors in the embolized lobes and non-embolized liver parenchyma were calculated using the computed tomography (CT) volume values at the time of tumor identification, and before and after PVE.

Result: The median tumor growth rate was 0.59 cm³/day (range 0.22-6.01 cm³/day) before PVE and 2.37 cm³/day (range 0.29-13.97 cm³/day) after PVE (P = 0.018). The tumor growth acceleration ratios ranged from 1.50 to 7.46 (median 2.65) in the six HCCs, and were 1.00 and 1.32 in the two CCCs. There was no apparent correlation between the tumor growth rate after PVE and the growth rate of non-embolized liver parenchyma (median 6.00 cm³/day, range 1.24-11.0 cm³/day).

Conclusion: Liver tumor growth in an embolized lobe accelerates after PVE, in patients with HCC.     

Impact of digital imaging on radiation doses to the patient during X-ray examination of the urinary tract

Purpose: To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department.

Material and Methods: IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector.

Results: A dose reduction from 41.8 Gycm² to 31.5 Gycm² was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm² was achieved using the flat panel detector.

Conclusion: The introduction of the flat panel detectors made a considerable dose reduction possible.     

Diffusion-weighted magnetic resonance imaging of cerebrospinal fluid in patients with and without communicating hydrocephalus

Background: Recent concepts about cerebrospinal fluid (CSF) circulation in communicating hydrocephalus (CoHy), which is also termed “restricted arterial pulsation hydrocephalus,” suggest reduced arterial pulsations of subarachnoid vessels with a smaller amount of CSF shifted in subarachnoid spaces during the early systole. The postulated restriction of subarachnoid arterial pulsations in CoHy should induce a smaller motion artifact and reduced local stream effects in CSF in magnetic resonance (MR) diffusion-weighted imaging (DWI).

Purpose: To investigate the maximum diffusivity in CSF in patients with and without CoHy using DWI.

Material and Methods: 12 patients without CSF circulation disturbances and six cases with proven CoHy were assessed. Diffusion was measured in six noncollinear directions without triggering the arterial pulse wave (scan time 6:45 min, voxel size 2×2×2 mm). Due to expected artifacts, the calculated maximum diffusivity was called apparent diffusivity. Regional high and low apparent diffusivity was assessed in CSF spaces on newly created 3D CSF motion maps.

Results: Patients with regular CSF circulation exhibited high apparent diffusivity in CSF in basal subarachnoid spaces, whereas apparent diffusivity was low there in patients with CoHy.

Conclusion: DWI opens a feasible approach to study CSF motion in the neurocranium. Restricted arterial pulsations seem to be involved in CoHy.     

Bronchial stump fistula: treatment with covered, retrievable, expandable, hinged stents--preliminary clinical experience

Purpose: To evaluate the preliminary clinical efficacy and retrievability of a covered, retrievable, metallic hinged stent in the treatment of bronchial stump fistula (BPF).

Material and Methods: Between April 2003 and March 2005, eight patients with bronchial stump fistula after pneumonectomy or lobectomy were treated with two types of covered, retrievable, metallic hinged stents. Type A stent was placed in six patients and type B in two under fluoroscopic guidance. The stent was removed with a retrieval set when BPF was healed or complications occurred.

Results: Stent placement in the bronchial tree was technically successful in all patients, without procedure-related complications. Immediate closure of the BPF was achieved in all patients after the procedure. Stents were removed from all patients but one. Removal of the stents was difficult in two patients due to tissue hyperplasia. Patients were followed for 4-16 months. Placement of the stents remained stable in all patients except one due to severe cough. Permanent closure of BPF was achieved in seven (87.5%) of eight patients.

Conclusion: Use of a covered, retrievable, expandable, metallic hinged stent is a simple, safe, and effective procedure for the closure of bronchial stump fistula. Retrieval of the stent seems feasible.     

Radiological contrast media and pancreatic blood perfusion in anesthetized rats

Background: Radiological contrast media (CM) have been suggested to be able to impair pancreatic microcirculation.

Purpose: To evaluate the effects of an iso-osmolar (iodixanol, 290 mOsm/kg H₂O) and a low-osmolar (iopromide, 660 mOsm/kg H₂O) CM on total pancreatic and islet blood perfusion.

Material and Methods: Thiobutabarbital-anesthetized rats were injected with iodine-equivalent doses (600 mg I/kg body weight) of iodixanol or iopromide. Saline or low-osmolar mannitol (660 mOsm/kg H₂O) solutions served as control substances. Blood perfusion measurements were then carried out with a microsphere technique.

Results: Iso-osmolar iodixanol had no effects on blood perfusion. Low-osmolar iopromide increased total pancreatic blood perfusion, whereas islet blood perfusion was unchanged. No differences were seen when mannitol solutions were given.

Conclusion: Neither an iso-osmolar nor a low-osmolar CM affected pancreatic islet blood perfusion, whereas the low-osmolar CM increased total pancreatic blood perfusion. The absence of hemodynamic effect of low-osmolar mannitol suggests that the hyperosmolality per se of iopromide versus iodixanol does not induce the hemodynamic effect. The consequences of the effect of iopromide for pancreatic function remain to be established.     

The rotation ratios method: a method to describe altered pelvic orientation in sequential radiographs

Background: A method to describe pelvic rotations between pairs of standard sequential pelvic anteroposterior radiographs based on a pelvic phantom is described in a former study.

Purpose: To expand this method into clinical use based on clinical data.

Material and Methods: Teardrop distances were measured on 262 pelvic radiographs from 46 patients in a clinical material using a computer program designed to perform measurements on digital radiographs. Anthropometric data recorded from 141 pelvises in an anatomical collection were employed in a computer program designed to simulate radiographs of virtual objects. Virtual rotations of the pelvises were carried out with 4653 virtual radiographs obtained. Virtual radiographic measures were analyzed.

Results: A statistically significant difference of 8 mm between mean teardrop distance in females (120 mm) and males (112 mm) was found in the clinical material. A set of formulas describing the relations between differences of two rotation ratios and pelvic rotations were derived. Four simple regression analyses were carried out with the use of virtual measures. Adjusted teardrop distances were implemented.

Conclusion: A clinical method to describe pelvic rotations using standard pelvic radiographs was developed.     

Sonographically guided 11-G directional vacuum-assisted breast biopsy as an alternative to surgical excision: utility and cost study in probably benign lesions

Purpose: To evaluate the utility and economic costs of the 11-G vacuum-assisted biopsy probe under ultrasound (US) guidance as an alternative to surgical excision in patients with probably benign lesions.

Material and Methods: US-guided 11-G vacuum-assisted biopsy was performed in 102 probably benign breast lesions in 97 women who refused radiological follow-up. Complete removal of the lesion was intended in all cases. Open biopsy was done if questionable pathologic findings were present. Treatment was indicated if the diagnosis was malignant. Economic costs were estimated taking into consideration monetary expenses generated to the public health system, as well as expenses for the patients receiving percutaneous and open surgical biopsy.

Results: Median patient age was 42 years (range 18-77). Median lesion size was 14.7 mm (range 6-30 mm). Complete removal of the lesion seen at imaging was achieved in 72.5% of cases. Adequate tissue samples for histopathological evaluation were obtained in all cases. Surgical biopsy was recommended in nine cases. One patient diagnosed with mucinous carcinoma underwent immediate surgical treatment. The remaining 87 women with 92 lesions were included in a follow-up program. Economic cost of the 11-G vacuum-assisted percutaneous biopsy was 82% lower than the surgical biopsy (total savings in this series: €136,402.84). Time spent for the patient was 71% less in percutaneous biopsy than in surgery.

Conclusion: Ultrasound-guided 11-G directional vacuum-assisted breast biopsy is an accurate and less expensive procedure that can be used as an alternative to open surgical excision in a selected group of patients.     

Diagnostic performance of computed tomography colonography and colonoscopy: a prospective and validated analysis of 231 paired examinations

Background: Detection of colorectal tumors with computed tomography colonography (CTC) is an alternative to conventional colonoscopy (CC), and clarification of the diagnostic performance is essential for cost-effective use of both technologies.

Purpose: To evaluate the diagnostic performance of CTC compared with CC.

Material and Methods: 231 consecutive CTCs were performed prior to same-day scheduled CC. The radiologist and endoscopists were blinded to each other's findings. Patients underwent a polyethylene glycol bowel preparation, and were scanned in prone and supine positions using a single-detector helical CT scanner and commercially available software for image analysis. Findings were validated (matched) in an unblinded comparison with video-recordings of the CCs and re-CCs in cases of doubt.

Results: For patients with polyps ≥5 mm and ≥10 mm, the sensitivity was 69% (95% CI 58-80%) and 81% (68-94%), and the specificity was 91% (84-98%) and 98% (93-100%), respectively. For detection of polyps ≥5 mm and ≥10 mm, the sensitivity was 66% (57-75%) and 77% (65-89%). A flat, elevated low-grade carcinoma was missed by CTC. One cancer relapse was missed by CC, and a cecal cancer was missed by an incomplete CC and follow-up double-contrast barium enema.

Conclusion: CC was superior to CTC and should remain first choice for the diagnosis of colorectal polyps. However, for diagnosis of lesions ≥10 mm, CTC and CC should be considered as complementary methods.     

Imaging of four-corner fusion (SLAC arthrodesis) of the wrist with 64-slice computed tomography

Purpose: To find out whether it is possible to evaluate the healing of wrist arthrodesis, carried out with a metallic spider plate, by means of 64-slice computed tomography (CT).

Material and Methods: 18 CT examinations were performed in 12 patients 2 weeks to 37 months following scapholunate advanced collapse (SLAC) arthrodesis fixed with a metallic plate. Ten patients also had plain films of the wrist. Radiation doses were estimated.

Results: Plain films were difficult to evaluate due to overprojection of the spider plate. With 64-slice CT, however, it was possible to evaluate the healing process in all patients in spite of metallic artifacts. Radiation doses were low.

Conclusion: The healing of SLAC arthrodesis of the wrist is difficult to evaluate with conventional radiography due to the metallic plate. By means of 64-slice CT, however, it was possible to “see under” the plate in all 12 patients.     

Pulmonary perfusion in acute pulmonary embolism: agreement of MRI and SPECT for lobar, segmental and subsegmental perfusion defects

Purpose: To assess prospectively the agreement of magnetic resonance (MR) pulmonary perfusion with single-photon emission computed tomography (SPECT) perfusion for perfusion defects down to the subsegmental level in patients with suspected pulmonary embolism (PE).

Material and Methods: In 41 patients with suspected PE, contrast-enhanced MR pulmonary perfusion (3D-FLASH, TR/TE 1.6/0.6 ms) was compared to SPECT perfusion on a per-examination basis as well as at the lobar, segmental, and subsegmental level.

Results: The MRI protocol was completed in all patients, and mean examination time was 3 min 56 s. MR perfusion showed a very high agreement with SPECT (kappa value per examination 0.98, and 0.98, 0.83, and 0.69 for lobar, segmental, and subsegmental perfusion defects, respectively). Of 15 patients with PE, MR perfusion detected 14 cases.

Conclusion: The very high agreement of MR perfusion with SPECT perfusion enables the detection of subtle findings in suspected PE.