Cumulative radiation dose after lung transplantation in patients with cystic fibrosis.

PURPOSE: The purpose of this study was first to evaluate the imaging-related cumulative post-transplantation radiation dose in cystic fibrosis (CF) lung transplantation (LT) recipients and second, to identify the occurrence and type of malignancies observed after LT. MATERIALS AND METHODS: A total of 52 patients with CF who underwent LT at our institution between January 2001 and December 2006 with at least 3 years of survival were retrospectively included. There were 27 men and 25 women with a mean age of 24.4±9.2 (SD) years (range: 7.6-52.9 years) at the time of LT. Calculation of cumulative effective and organ doses after LT were based on dosimetry information and acquisition parameters of each examination. Cumulative radiation doses were calculated until June 2016, but stopped at the time of de novomalignancy diagnosis, for patients developing the condition. RESULTS: Patients received a mean cumulative effective dose of 110.0±51.6 (SD) mSv (range: 13-261.3 mSv) over a mean follow-up of 8.1±3.6 (SD) years (range: 0.5-13.5 years), with more than 100mSv in 5 years in 19/52 patients (37%). Chest CT accounted for 73% of the cumulative effective dose. Mean doses to the lung, breast and thyroid were 152.8±61.1 (SD) mGy (range: 21.2-331.6 mGy), 106.5±43.2 (SD) mGy (range: 11.9-221.4 mGy) and 72.7±31.8 (SD) mGy (range: 9.5-165.0 mGy), respectively. Nine out of 52 patients (17%) developed a total of 10 de novo malignancies, all but one attributable to immunosuppression after a mean post-transplantation follow-up period of 11.1±3.5 (SD) years (range: 3.7-16.3 years). Six-month cumulative effective dose was not greater in patients with de novomalignancies than in those without de novomalignancies (28.9±14.5 (SD) mGy (range: 13.0-53.4) vs 25.6±15.3 (range: 5.0-69.7), respectively, P>0.05). CONCLUSION: The cumulative effective dose exceeded 100 mSv in 5 years in 37% of LT recipients, the reason why continuous efforts should be made to optimize chest CT acquisitions accounting for 73% of the radiation dose.

[Life threatening haemoptysis associated with partial abnormal pulmonary venous return and pulmonary arterial hypertension]. / Hémoptysie grave, retour veineux pulmonaire anormal partiel et hypertension artérielle pulmonaire.

A 73-year-old man with chronic respiratory insufficiency was referred to the intensive care unit because of life threatening haemoptysis and hypoxemia. The patient was in respiratory failure with pulmonary arterial hypertension. The bleeding was issuing from the left inferior lobe. A small arterio-venous fistula was suspected on tomodensitometry. Arterial embolization was contraindicated because of diffuse vascular disease. A left inferior lobectomy was performed. The left superior pulmonary vein was draining into the brachiocephalic vein forming a partial anomalous pulmonary venous return. An anatomic restoration of the venous return to the left atrium was performed. The postoperative course was uneventful. No recurrence of haemoptysis was observed, after 9-month follow-up the vascular anastomosis was patent. Despite the pulmonary vascular bed reduction following lobectomy, echocardiography showed a globally mild improvement of cardiac status that might be attributed to right heart preload amelioration.

[Squamous cell carcinoma of the trachea: imaging lymph node mapping]. / Cancer épidermoïde de la trachée: imagerie de l'atteinte ganglionnaire.

The anatomy of the trachea lymphatics is poorly understood and the only researches date back to more than one century. Tracheal tumors are very rare, miscellaneous and variously lymphophilic. The cancers of the trachea have no TNM and their lymph node metastases are little studied despite their poor prognosis. We observed 2 cases of squamous cell carcinoma, one in the cervical and the other in the intrathoracic trachea. TDM-3D reformats demonstrated metastatic lymph nodes of the right para-tracheal lymph node chain (2R and 4R) in both patients and in the cervical lymph nodes (right recurrent nerve lymph node chain) in the patient with cervical tumor. Right location of the mediastinal metastases may be explained by the anatomy of the lymph node chain drainage of the lung segments, the right para-tracheal chain being the only one to regularly possess lymph nodes at that level. The right recurrent nerve lymph node metastases of the cervical tumor are explained by common lymph drainage of the cervical trachea towards larynx lymph centres. Besides lymph node metastases, cancers prognosis may also depends on its location in the trachea. Thus, the tracheal tumors are complex and constitute quite as many orphan tumors. Multicentric studies are mandatory to better understand their behavior. Means provided by new imaging techniques might permit establishing a veritable TNM lymph node mapping of these tumors.

[Diaphragmatic bronchogenic cyst: an exceptional location]. / Kyste bronchogénique diaphragmatique: une localisation exceptionnelle.

A 64-year-old man complained of persistent dyspnea and bilateral basi-thoracic pain with shoulder irradiation. Chest computed tomography revealed a heterogeneous left diaphragmatic mass, while magnetic resonance imaging showed hypo-T1 and hyper-T2 signal. Positron-emission tomography did not show any hypermetabolism. Video-assisted thoracic surgery was decided. At inspection, tumour appeared within the posterior costal part of the diaphragmatic muscle. Tumour resection was extended to a 8-cm-long portion of the lumbar part of diaphragm. Diaphragm was repaired with non-absorbable interrupted sutures. Postoperative course was uneventful. Final pathology revealed an intra-diaphragmatic bronchogenic cyst, which is an exceptional condition. Primary diaphragmatic tumours are very rare and preoperative diagnosis cannot be affirmed. Embryologic hypotheses (migration along the oesophagus or envelopment within diaphragmatic precursors of an abnormal supernumerary lung bud) including recent molecular findings of deregulated pathways (fibroblast growth factor-10 and NOTCH) are discussed.

Radiological evaluation of response to treatment: application to metastatic renal cancers receiving anti-angiogenic treatment.

Targeted therapies have considerably improved the prognosis of patients with metastatic renal cancer (mRCC) but there are no reliable response assessment criteria reflecting the clinical benefits, because there is no regression in size, or it is delayed. Such criteria would help early identification of non-responders, who would then benefit from a change of treatment, and would avoid their being subjected to unnecessary side effects related to the treatment. We will review the imaging techniques currently available for evaluating tumour response in mRCC patients, including the response evaluation criteria in solid tumours (RECIST), the Choi criteria, the modified Choi criteria, and the CT size and attenuation criteria (SACT). We will also discuss functional imaging techniques, which are based on the physiological characteristics of the tumours, such as perfusion CT, magnetic resonance imaging or ultrasound (DCE-CT, DCE-MRI, DCE-US), diffusion MRI, BOLD MRI and new positron emission tomography (PET) tracers. It is not possible at present to propose a unanimously acknowledged criterion for evaluating tumour response to targeted therapy. However, there is a real need for this according to oncologists and the pharmaceutical industry, and radiologists need to be involved in reflecting on the subject.

[Diaphragmatic palsy and dysfunction: from physiology to surgery]. / Dysfonctions et paralysies diaphragmatiques : de la physiopathologie au traitement chirurgical.

The clinical presentations of diaphragm dysfunctions vary according to etiologies and unilateral or bilateral diseases. Elevation of the hemidiaphragm from peripheral origins, the most frequent situation, requires a surgical treatment only in case of major functional impact. Complete morphological and functional analyses of the neuromuscular chain and respiratory tests allow the best selection of patients to be operated. The surgical procedure may be proposed only when the diaphragm dysfunction is permanent and irreversible. Diaphragm plication for eventration through a short lateral thoracotomy, or sometimes by videothoracoscopy, is the only procedure for retensioning the hemidiaphragm. This leads to a decompression of intrathoracic organs and a repositioning of abdominal organs without effect on the hemidiaphragm active contraction. Morbidity and mortality rates after diaphragm plication are very low, more due to the patient's general condition than to surgery itself. Functional improvements after retensioning for most patients with excellent long-term results validate this procedure for symptomatic patients. In case of bilateral diseases, very few bilateral diaphragm plications have been reported. Some patients with diaphragm paralyses from central origins become permanently dependent on mechanical ventilation whereas their lungs, muscles and nerves are intact. In patients selected by rigorous neuromuscular tests, a phrenic pacing may be proposed to wean them from respirator. Two main indications have been validated: high-level tetraplegia above C3 and congenital alveolar hypoventilation from central origin. After progressive reconditioning of the diaphragm muscles following phrenic pacing at thoracic level, more than 90% of patients can be weaned from respirator within a few weeks. This weaning improves the quality of life with more physiological breathing, restored olfaction, better sleep and better speech. The positive impact of diaphragm stimulation has also been evaluated in other degenerative neurological diseases, particularly the amyotrophic lateral sclerosis. For either central or peripheral diaphragm dysfunctions, a successful surgical treatment lies on a strict preoperative selection of patients.

[Lymphatics and lung transplantation. A review]. / Lymphatiques et transplantation pulmonaire : revue.

The role of lymph circulation in lung transplantation (LTx) has not really been studied since the first animal models, which allowed the development of solid organ transplantations. However, the oedema observed in the grafts immediately after LTx often remains unpredictable and unexplained. Although it is an integral part of the entity called "primary graft failure". Despite its multifactor aspects making the interpretation difficult, the possibility of a change in the lymph circulation is proposed to explain an oedema occurrence. The animal models focusing on this point were mainly developed in small bowel transplantation because of interesting similarities with LTx. The analysed criteria were the consequences of lymphatic vessels interruption as well as their regeneration modalities after LTx. These studies also analysed the role of lymphatic vessels in the rejection induction, the local immune response and the occurrence of obliterative bronchiolitis. This review allowed analysing the studies, which approached the lymphatic vessel issue in transplantation.

[Lung volume reduction surgery for emphysema and bullous pulmonary emphysema]. / Chirurgie de réduction volumique et des bulles géantes dans l'emphysème pulmonaire.

The improvement of respiratory symptoms for emphysematous patients by surgery is a concept that has evolved over time. Initially used for giant bullae, this surgery was then applied to patients with diffuse microbullous emphysema. The physiological and pathological concepts underlying these surgical procedures are the same in both cases: improve respiratory performance by reducing the high intrapleural pressure. The functional benefit of lung volume reduction surgery (LVRS) in the severe diffuse emphysema has been validated by the National Emphysema Treatment Trial (NETT) and the later studies which allowed to identify prognostic factors. The quality of the clinical, morphological and functional data made it possible to develop recommendations now widely used in current practice. Surgery for giant bullae occurring on little or moderately emphysematous lung is often a simpler approach but also requires specialised support to optimize its results.

Diagnostic accuracy of magnetic resonance imaging for an acute pulmonary embolism: results of the 'IRM-EP' study.

BACKGROUND: Magnetic resonance imaging (MRI) has not been validated as an alternative diagnostic test to computed tomography angiography (CTA) in patients with suspicion of a pulmonary embolism (PE). OBJECTIVES: To evaluate performance of current MRI technology in diagnosing PE, in reference to a 64-detector CTA. PATIENTS/METHODS: Prospective investigation including 300 patients with a suspected PE, referred for CTA after assessment of clinical probability and D-dimer testing. MRI protocol included unenhanced, perfusion and angiographic sequences. MRI results were interpreted by two independent readers, to evaluate inter-reader agreement. Sensitivity and specificity were evaluated globally and according to PE location and to clinical probability category. RESULTS: Of 300 enrolled patients, 274 were analyzed and 103 (37.5%) had a PE diagnosed by CTA. For patients with conclusive MRI results (72% for reader 1, 70% for reader 2), sensitivity and specificity were 84.5% (95% confidence interval [CI], 74.9-91.4%) and 99.1% (95% CI, 95.1-100.0%), respectively, for reader 1, and 78.7% (95% CI, 68.2-87.1%) and 100% (95% CI, 96.7-100.0%) for reader 2. After exclusion of inconclusive MRI results for both readers, inter-reader agreement was excellent (kappa value: 0.93, 95% CI: 0.88-0.99). Sensitivity was better for proximal (97.7-100%) than for segmental (68.0-91.7%) and sub-segmental (21.4-33.3%) PE (P < 0.0001). Sensitivity was similar for both readers within each clinical probability category. CONCLUSIONS: Current MRI technology demonstrates high specificity and high sensitivity for proximal PE, but still limited sensitivity for distal PE and 30% of inconclusive results. Although a positive result can aid in clinical decision making, MRI cannot be used as a stand-alone test to exclude PE.

[Mediastinal cysts: clinical approach and treatment]. / Les kystes du médiastin: approche diagnostique et traitement.

Mediastinal cysts (MC), mainly from embryonic origin, are benign and rare malformative lesions, gathering several varieties according to tissue origin. Diagnosis is mostly obtained thanks to tomodensitometry performance and sometimes by magnetic resonance imaging. It may be more difficult in some atypical topographies and in case of bulky MC. The most frequent, springing from division abnormality from embryonic foregut ("foregut cysts" in English literature), are primarily bronchogenic cysts (50 to 60 % of MC), which are symptomatic in 30 to 80 % of cases. Coelomic cysts, lined by a mesothelium, result from embryologic abnormality by incomplete fusion of mesenchymal coelomic lacunae. Rarely symptomatic, excepted in cases of very large cysts, they are mainly pleuropericardic cysts (PPC) that represent 30 % of MC. Thymic cysts, around 15 % of MC, are most often asymptomatic. Cystic lymphangiomas (CL) are congenital lymphatic malformations more frequent and symptomatic in children. Diagnosed in older patients, they are most often acquired and asymptomatic. The only radical and definitive treatment is complete surgical resection of the cyst. It allows suppression of symptoms, procurement of a formal diagnosis and prevention of complications. This resection, generally indicated for all symptomatic cysts, large-sized even asymptomatic and in case of non formal diagnosis, is now recommended for all kinds of cysts except for asymptomatic PPC. This strategy is justified considering morbidity and mortality rising rates in patients treated by surgical resection at time of local complications of the cyst. Surgery is commonly performed by videothoracoscopy or by video-assisted mini-thoracotomy, mainly for PPC and CL. The more conventional thoracotomy is performed in surgery for cysts, which are adhesive to nearby structures. PPC just need a simple follow-up, and surgery is required only in case of symptoms and increasing size. In total, surgical indications for MC are large and accepted because of null postoperative mortality and very low rate of morbidity thanks to mini-invasive surgery. This militates for early surgery, without waiting for cystic complications leading to peroperative difficulties and increasing risks. This review presents the characteristics of those different cysts and the strategies currently acknowledged for the treatment.

[Adrenocortical secretory tumors]. / Tumeurs sécrétantes de la corticosurrénale.

Adrenocortical tumors are rare and mostly non-secreting; their discovery is incidental. When secreting, they produce steroid excess and result in a clinical presentation such as the Cushing syndrome, primary aldosteronism, virilization or feminization syndrome. Such tumors are mostly sporadic but can belong to hereditary syndromes predisposing to tumors. The diagnosis of secreting adrenocortical tumors is based upon clinical presentation and biological data associated with specific biological assessments. Adrenal imaging has been considerably improved with the development of CT scan, which can be completed by MRI if necessary. Most of adrenocortical tumors are adenoma, nevertheless some of them can be malignant and the prognosis of such carcinomas is poor. Management of secreting adrenocortical tumors requires surgery in most of the cases and laparoscopic access is now widely used and provides good results in the treatment of benign tumors.

[Non-secreting adrenal tumours]. / Tumeurs non sécrétantes de la surrénale.

This paper presents the clinical features, imaging methods and treatment of non-secreting adrenal tumours. Adrenal incidentalomas are especially discussed. The main histological types of adrenal non-secreting tumours are evoked. Therapeutic considerations are discussed.

[MR imaging of ano-perineal suppurations]. / IRM des suppurations ano-périnéales.

A good digital examination is usually sufficient for the diagnosis and the treatment planning of anal fistulae. Cross-sectional imaging techniques, however, can accurately identify deep abscesses and characterize complex fistulae. MRI is well suited for this examination, with almost no motion artifact, excellent contrast between muscles and fatty spaces, and multiplanar acquisition. A fistula starts from an internal opening in the digestive tube and can end in an abscess cavity or open at the skin at an external opening. The cryptoglandular anal fistulae (fistula-in-ano) are non-specific in origin and are usually simple, whereas specific fistulae are due to many diseases such as Crohn's disease, tuberculosis, trauma, radiation, colloid carcinoma, hidradenitis suppurative, actinomycosis or lymphoma and are often complex. MRI appears useful in the cases with recurrent fistulae, Crohn's disease, when the secondary orifice is atypically placed, during a multistep treatment for complex fistulae, or when an anal stenosis forbids a clinical or ultrasound examination. A good knowledge of the perineum anatomy is required for analysing the fistula tracts. The muscle planes separate fatty spaces which have an important role in the spread of the disease: sub-mucosal space, marginal space, intersphincteric space, postanal space of Courtney, supralevator space, and the two ischioanal spaces on both sides of the anal canal. The anal canal is surrounded by the ring-like internal sphincter, which continues the internal muscularis propria of the rectum, and the external sphincter, which is intermingled with the puborectalis muscle. We perform our MRI examination with an external phased array coil, and we place a cannula to identify the anal canal. The T2W sequences give the more interesting information, but the sequences with fat-suppression and gadolinium chelate injection are also very useful. The MRI examination allows the analysis of: 1) the location of the fistula tracts according to Park's classification, 2) the location of the internal opening, 3) the locations of the external opening(s), 4) the location of deep abscesses, 5) the long distance extensions, 6) the state of the ano-rectal wall and the perirectal spaces, 6) the damages of the anal sphincter.

Ebstein's anomaly: repair based on functional analysis.

OBJECTIVE: 'Classical' repair of Ebstein's anomaly is usually performed with transverse plication of the atrialized chamber. However, the anterior leaflet has restricted motion which is an important factor of the tricuspid valve insufficiency. We studied the long term results of mobilization of the anterior leaflet associated with longitudinal plication of the right ventricule. METHODS: From 1980 to July 2002, 191 patients (mean age 24.4+/-15 years (1-65)) were operated on. Anterior leaflet function was assessed on pre-op echocardiography and on surgical examination. Conservative surgery was possible in 187 patients (98%) and included mobilization of the anterior leaflet, longitudinal plication of the right ventricle and prosthetic annuloplasty in adults. Bidirectional cavo-pulmonary shunt was associated in 60 patients. Four patients had valve replacement. RESULTS: Hospital mortality occurred in 18 patients: 9% (95%CL: 6-15%) due to right ventricle (RV) failure in nine patients. Mean follow-up was 6.4 years (0.07-22). Actuarial survival was 82% at 20 years. Tricuspid valve insufficiency was 1 or 2+ in 80% of the cases. Reoperation occurred in 8% (16 patients). A successful second repair was obtained in ten patients. Electron beam computerized tomography (20 patients) demonstrated improved left ventricle ejection fraction 56-66% (P<0.05). Supraventricular tachycardia and pre-excitation syndromes were reduced from 23 to 5%. CONCLUSION: Conservative surgery is indicated for all symptomatic patients. The incidence of valve repair is high when leaflet mobilization is performed. Valve replacement can be avoided in most cases. Functional and hemodynamic results are excellent.

Determining humeral retroversion with computed tomography.

BACKGROUND: The purpose of this study was to develop and standardize a technique in which computed tomography images are used to determine the humeral torsion angle with landmarks that can be used during surgery. METHODS: One hundred and twenty cadaveric humeri were studied. The retroversion of these anatomical specimens was measured on a computed tomography scan and compared with the direct measurements of the specimens. The retroversion of the humerus was measured by determining the orientation of the proximal articular surface of the humerus with respect to the transepicondylar line of the distal part of the humerus and the forearm axis. To evaluate this method of measuring retroversion, the protocol was tested in patients before and after shoulder arthroplasty. RESULTS: The degree of reproducibility of the measurements made on the computed tomography scan was evaluated by determining the interclass correlation coefficient. The interclass correlation coefficient was considered good (between 0.85 and 0.90) for the measurements of the normal humeri when the orientation of the articular surface measured in the distal part of the humeral head, the epicondylar axis, and the ulnar axis were used as references. There was a significant difference (p < 0.01) between the mean angular orientation of the proximal articular surface with respect to the epicondylar axis (17.6 degrees ) and the mean angular orientation of the proximal articular surface with respect to a line perpendicular to the forearm axis (28.8 degrees ). Despite a wide variation in the humeral torsion angle among the specimens from the different cadavera, the angle varied little between the two normal humeri of the same individual (mean side-to-side difference, 2.1 degrees ). CONCLUSION: This study demonstrated that retroversion of the proximal part of the humerus can be reliably measured with computed tomography. CLINICAL RELEVANCE: Determining retroversion with computed tomography is more accurate than palpating the epicondylar axis or using the forearm as a goniometer during surgery. Computed tomography is useful for measuring the amount of rotation of humeri with a malunited fracture or severe arthritic deformity.

[Bilateral pleurisy and cardiac tamponade. A rare etiology: pancreatico-pleural fistula]. / Pleurésie bilatérale et tamponnade péricardique. Une étiologie rare: la fistule pancréatico-pleurale.

Pancreatico-pleural fistula is a rare complication of chronic pancreatitis. It commonly presents with small, but recurrent, pleural effusions. Pericarditis rarely occurs in this context. We report a case presenting with bilateral large pleural effusions associated with cardiac tamponade. The diagnosis was suspected on detection of high concentration of pancreatic enzyme in the pleural fluid and was confirmed by both endoscopic retrograde pancreatography and magnetic resonance pancreatography. Both examinations demonstrated a fistula and a calculus of the Wirsung duct. In addition, they identified a pancreas divisum, a congenital abnormality which can rarely lead to complications. The usual medical and endoscopic management of this condition failed and a surgical solution for the fistula was needed. This case is unique due to the dramatic presentation of this complication of pancreas divisum and to the complexity of treatment required.

Follow-up electron beam CT for the management of early phase Takayasu arteritis.

PURPOSE: The purpose of this work was to assess typical findings of Takayasu arteritis on serial CT examinations following therapy. METHOD: Serial CT studies were performed on 16 patients with early phase Takayasu arteritis. Mural or luminal changes of the aorta on successive CT scans were compared with clinical data. RESULTS: Vascular lesions progressed during follow-up in 6 of 16 patients. In one patient, progression of lesions was symptomatic. In the other five of six patients with worsening lesions, vascular progression occurred without new clinical symptoms and was first identified on CT scans. One of these five had dilatation of the ascending aorta and required aortic repair. Four others had progression of stenotic vascular lesions leading to changes in medical treatment only or in combination with either surgery or angioplasty. For two of them, CT examinations showed decreased mural lesions after changes in medical treatment. CONCLUSION: CT examinations performed in treated patients with Takayasu arteritis demonstrate either regression, stabilization, or progression of vascular lesions. Serial CT examinations may thus be useful for evaluating response to treatment.

[Value of helical CT in Takayasu arteritis]. / Apport du scanner hélicoïdal dans la maladie de Takayasu.

In the past, the diagnosis and course of Takayasu arteritis were monitored by following angiographic findings, in addition to clinical symptoms and biological tests. More recently, cross-sectional imaging techniques especially Computed Tomography (CT) depicted mural changes in aorta and main vessels in this disease. Within the same acquisition, spiral mode also allows to show luminal changes, similarly to conventional angiography. In addition to its diagnostic value especially in the early phase of the disease, CT seems accurate in the follow-up of treated patients and may be proposed as a therapeutic guide. CT features are presented, according to the stage of the disease and the vessels involved.

Infectious pseudoaneurysms suspected at echocardiography: electron-beam CT findings.

PURPOSE: To review the electron-beam computed tomographic (CT) findings in patients with clinical endocarditis and suspected of having perivalvular pseudoaneurysms at echocardiography and to compare these findings with echocardiographic data. MATERIALS AND METHODS: Data on 17 patients who underwent electron-beam CT for suspicion of perivalvular infectious pseudoaneurysm at echocardiography were retrospectively reviewed. Thirteen patients had a history of valvular surgery. Electron-beam CT findings-lesion size, number, extent, and relationships with surrounding structures, and associated lesions-were compared with echocardiographic and surgical and/or autopsy data. RESULTS: In all patients, electron-beam CT depicted one or more abnormal cavities that filled with contrast material after bolus injection. The mean size (3.5 cm) and number (n = 21) of pseudoaneurysms recorded with electron-beam CT were greater than those recorded with echocardiography (2.9 cm and n = 13, respectively). Associated electron-beam CT findings included valvular vegetations in three patients; mediastinitis in two; and coronary arterial involvement in six. In eight (47%) patients, electron-beam CT depicted a pseudoaneurysm or an additional pseudoaneurysm that was only suspected-not depicted-at echocardiography. Transthoracic and transesophageal echocardiography resulted in underestimation of lesion number, size, and extent and associated lesions, particularly in patients with valvular prostheses or voluminous lesions. CONCLUSION: Thoracic infectious pseudoaneurysms are well depicted with electron-beam CT, which may be a useful addition to echocardiography for detection of this disease and thus help in preoperative planning.